EPA/600/R-20/142 | December 2020
www.epa.gov/homeland-security-research
United States
Environmental Protection
Agency
oEPA
Assessment of Municipal Solid
Waste Energy Recovery
Technologies
Final Report
Office of Research and Development
Homeland Security Research Program
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Assessment of MSW Energy Recovery Technologies
9C)
Progress for a Stronger Future
Assessment of Municipal Solid Waste
Energy Recovery Technologies
Final R
Susan Thorneloe
Office of Research and Development,
Center for Environmental Solutions and Emergency Response
U.S. Environmental Protection Agency
Research Triangle Park, NC
Keith Weitz
U.S. EPA Contract Number EP-D-11-084, Work Assignment 4-04, Task 8c
RTI International, Research Triangle Park, NC
Jenny Stephenson
U.S. Environmental Protection Agency, EPA Region 9
San Francisco, CA
Ozge Kaplan
Office of Research and Devlopment
Center for Environmental Measurement and Modeling
U.S. Environmental Protection Agency
Research Triangle Park, NC
Preparedfor: U.S. Environmental Protection Agency, Research Triangle Park, NC
EPA/600/R-20/142
December 2020
Prepared by: RTI International, Research Triangle Park, NC
Eastern Research Group, Lexington, MA
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Assessment of 'MSW Energy Recovery Technologies
Table of Contents
Acronyms vi
Acknowledgements viii
Disclaimer ix
Foreword x
Executive Summary xi
Chapter 1: Introduction 1
1.1 Current State of Energy Recovery From Municipal Solid Waste in the US 1
1.2 Report Objectives and Structure 2
1.3 Quality Assurance and Data Limitations 3
Chapter 2: Conventional Energy Recovery from Waste 4
2.1 Landfill 4
2.2 Mass Burn Facilities 8
2.3 Modular Systems 9
2.4 Refuse-Derived Fuel Systems 10
2.5 Non-Waste Fuel NHSM Combustion for Energy 10
Chapter 3: MSW Gasification 13
3.1 MSW Gasification Process Description 13
3.1.1 General Process Flow 13
3.1.2 Process Flow Variations 15
3.2 Technical Considerations and Challenges 16
3.3 MSW Gasification Facilities 16
Chapter 4: MSW Pyrolysis 21
4.1 MSW Pyrolysis Process Description 21
4.1.1 General Process Flow 21
4.1.2 Process Variations 23
4.2 Technical Considerations and Challenges 25
4.2.1 Typology Considerations 25
4.2.2 Feedstock Requirements and Dependence 26
4.3 MSW Pyrolysis Facilities in the US 26
Chapter 5: MSW Anaerobic Digestion 31
5.1 Anaerobic Digestion Process Description 31
5.1.1 General Process Flow 32
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Assessment of MSW Energy Recovery Technologies
5.1.2 Process Flow Variations 33
5.2 Technical Considerations and Challenges 34
5.3 Anaerobic Digestion Facilities 35
Chapter 6: Life Cycle Environmental Profiles 38
6.1 LCI Data Review 38
6.1.1 Pyrolysis LCI Data 39
6.1.2 Gasification LCI Data 40
6.1.3 Anaerobic Digestion LCI Data 41
6.1.4 Review Papers and Other Relevant Literature 41
6.2 LCI Data Compilation 41
6.3 LCI Data Coverage and Gaps 42
6.4 LCI Comparison to Conventional WTE and Landfill 46
6.4.1 Energy Consumption and Production 47
6.4.2 Water Consumption 50
6.4.3 Carbon Emissions 50
6.4.4 Solid Residuals 53
Chapter 7: Findings and Observations 55
7.1 Advantages and Disadvantages of Conversion Technologies 55
7.2 Life Cycle Environmental Performance 56
7.3 Risk Profiles for Conversion and Conventional Technologies 57
7.3.1 Economics 57
7.3.3 Permitting Requirements 60
7.4 Additional Considerations 61
7.7 Key Data Gaps and Recommendations for Future Research 62
References 63
Attachment A:_Listing of Waste-To-Energy Facilities in the US 67
Attachment B:_Listing of Stand-Alone and Co-Digestion Facilities in the US 71
Attachment C: Definitions 75
Attachment D: Pyrolysis Life Cycle Inventory Data Compiled from the Literature 77
Attachment E: Gasification Life Cycle Inventory Data Compiled from the Literature 83
Attachment F: Decision Makers Guide for Assessing Municipal Solid Waste
Energy Recovery Technologies 90
in
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Assessment of 'MSW Energy Recovery Technologies
List of Tables
Number Page
Table 1. Facilities that make RDF from MSW or Combust RDF in the US 11
Table 2. Facilities that Process MSW into a Non-Waste Fuel for Combustion in the US 12
Table 3. MSW Gasification Facilities 18
Table 4. Pyrolysis Facilities Operating on Plastics from MSW 28
Table 5. Stand-Alone Multi-Source Anaerobic Digestion Facilities 37
Table 6. Summary of Pyrolysis Life Cycle Inventory Literature Review 39
Table 7. Summary of Gasification Life Cycle Inventory Literature Review 40
Table 8. Summary of Anaerobic Digestion Life Cycle Inventory Literature Review 41
Table 9. Summary of Review Articles 41
Table 10. Inventory Data within the Literature 42
List of Figures
Number Page
Figure ES- 1. Municipal solid waste conversion facilities xiii
Figure ES- 2. Total population and low-income percentile ranking xv
Figure ES- 3. Recycling, composting, combustion with energy recovery and landfilling of
materials in MSW, 1960 to 2017 xviii
Figure 1. Landfill gas to energy project in the US (2019) 5
Figure 2. Operational landfill gas to energy projects by type in the US (2019) 6
Figure 3. Process flow diagram for a conventional MSW landfill 7
Figure 4. Mass burn process flow diagram (US EIA, 2018) 9
Figure 5. General MSW gasification process flow diagram 14
Figure 6. MSW gasification facilities 17
Figure 7. General pyrolysis process flow diagram 22
Figure 8. MSW pyrolysis facilities 27
Figure 9. General single-stage MSW anaerobic digestion process flow diagram 32
Figure 10. Stand-alone and multi-source anaerobic digestion facilities 36
Figure 1 la. Net energy production for MSW feedstock 48
Figure 12. Net average life cycle water consumption 50
Figure 13a. Net carbon dioxide equivalent emissions for MSW feedstock 52
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Assessment ofMSW Energy Recovery Technologies
Figure 14. Net average life cycle solid residues generated 54
Figure 15. Total population and percentile low-income within one mile of each facility 59
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Assessment of 'MSW Energy Recovery Technologies
Acronyms
AD
anaerobic digestion
BTU
British thermal unit
C
Celsius
CISWI
commercial and solid waste incinerators
CO
carbon monoxide
DST
decision support tool
GHG
greenhouse gas
GWP
global warming potential
HDPE
high density polyethylene
IGCC
integrated gasification combined cycle
kg
kilogram
L
liter
LCA
life cycle assessment
LCI
life cycle inventory
LDPE
low density polyethylene
LMOP
Landfill Methane Outreach Program
MACT
Maximum Achievable Control Technology
MJ
mega joule
MRF
materials recovery facility
MSW
municipal solid waste
MW
megawatt
NAAQS
National Ambient Air Quality Standards
NHSM
Non-Hazardous Secondary Material
NNSR
Nonattainment New Source Review
N02
nitrogen dioxide
NOx
nitrogen oxides
NOAA
National Oceanic and Atmospheric Administration
PET
polyethylene terephthalate
PM
particulate matter
PP
polypropylene
PS
polystyrene
PSD
Prevention of Significant Deterioration
PVC
polyvinyl chloride
RCRA
Resource Conservation and Recovery Act
RDF
refuse-derived fuel
SHC
Sustainable and Healthy Communities
SWOLF
Solid Waste Optimization Life-cycle Framework
Syncrude
synthetic petroleum or synthesis petroleum
Syngas
synthetic gas or synthesis gas
Ton
2,000 pounds
Tonne
Metric ton (2,204.6 pounds)
voc
volatile organic compound
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Assessment ofMSW Energy Recovery Technologies
WRRF Water Resource Recovery Facilities
WTE waste-to-energy
WWTP waste-water treatment plant
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Acknowledgements
This report was prepared to provide an understanding of options for technologies to "manage" plastics,
glass, metals, paper, food waste, and other materials that comprise municipal solid waste. This has been a
challenging topic due to many of the emerging technologies not being successful and currently not in
operation. Comparing emerging technologies with established technologies is difficult primarily due to
the lack of long-term performance data. Using life-cycle methodology and all available data, we
compared emerging technologies for materials management versus established technologies (i.e.,
combustion and landfilling).
As a project team, we met often to discuss the results and how best to communicate including the
uncertainties. We want to acknowledge the contributions of the RESES team - Carol Staniec (Region 5),
and Steve Wall (Region 9) and Charles Swanson (Region 9). Carol Staniec (Region 5) provided her
expertise on anaerobic digesters and their deployment in the U.S. Charles Swanson (Region 9) conducted
the EJSCREEN evaluation working to document potential environmental justice concerns. Steve Wall
(Region 9) contributed to the landfill section and the explanation of how EPA defines waste as a fuel. We
also acknowledge the contributions of the external reviewers, quality assurance review, peer reviews and
administrative review.
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Assessment of MSW Energy Recovery Technologies
Disclaimer
The research described here has been funded, in part, by the U.S. Environmental Protection Agency
Contract EP-D-11-084 to RTI International. It has been subject to the Agency's review, and it has been
approved for publication as an EPA document. Mention of trade names or commercial products does
not constitute endorsement or recommendation for use.
The research described in this study had been funded as part of the Sustainable and Healthy Communities
(SHC) research program to help communities make better decision to sustain a healthy society and
environment. This research is a product from SHC's Regional Sustainability and Environmental Sciences
(RESES) program to support Regional priorities. The research team for this work includes Jenny
Stephenson, Steve Wall, and Charles Swanson from EPA Region 9, Carol Staniec from
EPA Region 5, David Langston from EPA Region 4, Ozge Kaplan from the Center for Environmental
Measurement and Modeling, and Susan Thorneloe of the Center for Environmental Solutions and
Emergency Response.
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Assessment of MSW Energy Recovery Technologies
Foreword
The US Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. To meet this mandate, EPA's research program is providing
data and technical support for solving environmental problems today and building a science knowledge
base necessary to manage our ecological resources wisely, understand how pollutants affect our health,
and prevent or reduce environmental risks in the future.
The Center for Environmental Solutions and Emergency Response (CESER) within the Office of
Research and Development (ORD) conducts applied, stakeholder-driven research and provides responsive
technical support to help solve the Nation's environmental challenges. The Center's research focuses on
innovative approaches to address environmental challenges associated with the built environment. We
develop technologies and decision-support tools to help safeguard public water systems and groundwater,
guide sustainable materials management, remediate sites from traditional contamination sources and
emerging environmental stressors, and address potential threats from terrorism and natural disasters.
CESER collaborates with both public and private sector partners to foster technologies that improve the
effectiveness and reduce the cost of compliance, while anticipating emerging problems. We provide
technical support to EPA regions and programs, states, tribal nations, and federal partners, and serve as
the interagency liaison for EPA in homeland security research and technology. The Center is a leader in
providing scientific solutions to protect human health and the environment.
Gregory Sayles, Director
Center for Environmental Solutions and Emergency Response
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Assessment of 'MSW Energy Recovery Technologies
Executive Summary
Sustainable materials management is a systemic approach to using and reusing materials more
productively over their entire life cycles. It represents a change in how our society thinks about the use of
natural resources and environmental protection.
The United States Environmental Protection Agency (EPA) has established a Non-Hazardous Materials
and Waste Management Hierarchy1, which prioritizes and ranks the various management strategies from
most to least environmentally preferred. The hierarchy places emphasis on reducing, reusing, and
recycling as key to sustainable materials management. Some communities are also interested in assessing
waste-to-energy alternatives for non-recyclable material, contaminated recovered materials that don't
meet specifications for recycling, and residue streams that are not recycled due to market limitations.
A conventional waste-to-energy (WTE) facility accepts unprocessed municipal solid waste (MSW) which
is burned in a large combustion unit to generate electricity or utilized in a combined heat and power
system. They further recover ferrous and non-ferrous materials that is sold into the recycle market. In the
US waste-to-energy facilities with energy recovery began in the early 1980s. EPA (2018) reports 13% of
MSW was combusted in 2015, down from a high of 17% in 1996. There are 732 operating WTE facilities
in the US, down from 112 in 1997. In contrast, WTE is more prevalent in Europe. Food waste and other
biodegradable waste are not allowed to be landfilled in Europe. Therefore, more digestion of food waste
and other recovery technologies are more widely used in Europe resulting in less carbon emissions per ton
of waste than how the materials are managed in the U.S. As long as the cost of landfills do not consider
the environmental externalities such as increased carbon emissions per ton of waste, the technologies
described in this report will have a more difficult time being cost competitive. (Thorneloe, 2019)3;
(Kaplan, et al., 2009)4
Waste "conversion technologies" such as gasification and pyrolysis are less established in the US and the
world. These technologies differ from conventional WTE in that they do not directly combust MSW.
Instead they convert MSW feedstock via partial-oxygen or oxygen-absent thermochemical. The resulting
gases can be combusted to produce electricity or further processed into a liquid fuel or chemical
commodity product. Such conversion technologies are considered "energy recovery" and preferable to
"treatment and disposal" on EPA's waste management hierarchy. However, the ability to draw life cycle
environmental performance conclusions between US conversion technologies to conventional options
such as WTE and landfill disposal is limited due to the general lack of conversion technology operational
history, experience and available long term data (more than 5 years) to establish environmental and
economic performance overtime.
In contrast to waste conversion technologies, WTE and landfill facilities have decades of environmental
and economic performance data. WTE facilities are required to conduct performance tests and use
1 https://www.epa.gov/smm/sustainable-materials-management-non-hazardous-materials-and-waste-management-
hierarchy
2 Michaels and Shiang, 2016. 2016 Directory of Waste-To-Energy Facilities, http://energyrecovervcouncil.org/wp-
content/uploads/2016/05/ERC-2016-directorv.pdf
3 Thorneloe, S. 2019. Section 22 "Management of Solid Wastes" (22-69 - 22-93) in Perry's Chemical Engineers'
Handbook, 9th Edition, New York: McGraw-Hill.
4 Kaplan PO, DeCarolis J, and Thorneloe S. 2009. Is it better to burn or bury waste for clean electricity generation?
Environ. Sci. Technol., 43(6): 1711-1717.
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Assessment of 'MSW Energy Recovery Technologies
continuous emissions monitoring providing data on 100% of US facilities5. Models are used to quantify
landfill emissions due to difficulty in measuring fugitive loss from landfills. Landfills are not a steady-
state process and are constantly changing due to (1) changes in waste composition, (2) landfill design,
operation, and maintenance, (3) barometric pressure and (4) extreme weather events. Once waste is
buried, the landfill owner/operator has up to 5 years to install gas collection into the buried waste. As a
result, emissions from readily decomposing waste such as food waste is emitted to the atmosphere since
there is no capture of the methane (Levis et al., 2010) from waste burial until controls are installed 3 to 5
years after initial burial. Once a landfill "closes" or ceases accepting waste, emissions are thought to
decline over time based on the use of a first-order decomposition equation referred to as the landfill gas
emissions model (LandGEM)6. Satellite data suggest that landfill emissions may be understated by a
factor of 2. (Duren et al., 2019) Regardless of the uncertainty in calculating landfill emissions, we have
modeled landfills taking into account the uncertainty when comparing emissions to either WTE or waste
conversion technologies.
In assessing conversion technologies, it is important to understand which MSW feedstock(s) can be
managed by the technology, what pre-sorting or processing is required, whether minimum quantities of
MSW must be provided, net energy balance, emissions data, environmental permit requirements, and the
types and quantities of solid and hazardous residuals requiring management or disposal.
Technology Landscape
The following table provides an overview of conversion technologies and the potential portion of total US
MSW generation that could potentially be managed with these technologies:
Technology
MSW Feedstocks
Accepted by
Operating Facilities
Portion of Total
MSW
Residual Generation
Requiring Disposal
(by weight)
Number of Facilities
Currently Operating
in the US
Anaerobic Digestion
Food and yard
waste
Approximately
28%
Approximately 5-
10%a
25+ stand alone
multi-source
commercial facilities7
Gasification
MSW
Approximately
83%b
Greater than 10%c
2 operating facilities
Pyrolysis
Plastics
Approximately
13%b
Greater than 10%
4 operating facilities
WTE
MSW
100%
Approximately 15-
25%
73 commercial
facilities
WTE, waste-to-energy; MSW, municipal solid waste
adoes not include digestate which typically is composted
bbased on the usable fraction of the US average composition of MSW
c Gasification will have the same amount of ash potential as WTE but does not convert all the carbon; therefore, it will always
have more solid residual than complete combustion as occurs in a WTE facility
5 Thorneloe, S. 2019. Section 22 "Management of Solid Wastes" (22-69 - 22-93) in Perry's Chemical Engineers'
Handbook, 9th Edition, New York: McGraw-Hill.
6 Landfill Gas Emissions Model (LandGEM) Version 3.02 User's Guide, EPA-600/R-05/047, May 2005.
7 EPA's Anaerobic Digestion Data Collection Project collects and summarizes data on Anaerobic Digestion
Facilities. The 2015 survey results are available at https://www.epa.gov/anaerobic-digestion/anaerobic-digestion-
tools-and-resources#ADdata New reports will be published in 2019 and 2020.
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This report includes definitions for pyrolysis, gasification and anaerobic digestion (AD) technologies,
process descriptions, listings of active projects and facilities in North America, and characterization of life
cycle environmental impacts. This report provides an update to the 2012 EPA report, State of Practice for
Emerging Waste Conversion Technologies, (US EPA, 2012). Key updates include current information
about the conversion technology landscape and a literature review to provide data for characterizing the
life-cycle environmental performance of technologies. The literature review yielded 60 total studies of
which 48 were conducted since 2012.
Through this study, 30 pyrolysis and gasification technology projects and more than 40 operating MSW-
based AD facilities were identified in North America. Figure ES-1 shows the location of stand-alone
current active gasification, pyrolysis, and AD projects in North America. While MSW-based conversion
technology is still emerging in the US, these technologies have been utilized used for the management of
MSW in other parts of the world, such as Australia, Canada, Europe, and Japan albeit in a limited
capacity. A key aspect of international applications is that they are part of MSW collection and
management systems with advanced material sorting and processing, such as source segregated organics
collection.
Edmonton
Vancouver
Quebec
Montreal
Canada
Legend
Pyrolysis
Anaerobic Digestion
A Operating
• Anaerobic Digestion
A Not Operating
O Not Operating
Gasification
¦ Operating
~ Not Operating
Figure ES-1. Municipal solid waste conversion facilities.
Since the 2012 EPA report, State of Practice for Emerging Waste Conversion Technologies (US EPA,
2012), AD has grown rapidly with more than 25 stand-alone facilities that accept multi-source food waste
that process food and other organic fractions of MSW. Additionally, there are many more solely industrial
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Assessment of 'MSW Energy Recovery Technologies
source and wet AD projects diverting food scraps and other organic materials to wastewater treatment
plants with excess capacity, but these projects are not included in this report.
Of the 35 gasification and pyrolysis emerging technology companies identified in the 2012 EPA report,
six of the companies are operating at commercial or demonstration scale today. Two of the projects,
Environ and Green Power Inc., resulted in multi-million-dollar fraud judgements against the CEOs. There
are several other projects that have ended with lawsuits and settlements for unpaid services and breaches
in contracts. Currently, there are only one gasification and two pyrolysis facilities operating at a
commercial scale in the US using fractions of MSW as feedstock.
Siting Facilities
Traditionally, businesses and local agencies involved in the siting of facilities strive to comply with
planning and zoning regulations but may overlook the negative physical, social, and economic effects of
site activities. Businesses and local agencies that take the time to meaningfully engage communities
surrounding proposed facilities and consider the potential burden to vulnerable communities typically
have a more efficient permitting process.
In order to better understand communities around conversion technology and conventional WTE
facilities, EPA used EJSCREEN to assess income levels around these facilities. EJSCREEN8 is an online
publicly available EPA environmental justice mapping and screening tool that provides a nationally
consistent dataset and an approach for combining environmental and demographic indicators.
For this analysis, MSW energy recovery facilities (currently operating and under construction) were
mapped and evaluated by state percentile for low-income level within one mile of each facility. Figure
ES-2 compares population and percentile low-income around the facilities. Of the 111 facilities mapped,
29 are surrounded by predominantly low-income communities. Newer technologies tend to be in areas
with lower population densities, and older technologies such as mass burn are more often surrounded by
denser populations. Therefore, -25% of the facilities are in low-income communities.
8 EPA, EJSCREEN: Environmental Justice Screening and Mapping Tool, https://www.epa.gov/eiscreen
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Above the 80th
Percentile Low
Income
Technology Type
Anaerobic
• Digestion
• Gasification
Mass Burn
C Pyrolysis
9 Refuse Derived
Fuel
2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 22,000 24,000 26,000 28,000 3
Total Population
Figure ES- 2. Total population and low-income percentile ranking
within one mile of each facility.
Life Cycle Environmental Performance
The ability to draw concrete and definitive conclusions about the life-cycle environmental performance of
conversion technologies to each other and to conventional options such as WTE and landfill disposal is
limited due to the general lack of operational history, experience and accompanying data. However, from
review and analysis of life cycle inventory (LCI) studies available for MSW conversion technologies, the
technologies present theoretical energy production benefits comparable to conventional WTE. However,
energy production for conversion technologies will vary significantly based on the exact feedstock used,
net energy balance, process efficiency and any requirements for preprocessing of feedstock or post-
processing of product streams. This is true of any emerging technology especially technologies accepting
solid waste, which can also vary by composition and quantity.
Conversion technologies and conventional WTE and landfill options generate gaseous, liquid and solid
emissions that require additional treatment or disposal. The literature data summarized in this report
suggest that gasification and pyrolysis can result in carbon equivalent emissions comparable to
conventional technology.9 This is due to the carbon emissions associated with the combustion of the
9Note that discrepancies can exist between measured data and model estimates for conventional and emerging
conversion technologies. Due to the challenges in measuring fugitive loss from landfills, the CAA relies of the use
of use of LandGEM - a first-order decomposition equation - that was developed with field data collected in the
1990s (EPA, 2008). Emissions from buried waste occur for decades whereas other technologies produce emissions
instantaneously. Landfill measurements are on a on a small-scale basis - not statistically representative. In contrast.
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syngas or synfuel product, which is considered fossil energy. Conversely, the use of biogenic (i.e.,
organic) feedstock in either conventional or conversion technologies will result in a biogenic energy
product that is considered carbon neutral. For example, AD of food waste will create biogenic energy
that is considered carbon neutral. Likewise, landfills also produce biogenic energy and the organic
fraction of waste combusted in a WTE plant (or gasification or pyrolysis) is considered biogenic with
respect to carbon accounting.
All conversion technologies produce residual solid, which sometimes include hazardous waste streams
(e.g., ash, char, wax, slag, and digestate), that requires additional treatment (e.g., via a compost facility or
WTE) or disposal in solid or hazardous waste landfill. Conversion technology by-products may also
require treatment or disposal if a viable end-use or market cannot be found. The data available from the
literature show that conversion technologies generally produce as much or higher amounts of residuals as
conventional WTE. With conventional WTE, approximately five to fifteen percent of the volume1"
remains as ash, which is typically sent to a landfill and often used by the landfill operators as alternate
daily cover.
The exact amounts of solid residuals generated will be dictated by the feedstock composition and the level
of acceptable contamination by specific conversion technology. In general, it could be expected that a
mixed feedstock (e.g., bulk MSW, materials recovery facility [MRF] residuals) will generate greater
amounts solid residuals than a source segregated feedstock (e.g., plastics, food waste).
Other challenges found in applying life cycle data to analyze MSW-based conversion technologies
include:
¦ different MSW feedstocks accepted by different technologies and process designs limit the ability
to directly compare life cycle results
¦ wide variety of end-products produced by conversion technologies can create wide-ranging
estimates of life cycle offsets
¦ system boundaries not consistently applied among life cycle studies found in the literature,
particularly with regard to the inclusion or exclusion of pre- and post-processing activities
¦ available life cycle data from the literature represent different time spans and at different points in
technology development cycles, which can lead to wide-ranging technology performance
estimates
Key Advantages and Challenges
A primary advantage for conversion technologies as compared to WTE or landfill disposal is often
presented as the potential variety and flexibility of products that can be generated. Syngas from
gasification gas can be used on-site to generate electricity, or it can be further refined to produce a variety
for WTE, data is available for 100% of US facilities which are required to conduct performance tests for multiple
pollutants that are compared to health benchmarks. In addition, WTE facilities are required to provide continuous
emission monitoring of outlet emissions with data accessible 24/7. For landfills, there are challenges in how best to
measure total fugitive loss with leaks occurring in response to drought, soil erosion, and slide slopes. Using ground-
based optical remote sensing technology at three landfills, results found fugitive loss ranged from 38 to 88% (US
EPA, 2007). Barometric pressure, extreme weather events, and changes in design and operation will result in
changes in fugitive loss. Recent data appearing in Nature suggests that current US GHG inventories may be
understated for landfill emissions. Therefore, estimates of life-cycle enviromnental tradeoffs are more uncertain for
landfills than for WTE.
111 https://www.epa.gov/smm/sustainable-materials-management-non-hazardous-materials-and-waste-management-
hierarchy
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of chemicals, including liquid fuels. Syncrude from pyrolysis can produce high-value products including
naphtha, kerosene, and gas-oil, from poly olefin feedstocks. Biogas from AD, or landfill gas, can be used
on-site to generate electricity, used directly or it can be further refined to produce transportation fuels.
Since there are few operating gasification and pyrolysis facilities in the US, it's not yet clear that they will
be able to produce the wide variety of products touted by vendors.
A key challenge for conversion technologies as compared to conventional WTE and landfill disposal is
the need for consistent and quality feedstock for the process to work effectively, and in many cases, the
limited feedstocks accepted (e.g., plastic, specific plastic resins, organic materials). Unlike WTE and
landfill where bulk MSW feedstock is readily accepted, feedstock supply, preprocessing and handling can
represent challenges that can have significant impacts on the performance and economics of the
conversion technology. Other key disadvantages cited in the literature include difficulties encountered
scaling up facilities from demonstration to commercial scale and unpredictable specifications of the
energy product that is generated from the conversion technology. These specifications are highly
dependent on the types and mixtures of feedstock used.
Another challenge for conversion technologies is the cost, which can include technology and facility
costs, permitting, feedstock segregation and processing, operational costs, and disposal or management
costs for residuals such as ash or digestate. Put-or-pay contracts, sometimes used by conversion
technology companies, obliges the community to either to provide predefined minimum amounts of clean
feedstock for a specific period, or to pay for any shortfall. Cost is not only a factor for conversion
technologies but also impacts composting, recovery/recycling, and WTE. As shown in Figure ES-3, in
2017 more than 50% (or 140 million tons out of 268 million tons) of MSW generated was buried in
landfills in the US (US EPA, 2018). With the current loss in recycling markets, that is also a challenge for
communities looking to recover more energy and resources from solid waste.
In addition to the potential financial cost of put-or-pay contract requirements, feedstock quantity
shortfalls, the requirements may result in disincentivizing potential and existing waste reduction, reuse,
and recycling programs. In Honolulu, a 20-year "put-or-pay" contract requires the City and County of
Honolulu's Department of Environmental Services to provide 800,000 tons of MSW annually to the WTE
contractor or pay a penalty for any lost revenue from energy sales. From 2013 to 2016, the city had to pay
WTE facility contractor over $6.2 million in penalties for not supplying enough waste. Honolulu
discontinued public school recycling programs to shift recyclable materials to the WTE facility.
Although the "put or pay" contract has a role to play that impacts recycling rates, so does the crash in
recyclable commodity values and the lack of markets.11 Also, the cost to landfill compared to other
alternatives including WTE and recycling, results in more waste being landfilled.
Conversion technology facilities are not well established in the US, and an inventory updating the number
of facilities in the US that is presented in this report shows a decline in the number of facilities with
economics and lack of viable feedstock being a major challenge and resulting in facility closures. For
example, of the 35 gasification and pyrolysis facilities identified in the 2012 report, only six are operating
in 2019. Some of the companies never got past the planning and funding stage, some couldn't scale up
operations, and some resulted in fraud judgements against the conversion technology companies.
In addition to the technical feasibility and performance of waste conversion technologies, there are
several key institutional and social challenges that need to be considered including the lack of precedent
and ambiguities regarding regulatory permitting and negative public perception. Hence, some
stakeholders use the terms "chemical recycling" or "advanced plastic recycling" to describe the use of
pyrolysis or gasification to convert plastics.
"https://\vww.civilbeat. org/2017/11/recYcle-or-incinerate-the-battle-or-the-blue-bins/
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Assessment of 'MSW Energy Recovery Technologies
*Landfilling after composting, recycling and combustion with energy recovery. Includes combustion without energy recovery.
The top line measures generation, because generation = recycling + composting + combustion with energy recovery + landfilling.
Figure ES- 3. Recycling, composting, combustion with energy recovery and landfilling of
materials in MSW, 1960 to 2017.
Key Data Gaps and Recommendations for Future Research
Making direct and meaningful comparisons between conversion technologies and conventional
technologies is challenging due to inherent differences among the processes and lack of operating data for
characterizing cost and environmental performance.
While operating data may be more readily available in other regions of the world, such as Europe, there is
a need for operating data for facilities in the US to better assess their performance with US feedstock and
demonstrate their potential in the US context. Therefore, as plants are built, they should be encouraged to
submit data relative to cost, energy consumption and environmental concerns.
Additional research that could be done in the future to advance the understanding of conversion
technologies might include examining data ranges for operating conversion facilities outside of the US
relative to cost and environmental aspects for key parameters such as air, water, and waste emissions;
feedstock composition and preprocessing requirements; net energy balance, post-processing requirements
for end-products (e.g., syngas cleaning, ash requiring disposal), beneficial offsets for different by-
products, and market prices for saleable products.
Additional research on the net energy balance of conversion technologies is also needed. A key
consideration for assessing conversion technologies should include an assessment of how efficient the
conversion process is. It is not clear whether conversion technology facilities may consume more energy
than they produce. In Europe, mechanical biological treatment is in use and should be included in future
evaluations. Although the cost is such that there aren't any in the US, if carbon were given a value to
increase reductions, then mechanical biological treatment and other technologies may become more
advantageous while also protective of human health and the environment.
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Assessment ofMSW Energy Recovery Technologies
Research is also needed to collect case studies highlighting permitting challenges and successful solutions
on the conversion technologies. This information would be useful to communities evaluating these
technologies.
In addition to conducting a review of conversion technologies, a goal of the RESES project is to develop
a Decision Makers Guide for Assessing Municipal Solid Waste Energy Recovery Technologies. This is a
summary of information contained in the report and is provided as Attachment F. Visuals are provided to
illustrate the different options for the different feedstocks in municipal solid waste. For those not wanting
the details of the report, they may want to focus on Attachment F.
Executive Summary References
Levis JW, Barlaz MA, Themelis NJ, Ulloa P. (2010). Assessment of the state of food waste treatment in
the United States and Canada. Waste Manage., 30(8-9): 1486-1494, DOI:
10.1016/j.wasman.2010.01.031
Duren RM, Thorpe AK, Foster KT, et al. 2019.. California's methane super-emitters. Nature (575)
180-184.
Kaplan PO, DeCarolis J, and Thorneloe S. 2009. Is it better to burn or bury waste for clean electricity
generation? Environ. Sci. Technol., 43(6): 1711-1717.
Thorneloe, S. 2019. Section 22 "Management of Solid Wastes" (22-69 - 22-93) in Perry's Chemical
Engineers' Handbook, 9th Edition, New York: McGraw-Hill.
US EPA. 2018. Advancing Sustainable Materials Management: 2015 Tables and Figures. Washington,
DC: US Environmental Protection Agency, Office of Resource Conservation and Recovery.
US EPA. 2012. State-of-Practice for Emerging Waste Conversion Technologies. EPA 600/R-12/705.
Research Triangle Park, NC: US Environmental Protection Agency, Office of Research and
Development.
US EPA. 2007. Evaluation of Fugitive Emissions Using Ground-Based Optical Remote Sensing
Technology. EPA/600/R-07/032. Research Triangle Park, NC: US Environmental Protection Agency.
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Assessment of MSW Energy Recovery Technologies
Chapter 1:
Introduction
Sustainable Materials Management is a systemic approach to using and reusing materials more
productively over their entire life cycles. It represents a change in how society thinks about the use of
natural resources and environmental protection. By looking at a product's entire life cycle, we can find
new opportunities to reduce environmental impacts, conserve resources and reduce costs.
The US Environmental Protection Agency (EPA) developed the non-hazardous materials and waste
management hierarchy in recognition that no single waste management approach is suitable for managing
all materials and waste streams in all circumstances. The hierarchy ranks the various management
strategies from most to least environmentally preferred. The hierarchy places emphasis on reducing,
reusing, and recycling as key to sustainable materials management. Source reduction can result from any
activity that reduces the amount of a material or agricultural input needed and therefore used to make
products or food. It is important to recognize that source reduction, reuse, recycling, and composting have
been identified as preferred materials management approaches preferred over energy recovery. Discards
to landfills is the least preferred and results in emissions over multiple decades as biodegradable waste
decomposes.
Waste Management Hierarchy
1.1 Current State of Energy Recovery From Municipal Solid Waste in
the US
Recovering energy from waste has long been an attractive concept. Waste needs to be managed and there
is a seemingly endless supply, so much so that it's considered a renewable fuel. In 2017, Americans
generated approximately 268 million tons of municipal solid waste (MSW), which is the trash thrown
away by consumers.12 More than half of it was landfilled and a quarter was recycled. Nearly 13% (33.6
million tons) was combusted with energy recovery at waste-to-energy (WTE) facilities. The US Energy
Source Reduction & Reuse
Recycling / Composting
Energy Recovery
Treatment
t; & Disposal
V /
12 US EPA. "Advancing Sustainable Materials Management: 2017 Factsheet," November 2019. EPA530-F-19-007.
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Assessment of 'MSW Energy Recovery Technologies
Information Administration reported that in 2015, WTE facilities provided about 0.4% of the total US
electricity generation and had a total generating capacity of 2.3 gigawatts13.
Currently, there are 73 WTE facilities operating in the US, with the majority utilizing mass burn
combustion (Appendix A). Most of these facilities have been operating for more than 20 years. The West
Palm Beach WTE facility started operation on July 18, 2015 and was the first one built since 1995.14
More recently, the focus has been on emerging waste-to-energy technologies that convert waste into
energy products rather than burn it in a combustion unit. These "conversion technologies" differ from
mass burn WTE facilities in that they do not directly combust feedstock but rather convert it via partial-
oxygen or oxygen-absent thermochemical processes. The resulting gases can be combusted to produce
electricity or further processed into a liquid fuel or chemical commodity product. Another difference that
makes it difficult to compare emerging technologies to demonstrated technologies is the lack of longer-
term data (greater than 5 years) to establish economic and environmental performance. Often, only vendor
data is available, which tend to provide optimistic claims.
For the purposes of this report, conversion technologies of focus include gasification, pyrolysis, and
anaerobic digestion (AD). The heterogenous nature of MSW makes it challenging to efficiently create
energy products from a feedstock that has a widely varying chemical constituency.15 To address this, the
MSW feedstock needs to be effectively sorted or separated and processed. None of the conversion
technologies can convert MSW to an energy product without sorting and processing. Furthermore, no
country to date has had favorable experience using MSW as feedstock for gasification or pyrolysis.
However, there is wider use in other countries - as in the US - of anaerobic decomposition for food waste
that prevents landfilling of food waste and permits recovery of nutrients for healthy soil.
1.2 Report Objectives and Structure
As these conversion technologies are being promoted and distributed by private sector stakeholders across
the US, local communities and municipalities will need to better understand not only the novelty and
potential of each technology type, but also the potential technical, environmental, economic and social
impacts of the technologies in their local context. Because of the high-cost failure of numerous
conversion technology projects, the National Waste and Recycling Association and the Solid Waste
Association of North America developed a "Briefing for Elected Officials" including an "Emerging
Waste Management Technology Project Development Checklist."16
This report aims to be a resource for communities wanting to better understand these technologies, their
risk profiles, and how their life-cycle environmental impacts compare to conventional options for energy
recovery from MSW. Chapter 2 provides an overview of conventional options for energy recovery from
MSW including landfill and WTE systems. Chapters 3—5 include definitions, process descriptions and
existing facilities for emerging gasification, pyrolysis and AD. Chapter 6 includes life cycle inventory
13 https://www.eia. gov/todavinenergy/detail.php?id=25732
14 MSW Management. James Warner. Waste-to-Energv: The Lost Decades. July/August 2015.
* Select facilities in Canada are also included as they provide direct operational experience.
15 Joint Institute for Strategic Energy Analysis, "Waste Not, Want Not: Analyzing the Economic and Environmental
Viability of Waste-to-Energy (WTE) Technology for Site-Specific Optimization of Renewable Energy Options."
February 2013. https://www.nrel.gov/docs/fV13osti/52829.pdf
16 National Waste and Recycling Association of North America and Solid Waste Association of North America,
Briefing for Elected Officials Effective Responses to Emerging Waste Management Technology Proposals
(February 2017), and Emerging Waste Management Technology Project Development Checklist (February 2017)
https://cdn.vmaws.com/wasterecvcling.site-vm.com/resource/resmgr/docs/Unsolicited-proposals-and-em.pdf
and https://cdn.ymaws.com/wasterecycling.site-ym.com/resource/resmgr/docs/Emerging-technologies-projec.pdf
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Assessment of 'MSW Energy Recovery Technologies
(LCI) data available from the literature for emerging technologies and life-cycle environmental
comparisons of those technologies to conventional options. EPA's municipal solid waste decision support
tool (MSW DST17) was used to develop the LCI profiles for conventional options. Chapter 7 provides a
summary of findings and observations including key data gaps and recommended future research needs.
Attachment C provides a list of additional definitions.
1.3 Quality Assurance and Data Limitations
This project involved collecting and analyzing secondary data for technologies to recover energy from
MSW. The data and information contained in this report were collected from the publicly available
literature for emerging energy recovery technologies in combination with modeled data developed by
applying EPA's MSW DST using US national average assumptions.
This work was conducted under an approved quality assurance project plan. The appropriateness of the
data and their intended use were assessed with respect to the data source, the data collection timeframe,
and the scale of the geographic area that the data represent. Preference was given to data that have
undergone peer or public review (e.g., those published in government reports and peer-reviewed journals)
over data sources that typically do not receive a review (e.g., conference proceedings, trade journal
articles, personal estimates). However, where peer-reviewed data did not exist, parameters and
assumptions were developed from the next highest quality available sources (e.g., grey literature, and
product specification data sheets from manufacturers). Preference was given to more recent data over
older data. In this report, the sources of all data and any identified assumptions and limitations are
presented.
17 https://mswdst.rti.org/
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Assessment of 'MSW Energy Recovery Technologies
Chapter 2:
Conventional Energy Recovery from Waste
Landfill and direct combustion have been traditional management options for MSW in the US. There are
almost 600 operational landfill gas to energy projects in the US, most of which utilize landfill gas to
produce electrical energy.18 Today's MSW combustion plants operating in the US are designed to
generate electricity (and possibly heat) and recover recyclable metals. Because these plants combust
MSW and recover energy, they are often called waste-to-energy (WTE) plants or resource recovery
facilities. Common technologies for the combustion of MSW include mass burn facilities, modular
systems and refuse-derived fuel systems. According to the US Energy Information Administration, in
2016, 71 WTE (mass burn and refuse-derived fuel (RDF) plants generated approximately 14 billion
kilowatt hours of electricity from burning 30 million tons of MSW, comprised primarily of biomass and
plastics.19
Although the focus of this report is evaluating waste conversion technologies, landfills and combustion
are included to provide a basis for comparison. The ideal goal is to maximize resource and energy
recovery from waste and minimize the impact of waste management on human health and the
environment. Energy can be recovered from landfills but not as efficiently as combustion of waste.
Kaplan et al. (2009) found that WTE (or mass burn combustion) can generate an order of magnitude more
electricity than landfill gas to energy given the same amount of waste. Only the biodegradable portion of
landfilled waste contributes methane and the inefficiencies in gas collection and capture result in much of
the methane leaking and not being utilized for its energy potential. Whereas, mass burn or waste
conversion does recover more resources and generate more electricity as compared to landfilling.
2.1 Landfill
In the US, more than 140 million tons (or 52%) of MSW is landfilled (US EPA, 2019). Biodegradable
components such as food waste, paper, yard debris, septic sewage sludge and other organics will
decompose and produce methane that can be captured and utilized for its energy value. Figures 1 and 2
provide a distribution landfill gas to energy projects using data provided by EPA's Landfill Methane
Outreach Program (LMOP).
In the US, municipal landfills are required to meet federal Resource Conservation and Recovery Act
(RCRA) Subtitle D design and operation standards, codified in 40 CFR 258, which require that the
facility, among other requirements, have a composite liner system, final cover, and groundwater
monitoring system. Landfills are also required to meet federal Clean Air Act standards that require
collection and capture of gas prior to combustion in a flare or to generate electricity using gas-fed or
steam-fed turbines, lean-burn or rich burn engines, or to replace boiler fuel with landfill gas. The landfill
air rules2" require that gas be collected within 3 to 5 years of waste burial. As a result, gas generated over
this time is emitted to the atmosphere (Levis et al., 2010). Even once gas is collected, the capture
efficiency has been found to range from 38 to 88%21 meaning that not all methane is captured and
18 https://www.epa.gov/lmop/landfill-gas-energy-proiect-data
19 US Energy Information Administration. Waste-to-energy.
https://www.eia.gov/energvexplained/?page=biomass waste to energy
211 https://www.epa.gov/stationarv-sources-air-pollution/municipal-solid-waste-landfills-new-source-perfonnance-
standards
21 Quantifying Methane Abatement Efficiency at Three Municipal Solid Waste Landfills, EPA/600/R-11/033, Jan
2012.
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Assessment of MSW Energy Recovery Technologies
controlled. Methane is a potent greenhouse gas 28 to 36 times more effective than CO2 at trapping heat in
the atmosphere over a 100-year period.22
With the cost of landfills less than other management options and without a value for environmental
externalities such as carbon emissions, most communities will continue to discard residential and
commercial waste in a landfill. However, recent reports suggest that landfill carbon emissions may be
understated as compared to oil and gas industry and the agriculture industry (Ren et al., 2018; Peischl et
al., 2013). Through testing using satellites by the National Oceanic and Atmospheric Administration
(NOAA), the largest methane emitters in California were found to be 30 landfills contributing 41% of
total methane emissions (Duren et al., 2019). Using landfill gas to generate energy and reduce methane
emissions produces positive outcomes for local communities and the environment. Landfill gas
utilization projects reduce carbon emissions, reduce air pollution by offsetting the use of non-renewable
resources, reduce environmental compliance costs, provide health and safety benefits, and can provide
benefit to the community and economy. As shown in Figure 1, there are almost 600 operating projects
with the majority producing electricity (Figure 2).
Candidate Landfills: 476
Operational Projects: 595
Construction Projects: 8
Shutdown Projects: 309 ' Planned Projects: 41
Figure 1. Landfill gas to energy project in the US (2019).
22 https://www.ipcc.cli/report/ar5/svr/
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Assessment of 'MSW Energy Recovery Technologies
RNG / Local Use: 7
1
Renewable Natural Gas (RNG)
RNG I Pipeline Injection: "
Direct Use: 104
Qectricity: 429
Figure 2. Operational landfill gas to energy projects by type in the US (2019).23
Figure 3 presents a process flow diagram for a conventional MSW landfill. As shown, incoming waste is
deposited on the working face of the landfill where it is spread, compacted, and covered with daily cover
material (usually soil). Once the active cell is filled, intermediate cover will be placed on the cell and a
new cell opened. When all cells at the site have been filled, a final cover system will be installed although
often interim caps are used prior to a final cover installation.
23 https://www.epa.gOv/lmop/basic-infonnation-about-landfill-gas#landfill
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Assessment of MSW Energy Recovery Technologies
• Composite Liner. The liners are
made of a clay layer and a
synthetic layer, which offer
different cracking resistent
properties. Also, the liners prevent
leachate from seeping into the
groundwater.
Clay layer: Compacted clay creates a
natural layer due to its ability to clump
together and hold in liquid.
Plastic Liner: The liner is made from
high density polyethylene (HOPE) or
polyvinyl chloride.
Landfill Layers & Protective Measures
Crushed Rock Layer. Crushed
i rock is placed around leachate
pipes to prevent clogging.
0 Methane Gas Collection
System. Methane gas forms
pockets at the center and
bottom of the landfill, so
pipes run throughout the landfill
collecting the gas and senting it to a
collection well.
e
Leachate Collection Pipes.
Leachate pipes are placed on
top of the plastic liner to
collect leachate for treatment.
o
Trash Layer. Trash is dumped
and compacted into cells,
which can be several acres in
OSoil Cover Layer. At the
end of the work day, the
working face or where
trash was dumped is
covered with up to six inches of
soil. The soil is used to minimize
the odor, control litter and
discourage animals and insects,
thus protecting public health.
0 Final Cap. When a landfill
is full and regulations
state that it cannot
accept more trash, it
must be closed. A final cap is
installed over the landfill. The
cap is made from a synthetic
plastic followed by a four foot
layer of dirt. Grass and shallow
rooted plants are are planted on
topp to prevent the erosion of
the soil cap.
o
Fencing for litter
control.
Vegetation for sound
and dust control.
Groundwater
monitoring to ensure
protection of drinking
water sources from
leachate.
Continued methane
collection and
monitoring.
Figure 3. Process flow diagram for a conventional MSW landfill.24
24 Source: https://www.tes.com/lessons/gfliTlsasHKOaeg/whY-should-we-care-about-garbage
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Assessment of 'MSW Energy Recovery Technologies
The quantity and composition of the MSW in the landfill directly impacts landfill gas production. A
landfill that accepts large fractions of organic wastes, for example, will generally have higher greenhouse
gas (GHG) emissions than a landfill that accepts little organic wastes or only inorganic materials. The
composition of landfill gas is generally assumed to be 50% CH4 and 50% carbon dioxide (CO2) based on
volume (US EPA, 2011). The CO2 fraction of landfill gas is considered biogenic in nature and has an
associated global warming potential (GWP) of zero. CO2 emissions that are produced from landfill gas
combustion using a flaring or energy recovery system are also considered biogenic. Combustion of
landfill gas via a flare and/or energy recovery system will destroy almost all of the CH4, converting it to
CO2. However, landfill gas also contains small amounts of nitrogen, oxygen, and hydrogen; less than 1%
non-methane organic compounds (NMOCs); and trace amounts of inorganic compounds (US EPA,
2014b). Where landfill gas is combusted in a flare and/or energy recovery system, criteria and hazardous
air pollutants are generated (US EPA, 2008 and 2007).
Landfill gas can escape the gas collection system and pass through the cover soil, cracks in the cover or
leaks around the gas wells. For landfill gas that passes through the cover soil, a fraction of the CH4 can be
oxidized by methanotrophic organisms in the soil. The exact fraction of CH4 oxidized will vary by site-
specific conditions. Landfill gas takes the path of least resistance and leaks occur that will vary overtime
based on changes in landfill design and operation. As stated earlier, landfill owner/operators have up to 3
to 5 years to install gas control, meaning all gas being generated during that time is lost to the atmosphere.
Also, landfills operate for decades and once they cease accepting waste, there can be emissions for many
decades in the future. The Subtitle D requirements, codified in 40 CFR 258, require liners and leachate
control system be used to limit waterborne contaminants in the uppermost aquifer within prescribed
limits. In states that have received EPA program approval for 40 CFR 258.4 research, development, and
demonstration permits, MSW landfills can also be managed as "wet" landfills where liquids are added to
enhance biodegradation of organics and gas production for energy recovery. The amount of leachate
generated is generally governed by the moisture content of the MSW and the precipitation at the landfill.
Post-placement of MSW, the fraction of precipitation that becomes leachate will decrease as the buried
waste is covered with an intermediate and/or final cover. Leachate collection systems are designed to
capture the leachate so that it can be removed from the landfill and treated on- or off-site. Thus, the
releases for waterborne contaminants from the landfill include the post-treatment releases as well as any
releases that escape the leachate collection system. (Thorneloe, 2019)
2.2 Mass Burn Facilities
The majority of WTE plants in the US use mass burn combustion to burn waste to generate heat and
electricity. Attachment A lists the 63 currently active mass burn plants in the US. Attachment A also list
13 refuse-derived fuel (RDF) and 4 modular (i.e., portable) WTE plants. Most of these facilities have
been operating for more than 20 years. Only one new WTE facility has been built since 1995.25 As shown
in Figure 4, a mass burn WTE plant accepts unprocessed MSW, which is burned in a large combustion
unit with a boiler. Steam from the boiler is used to generate electricity or utilized in a combined heat and
power system. Ferrous metal and other metals are recovered and recycled.
25 James Warner. Waste-to-Energv: The Lost Decades. MSW Management. July/August 2015.
* Select facilities in Canada are also included as they provide direct operational experience.
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Assessment of MSW Energy Recovery Technologies
Figure 4. Mass burn process flow diagram (US EIA, 2018).
(Note: Fly ash and bottom ash are shown as being treated separately, which is common in Europe. In the US, the ashes are
typically handled together as a combined ash)
An air pollution control system cleans the combustion gases, to levels significantly below Maximum
Achievable Control Technology (MACT) regulator}' standards, prior to their release to the atmosphere.
The amount of combustion residues, or ash, generated depends on the composition of the MSW
combusted and ranges from 15-25 percent (by weight) and from 5-15 percent (by volume) of the MSW
processed.l<> Generally, MSW combustion residues consist of two types of material: fly ash and bottom
ash. Fly ash includes fine particles removed from the flue gas and residues from other air pollution control
devices, such as scrubbers. Fly ash typically amounts to 3-7% percent by weight of the total ash. Bottom
ash comprised the remaining ash by weight and includes the main chemical constituents such as silica
(sand and quartz), calcium, iron oxide, and aluminum oxide as well as un-oxidized amounts of iron and
aluminum. In the US, the bottom and fly ash streams are mixed together at the facility and handled as a
combined ash. Combined bottom ash usually has a moisture content of 20-30 percent by dry weight. The
chemical composition of the ash varies depending on the original MSW feedstock and the combustion
process. The ash that remains from the MSW combustion process is typically sent to landfills, either as
beneficial daily cover, co-mingled with regular MSW, or in a separate ash monofill.
2.3 Modular Systems
Modular WTE Systems burn unprocessed MSW. They differ from mass burn facilities 111 that they are
much smaller and are portable. They can be moved from site to site. Attachment A list 4 modular WTE
plants.
2%ttps://www.a);i.i'ov/simiyeiiergv-recovery-combus1ion-mimicipal-solid-waste-msw#HowWorks
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Assessment of 'MSW Energy Recovery Technologies
2.4 Refuse-Derived Fuel Systems
Refuse-derived fuel systems use mechanical methods to shred incoming MSW, separate out non-
combustible materials, and produce a combustible mixture that is suitable as a fuel in a dedicated furnace
or as a supplemental fuel in a conventional WTE boiler system. After shredding and noncombustible
materials are removed, the remaining material is either conveyed to a nearby RDF combustion facility for
use or transported to an RDF combustion facility (or possibly to an industrial or utility user) located
elsewhere. The RDF can either be used as-is (shredded fluff) or compressed into pellets, bricks, or logs
for transportation, storage or sale. RDF processing facilities are typically located near a source of MSW,
while the RDF combustion facility can be located elsewhere. RDF is often combusted with other biomass
materials or with fossil fuels to produce renewable energy sources.
According to the Energy Recovery Council (Michaels and Shiang, 2016), there are 13 RDF WTE plants
operating in the US. Table 1 provides a listing of facilities that make RDF from MSW or combust RDF.
2.5 Non-Waste Fuel NHSM Combustion for Energy
Another type of refuse-derived fuel WTE system being built today aims to make an engineered non-waste
fuel out of MSW, or other non-hazardous waste materials, for off-site use in a cement kiln or boiler to
supplement or as a substitute for traditional fuels. This type of RDF requires more sorting and processing
than traditional RDF and typically aims for a high-BTU/lb fuel with low moisture and low chloride
content. Additionally, this engineered non-waste fuel requires a site-specific non-waste fuels
determination following the requirements of the Resource Conservation and Recovery Act (RCRA) Non-
Hazardous Secondary Material (NHSM) rule.
The NHSM rule identifies criteria for determining which NHSMs are, or are not, solid wastes when used
as fuels or ingredients in combustion units. Units combusting NHSMs that are solid waste are subject to
the requirements of Section 129 of the Clean Air Act (CAA), while units that combust NHSMs that are
not solid waste may be subject to regulations promulgated under CAA Section 112. The NHSM rule was
developed under the RCRA in conjunction with three rules under the Clean Air Act-the major boiler, area
boiler and the commercial and industrial solid waste incineration rules. The rules are codified at 40 CFR
Parts 60 and 241.
Under CAA Section 129 EPA has issued emission standards for Commercial and Solid waste Incinerators
(the CISWI rule). The types of facilities under the CISWI rule are boilers and process heaters, industrial
furnace and incinerators. Under section 129 of the Act, the standards include limiting emissions of nine
air pollutants (i.e., particulate matter, carbon monoxide, dioxins/furans, sulfur dioxide, nitrogen oxides,
hydrogen chloride, lead, mercury, and cadmium). Section 129 standards apply to any facility that
combusts any commercial or industrial solid waste material, including those that combust solid waste for
energy recovery purposes.
NHSMs that are combusted are generally considered solid waste. If a unit does not combust a material
that the NHSM rule defines as a solid waste, the unit will instead be subject to the 112 NESHAP
standards. NHSMs that are considered non-wastes when combusted are identified in 40 CFR 241.3 and
241.4 and can be subject to emissions standards under CAA section 112 for control of Hazardous Air
Pollutants from sources such as utilities, boilers, process heaters and cement kilns.
There are three routes to a non-waste NHSM determination that determine whether a material is a waste
or a non-waste:
1. Site-specific "self-determination" requirements under 40 CFR 241.3(b). A combustion source
must make a waste or non-waste determination for the NHSM used as fuel managed within their
control (241.3(b)(1)); or for ingredients (241.3(b)(3)); or for fuel or ingredient products produced
from processed discarded NHSM (241.3(b)(4)).
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Assessment of'MSW Energy Recovery Technologies
2. Petitions under 40 CFR 241.3(c). Sources may petition for a non-waste determination from the
EPA Regional Administrator for a material used as a fuel that has not been discarded and is not
managed within their control.
Table 1. Facilities that make RDF from MSW or Combust RDF in the US
Operational Status
Facility Name &
Operator
City
State
Operating - makes RDF from MSW
Prairieland Solid Waste Management
Resource Recovery Facility
Truman
MN
Operating - makes RDF from MSW
Recycling & Energy Center
Ramsey/Washington Recycling and Energy
Board
Newport
MN
Operating-combusts RDF
Mid-Connecticut Resource Recovery Facility
NAES Corp.
Harford
CT
Operating-combusts RDF
Miami-Dade County Resource Recovery
Facility Covanta Dade Renewable Energy, LLC
Miami
FL
Operating-combusts RDF
Palm Beach Renewable Energy Facility #1
Babcock & Wilcox
West Palm
Beach
FL
Operating (this facility also utilizes
mass burn) - combusts RDF
Honolulu Resource Recovery Venture-
HPOWER Covanta Honolulu Resource
Recovery Venture
Kapolei
HI
Operating-combusts RDF
Arnold 0. Chantland Resource Recovery Plant
City of Ames
Ames
IA
Operating-combusts RDF
Penobscot Energy Recovery Company
ESOCO Orrington, Inc.
Orrington
ME
Operating-combusts RDF
SEMASS Resource Recovery Facility
Covanta SEMASS, LP.
West Wareham
MA
Operating-combusts RDF
Detroit Renewable Power
Detroit Renewable Energy, LLC
Detroit
Ml
Operating-combusts RDF
Red Wing Steam Plant
Northern States Power Co - Minnesota
Red Wing
MN
Operating-combusts RDF
Wilmarth Plant
Northern States Power Co - Minnesota
Mankato
MN
Operating - combusts RDF
Wheelabrator Portsmouth
Wheelabrator Portsmouth Inc.
Portsmouth
VA
Operating-combusts RDF (mostly
biomass/wood)
French Island Generating Station
Northern States Power Co - Minnesota
La Crosse
Wl
Closed 201927
Elk River Station
Great River Energy
Maple Grove
MN
MSW, municipal solid waste; RFD, refuse-derived fuel
27 EE Online. Great River Energy: Elk River project stops operations, prepares for closure. Feb. 25, 2019.
https://electricenergvonline.com/article/energv/categorv/biofuel/83/750958/elk-river-proiect-stops-operations-
prepares-for-closure.html
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Assessment of'MSW Energy Recovery Technologies
3. Categorical non-waste determinations under 40 CFR 241.4. Materials that are listed in 40
CFR 241.4(a) have been determined to be non-waste materials by the EPA Administrator, so do
not need to conduct a site-specific determination for these materials. A source may petition the
Administrator for a categorical non-waste determination under 40 CFR 241.4(b).
Under the NHSM Rule, the determination that a waste material has been processed into a non-waste fuel
is made by the facility and is self-implementing. Specifically, the NHSM Rule regulations require that a
facility processing waste material into a fuel perform a demonstration showing that the material and site-
specific process satisfy 40 CFR 241 's processing and legitimacy requirements and maintain such
demonstration in their records and provide such demonstration to facilities who would combust the non-
waste fuel.
Although not required, some facilities have sought EPA concurrence on their determinations and, in some
instances, EPA has issued clarification letters for projects that have processed MSW waste material into
an engineered fuel product. EPA's letters28 concurred, for those instances, that the facilities had provided
an adequate demonstration showing their materials were processed into a new fuel product (per 40 CFR
241.3(b)(4)), meeting the processing definition of 40 CFR 242.2 and the legitimacy criteria 40 CFR
241.3(d)(1). Copies of these EPA concurrence letters are available at:
https: //rcrapublic. epa. gov/rcraonline/topics .xhtml#W
Table 2 provides a listing of facilities that are or are planning to process MSW into a non-waste fuel and
have made a site-specific "self-determination" satisfying the requirements of 40 CFR 241.3(b). This list
was pulled from RCRA Online of organizations that have received NHSM clarification letters from EPA29.
Table 2. Facilities that Process MSW into a Non-Waste Fuel for Combustion in the US
Operational Status
RCRA Online
Number
Facility Name & Operator
City
State
Under construction30 - will
make solid recovered fuel from
MSW
14863
Accordant Energy LLC (formerly
ReCommunity) / RePower South LLC
Moncks
Corner
SC
Under construction - will make
solid recovered fuel from MSW
14838
Entsorga West Virginia
Martinsburg
wv
Both facilities recently closed31
- makes solid recovered fuel
from MSW
14869
Waste Management SpecFUEL
San Antonio
Philadelphia
TX
PA
Expected to be operational in
20 1932 - will make solid
recovered fuel from MSW
14909
14910
Coastal Resources of Maine /
Fiberight LLC33
Hampden
ME
MSW, municipal solid waste; RCRA, Resource Conservation and Recovery Act
28 https://rcrapublic.epa.gOv/rcraonline/topics.xhtml#W
29 EPA Clarification Letters are available on RCRA Online at https://rcrapublic.epa.gOv/rcraonline/topics.xhtml#W
311 Biomass Magazine. Accordant Energy LLC. Construction begins on facility producing MSW-derived fuel. March
8, 2018. http://biomassmagazine.com/articles/15127/construction-begins-on-facility-producing-msw-derived-fuel
31 As of Sept 2020, Waste Management confirmed that both sites are closed.
32 Mainebiz. Fiberight $7 OM waste-to-energy plant finally ramping up. 20 Feb 2019.
33 Fiberight facility was just sold; do not know if operations will continue
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Assessment of 'MSW Energy Recovery Technologies
Chapter 3:
MSW Gasification
Gasification is a thermal process that, in a controlled oxygen environment, converts organic or fossil fuel
carbon-containing material - such as coal, petroleum, plastics, or biomass - to syngas, char, and ash. The
process is similar to pyrolysis, except that oxygen (as air, concentrated oxygen, or steam) is added to
maintain a reducing atmosphere in the reactor. A reducing atmosphere exists when the quantity of oxygen
available is less than the stoichiometric ratio for complete combustion. The process primarily forms
carbon monoxide and hydrogen, and other constituents such as methane, particularly when operating at
lower temperatures. The primary product of gasification, syngas, can be converted into heat, power, fuels,
fertilizers and chemical products, or used in fuel cells.
3.1 MSW Gasification Process Description
The literature and technology vendors use different names for gasification and different variations for
gasification processes in their technology descriptions which can cause confusion. Technological
processes can be simplified into three core types of gasification, including:
¦ High temperature gasification—High temperature gasification reactors can reach up to 1,200
°C and produce an inert byproduct, or slag, that does not need further processing to be stabilized.
The syngas produced may be combusted to generate steam, which can be used for power and/or
heat generation; however, the resultant syngas may also be used for other applications such as
chemicals production. This technology may process a mix of carbonaceous waste including
paper, plastics, and other organics with a moisture content of up to 30%. Higher moisture content
feedstock would likely require drying before entering the reactor chamber.
¦ Low temperature gasification—Low temperature gasification reactors operate at temperatures
between 600 and 875 °C and produces syngas as the main product and ash as a byproduct, which
may require stabilization. The ash can be sent to a vitrification34 process to makes it inert and
available for other uses. Syngas is typically used for electricity generation using an Internal
Combustion Engine. This process can also recover steam energy.
¦ Plasma gasification—Plasma gasification converts the selected waste streams which can include
paper, plastics, organics, biomedical waste hazardous waste and hazmat materials to syngas and
slag. In this technology, the gasification reactor uses a plasma torch where a high-voltage current
is passed between two electrodes to create a high-intensity arc, which in turn rips electrons from
the air and converts the gas into plasma or a field of intense and radiant energy with temperatures
more than 1000 °C. The heated and ionized plasma gas is used to treat the feedstock and produce
syngas and slag.
3.1.1 General Process Flow
Despite variations in operating cost, efficiency and processing capacity among the technologies profiled
in this report, most gasification technologies follow a general process flow which is illustrated in Figure
5 and outlined below.
1. MSW Feedstock: MSW feedstock accepted at gasification facilities will typically require
additional processing regardless. Depending on the specific composition of the MSW feedstock
34 Vitrification is a waste disposal method to immobilize and encapsulate materials. In the vitrification process, high
temperatures (1100°C-1600°C) are employed to melt the materials into a liquid which on cooling, transforms the
material into an amorphous glass like solid and permanently captures the waste.
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Assessment of 'MSW Energy Recovery Technologies
received, preprocessing may be required, or the feedstock may be used as-is for immediate input
into the gasifier.
2. Preprocessing: In most cases, preprocessing of the MSW feedstock is used to remove any
unwanted materials. In addition, shredding of the feedstock is typical to create more
homogenous-sized particles prior to input to the gasifier.
3. Gasifier: Feedstock is fed into the gasifier along with a controlled amount of air or oxygen (and
possibly steam). A sequence of reactions takes place, with temperatures ranging from 593 to 892
°C, and syngas is produced. Solid residues (e.g., char) also are produced and removed from the
gasifier and sent to disposal (or possibly reused).
4. Primary Syngas Cleaning: Initial syngas cleaning is designed to remove impurities (e.g., dust,
ash, tar) so that the gas can be used in combustion engines.
5. Catalytic Reaction / Purification: Further purification of syngas includes removal of carbon
monoxide and impurities, such as heavy hydrocarbons, hydrogen sulfide, ammonia, hydrogen
chloride, methane and other trace contaminants by a catalytic synthesis. While the catalysts used
by profiled companies are proprietary, biogas plants conventionally will use transition metals,
reforming catalysts like ruthenium (Ru), palladium (Pd), platinum (Pt), rhodium (Rh) and nickel
(Ni) based catalysts for catalytic reactions / purification.
6. Product Conditioning: Depending on the specific fuel characteristics or chemical product
requirements, additional conditioning may be required.
Air/Oxygen
Optional steps
or flows
Char and
Other Residues
Wastewater
Direct Use
Electricity Generation
Liquid Fuel Product
* Preprocessing can include shredding, screening, washing and/or drying depending on MSW feedstock.
Figure 5. General MSW gasification process flow diagram.
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Assessment of MSW Energy Recovery Technologies
3.1.2 Process Flow Variations
Several variations exist in gasification process design that present individual challenges and opportunities
for operators. In this section, the most common challenges and considerations in gasification applications
as found in the literature are summarized.
Common Gasification Process Designs
¦ Integrated Gasification Combined Cycle (IGCC). IGCC plants feed a carbon resource into the
gasifier with oxygen and steam that respectively produces raw syngas. The raw syngas is cleaned
of particulate matter and sulfur and subsequently fed into a combustion turbine (e.g., for heat
recovery and power generation). A key variation in IGCC plants relates to whether carbon is
captured (e.g., through reactions with water) as IGCC plants typically do not require CO2
separation.
¦ Fixed/Moving Bed Gasification. Non-slagging and slagging versions of fixed/moving bed
gasification, both process feedstock in a counter current flow of gas and solids. A key challenge
of this gasification process relates to the inconsistency and agglomeration of particles that hinder
inter-phase mixing, reacted carbon and conversion rates. This simpler process of fixed/moving
bed gasification, where gas and solids move in a co-current manner is similar to many other
gasification process types including entrained flow gasification. (In entrained-flow gasifiers,
fine coal feed and the oxidant [air or oxygen] and/or steam are fed co-currently to the gasifier.
This results in the oxidant and steam surrounding or entraining the coal particles as they flow
through the gasifier in a dense cloud. Entrained-flow gasifiers operate at high temperature and
pressure—and extremely turbulent flow—which causes rapid feed conversion and allows high
throughput.)
¦ Fluidized Bed Gasification. Fluidized bed gasification allows for a well-mixed reaction where
processes take place simultaneously throughout bed. While more complicated to operate, this
gasification process allows for more optimal mixing of gas and solids, lower ash rates on particles
and better conversation rates.
Common Variations in Gasification Process Designs
¦ Atmospheric vs. Pressurized. Gasifiers can operate at both atmospheric or pressurized levels (as
high as 900 psia). Atmospheric and pressurized levels contribute to the gasification process in
various ways. A highly pressurized gasifier for example, complements an IGCC operation
through feeding syngas directly into the fuel control system of the gasifier. Higher pressure
gasification mitigates the cost and difficulty of cleanup operations, due to producing a less
voluminous flow of syngas.
¦ Air-blown vs. Oxygen-blown. The supply of oxygen in gasification reactors is essential to
produce high calorific value syngas. Oxygen can be delivered in gasification, through simply
blowing natural air into the process or using high purity oxygen, produced by advanced cryogenic
air separation units. Air-blown gasifiers tend to be more popular for smaller or lower temperature
gasifiers (e.g., non-slagging) and are also far more affordable to operate. Gasifiers that are fed by
air separation units operate at much higher costs but also produce a syngas with a calorific value
up to three times that of air blown gasifiers.
¦ Quench vs. Heat Recovery. All gasification processes must cool exiting syngas (normally to
approximately 100 C) to apply standard acid gas removal technologies. Cooling and heat capture
processes will normally pass through one of two cooling mechanisms. In the more advanced, and
expensive cooling procedure, syngas will be cooled via a series of advanced heat exchangers (that
can recover the heating value of the syngas for use in a steam cycle of an IGCC). In a lower cost
and simpler mechanism, syngas will be cooled through contact with cool water (the "quench"
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Assessment of 'MSW Energy Recovery Technologies
process")- While this latter option provides better CO2 capture opportunities, it does not offer the
same heat recovery potential of mechanized heat recovery systems and may therefore only be
desirable where a lower quality or lower cost feedstock is used.
3.2 Technical Considerations and Challenges
Gasification technology designed for MSW feedstock presents several advantages as well as challenges
that can include feedstock requirements, institutional support and permitting. Understanding these
technical considerations and challenges can help communities determine the potential role of gasification
technology in their local context.
Feedstock Supply and Preprocessing
Feedstock capacities for gasification facilities identified range from 20 to 100 tons per day. Gasification
companies require specific waste streams for their feedstock that often need to be sourced and contracted
from a mix of individual waste consignments such as MSW collection contractors (or municipalities),
materials recovery facilities (MRFs), or construction and demolition waste contractors. The energy output
and emissions produced by gasification is highly sensitive to the composition of the MSW feedstock and
facilities will tailor the mix of MSW-derived feedstock to achieve desired levels of energy output and/or
process emissions. High heating-value feedstock (e.g., plastics) generally will produce more energy
output on a per ton basis than lower heating-value feedstock (e.g., organics).
Most gasification technologies require preprocessing of the MSW feedstock before it enters the gasifier.
Preprocessing can include shredding, drying, and pelletizing. Companies profiled, such as Enerkem, Alter
NRG, have such preprocessing requirements. The benefit of feedstock preprocessing is that it can
improve the quality of the syngas as well as process byproducts to enhance the possibility of their reuse.
Companies reviewed in this study specifically noted high moisture content and contamination levels (e.g.,
asbestos, contaminated wood, marine wood debris) as challenges.
3.3 MSW Gasification Facilities
Internet research yielded information to identify companies with gasification projects using MSW
feedstock. Figure 6 provides a map of the MSW gasification facilities in the US (and Canada) that are
operating or in development stages and non-operational. Table 3 provides additional information about
these facilities.
These searches yielded 60 total studies that were included in the companion literature review Excel®)
tracking template. There were 48 studies conducted since 2012. After this initial search effort, the studies
were scanned to determine the technologies and feedstocks assessed as well as the geographic location of
the study. An evaluation was conducted to generate a short summary and a rating for the relevance of
each study relative to the project scope using a low/medium/high scale. Examples of low relevance
studies include those that did not evaluate the technologies of concern, provided no inventory data or used
data from another source, or explicitly focused on developing countries. Examples of medium relevance
studies include those that provide some parameters for the technologies of concern or provide significant
data for related technologies which may be useful (e.g., 'combustion" or 'incineration"). A high relevance
study is defined as one that provides significant data for the technologies of concern.
Twenty-three studies out of the sixty identified were deemed to be of medium and high relevance. LCI
data from these studies was extracted and compiled in a Microsoft Excel workbook. Data compiled were
subsequently harmonized in terminology (i.e., labeling of parameters) and normalized to common units
(e.g., kg, L, mega joule [MJ]) per tonne of feedstock.
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Assessment of MSW Energy Recovery Technologies
Edmonton
' Vancouver
Quebec
Montreal
Legend
Gasification
¦ Operating
~ Not Operating
Figure 6. MSW gasification facilities
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Assessment of'MSW Energy Recovery Technologies
Table 3. MSW Gasification Facilities
Name City State Technology Feedstock Main Product Operating Status
Operating
Enerkem35
Alberta
Canada
Gasification
MSW
Ethanol
Operating 350 ton/day capacity facility.
Sierra Energy
Monterey
CA
Gasification
MSW
Syngas to electricity
to diesel
20 ton/day capacity demonstration facility at Fort
Hunter Liggett.36
In Development
Fulcrum
BioEnergy,
InEnTec, LLC
McCarran
NV
Gasification
MSW
Syngas to diesel and
jet fuel
Under construction. In September 2014, Fulcrum
received a $105 million loan guarantee from the
USDA as part of the Biorefinery Assistance
Program. The feedstock processing facility, phase
1, has been operating since 2016. Construction of
the biorefinery, phase 2, started in May 2018. The
plant is expected to be operational in 2020.37
Not Operating or Unknown Operating Status
Alter NRG
Madison
PA
Gasification
MSW
Syngas
Demonstration facility was retired in 2014.38
Cirque Energy
LLC
Midland
Ml
Gasification
MSW
Syngas to electricity
and steam
Not built. The project was cancelled in 2012 due
to market uncertainties.39
35 Reports of this project describe it as being in disrepair and not operating at capacity.
36 U.S. Army Garrison Fort Hunger Liggett The Golden Guidon. December 2017 Sierra Energy Prepares to Turn on FastOx Gasification Plant at FHL.
https ://www. dvidshub. net/publication/issues/36873
37 Press Release - Fulcrum BioEnergy, Inc. Fulcrum BioEnergv breaks ground on Sierra Biofuels Plant. May 16, 2018 https://www.prnewswire.com/news-
releases/fulcrum-bioenergy-breaks-ground-on-sierra-biofuels-plant-300649908.html
38 Alter NRG. Projects http://www.alternrg.com/waste to energy/projects/ accessed as of 8/1/2018.
39 Cirque Energy - Midland Power Station http://www.ciraue-energv.com/proiects/mps.html/ accessed as of 8/1/2018
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Assessment of'MSW Energy Recovery Technologies
Name City State Technology Feedstock Main Product Operating Status
Enerkem
Inver Grove
Heights
MN
Gasification
MSW
Ethanol
Planning (anticipated construction 2020)40
Enerkem
Pontotoc
MS
Gasification
MSW
Ethanol
Not built. In 2010, DOE awarded $50 million in
cost share funding to Enerkem, Inc. for the final
design, construction, and operation of a proposed
Heterogeneous Feed Biorefinery Project41
Entech
Renewable
Energy
Huntington
Beach
CA
Gasification
n/a
n/a
Not built. In 2013 the project was placed on an
indefinite hold due to economic and financial
constraints.42
InEnTech/WM
Arlington
OR
Gasification
MSW
Hydrogen
Not operational.43
Ineos
Vero Beach
FL
Gasification
MSW, biomass
Ethanol
Ceased operations in 201644. Received $125
million in federal grants and guaranteed loans. In
2012 the facility came online but had limited
production due to technical challenges.45
411 Star Tribune. Erin Adler. Inver Grove Heights biofuelplant still on track, but hurdles remain. July 21, 2018. http://www.startribune.com/inver-grove-heights-
biofuel-plant-still-on-track-but-hurdles-remain/488810231/
41 Enerkem, Inc. Enerkem Awarded $50 Million Funding by U.S. Department of Energy for its Mississippi Biorefinery Project. December 7, 2009.
https://www.newswire.ca/news-releases/enerkem-awarded-50-million-funding-bY-us-department-of-energv-for-itsmississippi-biorefinerv-proiect-
539048711.html
42 Memo County of Los Angeles Department of Public Works. "Board Motion of April 20, 2010, item No. 44 Conversion Technologies in Los Angeles County
Six-Month Status Update: October 2012 through April 2013 Update." April 29, 2013
http://dpw.lacountv.gov/epd/conversionteclinology/CT 6 month report cover memo To Each Supervisor 04-29-13.pdf
43 Communication with Oregon DEQ. July 2019.
44 Biomass Magazine. E. Voegele. Ineos Bio to sell Ethanol Business, including Vero Beach Plant. 2016. http://biomassmagazine.com/articles/13662/ineos-bio-
to-sell-ethanol-businessincluding-vero-beach-plant.
45 TC Palm. Lucas Daprile. Investigation: INEOS failed despite SI 29 million in taxpayer subsidies. January 17, 2017
https://www.tcpalm.com/storv/news/2017/01/17/ineos-closes-vero-beach-biofuel-plant/96412616/
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Assessment of 'MSW Energy Recovery Technologies
Name City State Technology Feedstock Main Product Operating Status
Taylor
Biomass
Montgomery
NY
Gasification
MSW
Syngas to electricity
Not built. Seeking funding and in the conceptual
phase since 2000.46
Westinghouse
/Coronal/Alter
NRG
International
Falls
MN
Gasification
n/a
n/a
Not built. Planning began in 2008 and included
more than $5 million for a feasibility study funded
by US DOE and the Minnesota Pollution Control
Agency.47
Ze-Gen
New Bedford
MA
Gasification
MSW
Syngas
Pilot facility closed in 2010.48
MSW, municipal solid waste; n/a, not applicable
46 Times Herald-Record. Amanda Spadaro. Taylor biomass project could get financing by Sept. 30. July 6, 2017.
https://www.recordonline.com/news/20170706/tavlor-biomass-proiect-could-get-financing-bv-sept-3Q
47 International Falls Journal. Emily Gedde. RECAP still on the radar. May 9, 2017.
48 Boston Business Journal. Kyle Alspach. Ze-gen to halt New Bedford plant. August 31, 2010.
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Assessment of 'MSW Energy Recovery Technologies
Chapter 4:
MSW Pyrolysis
Pyrolysis is defined as an endothermic process, also referred to as cracking, using heat to thermally
decompose carbon-based material in the absence of oxygen. The main products of pyrolysis include
gaseous products (syngas), liquid products (typically oils), and solids (char and any metals or minerals
that might have been components of the feedstock). In the US, pyrolysis feedstock usually consists of
mixed plastics or specific plastic resins and the resulting liquid petroleum-type products generally require
additional refining. Pyrolysis feedstock can also include biomass (e.g., forest or agricultural residues).
However, in the context of MSW, the likely feedstock will be plastics. Application of pyrolysis to MSW
plastics generate a gaseous mixture of carbon monoxide (CO) and hydrogen called "syngas" that can be
used for steam and electricity generation and some produce liquids such as a "crude oil" or heavy fuels.
Products of processes are commonly reported, but the list and proportion of each differs depending on
technology design, reaction conditions and feedstock.
4.1 MSW Pyrolysis Process Description
The literature and technology vendors use different names for pyrolysis (e.g., catalytic cracking) and
different process variations which can cause confusion. Technological processes can be simplified into
three core types of pyrolysis, including:
¦ Thermal pyrolysis —The feedstock is heated at high temperatures (350-900 C) in the absence
of a catalyst. Typically, thermal cracking uses mixed plastics from industrial or municipal sources
to yield low-octane liquid and gas products. These liquid and gas products require further refining
to be upgraded to useable fuel products.
¦ Catalytic pyrolysis —The feedstock is processed using a catalyst. The presence of a catalyst
reduces the required reaction temperature and time (compared to thermal pyrolysis). The catalysts
used in this process can include acidic materials (e.g., amorphous silica-alumina), zeolite minerals
(e.g., HY, HZSM-5, mordenite), or alkaline compounds (e.g., zinc oxide). This method can be
used to process a variety of plastic feedstock, including polyethylene terephthalate (PET), low-
density polyethylene (LDPE, #4), high density polyethylene (HDPE, #2), polypropylene (PP, #5),
and polystyrene (PS, #6). The resulting products can include liquid and gas products that require
further refining to be upgraded to useable fuel products.
¦ Hydrocracking (sometimes referred to as "hydrogenation")—The feedstock is reacted with
hydrogen and a catalyst. The process occurs under moderate temperatures and pressures (e.g.,
150-400°C and 30-100 bar). Most research on this method has involved generating gasoline
fuels from various waste feedstocks, including MSW plastics, plastics mixed with coal, plastics
mixed with refinery oils and scrap tires. The resulting products can include liquid and gas
products that require further refining to be upgraded to useable fuel products.
4.1.1 General Process Flow
Despite the variations in operating cost, efficiency and processing capacity among the technologies
profiled in this report, most pyrolysis technologies follow a general process flow, described below and
illustrated in Figure 7.
1. MSW Feedstock: Feedstocks can include processed/treated (e.g., presorted, preprocessed
plastics) or unprocessed MSW. Depending on the specific feedstock(s) accepted and/or received,
preprocessing at pyrolysis facility may be required or the feedstock is used as-is and directly fed
into the processing line.
2. Preprocessing: Preprocessing may be required and can include shredding, sorting, washing
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Assessment of 'MSW Energy Recovery Technologies
and/or drying to ensure the feedstock meets the specifications of the technology. For example,
non-recyclable plastics waste that has already been sorted at a MRF may need to be shredded into
smaller (.25" to 2") particles to ensure complete combustion or meet the design specifications.
3. Densification: In some cases, the feedstock is low-density and thus it is processed into a higher
density material (e.g., pellets, cubes). Such densification may be done to increase the caloric
value per unit of volume, provide greater uniformity, and/or simplify storage and mechanical
feeding of the feedstock. This is particularly useful in processing low-density plastics such as film
plastics49 (i.e., outer protective covering or film).
Electricity
Natural Gas
Densification
N--'' J
Pre-melt/
Augur/
~
Extrusion
Heat
I
Optional steps
or flows
Water
Water
Condenser/
Distillation
Char
~ +
Wastewater
Syngas |
I Wax
*Preprocessingcan include shredding, screening, washingand/ordryingdependingon MSW feedstock.
Figure 7. General pyrolysis process flow diagram.
(Source: adapted from ACC, 2015)
4. Pre-melt / Auger / Extrusion: When necessary, pre-melting of plastic feedstock is done to create
a more homogeneous mixture and consistent feedstock. This process uses mechanical energy and
heaters, normally extruded through a rotating screw (auger) to create a consistent volume of
feedstock for input to the pyrolysis chamber(s).
5. Pyrolysis Chambers / Pyrolysis: Once the feedstock is fed into the pyrolysis chambers, it is
rapidly heated at high temperatures and in certain cases (e.g., catalytic pyrolysis) mixed with a
catalyst. Specific pyrolysis applications that take place in the pyrolysis chambers include:
49 Plastic film is defined and described well at this website: https://www.grafixplastics.com/plastic-film-what/
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Assessment of MSW Energy Recovery Technologies
¦ Thermal Pyrolysis involves degradation of plastic feedstocks using high temperature
(ranging from 350-900 °C in the absence of air).
¦ Catalytic Pyrolysis involves degradation of plastic feedstocks in the presence of a
catalyst and in the absence of air.
¦ Hydrocracking involves degradation of plastic feedstocks by reacting them with
hydrogen and a catalyst. The process occurs under moderate temperatures and pressures
(e.g., 150-400 °C and 30-100 bar).
Pyrolysis operators can also tailor the speed at which plastic feedstock is heated once fed into the
pyrolysis chambers, with two general variations which include fast or slow pyrolysis. Fast
pyrolysis entails rapid heating of feedstocks to approximately 500 °C in less than one or two
seconds, whereas slow pyrolysis can take several hours. Pyrolysis vapors are rapidly quenched
and captured. In slow pyrolysis, the process is characterized by lengthy feedstock and gas
residence times, low temperatures and slow heating rates. Heating temperature rates range from
0.1-2 °C per second and the prevailing temperatures are nearly 500 °C.
6. Catalyst: For catalytic pyrolysis, additives help to reduce required pyrolysis temperature and
reaction times (as compared to thermal pyrolysis). Catalysts additionally produce a higher value
hydrocarbon (e.g., leading to greater efficiency and value of the pyrolysis fuel products). While
catalyst data from profiled companies was in most cases, proprietary, several conventional
heterogeneous catalysts have long been employed in pyrolysis, that include solid acids (such as
zeolites, silica-alumina, alumina) and fluid catalytic cracking catalysts, mesostructured catalysts,
nanocrystalline and zeolites.
7. Distillation: Primary pyrolysis oil is fed into a distillation plant, where it is heated in the absence
of oxygen. Vapors from the boiling oils are condensed into liquid fuels via a cooling pipe, and
then separated through a water bubbler vaporizer. Distillation is carried out to separate the lighter
and heavier fractions of hydrocarbons present in the pyrolysis oil. The distillation is operated
between 116 °C and 264 °C approximately 73. 5% of pyrolysis oil is distilled out.
8. Oil Conditioning: Oil conditioning encompasses different processes necessary to stabilize oil
end products from volatile materials which allows them to be available for the markets. Oil
conditioning processes may include fractionation, distillation, hydrogenation and water
treatments.
4.1.2 Process Variations
Among the variations that exist in pyrolysis, key challenges and considerations relevant to the technology
can be broken by preprocessing, processing and post-processing steps.
Preprocessing (Feedstock Quality Control)
The relationship between pyrolysis operators and feedstock suppliers, in respect to preprocessing
requirements, is strongly highlighted in this report. Companies either depend on securing tailored and
consistent quality feedstock from their suppliers for a higher delivery fee or invest in enhancing their own
preprocessing capacity. Fine-tuning the quality of feedstock was, for most companies, essential to
realizing a financially feasible business operation. Key risk factors in feedstock included: the chip size of
feedstock (after shredding of feedstock); the mitigation of contaminants in the feedstock (wood, metal,
soil, fiber contaminants); and the removal of non-target plastics, most regularly cited as PET due to high
oxygen content and combustion risks, and polyvinyl chloride (PVC) due to combustion risks and chloride
lead to the formation of dioxin and acid gases.
If a company decides to invest in in-house capacity for preprocessing equipment, they must consider the
range of resources that this machinery may require including: water (to condense syngas vapors, oil
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Assessment ofMSW Energy Recovery Technologies
conditioning), natural gas (to initiate systems), hydrogen (sulfur, nitrogen and aromatic reduction;
enhancement of cetane number, density and smoke point), and catalysts (normally proprietary) to trigger
the reaction. While many of these resources are necessary in pyrolysis applications—regardless of
whether a feedstock supplier is involved in preprocessing activities—the quantity, efficiency and
applications of these resources differ.
In two unverified case examples, Nexus Fuels reported that it could only accept feedstock levels that
contain under 1% of PVC, in comparison with Renewlogy (formerly PK Clean) that can accept up to a
40% mix of PVC and PET in feedstock (ACC, 2015). While Nexus Fuels and Renewlogy differ in the
type of pyrolysis they employ (hydrocracking pyrolysis and catalytic pyrolysis respectively), the report
notes that Renewlogy has invested substantially in enhancing its own proprietary technology and catalyst
to accept a broader range of plastic sub-typologies and reduce long-term operational costs.
Processing (Continuous vs. Batch Processing)
The ability of pyrolysis technology vendors to achieve higher fuel production and heat retaining
efficiency from their operations can depend on whether they operate a continuous or batch feedstock
system. Batch feedstock systems normally require companies to insert tailored quantities of specific
plastic feedstock into their processing lines at pre-determined intervals. The insertion of plastic feedstock
normally must complete its processing cycle, before a new insertion can be made—often requiring
companies to start and stop their machinery and lose out on sustained heat efficiency in their processing
lines. Companies operating a continuous feedstock system, by comparison, are normally capable of
capturing and retaining the heat value from produced hydrocarbons in their production lines (e.g.,
avoiding batch operation systems, where reactors constant heating and cooling procedures require
constant reboots and energy losses). In an unverified case example of the efficiency differences between
batch and continuous feedstock systems, Renewlogy claimed that their pyrolysis technology costs a
quarter the price of competing systems to operate, while producing greater yields due to their ability to
sustain heat value from produced hydrocarbons for continuous plastic processing.
Post-Processing (Indirect Outputs of Pyrolysis)
Several pyrolysis companies profiled in this report identified key considerations arising from the indirect
outputs of pyrolysis that either posed waste management challenges or challenges associated with
identifying markets for the sale or reuse of product outputs. Specific outputs included:
¦ Char: Char (also referred to as biochar) is considered a hazardous waste and specific licensing
(e.g., waste disposal licensing) and approvals are often required for its disposal. This results in
higher costs and challenging administrative hurdles that companies must face, should they not be
able to reuse the char or mitigate its production internally.
¦ Wax: Wax production (normally less than or equal to 10% by weight of incoming useable
feedstock) was cited as a challenge by some companies where: wax was either unable to be
processed into a marketable end product; where markets for processed wax products could not be
identified; or where wax products could not be reused in the processing line internally.
¦ Synthetic Crude Oils: Syncrude is a primary output of pyrolysis, which likely will require
additional refining or cleaning to meet market requirements. Certain companies, including Nexus
Fuels encountered difficulties via delayed quality testing of their fuels due to the delayed
installation of a commercial fractionation system. They additionally faced difficulties in
marketing synthetic crude oil to refineries—respectively requiring the company to make plans to
either reuse or store their fuel on-site.
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Assessment of 'MSW Energy Recovery Technologies
4.2 Technical Considerations and Challenges
Thermal and catalytic pyrolysis of MSW-based feedstock present several technical considerations and
challenges including feedstock typology challenges, feedstock quality and preprocessing requirements,
net energy balance, institutional support, and permitting. Understanding these technical considerations
and challenges can help communities determine the potential role of pyrolysis technology in their local
context.
4.2.1 Typology Considerations
Many different types of plastics are generated, and often mixed, as part of MSW. The inconsistency in
plastic composition and difficulty in anticipating the market trends of manufacturers can increase the cost
of fuel production by pyrolysis operators, while presenting greater challenges to companies in managing
and mitigating the impacts of chlorine (equipment corrosion) and char (hazardous waste management).
Specific considerations and challenges regarding common types of plastic are discussed below.
¦ HDPE and LDPE: These plastics perform differently with respect to whether a thermal or
catalytic pyrolysis is being employed. Thermal pyrolysis normally yields much higher wax
content from HDPE and LDPE feedstock, reducing the amount of liquid oil produced. Catalytic
pyrolysis, in comparison, normally achieves a full conversion of HDPE and LDPE to oil with
minimal yields of wax produced5". However recovery of the catalyst can be a significant issue.
¦ PET: The strong recycling market value for PET can result in this plastic being removed from
MSW and supply streams, potentially limiting its availability for pyrolysis. PET contains high
levels of oxygen that can lead to combustion in the pyrolysis reactor and can also contain
heteroatoms, which can create challenges in standard pyrolysis. Hydrocracking pyrolysis removes
heteroatoms, which form oil resources, while conserving catalysts. Hydrocracking pyrolysis is a
widely employed practice to avoid challenges associated with PET pyrolysis and is additionally
beneficial in requiring lower process temperatures and in producing higher quality fuels that do
not normally require further treatment for conversion51.
¦ PS: Typically, PS will produce a less viscous oil in both thermal and catalytic pyrolysis—
resulting it in being the most preferred waste typology by all reviewed companies in this study52.
¦ PVC: This plastic typology produces hazardous chlorine gas in both thermal and catalytic
pyrolysis applications. The presence of chlorine and the deposition of coke additionally affect the
catalytic activity of the catalyst. PVC also contains dioxin-producing chlorides and can lead to the
formation and emission of hydrochloric acid (HCL). HCL emissions are often corrosive when
processed in pyrolysis technology and can be both expensive and labor intensive to remove.
¦ Other: A variety of other factors relevant to other types of plastics can present challenges to
pyrolysis technologies. These include: (1) inclusion of corrosive chlorines as flame retardants or
fillers by plastic manufacturers that can normally only be detected utilizing burn tests; (2) the
511 Rasliid, M. et al., (2016). Catalytic Pyrolysis of Plastic Waste: A Review. Available at:
https://www.researchgate.net/publication/304629166 Catalytic Pyrolysis of Plastic Waste A Review
51 Nzerem, P. C., (2013). Rheological Studies of Feedstock for the Hydrocracking of Waste Plastics.
https://www.escholar.manchester.ac.uk/api/datastream?publicationPid=uk-ac-man-
scw :215058&datastreamId=FULL-TEXT.PDF
52 Rasliid, M. et al., (2016). Catalytic Pyrolysis of Plastic Waste: A Review. Available at:
https://www.researchgate.net/publication/304629166 Catalytic Pvrolvsis of Plastic Waste A Review
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Assessment of 'MSW Energy Recovery Technologies
production of multi-layer plastics; and (3) the frequent changes of plastic compositions by plastic
manufacturers for cost, marketing and branding purposes.
4.2.2 Feedstock Requirements and Dependence
Pyrolysis companies have a strong reliance on securing consistent and quality-controlled feedstock, and
often indicate that the lack of formal feedstock partnerships as a challenge. Companies reviewed as part
of this study presented various means of securing feedstock requirements through both public and private
sector channels. Specific examples include:
¦ Nexus Fuels: to move beyond a pilot stage requires that a strategic project partner provide a
feedstock guarantee, with tax incentives, grants and labor provisions considered beneficial.
¦ Vadxx Energy LLC: dropped plans to invest in Cleveland, Ohio after the city of Akron, Ohio
provided more attractive tax and support incentives. It additionally signed a memorandum of
understanding with Houston-based Greenstar Recycling to provide raw material inputs for
Vadxx's first commercial plastics-to-oil unit.
¦ GEP Fuel: established close networks with the auto industry and conducted market research to
identify high levels of consumer plastic waste production in Carroll County, Indiana. It
additionally partnered with an existing rail network, owned by US Rail Corp, that is planned to
assist in the transport feedstock and product for the company.
In addition to securing consistent and clear agreements with public or private feedstock suppliers,
companies had clear preferences to the types of plastics53 they received as inputs. Companies profiled
overwhelmingly preferred the processing of Plastics 2 and sometimes 4, citing the lower energy rates and
poorer quality control of Plastics 5-7 (particularly film plastics). Vadxx Energy for example noted that
much of the plastic types (4-7) they received, contained additives and fillers that made them incompatible
or difficult to use as feedstock.
4.3 MSW Pyrolysis Facilities in the US
Internet research yielded information to identify companies with pyrolysis projects using MSW feedstock.
Figure 8 provides a map of the MSW pyrolysis facilities in the US (and Canada) that are operating or that
are in development stages and non-operational. Table 4 provides additional information about these
facilities.
53Plastic resin codes can be found here: https://plastics.americanchemistrv.com/Plastic-Resin-Codes-PDF/
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Assessment of MSW Energy Recovery Technologies
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Assessment of'MSW Energy Recovery Technologies
Table 4. Pyrolysis Facilities Operating on Plastics from MSW
Name
City
State
Technology
Feedstock
Main Product
Operating Status
Operating
Agilyx
Tigard
OR
Pyrolysis
PS
Styrene oil
Operating. In 2013, the Tigard facility processed
plastics to crude oil. It went dormant. In 2018, it
reopened a 10 ton/day capacity facility for converting
polystyrene to styrene oil.54
JBI /
Plastics20il
Niagara
Falls
NY
Pyrolysis
HDPE, LDPE, PP
Fuel oil #2, fuel oil
#6
Operating at limited production of its 22 ton/day
capacity as of August 2018.55 In 2014, the facility
suspended its plastic processing and fuel production
operations.56
Nexus Fuels
Atlanta
GA
Pyrolysis
HDPE, LDPE, PP,
PS
Gasoline, diesel
Gasoline
Operating on a discontinuous basis. Has a stated
capacity of 50 tons/day.
Renewlogy
Salt Lake
City
UT
Pyrolysis
Mixed plastics
Naptha, diesel fuel,
kerosene, light fuels
Has a stated capacity of 10 tons/day. Operations
paused for most of 2019 as the facility upgraded its
preprocessing equipment.57
In Development
Brightmark
Energy/
RESpolyflow
Ashley
IN
Pyrolysis
Mixed plastics
Naptha, diesel fuel,
waxes
Under construction which began in 2019.58 In the
planning phase since 2015. In 2018, the Steuben
County Board of Commissioners loaned RES Polyflow
54 Press Release from Agilyx. Agilyx opens the world's first commercial waste polystyrene-to-styrene oil chemical recycling plant. April 24, 2018.
https://www.agilyx.com/application/files/6015/2510/8377/agilyx_opens_tigard_plant.pdf
55 Press Release from Plastic20il. PlasticlOil Announces Plan to Resume Fuel Production and Sales and Amends Veridisvn Agreement. August 10, 2018.
http://www.plastic2oil.eom/site/news-releases-master/2018/08/10/plastic2oil-announces-plan-to-resume-fuel-production~sales-and-amends-veridisyn-agreement
56 Accesswire. Letter to PlasticlOil Stockholders from Richard Heddle, Chief Executive Officer. November 24, 2014. https://finance.yahoo.com/news/letter-
plastic2oil-stockholders-richard-heddle-150000520.html
57 WasteDive. Pyzyk, Katie. Boise, Idaho mixed plastics program could expand following changes. July 24, 2019. https://www.wastedive.com/news/boise-idaho-
mixed-plastic-program-could-expand-following-changes/559418/
58 Recycling Today. Cottom, Theresa. Brightmark Energy breaks ground on plastics-to-fuel plant. 22 May 2019.
https://www.recyclingtoday.com/article/brightmark-energy-plastics-to-fuel-groundbreaking/
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Assessment ofMSW Energy Recovery Technologies
Name
City
State
Technology
Feedstock
Main Product
Operating Status
$1.5 million and offered them a 10-year tax abatement
for the facility to be built near Ashley.59
Renew
Phoenix/
Renewlogy
Phoenix
AZ
Pyrolysis
Mixed plastics
Naptha, diesel fuel,
kerosene, light fuels
In the planning stage for a facility in Phoenix, AZ.
Expected to be operational in 2020. In 2019, the
Phoenix Public Works Department chose Renew
Phoenix for a 10-year contract.60 Renewlogy was
awarded a grant through the Arizona Innovation
Challenge.61
Rialto
Bioenergy
Rialto
CA
AD and
pyrolysis
Food waste,
municipal
biosolids
Biochar (fertilizer)
Under construction. The anaerobic digester is
expected to be operational in 2020.62 Pyrolysis unit
included in design.
Not Operating or Unknown Operating Status
Climax Global
Energy
Blackwell
SC
Pyrolysis
Mixed plastics
Syncrude,
petrochemicals
Never started operations and defaulted on its rent to
Barnwell County.
Envion
Derwood
MD
Pyrolysis
n/a
n/a
Never built. In 2012, Envion owner, Michael Han was
convicted of fraud.63
GEP Fuel &
Energy
Camden
IN
Pyrolysis
Mixed plastics
Diesel fuel
Not built. Planning began in 2016.
59 Indiana Economic Digest. Mike Marturello. RES Polvflow ties up loose ends with Steuben County in quest for funding. July 18, 2018.
https://indianaeconomicdigest.com/main. asp?SectionID=31&SubSectionID=67&ArticleID=92832
611 WasteDive. Pyzyk, Katie. Phoenix awards contract to Renewlogy for chemical recycling project. 5 April 2019. https://www.wastedive.com/news/phoenix-
awards-contract-to-renewlogy-for-chemical-recycling-project/552055/
61 TechConnect. Arizona Innovation Challenge Fall '17: Transforming Plastic into Clean Fuel. April 3, 2018.
62 Anaergia Launches Rialto, Calif., Food Diversion, Energy Recovery Plant. 12 Mar 2019. https://www.waste360.com/anaerobic-digestion/anaergia-launches-
rialto-calif-food-diversion-energy-recovery-plant
63 Palm Beach Post. Jeff Ostrowski. Former defense secretary says West Palm Beach business man defrauded him of $32 million. October 18, 2012.
https://www.pahnbeachpost.com/news/fonner-defense-secretarv-says-west-palm-beach-businessman-defrauded-liim-million/pLoHwoEKze3oliKLM5htxbO/
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Assessment of'MSW Energy Recovery Technologies
Name City State Technology Feedstock Main Product Operating Status
Green Power
Inc
Pasco
WA
Pyrolysis
n/a
n/a
Not operating. In 2009, Washington State ordered it to
stop because it lacked the necessary air-quality
permits.64 In 2015, the CEO, Michael Spitzauer, was
convicted of fraud.65
International
Environmental
Solutions
Romoland
CA
Pyrolysis
n/a
n/a
The pilot facility ceased operations in 2010. In 2012,
International Environmental Solutions declared
bankruptcy.
New Hope
Tyler
TX
Pyrolysis
HDPE, LDPE, PP,
PS
Fuel oil #2, fuel oil
#4
Unknown.
Oneida Seven
Generations
Corporation
Green Bay
Wl
Pyrolysis
n/a
n/a
Not built. In 2018, the City of Green Bay will pay the
Oneida Seven Generations Corporation $2.5 million in
a legal settlement.66
Vadxx
Akron
OH
Pyrolysis
Mixed plastics
Diesel oil, naphtha,
syngas, waxes
Not operating. Operated a bench scale model for a
short time in 2017.67
MSW, municipal solid waste; n/a, not applicable, HDPE, high density polyethylene; LDPE, low density polyethylene, PP, polypropylene; PS, polystyrene
64 Associated Press. Phuong Le. Waste-to-fuel project CEO accused of fraud; Cheyenne plant never materialized. January 9, 2014.
https://trib.com/business/energy/waste-to-fuel-project-ceo-accused-of-fraud-cheyenne-plant/article_0e6ca24a-0dl8-5175-affe-4a9626a3cd09.html
65 Tri-City Herald. Kristi Pihl. Green Power founder sentenced in 'sophisticated' $13 million fraud. June 10, 2015. https://www.tri-
cityherald.com/news/local/crime/article32228337.html
66 USA Today Network-Wisconsin. Jonathan Anderson. Green Bay to pay $2.5 million to settle lawsuit over waste-to-energy plant. February 12, 2018.
https://www.greenbaypressgazette.eom/story/news/2018/02/12/green-bay-pay-2-5-million-settle-lawsuit-over-waste-energy-plant/328895002/
67 Communication with Ohio EPA July 2019.
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Chapter 5:
MSW Anaerobic Digestion
AD is the biochemical decomposition of organic matter into methane (CH4) gas and CO2 by
microorganisms in an anaerobic environment. The process does require any input heat source. Byproducts
include air emissions and also solid and/or liquid digestate. The anaerobic processes occur naturally and
are the principal processes by which methane is created from organics in landfills. The same basic process
occurs in a more controlled environment of an anaerobic digester facility. The anaerobic digester is a built
system for excluding oxygen from organic material and producing biogas. The biogas produced from an
AD facility can be used directly to generate electrical energy or can be additionally treated to allow
injection into the pipeline. The solid and liquid digestate can be land applied, composted, used as a soil
amendment or processed into fertilizer pellets. The liquid digestate can be further processed to
concentrate nitrogen or phosphorous chemicals. These chemicals can be sold outright or added to
fertilizers.
5.1 Anaerobic Digestion Process Description
AD technologies can be grouped into two basic classes: wet (liquid) and dry (solid). Common design
types for AD systems include:
¦ Single-stage wet digesters: Single-stage wet digesters include one vessel (or a series of single
vessels). These systems are simpler to design, build, and operate and generally less expensive to
build and operate. The loading rate for single-stage digesters is limited by the ability of
methanogenic organisms to tolerate the sudden decline in pH that results from rapid acid
production during hydrolysis. Hydrolysis is the first stage of the chemical reactions that occur in
the anaerobic digestion process.
¦ Single-stage dry digesters: Single-stage dry digesters where the feedstock is in a solid state (i.e.,
can be handled with a front-end loader and is considered stackable) and normally little or no
additional water is added. The digestion process can be done in a batch or continuous mode. In
batch mode, feedstock is loaded into chamber(s) and held until the end of its retention time (30-
45 days). The liquid digestate stream is usually captured and recirculated throughout the retention
time. In continuous mode, new feedstock is continuously fed to the digester and digestate is
continuously removed, additional liquids may be added as needed.
¦ Two-stage digesters: Two-stage AD systems separate the acid-producing fermentation process
from the methanogenesis process, which allows for higher loading rates for high nitrogen
containing materials. Total solids concentration in the reactor is an important variable and
feedstock is typically diluted with process water during the preprocessing phase to ensure the
desirable solids content is achieved.
¦ Water Resource Recovery Facilities: In the US, the use of AD at WRRFs, also known as
publicly owned water treatment works, dates back to the 1900s. Over 1,200 US WRRFs produce
clean water and these facilities have anaerobic digesters that treat wastewater solids and produce
biogas. While a number of these WRRFs flare-off the biogas produced in this process, more than
half use the biogas they produce as an energy resource for producing electricity or usable heat. Of
the facilities using their biogas for energy, about one third are generating electricity that is used
for operations at the facility. Of the WRRFs generating electricity from biogas, almost 10 percent
sell this electricity to the grid. About 3 percent of the WRRFs with digesters process the biogas
into a form that is pure enough to inject into natural gas pipelines. [Note: AD at WRRFs is not
covered in detail in this report because it is does not involve new conversion technology facilities
and the use of AD at WRRFs has become quite widely established.]
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Assessment of 'MSW Energy Recovery Technologies
5.1.1 General Process Flow
Although there are many different design and configuration options, the AD process for MSW feedstocks
is illustrated in Figure 9 and generally consists of the following steps:
1. MSW Feedstock: AD systems typically rely on source separated organic MSW feedstock can
include pre and post-consumer food waste, fats oils and greases, yard trimmings and paper
products.
Optional steps
or flows
Water
Moisture
Addition
De-watering
Heat
from combined heat and power
( \ Cor
( Digestate J ~
Land application
Compost
Soil amendment
Fertilizer
Water
Wastewater
*Preprocessingcan include shreddingand screeningdependingon MSW feedstock.
Direct Use
Electricity Generation
Liquid Fuel Product
Figure 9. General single-stage MSW anaerobic digestion process flow diagram.
2. Preprocessing: Preprocessing of the MSW feedstock can include shredding and screening to
remove any unwanted materials. Even if source-separated organics are received, they will likely
require preprocessing to remove any metal, plastic and other contaminants, including packaging
materials.
3. Digestion: The organic feedstock and various types of bacteria are put in an airtight container
called a digester. Within the digester, the digestion process occurs and includes the following four
phases:
¦ Hydrolysis: Large proteins, fats and carbohydrates are broken down into amino acids,
long-chain fatty acids, and sugars with the interaction of water.
¦ Acidogenesis: The process by which simple monomers are converted into the volatile
fatty acids, such as lactic, butyric, propionic, and valeric acid. This phase is also known
as the fermentation step.
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Assessment of MSW Energy Recovery Technologies
¦ Acetogenesis: The process by which the bacteria consume the fermentation products and
create acetic acid, CO2, and H2.
¦ Methanogenesis: The process by which the organisms consume the acetate and it is
converted into CH4 and CO2 while H2 is consumed.
4. Biogas Storage: Biogas generated from the digester(s) will be collected and piped to a storage
tank for use or further upgraded.
5. Solid Digestate Handling: Digestate resulting from the AD process may require dewatering to be
directly land applied or to be aerobically cured into a mature compost product. The digestate may
also be used as a soil amendment or as an ingredient used to produce fertilizer. If there is no end
market/use for the digestate, it will require disposal. Water recovered from dewatering may be fed
back into the digester or treated before discharge. If the water is being discharged to a sanitary
district, pretreatment of the wastewater may be necessary.
6. Liquid Digestate Handling: Liquid digestate streams that contain significant amounts of
nutrients (phosphorous, nitrogen or potassium) may be further processed into marketable
products. Some of the technologies to recover or remove these elements include membrane
separation, evaporation, and precipitation.
5.1.2 Process Flow Variations
Standard AD processes can be tailored to end-use needs, allowing for both large scale operations that
meet nationwide energy needs (e.g., more than 1 MW equivalent) and small on-site energy production
requirements (e.g., 25-250 KW equivalent). Under proper management, storage capacity and the optional
identification of markets, a range of AD byproducts can provide additional revenue streams for operators.
Common byproducts such as digestate solids, fiber or biofiber (contained in the effluent of common AD
technologies) can be used in a range of applications including as organic fertilizer, livestock bedding,
compost, fuel pellets, and construction materials such as fiber boards and composite materials.
Feedstock Processing
Feedstock processed in primary and (optional) secondary digesters may serve different purposes at a later
output stage based on the technologies that are being employed by the specific plant (e.g., sludge and
biogas dryers, combined heat and power plants, gas upgrading technology).
Specific variations in both the outputs of digestate and biogas may include:
¦ Digestate: A liquid filtrate (e.g., liquid fertilizer) or solid fiber output that may be used as
compost, animal bedding, fiberboard. Digestate is produced by the AD separator system and
sourced from the feedstock slurry.
¦ Biogas: Biogas derived fuels (e.g., methane) in addition to heat and steam that can be applied to
gas burners and boilers (e.g., for space heating); turbines and generators (e.g., to produce both
heat and power); or compressed and refined (e.g., to produce a higher-grade vehicle/transport
fuel).
Biogas Upgrading
Depending on the end-use for the biogas, particularly for pipeline injection or vehicle fuels, upgrading of
the biogas may be necessary. The goal of upgrading is generally to remove carbon dioxide to increase the
methane concentration of the biogas. Depending on the feedstock and the system design, biogas is
typically 55 to 75 percent methane (natural gas contains 99 percent methane). Upgrading also removes
contaminants such as hydrogen sulfide and siloxanes using water-based scrubber systems or techniques
(e.g., membrane separation, activated carbon).
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Assessment of 'MSW Energy Recovery Technologies
The resulting biogas product can be used directly, combusted in a turbine or internal combustion engine
to generate electricity or converted to a liquid fuel product. If used to generated electricity, combined heat
and power systems can be employed where the heat from the combustion of biogas is captured and can
also be used to heat nearby buildings and/or the digester.
5.2 Technical Considerations and Challenges
AD of MSW presents several technical considerations and challenges that can include feedstock pre-
treatment requirements, process optimization, economies of scale, institutional support and socio-
economic aspects. Understanding these technical considerations and challenges can help communities
determine the potential role of AD technology in their local context.
5.2.1 Feedstock Supply and Preprocessing
The removal of inorganic materials (e.g., glass, plastic, metal, sand), wood waste, bone waste, soil and
chemical contaminants (e.g., pesticides, antibiotics) from AD feedstock can be a challenge to ensuring
optimal processing in the reactor. This may particularly be true for large scale AD operators who rely on
feedstock that originated from mixed MSW (from local municipal partnership). Undesirable and
contaminant feedstock led to clogging of pumps, contamination and poor biogas production. The most
commonly practiced presorting and pretreatment activities consisted of particle size reduction, seeding,
addition of metals, thermal and thermochemical pretreatment, ultrasonic pretreatment and alkali
pretreatment.
5.2.2 Process Optimization
The constant and intensive task of monitoring and maintaining optimal chemical conditions of AD during
processing was highlighted by companies as a key challenge to ensuring optimal biogas and digestate
production. Specific chemical challenges noted by companies included the level of ammonia produced
during processing (e.g., from poultry litter) and hydrogen sulfide that can break down the concrete
structure of tanks and reduce the biogas and heat production. Key monitoring activities focused on the
pH, nitrogen, methane, volatile fatty acids, alkalinity, ammonia concentration, and retention time of AD
processing.
Companies such as Zero Waste Energy Development Company (ZWEDC) highlighted the importance of
contamination in their feedstock, noting their right to refuse any incoming load of feedstock that
contained more than 30% paper and/or fiber materials and more than 0.25% glass. Other companies, such
as CR&R invested in magnet and eddy current separator technology that removes ferrous and nonferrous
metals as well as a grinder that size reduces the feedstock to less than 2 inches for optimal plant
performance.
5.2.3 Large vs. Small Scale Operations
The administrative and logistical hurdles that small and large AD operators comparatively encounter,
presents a notable distinction in applicable challenges of AD processes. For example, small-scale AD
plants that process up to 7,500 tons per year and produce approximately 25-250 Kw(e) often source their
feedstock on-site for convenience and at little to no transport and logistical cost.68 By comparison, large-
scale AD plant can process 30,000 tons or more per year and may serve nationwide energy demands
above lMWlMw(e)69 commonly depend on quality-controlled feedstock arrangements from transport
68 https://www.globalmethane.org/documents/AD-Training-Presentation Qct2016.pdf
69 https://www.globalmethane.org/documents/AD-Training-Presentation Qct2016.pdf
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Assessment of 'MSW Energy Recovery Technologies
and logistical suppliers of MSW and organic waste, prior agreements for feed in tariffs and power grid
connections, and partnerships with key technology providers to ensure the maintenance of the plant.
J.R. Simplot Potato Processing Plant and the American Crystal Sugar Company noted the importance of
establishing AD plants near both large urban metropolitan areas and agriculture production rich
geographies. Companies depend on well-developed collection routes for the aggregation of agricultural
food losses, excess prepared food, food scraps, and food manufacturing byproducts to realize an
economically feasible operation.
5.3 Anaerobic Digestion Facilities
Companies and operators of AD facilities that accept MSW feedstock (food waste) were identified via an
information collection request conducted by EPA (US EPA 2018). The EPA survey included facilities
that are stand-alone and co-digestion, including as waste-water treatment plants (WWTPs) and on-farm
digesters. For this report, the primary focus is stand-alone AD facilities.
Figure 10 provides a map of operating and not operating stand-alone and multi-source AD facilities in the
US. Table 5 lists the facilities. A full listing of AD facilities including industrial facilities and WTTPs
using excess digester capacity MSW feedstock is provided in Attachment B and is available along with a
listing of on-farm digestors in the EPA (US EPA 2018b) report.
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Assessment of MSW Energy Recovery Technologies
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Assessment of MSW Energy Recovery Technologies
Table 5. Stand-Alone Multi-Source Anaerobic Digestion Facilities
Facility Name
City
State
Feedstock
Operating
Blue Line Biogenic CNG Facility
South San Francisco
CA
Multi-Source
Buckeye Biogas LLC
Wooster
OH
Multi-Source
Buffalo BioEnergy
West Seneca
NY
Multi-Source
Central Ohio BioEnergy
Columbus
OH
Multi-Source
CH4 Generate Cayuga LLC
Auburn
NY
Multi-Source
City of Waterloo Anaerobic Lagoon
Waterloo
IA
Other
CleanWorld SATS
Sacramento
CA
Multi-Source
Collinwood BioEnergy
Cleveland
OH
Other
CRMC Bioenergy Facility
New Bedford
MA
Other
Dovetail Energy
Fairborn
OH
Multi-Source
Emerald BioEnergy
Cardington
OH
Multi-Source
Forest County Potawatomi Community Digester
Milwaukee
Wl
Multi-Source
Full Circle Recycle (Barham Farms)
Zebulon
NC
Multi-Source
Generate Fremont Digester, LLC
Fremont
Ml
Multi-Source
Generate Niagara Digester
Wheatfield
NY
Multi-Source
Greenwhey Energy
Turtle Lake
Wl
Multi-Source
Harvest Power Orlando
Lake Buena Vista
FL
Multi-Source
Haviland Energy
Haviland
OH
Multi-Source
Hometown BioEnergy
Le Sueur
MN
Multi-Source
Kline's Services
Salunga
PA
Multi-Source
Kompogas SLO LLC
San Luis Obispo
CA
Multi-Source
Magic Hat Resource Recovery Center
South Burlington
VT
Multi-Source
Michigan State Univ. - South Campus AD
Lansing
Ml
Multi-Source
Niagara BioEnergy
Wheatfield
NY
Multi-Source
North State Rendering
Oroville
CA
Multi-Source
Quantum Biopower
Southington
CT
Multi-Source
Stahlbush Island Farms
Corvallis
OR
Other
Three Creek BioEnergy, LLC
Sheffield Village
OH
Multi-Source
UW-Oshkosh Urban Dry Digester
Oshkosh
Wl
Multi-Source
Waste No Energy, LLC
Monticello
IN
Multi-Source
Zanesville Energy
Zanesville
OH
Multi-Source
Zero Waste Energy - San Jose
San Jose
CA
Multi-Source
Zero Waste Energy - Monterey
Marina
CA
Multi-Source
Not Operating
Rialto Bioenergy Facility (under construction)
Rialto
CA
Multi-Source
Source: US EPA, 2019
37
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Assessment of'MSW Energy Recovery Technologies
Chapter 6:
Life Cycle Environmental Profiles
The US and the international community are focusing increasingly on a life-cycle materials management
paradigm that considers the environmental impacts of materials at all life-cycle stages. Recognition is
growing that, since traditional environmental policies focus on controlling ""end-of-pipe" emissions, they
do not provide a means for systematically addressing environmental impacts associated with the
movement of materials through the economy.
The LCI data developed in the 2012 report, State of Practice for Emerging Waste Conversion
Technologies (US EPA, 2012), was based on technology vendor-supplied estimates for operating
parameters (e.g., unit of energy output and emissions per unit of feedstock input). In this report, LCI data
were collected for conversion technologies by performing a comprehensive literature review of recent
papers and reports covering the technologies. The LCI data resulting from this literature were compared
to modeled LCI data generated for the alternatives of conventional WTE and landfill using MSW DST.
6.1 LCI Data Review
Life cycle environmental profiles, including energy and resource inputs, emissions, product, and residual
outputs were developed for pyrolysis, gasification and AD technologies based on a literature review. The
literature review was conducted with peer-reviewed sources available from academic and trade
publications and technical reports from government agencies. Data was collected for each source within
the scope of the review. These data include authors, year of publication, title of article, journal name,
volume and page numbers, web address and access date. The review was conducted using the following
keywords independently and in combination:
¦ life cycle assessment, life cycle inventory, life cycle approach
¦ municipal solid waste, solid waste, MSW
¦ waste-to-energy, WTE
¦ waste conversion
¦ anaerobic digestion, AD
¦ pyrolysis
¦ gasification
¦ waste
¦ energy
¦ technologies
¦ inventory
¦ operations
¦ data
These searches yielded 60 total studies, which were included in the companion literature review Excel
tracking template. There were 48 studies that were conducted since 2012. After this initial search effort,
the studies were scanned to determine the technologies and feedstocks assessed as well as the geographic
location of the study. An evaluation was conducted to generate a short summary and a rating for the
relevance of each study relative to the project scope using a low/medium/high scale. Examples of low
relevance studies include those that did not evaluate the technologies of concern, provided no inventory
data or used data from another source, or explicitly focused on developing countries. Examples of
medium relevance studies include those that provide some parameters for the technologies of concern or
provide significant data for related technologies which may be useful (e.g., 'combustion" or
'incineration"). A high relevance study is defined as one that provides significant data for the technologies
of concern.
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Assessment of 'MSW Energy Recovery Technologies
Twenty-three studies out of the 60 identified were deemed to be of medium and high relevance. LCI data
from these studies was extracted and compiled in a Microsoft Excel workbook. Data compiled were
subsequently harmonized in terminology (i.e., labeling of parameters) and normalized converted to
common units (e.g., kg, L, MJ) per tonne of feedstock.
In conducting this review and analysis of waste conversion technologies, a number of challenges were
encountered pertaining to the ability to collect and validate certain technology and LCI data. Specific
limitations include:
¦ The viability of available information or data could not be independently verified due to the lack
of performance data or independent testing or verification. No attempt was made to directly
communicate with technology vendors (e.g., by email, telephone or direct contact) but rather data
and information were collected from publicly available sources.
¦ The dynamic nature of waste conversion technologies and markets. Many pyrolysis and
gasification facilities are at a pilot or semi-commercial stage. It was found that even facilities that
are commercial scale are often operating in more of a demonstration mode.
¦ The lack of facility-specific information publicly available online, either published by market
actors or third parties (e.g., the media, independent evaluations, academic studies). Several
companies reviewed did not have their own websites, while others operated websites that appear
to be several years out of date.
¦ LCI data available in the literature was found to be limited for the technologies studied. In several
cases, only one data point was found in the literature, which limited the ability to develop robust
LCI data ranges. In addition, it was difficult to determine scope and boundaries among sources,
thus limiting the ability to make direct comparisons. For example, one source may include
resource use and emissions associated with the conversion process as well as syngas cleaning and
combustion in a turbine or an internal combustion engine for electricity production. Another
source may include only the resource use and emissions associated with the conversion process
proper.
6.1.1 Pyrolysis LCI Data
The life cycle assessments7" (LCAs) of pyrolysis vary between gas production and the generation of other
products such as biochar or liquid feedstocks, which can be utilized as fuel or in chemical feedstocks. In
some cases, there is not a clear distinction between gasification and pyrolysis. Because pyrolysis is a
method of gasification or a process in other approaches to gasification, pyrolysis is sometimes referred to
as gasification or in conjunction with gasification within the literature. The LCAs for pyrolysis mainly
evaluated MSW, plastics, and dry organics as a feedstock because moisture inhibits the process and
demands more energy inputs to the process. Of the seven LCAs identified for pyrolysis shown in Table 6,
five represent western countries, with two explicitly evaluating US-based systems.
Table 6. Summary of Pyrolysis Life Cycle Inventory Literature Review
Citation
Location
Waste Feedstock
Relevance
Al-Salem et al., 2014
London, England
plastic solid waste, MSW
medium/high
Chakraborty et al., 2013
Delhi, India
MSW
medium
7" Life cycle assessment combines the life cycle inventory results into impact categories such as cancer and non-
cancer impacts, tropospheric ozone, climate change and other impact categories that affect human health and the
environment.
39
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Assessment of 'MSW Energy Recovery Technologies
Citation
Location
Waste Feedstock
Relevance
Evangelisti et al., 2015
United Kingdom
MSW
medium/high
Ibarrola et al., 2012
United Kingdom
green waste, food waste, wood waste,
cardboard, dense refuse-derived fuel
medium
Jones et al., 2014
United States
Wood
medium
Wang et al., 2015
United States
MSW
medium/high
Zaman, 2013
unspecified
MSW
medium
6.1.2 Gasification LCI Data
Gasification is described in multiple sources as an improved method of combustion due to the ability to
control certain emissions and is the most represented technology in the scope of this literature review. As
mentioned in the previous section, there often is not a clear distinction in the literature between
gasification and pyrolysis. There are several technologies that are referred to as gasification, including
pyrolysis. The majority of LCAs for gasification evaluated MSW as a feedstock because of the lower
sensitivity these technologies have relative to feedstock characteristics. Of the 13 LCAs identified for
gasification in Table 7, seven represent western countries, with only one explicitly evaluating US-based
systems.
Table 7. Summary of Gasification Life Cycle Inventory Literature Review
Citation
Location
Waste Feedstock
Relevance
Arafat et al., 2015
unspecified
food, yard, plastic, paper, wood, textile
medium/high
Arena et al., 2015
Europe
unsorted residual waste
medium/high
Chakraborty et al., 2013
Delhi, India
MSW
medium
Consonni and Vigano, 2012
Unspecified
MSW
medium/high
Del Alamo et al., 2012
unspecified
MSW
medium
Evangelisti et al., 2015
United Kingdom
MSW
medium/high
Ibarrola et al., 2012
United Kingdom
green waste, food waste, wood waste,
cardboard, RDF
medium
lonescu and Rada, 2012
Europe
MSW
medium
lonescu et al., 2013
Europe
MSW
medium
Kourkumpas et al., 2015
Europe
MSW, RDF
medium
Pressley et al., 2014
United States
RDF, MSW
medium/high
Smith et al., 2015
Unspecified
organic fraction of MSW
medium
Zaman, 2013
Unspecified
MSW
medium
MSW, municipal solid waste; RDF, refuse-derived fuel
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Assessment of 'MSW Energy Recovery Technologies
6.1.3 Anaerobic Digestion LCI Data
The primary solid waste feedstock considered in LCAs of AD was the organic fraction of MSW or food
wastes due in large part to the associated moisture content. Of the studies identified for AD, as shown in
Table 8, only three represent western countries, with only two explicitly evaluating US-based AD
systems. The US-based studies did not include LCI data set but rather data characterizing specific
elements of AD such as energy production and greenhouse gas (GHG) emissions that may be used to
construct an LCA.
Table 8. Summary of Anaerobic Digestion Life Cycle Inventory Literature Review
Citation
Location
Waste Feedstock
Relevance
Arafat et al., 2015
Unspecified
food, yard, plastic, paper, wood, textile
medium/high
Chakraborty et al., 2013
Delhi, India
MSW
medium
Evangelisti et al., 2014
United Kingdom
organic fraction of MSW
medium/high
Moriarty, 2013
United States
food waste
medium
Smith et al., 2015
Unspecified
organic fraction of MSW
medium
Williams et al., 2016
United States
animal manure, food, leaves, grass
medium/high
6.1.4 Review Papers and Other Relevant Literature
The following studies in Table 9 were broad in scope and included a variety of technologies and
feedstocks for comparison. These studies all rank high in terms of relevance and may provide useful
context and parameter ranges for the technologies. The references contained within these studies provide
additional data.
Table 9. Summary of Review Articles
Citation
Location
Waste Feedstock
Relevance
Arena, 2012
Unspecified
Various
high
Astrup et al., 2015
Various
Various
high
Kumar and Samadder, 2017
Global
Various
high
Laurent et al., 2014
Europe
Various
medium/high
6.2 LCI Data Compilation
The goal of the LCI data collection effort was to identify the most relevant data pertaining to the
conversion of MSW to energy through the utilization of pyrolysis, gasification, and AD in the US. To
best achieve that goal, data were prioritized as determined by metrics from the literature review. Only
studies with a medium relevance score or greater were considered. In addition, the geographic scope of
the studies was considered and were prioritized in the following order: US, other developed nations,
unspecified/global, and developing nations. The availability of data for each technology determined
whether parameters or single values were used and the uncertainty that may be associated with different
variables.
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Assessment of MSW Energy Recovery Technologies
LCI data were extracted from the identified literature sources and compiled in a Microsoft Excel
workbook. Data were normalized to a per ton basis to enable comparisons across studies with differing
functional units. Where multiple data points existed for a specific input or output, a range of data values
were developed. After all data were recorded, average values as well as a range of values were developed
for the primary input and output flows. Resulting data were reviewed to assess if any recorded data points
were outliers and should be removed.
6.3 LCI Data Coverage and Gaps
Table 10 presents a cursory overview of the LCI data available within the studies that received 'medium"
or greater relevance scores. Overall, the data available from the literature were found to be limited in
providing robust sets of LCI data for examination and analysis of waste conversion technologies. In many
instances, only one data source/point was found for an inventory inflow/outflow category.
The most complete coverage is for the gasification technology, which has the most representation within
the literature. Pyrolysis and AD have less coverage but a few key papers (Arena et al., 2015; Astrup et al.,
2015; Evangelisti et al., 2015; Wang et al., 2015; Williams et al., 2016) provide comprehensive data that
spans the areas of interest for the data collection effort for the targeted technology. Data specific to AD
technology accepting food waste and other MSW-based organics was found to be particularly limited.
Some of the fields in Table 8 remain empty where the data are not reported using the same classifications
or those categories are not associated with the technology modeled within the studies.
Table 10. Inventory Data within the Literature
Inputs and Outputs
Pyrolysis
Gasification
Anaerobic
Digestion
Power Consumption/ parasitic load
Al-Salem et al.,
2014
Jones et al., 2014
Wang et al., 2015
Ionescu and Rada,
2012
Evangelisti et al.,
2014
Total Solids
Pressley et al., 2014
Moriarty, 2013
Williams et al.,
2016
Volatile Solids
Pressley et al., 2014
Moriarty, 2013
Williams, 2016
Biodegradable
Volatile Solids
Moriarty, 2013
Williams, 2016
Inputs
AD Process
Characteristics
Conversion Efficiency
waste to methane
Kumar and
Samadder, 2017
Moriarty, 2013
Williams et al.,
2016
Conversion Efficiency
methane to electricity
Kumar and
Samadder, 2017
Moriarty, 2013
Smith et al., 2015
Williams et al.,
2016
Other inputs
Water
Al-Salem et al.,
2014
Evangelisti et al.,
2015 (SI)
Astrup et al., 2015
(SI)
Evangelisti et al.,
2015 (SI)
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Assessment of MSW Energy Recovery Technologies
Inputs and Outputs
Pyrolysis
Gasification
Anaerobic
Digestion
Jones et al., 2014
Wang et al., 2015
Oxygen
Catalysts and
chemicals
Al-Salem et al.,
2014
Arena et al., 2015
Astrap et al., 2015
(SI)
Diesel for
preprocessing
Jones et al., 2014
Wang et al., 2015
Caustic for gas
cleaning and cooling
Astrap et al., 2015
(SI)
Activated Carbon for
gas cleaning and
cooling
Arena et al., 2015
Astrap et al., 2015
(SI)
Feldspar for gas
cleaning and cooling
Evangelisti et al.,
2015 (SI)
Evangelisti et al.,
2015 (SI)
Supplemental
fuel use
Natural Gas
Astrap et al., 2015
(SI)
Electricity
Arena, 2012
Arena et al., 2015
Chakraborty et al.,
2013
Consonni and Vigano,
2012
Ionescu and Rada,
2012
Chakraborty et al.,
2013
Evangelisti et al.,
2014
Moriarty, 2013
Smith et al., 2015
Outputs
Energy product
Syngas
Al-Salem et al.,
2014
Del Alamo et al.,
2012
Arena, 2012
Consonni and Vigano,
2012
Ionescu and Rada,
2012
Pressley et al., 2014
Moriarty, 2013
Crude oil
Wang et al. 2015
Light fraction (liquid)
Al-Salem et al.,
2014
Gas fraction
Gasoline
Wang et al. 2015
Smith et al., 2015
Diesel
Wang et al. 2015
Residual gas
Material
byproducts
Sulfur
Salt
Al-Salem et al.,
2014
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Assessment of MSW Energy Recovery Technologies
Inputs and Outputs
Pyrolysis
Gasification
Anaerobic
Digestion
Slag
Char
Wang et al. 2015
Slag
Arena et al., 2015
Consonni and Vigano,
2012
Spent catalysts and
chemicals
Residuals
Solid residues
Al-Salem et al.,
2014
Evangelisti et al.,
2015
Arena, 2012
Evangelisti et al.,
2015
Inorganic sludge
Arena et al., 2015
Nonhazardous solid
waste
Evangelisti et al.,
2015
Del Alamo et al.,
2012
Evangelisti et al.,
2015
Water losses
Jones et al., 2014
PM
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Wang et al. 2015
Arena, 2012
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Smith et al., 2015
Zaman, 2013
Smith et al., 2015
Williams et al.,
2016
PM10
Wang et al. 2015
Air Emissions Data
Biogenic Carbon
Dioxide
Evangelisti et al.,
2015 (SI)
Jones et al., 2014
Wang et al. 2015
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015 (SI)
Kourkoumpas, 2015
Smith et al., 2015
Zaman, 2013
Evangelisti et al.,
2014
Smith et al., 2015
Williams et al.,
2016
Fossil Carbon
Dioxide
Jones et al., 2014
Arena et al., 2015
Astrap et al., 2015
(SI)
Methane
Jones et al., 2014
Wang et al. 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2014
Smith et al., 2015
Williams et al.,
2016
Hydrochloric Acid
Evangelisti et al.,
2015
Arena, 2012
Evangelisti et al.,
2015
Zaman, 2013
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Assessment of MSW Energy Recovery Technologies
Inputs and Outputs
Pyrolysis
Gasification
Anaerobic
Digestion
Sulfur Dioxide
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Arena, 2012
Arena et al., 2015
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Smith et al., 2015
Zaman, 2013
Smith et al., 2015
Williams et al.,
2016
Sulfur Oxide
Arena, 2012
Astrap et al., 2015
(SI)
Williams et al.,
2016
Mercury
Evangelisti et al.,
2015 (SI)
Arena, 2012
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015 (SI)
Zaman, 2013
Cadmium
Arena et al., 2015
Astrap et al., 2015
(SI)
Zaman, 2013
Hydrocarbons
Nitrous Oxide
Evangelisti et al.,
2015 (SI)
Arena, 2012
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015 (SI)
Williams et al. ,
2016
NOx expressed as
NO2
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Smith et al., 2015
Evangelisti et al.,
2014
Smith et al., 2015
Williams et al.,
2016
Carbon Monoxide
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Jones et al., 2014
Wang et al. 2015
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015
Evangelisti et al.,
2015 (SI)
Smith et al., 2015
Zaman, 2013
Evangelisti et al.,
2014
Smith et al., 2015
Williams et al.,
2016
Lead
Evangelisti et al.,
2015 (SI)
Arena et al., 2015
Astrap et al., 2015
(SI)
Evangelisti et al.,
2015 (SI)
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Assessment of 'MSW Energy Recovery Technologies
Inputs and Outputs
Pyrolysis
Gasification
Anaerobic
Digestion
VOC
Evangelisti et al.,
2015 (SI)
Arena et al., 2015
Evangelisti et al.,
2015 (SI)
Smith et al., 2015
Zaman, 2013
Evangelisti et al.,
2014
Smith et al., 2015
Williams et al.,
2016
Hazardous Air
Pollutant
Evangelisti et al.,
2015 (SI)
Evangelisti et al.,
2015 (SI)
Acetaldehyde
Total non-methane
organic carbon
Wang et al. 2015
Dioxins and Furans
Arena, 2012
Arena et al., 2015
Astrap et al., 2015
(SI)
Zaman, 2013
Cost Data
Cost per ton of design
capacity
Jones et al., 2014
Kumar and
Samadder, 2017
Chakraborty, 2013
Kumar and Samadder,
2017
Smith et al., 2015
Chakraborty et al.,
2013
Kumar and
Samadder, 2017
Moriarty, 2013
Smith et al., 2015
Williams et al.,
2016
AD, anaerobic digestion; PM, particulate matter; VOC, volatile organic compound
6.4 LCI Comparison to Conventional WTE and Landfill
In this section, select LCI data resulting from the literature review for pyrolysis and gasification
technologies are compared to modeled LCI data ranges for AD, conventional WTE and landfill developed
using the MSW DST. Since complete LCI data specific to the MSW-based feedstock AD were not
available from the literature, the AD model71 developed for the Solid Waste Optimization Life-cycle
Framework, or SWOLF (which is being incorporated into a forthcoming new version of the MSW DST)
was used to provide LCI data for AD. The ranges for AD represent average values for food and non-food
(e.g., yard wastes) organic waste constituents. The values for WTE and landfill with gas collection and
energy recovery were developed by modeling typical MSW feedstocks accepted by conversion
technologies including:
¦ MSW
¦ plastics
¦ food/organics
The MSW DST was developed to aid communities and solid waste planning in evaluating the cost and
life-cycle environmental impacts for different MSW management technologies and strategies. Default
national average settings were used for AD, WTE, and landfill design and operational parameters. For
landfill, gas management with energy recovery (via electricity generation) was modeled. The national
average grid mix for electricity production was used to calculate emissions associated with electricity
71Model documentation available at: http://www4.ncsu.edu/~iwlevis/AD.pdf
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Assessment ofMSW Energy Recovery Technologies
consumption and emission offsets in the case of AD, WTE and landfill. An uncertainty factor of 20
percent was applied to the average LCI results to develop ranges for AD, WTE, and landfill.
As highlighted in the previous sections (6.1—6.3), the data available from the literature were found to be
limited in terms of providing robust sets of LCI data for analysis and comparison to conventional WTE
and landfill disposal. Therefore, making direct LCI comparisons between conversion technologies and
between conversion technologies and conventional technologies is challenging. Findings from the
literature review point to common challenges:
¦ Different MSW feedstocks are accepted by different technologies. While conventional WTE and
landfill can accept bulk MSW as-is, conversion technologies often are tailored to specific
fractions ofMSW. Pyrolysis typically focuses on non-recycled plastics but also can include
facilities designed for conversion of biomass feedstock (typically non-MSW agriculture and
forestry residues). AD can be designed to accept food waste or mixed organics from MSW.
Gasification may accept bulk MSW or fractions thereof (e.g., MRF residuals) but will require
robust preprocessing to remove unwanted materials (e.g., glass, fines).
¦ A variety of end-products can be produced by conversion technologies. Gasification produces a
syngas product that may be used directly to generate electricity or transformed to a liquid fuel.
Pyrolysis produces a synthetic petroleum product that may be refined to a liquid fuel or into
chemical commodities. AD produces biogas and a digestate product that may be used as compost.
These differing products were normalized for comparative purposes by reporting in terms of
heating value (MJ / [mass unit]).
¦ LCA literature for conversion technologies are not always clear about system boundaries. Life
cycle burdens associated with waste collection transport, preprocessing of feedstock, post-
processing of product (e.g., syngas cleaning), and use (e.g., combustion) are often difficult to
discern in the data and may or may not be included altogether. Unless otherwise noted, the LCI
results assume collection is not part of the data boundaries.
¦ LCI data from the literature represent different time spans and technology development cycles.
Waste conversion is a developing technology. Vendors are continually refining process designs to
obtain greater efficiencies and more stable operations. Thus, the LCI data available in the
literature represents a wide range of technology design and various stages of technology
development and refinement. This can cause wide-ranging data and potential outliers. As an
example, one source for gasification included a novel syngas-cleaning technology that consumes
significantly greater amounts of water than other sources and may be considered an outlier.
The following sections contain LCI estimates for energy consumption, water consumption, carbon
emissions, and solid residuals. LCI results are presented on a per tonne of feedstock. Additional LCI data
for pyrolysis and gasification technologies are provided in Attachments D and E, respectively.
6.4.1 Energy Consumption and Production
The primary benefit touted for waste conversion technologies is their ability to generate energy products
from waste that otherwise would be disposed of in a landfill. However, they do not have the performance
data or proven ability to recover energy, metals, and other resources as a WTE facility. The residuals from
pyrolysis and gasification if managed by WTE would recover additional energy, which would not occur
in a landfill. Currently, most residuals are landfilled. Thus, the potential ability of conversion
technologies to achieve levels of energy recovery greater than conventional options is important to
consider. For conversion technologies, energy is consumed to power the conversion process, facility
equipment (e.g., rolling stock, feedstock preprocessing, air pollution control) and transport and disposal of
residuals in a landfill. Energy consumption results include data for electrical and fossil fuel energy
consumption. The net energy consumption results shown in Figures 1 la through 1 lc highlight that
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Assessment of 'MSW Energy Recovery Technologies
conversion technologies have the "potential" of energy recovery. However, conversion technologies do
not have the performance history that WTE facilities have in the US, Europe, and Japan. Those WTE
facilities which have 24/7 continuous monitoring data demonstrate that emissions are even lower than
regulatory standards. In considering waste conversion technology, the net energy production must
include both preprocessing and post-processing requirements for that technology.
Note that for WTE of MSW feedstock, as shown in figure 8a, ferrous metal recovery from combustion
ash is also included which provides an additional energy offset benefit per the consumption of energy
otherwise needed to produce virgin ferrous metal. In addition, differences in MSW feedstock composition
(and energy value) will significantly impact energy recovery. For gasification, it was not always possible
to determine the composition of MSW that was assumed in the literature sources whereas for WTE and
landfill a US average composition was modeled.
For plastics feedstock, as shown in figure 1 lb, it is surprising that the net energy results exhibit WTE as
performing better on an energy basis than pyrolysis. These results are difficult to reconcile as one would
expect gasification to be a more efficient process than a mass-burn WTE plant and yield better energy
returns. One possible explanation could be due to differences in the assumed MSW feedstock
composition and subsequent energy value as previously stated. Another factor may be the type of energy
that is assumed to be offset per each technology (i.e., electricity for WTE and fuel oil for pyrolysis).
These results may also be due to greater economies of scale for WTE, which are typically larger-scale
facilities with greater capacities and thus a lower parasitic power load relative to smaller-scale pyrolysis
facilities.
For food waste, as shown in figure 1 lc, net energy is more comparable among the options analyzed. It is
interesting to note that WTE is on par or a slightly better on an energy basis than AD. This may be due to
a more complete energy value of the food being recovered in WTE than AD, where the remaining carbon
in AD goes to digestate.
10,000
5,000
o
a>
a.
ai
o
-5,000
Gas tion
tion WTE
+
Landfill
-10,000
-15,000
-20,000
-25,000
Figure 11a. Net energy production for MSW feedstock.
(Note: WTE includes energy offsets associated with metals recovery and recycling.)
48
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Assessment of MSW Energy Recovery Technologies
-5,000
-10,000
-15,000
-20,000
-25,000
Figure 11b. Net energy production for plastic waste feedstock.
-25,000
Figure 11c. Net energy production for food/organic waste feedstock.
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Assessment of MSW Energy Recovery Technologies
6.4.2 Water Consumption
Water is typically not a process input for conversion technology facilities, except for AD when there is
not enough moisture in the feedstock. However, water can be consumed as part of feedstock
preprocessing (e.g., washing of plastics) as well as gas or fuel cooling/cleaning and air pollution control.
Figure 12 shows water consumption estimates available from the literature for conversion and
conventional waste treatment and disposal technology. A review of the gasification LCI data from the
literature revealed that one specific technology represented used a syngas cleaning process that appears to
consume large amounts of water. Including this large water consumption value pulls up the average from
approximate 9,000 kg of water per tonne to almost 70,000 kg of water per tonne. While this one data
point was an outlier and was excluded, it does highlight the need to carefully review data to determine
whether it captures all aspects of a conversion process. In this case, cleaning of the resulting syngas to
meet market requirements is the culprit. For other gasification technologies, the syngas cleaning stage
does not consume such large amounts of water or possibly is not included at all.
10,000
(U 9,000
£
1 8,000
£ 7,000
TS
6,000
3
£ 5,000
o
^ 4,000
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Assessment ofMSW Energy Recovery Technologies
Reductions and offsets of carbon emissions are directly related to the following aspects:
• Electrical energy production offsets carbon emissions from the generation of electrical energy
using fossil fuels in the utility sector.
• Materials recovery and recycling offsets carbon emissions by avoiding the consumption of energy
that otherwise would be used in materials production processes.
Carbon emissions are generally minimal for the conversion processes proper as the thermal, chemical and
biological reactions takes place in sealed reactors/vessels. Carbon emissions, namely CO2, will result
from any on-site combustion of fossil fuel to power vehicles and equipment and possibly to provide
additional heat to the process. For pyrolysis and gasification, the main source of carbon emissions will be
the end-use combustion of the syngas or synfuel product. For AD and landfill, combustion of the
recovered biogas product will produce biogenic CO2 emissions, which is typically considered to be
carbon neutral. Likewise, direct combustion of organics via WTE will produce biogenic CO2 emissions,
which are not included in the CChe calculations.
Figures 13a through 13c show the net total carbon equivalent emissions for conversion technologies as
compared to the modeled carbon equivalent emissions for WTE and landfill. Since CC^and methane data
were available from the literature, these data were used to normalize carbon equivalent emissions.
For MSW feedstock, as shown in figure 13a, landfills produce the highest carbon emissions, as expected.
Somewhat unexpected is that gasification exhibits higher carbon emissions than WTE. However, as
shown in figure 11a, WTE exhibited a better energy profile and carbon emissions will be closely tied to
energy. In addition, there are likely differences in carbon intensities of electricity grids being displaced
per the data sources for gasification that were not possible to normalize to the US average grid as used for
WTE (as well as for AD and landfill). In addition, it is not always possible to determine the composition
of MSW feedstock that was assumed in the literature sources for gasification, which will impact carbon
emission results. For AD, WTE and landfill the US average MSW composition is assumed.
Carbon emission results for plastics, as shown in figure 13b, exhibit net positive carbon emissions for
WTE and conversion technologies. Again, this is due to the direct combustion (via WTE) of plastics or
the combustion of fuel products (via gasification and pyrolysis) made from plastics producing fossil CO2
emissions. For food waste, as shown in figure 13c, it is interesting to note that AD exhibits higher carbon
emissions that WTE. This result is primarily due to the accounting of methane leakage for AD. The
combustion of food/organic feedstock in WTE and the combustion of biogas produced from AD will
result in biogenic carbon emissions that are not included in the carbon equivalency calculation.
51
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Assessment of 'MSW Energy Recovery Technologies
2,000
+
Landfill
-500
Figure 13a. Net carbon dioxide equivalent emissions for MSW feedstock.
(Normalized for reported CO2 and CH4 emission using a GWP of 1 for fossil CO2 and 25 for ChU; WTE
includes carbon offsets associated with metals recovery and recycling)
2,000
1,500
I" I \
1 500 T I
0 ®
Gasification Pyrolysis
-500
Figure 13b. Net Carbon Dioxide Equivalent Emissions for Plastic Waste Feedstock
(Normalized for reported CO2 and CH4 emission using a GWP of 1 for fossil CO2 and 25 for CH4)
1,500
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Assessment ofMSW Energy Recovery Technologies
2,000
1,500
-------
Assessment of MSW Energy Recovery Technologies
500
450
<¥ 400
£
£ 350
i-
£ 200
¦g
O 150
l/l
J* 100
50
0
+
Gasification Pyrolysis
AD
{
WTE
Landfill
Figure 14. Net average life cycle solid residues generated.
54
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Assessment of 'MSW Energy Recovery Technologies
Chapter 7:
Findings and Observations
To solve some of the waste sector's most pressing challenges and exploit some of its newest
opportunities, waste conversion technologies will continue to draw interest and investment. As these
conversion technologies are being promoted and distributed by private sector stakeholders across the US,
communities will need to better understand not only the novelty and potential of each technology type,
but also the potential technical, environmental, economic and social impacts of the technologies in their
local context.
Waste conversion technologies can provide technically feasible alternatives to conventional WTE and
landfill disposal for managing MSW, particularly for non-recyclable MSW fractions that otherwise would
be landfilled. Through this study, approximately 10 MSW gasification and pyrolysis technology projects
were identified in the US (and Canada). The study identified 2 operating gasification and 4 operating
pyrolysis facilities as of September 2019 dedicated to accepting MSW-based feedstock. In contrast, AD
systems have grown rapidly since 2012 with more than 25 facilities in the US that process wasted food
and other organic fractions of MSW.
One of the major goals of this research is to develop a Decision Makers Guide for Assessing Municipal
Solid Waste Energy Recovery Technologies. The guide is a summary of information contained in the
report and is provided as Attachment F. Visuals are provided to illustrate the different options for the
different feedstocks in municipal solid waste. Those working with island and tribal communities - as well
as other communities, may want to use Appendix F as a guide in helping support the unique needs of
island and tribal communities.
7.1 Advantages and Disadvantages of Conversion Technologies
There are only a few commercial waste conversion facilities accepting MSW feedstock and operating at
large scales. This has created concerns about the conversion technologies being feasible to build and
operate and therefore conventional WTE and landfill disposal may be considered lower-risk options.
Conversely, stand-alone AD systems and those co-digesting have grown rapidly in recent years due to a
heightened focus on diverting organic fractions of MSW (e.g., food waste) from being disposed in
landfills.
An often-cited advantage of conversion technologies as compared to WTE or landfill is their potential to
produce a wide variety of products. Syngas from gasification gas can be used on-site to generate
electricity or it has the potential to be further refined to produce a variety of chemicals, including
methanol, ethanol, and liquid fuels. Syncrude from pyrolysis can produce high-value products, including
naphtha, kerosene, and gas-oil from polyolefin feedstocks. However, such variety in gasification and
pyrolysis has yet to be demonstrated. Biogas from AD systems can be used on-site to generate electricity,
used directly, or can be further refined to produce compressed biogas or liquefied biogas products.
A key disadvantage of the conversion technology as compared to conventional WTE and landfill disposal
is the need for consistent and quality feedstock for the process to work effectively. Unlike WTE and
landfill where bulk MSW feedstock is readily accepted, the feedstock supply, preprocessing, and handling
can represent challenges that can have significant impacts on the performance of the conversion
technology. Other key disadvantages cited in the literature include difficulties encountered scaling up
facilities from demonstration to commercial scale and reliable specifications of the energy product that is
generated from the conversion technology. These specifications are dependent on the types and mixtures
of feedstock used.
Conversion technologies will not eliminate the need for landfill disposal. Compared to WTE and landfill
facilities that are often designed to accept thousands of tonnes per day of waste, conversion technologies
55
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Assessment of 'MSW Energy Recovery Technologies
are comparatively small in capacity at typically 50 to 300 tonnes per day and are designed around
accepting preprocessed MSW (rather than bulk MSW). In addition, the conversion technologies have
residual waste streams that can include non-processible feedstocks and non-reusable process residuals
(e.g., char). Feedstocks can also require disposal when the conversion technology facility is down for
scheduled and unscheduled maintenance, which could be 10-15% of its annual availability (or 36-55 days
per year).
7.2 Life Cycle Environmental Performance
Conversion technologies can provide alternatives for managing MSW as compared to conventional WTE
and landfill gas to energy projects. From a life cycle environmental perspective, readily available and
objective data and information about the performance of conversion technologies is limited due to less
operational history and experience. This lack of operational data and experience makes it difficult to
compare conversion technologies to each other and to the conventional options.
Findings from the literature review show common challenges in applying life cycle data, including:
¦ different MSW feedstocks accepted, by the different technologies and process designs, limit the
ability to directly compare life cycle results;
¦ the wide variety of end-products produced by conversion technologies create wide-ranging
estimates of life cycle offsets;
¦ system boundaries not consistently applied among life cycle studies found in the literature,
particularly with regard to the inclusion or exclusion of pre- and post-processing activities; and
¦ available life cycle data from the literature represent different time spans and at different points in
technology development cycles, which can lead to wide-ranging technology performance
estimates.
The review and analysis of the LCI data from the literature finds that MSW conversion technologies
appear to offer net energy production benefits. However, energy production for conversion technologies
will vary significantly based on the exact feedstock used, process efficiency, and any requirements for
preprocessing of feedstock or post processing of product streams. Conversion technologies may have a
slight theoretical advantage over conventional WTE and landfill gas-to-energy operations, in that the
energy conversion efficiency may be better and there is greater flexibility in tailoring end products to
meet market demands.
Both conversion technologies and conventional WTE and landfill options, generate gaseous, liquid, and
solid emissions that will require treatment or disposal. The literature review did not address hazardous air
pollutants, which can be present in gaseous emissions when materials are combusted or converted. For
carbon emissions, the literature data available show that pyrolysis and gasification technologies can result
in carbon equivalent emissions comparable to either conventional WTE or landfill disposal. This is due to
the carbon emissions associated with the combustion of the syngas or synfuel product which is considered
fossil energy. For AD systems, the resulting biogas product is considered biogenic energy and shows the
lowest carbon equivalent emissions of the options studied.
All conversion technologies will produce residual solid waste streams that will require additional
treatment (e.g., via WTE) or disposal in a landfill. Conversion technology by-products may also require
treatment or disposal if a viable end-use or market cannot be found. The data available from the literature
review show that conversion technologies produce as much or higher amounts of residuals than
conventional WTE. The exact amounts of solid residuals generated will be dictated by the feedstock
composition and the level of acceptable contamination of the feedstock for the specific conversion
technology. In general, it could be expected that an unprocessed mixed feedstock will generate greater
amounts of solid residuals than a source segregated feedstock (e.g., plastics, food waste).
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Assessment of 'MSW Energy Recovery Technologies
7.3 Risk Profiles for Conversion and Conventional Technologies
Waste conversion technologies differ in risk profiles based on the successful deployment of the
technology. As we have stated, feedstock availability, economics, and other factors can lead to low
probability of a successful technology deployment. Also, the price of landfilling waste remains the
lowest cost which might be different if environmental externalities are considered. Specially, some
technologies have been proven on a commercial scale while others are still in bench scale or small-scale
development and testing stages. Risk profiles72 for the conversion technologies and conventional MSW
management technologies presented in this report are provided in the table below:
Technology
Status Risk Profile73
Anaerobic Digestion
Proven technology; limited US commercial experience
with MSW
Moderate to Low
Composting
Proven commercial technology
Low
Landfill
Proven commercial technology
Low
Gasification / Pyrolysis
No operating experience with large-scale operations in
the US; Past failures
High
RDF Processing and
Combustion
Proven commercial technology; limited US commercial
experience
Moderate to Low
WTE Combustion
Proven commercial technology
Low
7.3.1 Economics
Cost estimates for conversion technologies are variable and uncertain due to limited data for commercial
scale operating facilities and the high variability in capital and operating costs dependent on location.
Capital costs include the purchase of land, construction, equipment, and management costs. Operating
costs typically include all facility costs related to MSW feedstock preprocessing, conversion (pyrolysis,
gasification, AD), post-processing of product (e.g., syngas cleaning), energy product combustion and
electricity generation, and regular maintenance and repair activities.
Revenue sources for conversion technologies can include energy product sales, tipping fees, and material
by-product sales. Similar to costs, specific data are limited and highly uncertain as they are highly
dependent on the quality of the products and local markets. Renewable energy or tax credits may also be a
source of revenue for conversion technologies if they meet certain requirements in GHG emissions.
7.3.2 Siting
Many factors including environmental impacts, economic incentives, feedstock availability, product off-
take agreements, and permitting requirements go into facility siting decisions. Consideration of the
surrounding community and potential health impacts are also critical factors. Businesses and local
agencies that take the time to meaningfully engage communities surrounding proposed facilities and
consider the potential burden to vulnerable communities typically have a more efficient permitting
process.
72 Adapted from Gershman, Brickner & Bratton, Inc. Presentation for Arizona Tribal Energy Association on Waste
to Energy Technologies. January 2018
73 This is not referring to risk to human health and the environment. This is communicating the level of risk in the
successful technology development.
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Assessment of MSW Energy Recovery Technologies
EPA's environmental justice mapping and screening tool called EJSCREEN is based on nationally
consistent data that combines environmental indicators in maps and reports.74 EPA used EJSCREEN to
evaluate the siting of conversion technology and conventional WTE facilities. For this analysis, 111
facilities (currently operating and under construction) were mapped and then evaluated by the income
levels of the communities within one mile of each facility. Low-income is defined as the number or
percent of a Census block group's population in households where the household income is less than or
equal to twice the federal poverty level. Low-income communities were identified as those with a low-
income population that ranks in the 80th percentile or higher for the state percentile ranking for low-
income. Low-income communities are more likely to experience disproportionate environmental harms
and risks as a result of greater vulnerability to environmental hazards.
¦ Of 111 facilities mapped, 29 are in low-income communities. See Figure 15 for the distribution
of facilities by technology type based on population and state percentile ranking for low income.
¦ By technology type, RDF facilities had the highest percent, at 64%, of facilities located within
one mile of low-income communities, followed by pyrolysis (43%) and mass burn (24%).
¦ While newer technologies (AD, gasification, and pyrolysis) tend to be in areas with lower
population densities, older technologies such as mass burn are surround by denser populations
with the potential to impact greater numbers of low-income individuals.
Total Number of
Above the 80th percentile
based on state percentile
ranking for low income
Technology Type
Facilities Mapped
Total #
Percent
RDF
11
7
64%
Pyrolysis
7
3
43%
Mass Burn
62
15
24%
AD
27
4
15%
Gasification
4
0
0%
AD, anaerobic digestion; RDF, refuse-derived fuel
74 US EPA EJSCREEN: Environmental Justice Screening and Mapping Tool, www.epa.gov/eiscreen
58
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Above the 80th
Percentile Low
Income
Technology Type
Anaerobic
• Digestion
• Gasification
Mass Bum
Pyrolysis
6 Refuse Derived
Fuel
0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 20,000 22,000 24,000 26,000 28,000 30,000
Total Population
Figure 15, Total population and percentile low-income within one mile of each facility.
Using EPA's EJSCREEN tool, 111 facilities were mapped to assess demographic information on total population and income at a Census block group level within
one mile of each facility. Based on the state percentile ranking for income, 29 facilities are surrounded by communities considered to be low-income because they
were at or above the 80th percentile.
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7.3.3 Permitting Requirements
State regulations and permitting requirements for conventional MSW adopt standards equal to or more
stringent than federal law, including the Resource Conservation and Recovery Act (RCRA) for the
management of solid wastes, the Clean Air Act (CAA) for controlling air emissions, and the Clean Water
Act (CWA) for discharges into water bodies. States can impose more stringent regulatory standards than
required by these federal statutes. Counties and local municipalities may also impose requirements under
their own authority, including building and siting codes.
There may or may not be separate regulations for conversion technologies and conventional WTE
technologies in some jurisdictions. An example is Oregon, which considers conversion technology
facilities to be solid waste disposal sites and has specific permitting requirements for conversion
technology facilities. Other states may have additional requirements, such as California and New York,
that require conversion technologies (gasification and pyrolysis) to use MSW-based feedstock in order to
qualify for credits under the renewable portfolio standards.
Information presented below was gathered from available information from state regulatory authorities.
Facility
State
Technology
Identified Permits
Agilyx
OR
Pyrolysis
Simple Air Contaminant Discharge Permit75
Nexus
GA
Pyrolysis
Air Quality Permit (Type: State Implementation Plan (SIP) Permit)
as an alternative fuel product manufacturing facility76
Renewlogy
UT
Pyrolysis
Considered a "small emitter" thus exempt from air permitting
requirements. No waste related permits.
Fulcrum
Bioenergy
NV
Gasification
Class II Air Quality Operating Permit.77 The MSW processing
operation is permitted as a material recovery facility.
Fort Hunter
Liggett Sierra
Energy
CA
Gasification
Received approvals from the Monterey Bay Unified Air Pollution
Control District and the Regional Water Quality Control Board.
Received an exemption from solid waste permitting requirements,
primarily because it is a resource recovery facility intended only
for demonstration purposes and not for profit, and that the facility
is funded primarily by government grants.78
Permitting conversion technologies can be challenging as their discharge may be covered under different
environmental statutes and be subject to different regulations from the federal government through the
local municipality. This makes permitting a new facility a challenging and can result in a lengthy
endeavor often taking several years. As conversion technologies may design innovative and cutting-edge
operating systems, for example, public authorities rarely have a precedent on which to base permitting
decisions on or knowing which permits and licenses to apply for and get approval. Permitting
classifications can also depend on whether MSW is preprocessed on- or off-site.
There may also be state or local odor control requirements. Odors are a concern for facilities that handle
MSW-based feedstock, particularly food and organic wastes. Odors can occur when unloading incoming
75 OR DEQ Facility Profiler. https://www.dea.state.or.us/msd/profilerreports/traacs.asp?id=34-9514-SI-01
76 Georgia Air Permit Search Engine, https://permitsearch. gaepd.org/
77 NDEP Air Records Search, https://documentviewerpublic.ndep.nv. gov/Common/Login.aspx?ReturnUrl=%2f
78 CalRecycle SWIS Facility Detail. Municipal Solid Waste to Energy Project (27-AA-0123)
https://www2.calrecvcle.ca.gov/swfacilities/Directorv/27-AA-0123
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Assessment of MSW Energy Recovery Technologies
feedstock, pretreatment holding tanks, storage areas, disposal as well as during the processes (e.g.,
shredding, grinding and sizing, opening AD chambers).
A number of vendors may advertise that their technology has the ability to reuse processed solid waste
and wastewater streams as feedstocks and in their process, but there may be differences by regulators as
to how these activities are permitted and under what statutes (e.g., Title V Permits, Water Quality
Permits, state land permits, industrial user permit to a WRRF).
In terms of permitting at the federal level, under the Clean Air Act, large conversion plants will likely be
required to obtain a Prevention of Significant Deterioration (PSD) permit, if the plant will be located in an
area that is meeting the National Ambient Air Quality Standards (NAAQS), or a Nonattainment New
Source Review (NNSR) permit, if it will be located in an area that is not meeting the NAAQS. For new
Integrated Gasification Combined Cycle (IGCC) plants, for example, PSD and NNSR permits often
require companies to spend a minimum of three months to prepare their applications and up to an
additional 12 months for the approval of the permits. Except for Indian Country and states without
approved PSD programs, PSD and NNSR permits are issued by states subject to EPA oversight. For
example, since Illinois does not currently have an EPA-approved PSD program, Illinois issues PSD
permits under a delegation agreement with EPA.
In two cases reviewed by the EPA in Illinois, one company, GreenSmith Environmental, that applied for a
Clean Air Act permit spent over 14 months and 10 months on their application and EPA review
respectively. Another company, Taylorville Energy Center spent over 10 months and 22 months on their
application and EPA review respectively.
7.4 Additional Considerations
Technology vendors identified and reviewed as part of this report often demonstrated a strong dependence
on technical institutional, academic and government support to design, build and operate their conversion
technology project to maximum efficiency. Gasification and pyrolysis companies face a variety of
economic, legal, contractual, and political challenges to realizing a successful and sustainable operation.
In addition to securing specific feedstock and product off-take agreements, companies may also actively
seek to establish their plants in locations with high disposal fees. A company or a hauler would want to
take the material for disposal to the least costly facility, and by having competitive or lower rates than
other non-sustainable disposal options, may influence waste producers to use more sustainable waste
management and recovery practices. Other considerations to locations include those with high natural gas
prices (that would provide their alternative fuels with a competitive edge—due to lower production costs)
and the ability to complement existing electricity infrastructure (e.g., steam turbine generators that are
connected to national grid).
AD companies reviewed as part of this study also highlighted the role of institutional, technical and
government support to realize a cost-efficient design, operational facility, and maintenance overtime.
The provision of having solid waste and wastewater feedstock agreements, a power purchase agreement, a
design supply agreement with the technology provider, multiple construction contracts and an operation
and maintenance agreement in place were all noted as important factors to attract investment and
establishing a successful AD business operation.
¦ Companies, including, Zero Waste Energy Development Company (ZWEDC) and Blue Line
Biogenic compressed natural gas facility that both operated dry fermentation anaerobic digestion
plants sought out exclusive guarantees for organic municipal waste supply/feedstock by the City
of San Jose and San Francisco, respectively, through 10 to 15-year organic feedstock supply
agreements. An additional company, CR&R secured municipal solid waste feedstock supply
agreements in Temecula, Wildomar, Lake Elsinore, Perris, Hemet, Calimesa, Riverside County,
San Jacinto and Canyon Lake, California, prior to constructing their plants.
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Assessment of 'MSW Energy Recovery Technologies
¦ An increasing trend for AD system companies is to partner with several ancillary business
operations, to ensure continuing economic success. For example, if one of the end products is a
sellable gas, AD systems have contracts with a hauling company or bus company that uses
renewable fuels. AD systems have also partnered with other companies to take a continuous
stream of feedstock (cheese operations), for example.
AD companies similarly highlighted a variety of legal and political challenges to realizing a more cost-
efficient operation. Specific examples may include the simplification of permitting requirements and
guidance for existing or innovative AD system trials and pilot tests. An area that AD companies noted
that was helpful to establish their facility was in states with active food waste bans from landfills or food
diversion ordinances and programs. Such ordinances and programs exist in several states including in
California, Connecticut, Vermont, Massachusetts, and Rhode Island and in cities, including, Austin, San
Antonio, Madison, Los Angeles, New York City, San Francisco, Seattle, Denver, Portland and Ann
Arbor. Such legal measures assist the AD operators in obtaining the supply and organic inputs they
require in urban areas. For example, the CRMC Bioenergy Project that serves Dartmouth and New
Bedford, Massachusetts, met its feedstock targets by providing one of the only legal methods for
businesses to send their organic waste following the state-wide ban on the disposal of commercial food
waste and other organics into landfills.
7.7 Key Data Gaps and Recommendations for Future Research
Making direct comparisons of different conversion technologies and conventional technologies is
challenging, in part due to differences among the processes and lack of operating data for characterizing
cost and environmental performance. While operating data may be more readily available in other regions
of the world, such as Europe, there is a need for operating data for facilities in the US to better assess their
performance and demonstrate their potential to the US market. Other technologies such as chemical
recycling and mechanical biological treatment should also be included in future evaluations.
Additional research that could be done to advance the understanding of conversion technologies might
include examining data for operating conversion facilities outside of the US and sensitivities of these
technologies relative to cost and environmental aspects for key parameters such as:
¦ feedstock composition (e.g., high vs. low heating value feedstock, biomethane potential),
¦ feedstock preprocessing requirements and associated cost and energy use,
¦ energy conversion efficiency and net energy production,
¦ post-processing requirements for end-products (e.g., syngas cleaning),
¦ recovery of materials for recycling (for mixed MSW technologies),
¦ beneficial offsets for different by-products,
¦ market prices for end-products, and
¦ market prices for recyclable and other byproduct streams.
Additional guidance is needed to better understand permitting requirements for conversion technologies.
Case studies highlighting permitting challenges and successful solutions would provide useful
information for communities.
On-going technology and innovations in the process designs, feedstocks and operating models will
continue to make the conversion technology sector dynamic and therefore updates to guidance and
recommendations can be expected. Changes in economics could occur if carbon reductions are required
resulting in some of these technologies being more attractive in the ability to minimize carbon emissions
while maximizing resource (including nutrients from food and yard waste) and energy recovery from
residential and commercial waste.
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Assessment of'MSW Energy Recovery Technologies
References
American Chemistry Council (ACC). 2015. American Chemistry Council. 2015. 2015 Plastics-To-Fuel
Project Developer's Guide. Washington, DC: American Chemistry Council.
Al-Salem SM, Evangelisti S, and Lettieri P. 2014. Life cycle assessment of alternative technologies for
municipal solid waste and plastic solid waste management in the Greater London area. Chemical
Engineering Journal, 244: 391-402. doi.org/10.1016/j.cej.2014.01.066
Arafat HA, Jijakli K, and Ahsan A. 2015. Environmental performance and energy recovery potential of
five processes for municipal solid waste treatment. Journal of Cleaner Production, 105: 233-240.
doi .org/10.1016/j .j clepro.2013.11.071
Arena U. 2012. Process and technological aspects of municipal solid waste gasification. A review. Waste
Management, 32(4): 625-639. doi.org/10.1016/j.wasman.2011.09.025
Arena U, Ardolino F, and Di Gregorio F. 2015. A life cycle assessment of environmental performances
of two combustion- and gasification-based waste-to-energy technologies. Waste Management, 41: 60-
74. doi.org/10.1016/j.wasman.2015.03.041
Astrup TF, Tonini D, Turconi R, and Boldrin A. 2015. Life cycle assessment of thermal waste-to-
energy technologies: Review and recommendations. Waste Management, 37: 104-115.
doi.org/10.1016/j.wasman.2014.06.011
Chakraborty M, Sharma C, Pandey J, and Gupta P. 2013. Assessment of energy generation potentials
of MSW in Delhi under different technological options. Energy Conversion and Management, 75:
249-255. doi.org/10.1016/j.enconman.2013.06.027
Consonni S and Vigand F. 2012. Waste gasification vs. conventional waste-to-energy: A comparative
evaluation of two commercial technologies. Waste Management, 32(4): 653-666.
doi.org/10.1016/j.wasman.2011.12.019
Del Alamo G, Hart A, Grimshaw A, and Lundstrom P. 2012. Characterization of syngas produced
from MSW gasification at commercial-scale ENERGOS Plants. Waste Management, 32 (10): 1835-
1842. doi.org/10.1016/j.wasman.2012.04.021.
Del Alamo G, Hart A, Grimshaw A, and Lundstrom P. 2012. Characterization of syngas produced
from MSW gasification at commercial-scale ENERGOS Plants. Waste Management, 32(10): 1835-
1842. doi.org/10.1016/j.wasman.2012.04.021.
Duren RM, Thorpe AK, Foster KT, et al. 2019. California's methane super-emitters. Nature (575)
180-184.
Evangelisti S, Lettieri P, Borello D, and Clift R. 2014. Life cycle assessment of energy from waste via
anaerobic digestion: A UK case study. Waste Management, 34(1): 226-237.
doi.org/10.1016/j.wasman.2013.09.013
Evangelisti S, Tagliaferri C, Clift R, Lettieri P, Taylor R, and Chapman C. 2015. Life cycle
assessment of conventional and two-stage advanced energy-from-waste technologies for municipal
solid waste treatment. Journal of Cleaner Production, 100: 212-223.
doi .org/10.1016/j .j clepro.2015.03.062
Ibarrola R, Shackley S, and Hammond J. 2012. Pyrolysis biochar systems for recovering
biodegradable materials: A life cycle carbon assessment. Waste Management, 32(5): 859-868.
doi .org/10.1016/j .wasman.2011.10.005
Ionescu G and Rada EC. 2012. Material and energy recovery in a municipal solid waste system:
practical applicability. International Journal of Environment and Resource, 1(1): 26-30.
63
-------
Assessment of'MSW Energy Recovery Technologies
Ionescu G, Rada EC, Ragazzi M, Marculescu C, Badea A, and Apostol T. 2013. Integrated municipal
solid waste scenario model using advanced pretreatment and waste to energy processes. Energy
Conversion and Management, 76: 1083-1092. doi.org/10.1016/j.enconman.2013.08.049
Jones SB, Snowden-Swan LJ, Meyer PA, Zacher AH, Olarte MV, and Drennan C. 2014. Fast
Pyrolysis and Hydrotreating: 2013 State of Technology R&D and Projections to 2017. Richland, WA:
Pacific Northwest National Laboratory, PNNL-23294.
Kaplan PO, DeCarolis J, and Thorneloe S. 2009. Is it better to burn or bury waste for clean electricity
generation? Environ. Sci. Technol, 43(6): 1711-1717.
Kourkoumpas D-S, Karellas S, Kouloumoundras S, Koufodimos G, Grammelis P, and Kakaras E.
2015. Comparison of waste-to-energy processes by means of life cycle analysis principles regarding
the global warming potential impact: applied case studies in Greece, France and Germany. Waste and
Biomass Valorization, 6(4): 605-621. doi.org/10.1007/s 12649-015-9367-2
Kumar A and Samadder SR. 2017. A review on technological options of waste to energy for effective
management of municipal solid waste. Waste Management, 69: 407-422.
doi .org/10.1016/j .wasman.2017.08.046
Laurent A, Bakas I, Clavreul J, Bernstad A, Niero M, Gentil E, Hauschild MZ, and Christensen
TH. 2014. Review of LCA studies of solid waste management systems - Part I: Lessons learned and
perspectives. Waste Management, 34(3): 573-588. doi.org/10.1016/j.wasman.2013.10.045
Levis JW, Barlaz MA, Themelis NJ, Ulloa P. (2010). Assessment of the state of food waste
treatment in the United States and Canada. Waste Manage., 30(8-9): 1486-1494, DOI:
10.1016/j.wasman.2010.01.031
Michaels T and Shiang I. 2016. 2016 Directory ofWaste-To-Energy Facilities. Arlington, VA: Energy
Recovery Council. http://energvrecovervcouncil.org/wp-content/uploads/2016/05/ERC-2Q16-
directorv.pdf
Moriarty K. 2013. Feasibility Study of Anaerobic Digestion of Food Waste in St. Bernard, Louisiana.
Golden, CO: National Renewable Energy Laboratory, NREL/TP-7A30-57082.
Peischl J, Ryerson TB, Brioude J, et al. 2013. Quantifying sources of methane using light alkanes in
the Los Angeles basin, California. Journal of Geophysical Research: Atmospheres, 118(10): 4974-
4990.
Pressley PN, Aziz TN, DeCarolis JF, Barlaz, He F, Li F, and Damgaard A. 2014. Municipal solid
waste conversion to transportation fuels: a life-cycle estimation of global warming potential and
energy consumption. Journal of Cleaner Production, 70: 145-153.
doi.org/10.1016/j.jclepro.2014.02.041
Ren X, Salmon OE, Hansford JR, et al. 2018. Methane emissions from the Baltimore-Washington Area
based on airborne observations: Comparisons to emissions inventories, Journal of Geophysical
Research: Atmospheres, 123(16). doi.org/10.1029/2018JD028851
Smith RL, Sengupta D, Takkellapati S, and Lee CC. 2015. An industrial ecology approach to
municipal solid waste management: II. Case studies for recovering energy from the organic fraction
of MSW. Resources, Conservation and Recycling, 104, Part A: 317-326.
doi.org/10.1016/j.resconrec.2015.05.016
Thorneloe, S. 2019. Section 22 "Management of Solid Wastes" (22-69 - 22-93) in Perry's Chemical-
Engineers 'Handbook, 9th Edition, New York: McGraw-Hill.
64
-------
Assessment of'MSW Energy Recovery Technologies
US Energy Information Administration (US EIA), 2018. US Energy Information Administration,
2018. How waste-to-energy plants work.
https://\\\v\\ .cia.gov/cncrgvc\plaincd/indc\.php?pagc=biomass waste to cncrgv#tab2
US Environmental Protection Agency (US EPA). 2019. Anaerobic Digestion Facilities Processing
Food Waste in the United States in 2016. EPA/903/S-19/001. Washington, DC: US Environmental
Protection Agency.
US EPA. 2018. Advancing Sustainable Materials Management: 2015 Tables and Figures. Washington,
DC: US Environmental Protection Agency, Office of Resource Conservation and Recovery.
US EPA. 2012. State-of-Practice for Emerging Waste Conversion Technologies. EPA 600/R-12/705.
Research Triangle Park, NC: US Environmental Protection Agency, Office of Research and
Development.
US EPA. 2008. Background Information Document for Updating AP42 Section 2.4 for Estimating
Emissions from Municipal Solid Waste Landfill. EPA/600/R-08-116. Washington DC: US Environmental
Protection Agency.
US EPA. 2007. Evaluation of Fugitive Emissions Using Ground-Based Optical Remote Sensing
Technology. EPA/600/R-07/032. Research Triangle Park, NC: US Environmental Protection Agency.
Wang H, Wang L, and Shahbazi A. 2015. Life cycle assessment of fast pyrolysis of municipal solid
waste in North Carolina of USA. Journal of Cleaner Production, 87: 511-519.
doi.org/10.1016/j.jclepro.2014.09.011
Williams R, Ely C, Marynowicz T, and Kosusko M. 2016. Evaluating the Air Quality, Climate &
Economic Impacts of Biogas Management Technologies. EPA 600/R-16/099. Cincinnati, OH: US
Environmental Protection Agency.
https://nepis.epa.gov/Exe/ZvPDF.cgi/P100QCXZ.PDF?Dockev=P 100QCXZ.PDF
Zaman AU. 2013. Life cycle assessment of pyrolysis-gasification as an emerging municipal solid waste
treatment technology. International Journal of Environmental Science and Technology, 10 (5): 1029-
1038. doi.org/10.1007/s 13762-013-0230-3
MSW Decision Support Tool Documentation
Combs AR. 2012. Life-Cycle Analysis of Recycling Facilities in a Carbon Constrained World. Thesis,
Master of Science. Raleigh, NC: North Carolina State University.
Curtis III EM and Dumas RD. 2007. A Spreadsheet Process Model for Analysis of Costs and Life-Cycle
Inventory Parameters Associated with Collection of Municipal Solid Waste. Raleigh, NC: North
Carolina State University.
Eleazer WE, Odle WS, Wang YS, and Barlaz MA. 1997. Biodegradability of municipal solid waste
components in laboratory-scale landfills. Environmental. Science & Technology, 31: 911-917.
Hodge KL, Levis JW, DeCarolis JF, Barlaz MA. 2016. A systematic evaluation of industrial, commercial,
and institutional food waste management strategies in the US Environ. Sci. Technol. 50(16): 8444-
8452, DOI: 10.1021/acs.est.6b00893
Jaunich MK, Levis JW, Barlaz MA, and DeCarolis JD. 2016. Lifecycle process model for municipal
solid waste collection. Journal of Environmental Engineering. 142(8, August).
Jaunich MK, Levis JW, DeCarolis JF, Gaston EV, Barlaz MA, Bartelt-Hunt SL, Jones EG, Hauser L, and
Jaikumar R. 2016b. Characterization of municipal solid waste collection operations. Resourc.
Conserv. Recyc., 114: 92-102, DOI: 10.1016/j.resconrec.2016.07.012
65
-------
Assessment of MSW Energy Recovery Technologies
Komilis DP, Ham RK. 2004. Life-cycle inventory of municipal solid waste and yard waste windrow
composting in the United States. J. Env. Eng., 130(11), 1390-1400.
Kosmicki B. 1997. Transfer Station Process Model. Raleigh, North Carolina: North Carolina State
University.
Levis J and Barlaz MA. 2014. Landfill Gas Monte Carlo Model Documentation and Results June 18,
2014. Report to ICF for the US EPA Waste Reduction Model (WARM). Available at:
https://19january2017snapshot.epa.gov/sites/production/files/2016-
03//1 anfl_gas_mont_carlo_modl.pdf
Levis JW, Barlaz MA, DeCarolis JF, Ranjithan SR. 2013. A generalized multistage optimization modeling
framework for life cycle assessment-based integrated solid waste management. Environ. Model!.
Softw., 50(2013): 51-65.
Levis J and Barlaz MA. 2013a. Composting Process Model Documentation. Raleigh, NC: North Carolina
State University.
Levis J and Barlaz M. 2013b. Anaerobic Digestion Process Model Documentation. Raleigh, NC: North
Carolina State University.
Nishtala SR. 1995. Design and Analysis of Material Recovery Facilities in an Integrated Solid Waste
Management System. Raleigh, North Carolina: North Carolina State University.
North Carolina State University. (1998). WTE Process Model Documentation. Available at:
https://mswdst.rti.org/docs/WTE Model OCR.pdf
Pressley PN, Levis JW, Damgaard A, Barlaz MA, DeCarolis JF. 2014. Analysis of material recovery
facilities for use in life-cycle assessment. Waste Management, 35:307-317.
doi: 10.1016/j.wasman.2014.09.012
RTI International. 2003. Life-Cycle Inventory Data Sets for Material Production of Aluminum, Glass,
Paper, Plastic, and Steel in North America. Prepared for EPA, Office of Research and Development,
Research Triangle Park, NC.
US EPA. 2011. Background Information Document for Life-Cycle Inventory Landfill Process Model.
Prepared by North Carolina State University and Eastern Research Group, Inc. under EPA Contract
No. EP-C-07-015. Available at: http://www4.ncsu.edu/~iwlevis/Landfill-2011.pdf: accessed as of
8/1/2018.
US EPA. 2003. A Laboratory Study to Investigate Gaseous Emissions and Solids Decomposition During
Composting of Municipal Solid Wastes. EPA-600/R-03-004. Research Triangle Park, NC: US
Environmental Protection Agency, Office of Research and Development..
66
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Attachment A:
Listing of Waste-To-Energy Facilities in the US
Primary> Sources:
Michaels and Shiang. 2016. 2016 Directory ofWaste-To-Energy Facilities, http://cncrgvrccovcrvcouncil.org/wp-
content/uploads/2016/05/ERC-2016-directorv.pdf
US Energy Information Administration. EIA-860, Annual Electric Generator Report, 2017. https://www.eia.gov/electricitv/data/eia860/
technology
type
Site name
Operator
City
State
Included as a WTE facility in the US
EIA 2017 Electric Generator Report
mass bum
Huntsville Waste-to-Energy Facility
Covanta Huntsville, Inc
Huntsville
AL
No. The generated steam goes to the U.S.
Army's Redstone Arsenal.
mass bum
Southeast Resource Recovery Facility
Covanta Long Beach Renewable Energy
Corp.
Long Beach
CA
yes
mass bum
Stanislaus County Resource Recovery Facility
Covanta Stanislaus, Inc.
Crows
CA
yes
mass bum
Bristol Resource Recovery Facility
Covanta Bristol, Inc.
Bristol
CT
yes
RDF
Mid-Connecticut Resource Recovery Facility
NAES Corp.
Harford
CT
yes
mass bum
Southeastern Connecticut Resource Recovery
Facility
Covanta Company Southeastern CT
Preston
CT
yes
mass bum
Wheelabrator Bridgeport
Wheelabrator Bridgeport, L.P.
Bridgeport
CT
yes
mass bum
Wheelabrator Lisbon
Wheelabrator Lisbon, Inc.
Lisbon
CT
yes
mass bum
Bay County Waste-to-Energy Facility
Engen, LLC
Panama City
FL
yes
mass bum
Flillsborough Comity Resource Recovery Facility
Covanta Hillsborough, Inc.
Tampa
FL
yes
mass bum
Lake County Resource Recovery Facility
Covanta lake, Inc.
Okahumpka
FL
yes
mass bum
Lee County Resource Recovery Facility
Covanta Lee, Inc.
Fort Meyers
FL
yes
RDF
Miami-Dade County Resource Recovery Facility
Covanta Dade Renewable Energy, LLC
Miami
FL
yes
RDF
Palm Beach Renewable Energy Facility #1
Babcock & Wilcox
West Palm
Beach
FL
yes
mass bum
Palm Beach Renewable Energy Facility #2
Babcock & Wilcox
West Palm
Beach
FL
yes
mass bum
Pasco County Solid Waste Resource Recovery
Covanta Pasco, Inc.
Spring Hill
FL
yes
mass bum
Pinellas County Resource Recovery Facility
Covanta Pinellas, Inc.
St. Petersburg
FL
yes
67
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Assessment ofMSW Energy Recovery Technologies
technology
type
Site name
Operator
City
State
Included as a WTE facility in the US
EIA 2017 Electric Generator Report
mass burn
McKay Bay Refuse-to-Energy Facility
Wheelabrator Mckay Bay, Inc.
Tampa
FL
yes
mass burn
Wheelabrator South Broward, Inc.
Wheelabrator South Broward, Inc.
Ft. Lauderdale
FL
yes
RDF
mass burn
Honolulu Resource Recovery Venture- HPOWER
Covanta Honolulu Resource Recovery
Venture
Kapolei
HI
yes
mass burn
Indianapolis Resource Recovery Facility
Covanta Indianapolis, Inc.
Indianapolis
IN
yes
RDF
Arnold O. Chantland Resource Recovery Plant
(also called the Ames Resource Recovery Plant)
City of Ames
Ames
IA
No. The Ames Electric Services Power
Plant is included, and it burns RDF from
the Ames Resource Recovery Plant
mass burn
Regional Waste Systems
Ecomaine
Portland
ME
yes
mass burn
Mid-Maine Waste Action Corporation
Mid-Maine Waste Action Corporation
Auburn
ME
yes
RDF
Penobscot Energy Recovery Company
ESOCO Orrington, LLC
Orrington
ME
yes
mass burn
Montgomery County Resource Recovery Facility
Covanta Montgomery, Inc.
Dickerson
MD
yes
mass burn
Wheelabrator Baltimore
Wheelabrator Baltimore, L.P.
Baltimore
MD
yes
mass burn
Haverhill Resource Recovery Facility
Covanta Haverhill, Inc.
Haverhill
MA
yes
Modular
Pioneer Valley Resource Recovery Facility
Covanta Springfield, LLC
Agawam
MA
yes
RDF
SEMASS Resource Recovery Facility
Covanta SEMASS, L.P.
West
MA
yes
mass burn
Wheelabrator Millbury
Wheelabrator Millbury, Inc.
Millbury
MA
yes
mass burn
Pittsfield Resource Recovery Facility
Covanta Pittsfield, LLC
Pittsfield
MA
yes
mass burn
Wheelabrator North Andover
Wheelabrator North Andover, Inc.
North
Andover
MA
yes
mass burn
Wheelabrator Saugus
Wheelabrator Saugus, Inc.
Saugus
MA
yes
RDF
Detroit Renewable Power
Detroit Renewable Energy, LLC
Detroit
MI
yes
mass burn
Kent County Waste-to-Energy Facility
Covanta Kent, Inc.
Grand Rapids
MI
yes
mass burn
Hennepin Energy Resource Center (HERC)
Covanta Hennepin Energy Resource
Minneapolis
MN
yes
mass burn
Olmsted Waste-to-Energy Facility (OWEF)
Olmsted County
Rochester
MN
yes
mass burn
Perham Resource Recovery Facility
Prairie Lakes Municipal Solid Waste
Perham
MN
yes
Modular
Polk County Solid Waste Resource Recovery
Facility
Polk County
Fosston
MN
No. The steam goes to 3 nearby
customers
mass burn
Pope/Douglas Waste-to-Energy Facility
Pope/Douglas Solid Waste Point Powers
Board
Alexandria
MN
No. The steam is used by a 3M
manufacturing plant, a nearby hospital,
and school.
RDF
Red Wing Steam Plant
Northern States Power Co - Minnesota
Red Wing
MN
yes
68
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Assessment ofMSW Energy Recovery Technologies
technology
type
Site name
Operator
City
State
Included as a WTE facility in the US
EIA 2017 Electric Generator Report
RDF
Wilmarth Plant
Northern States Power Co - Minnesota
Mankato
MN
yes
mass burn
Wheelabrator Concord
Wheelabrator Concord, L.P.
Penacook
NH
yes
mass burn
Covanta Camden Energy Recovery Center
Covanta Camden GP, LLC
Camden
NJ
yes
mass burn
Essex County Resource Recovery Facility
Covanta Essex Company
Newark
NJ
yes
mass burn
Union County Resource Recovery Facility
Covanta Union, LLC
Rahway
NJ
yes
mass burn
Wheelabrator Gloucester Company
Wheelabrator Gloucester Company, L.P.
Westville
NJ
yes
mass burn
Babylon Resource Recovery Facility
Covanta Babylon, Inc.
West Babylon
NY
yes
mass burn
Covanta Flempstead
Covanta Hempstead Co.
Westbury
NY
yes
mass burn
Dutchess County Resource Recovery Facility
Wheelabrator Dutchess County
Poughkeepsie
NY
yes
mass burn
Fluntington Resource Recovery Facility
Covanta Huntington
East Northport
NY
yes
mass burn
MacArthur Waste-to-Energy Facility
Covanta MacArthur Renewable Energy,
Ronkonkoma
NY
yes
mass burn
Niagara Falls Resource Recovery Facility
Covanta Niagara company
Niagara Falls
NY
yes
mass burn
Onondaga Resource Recovery Facility
Covanta Onondaga, L.P.
Jamesville
NY
yes
Modular
Oswego County Energy Recovery Facility
Oswego County
Fulton
NY
yes
mass burn
Wheelabrator Fludson Falls
Wheelabrator Hudson Falls, LLC
Hudson Falls
NY
yes
mass burn
Wheelabrator Westchester
Wheelabrator Westchester, L.P.
Peekskill
NY
yes
Mass Burn
Covanta Tulsa Renewable Energy Facility
Covanta Tulsa Renewable Energy, LLC
Tulsa
OK
yes
mass burn
Marion County Solid Waste-to-Energy Facility
Covanta Marion, Inc.
Brooks
OR
yes
mass burn
Covanta Plymouth Renewable Energy
Covanta Plymouth Renewable Energy
Conshohocken
PA
yes
mass burn
Delaware Valley Resource Recovery Facility
Covanta Delaware Valley, L.P.
Chester
PA
yes
mass burn
Lancaster County Resource Recovery Facility
Covanta Lancaster, Inc.
Bainbridge
PA
yes
mass burn
Susquehanna Resource Management Complex
Covanta Harrisburg, Inc.
Harrisburg
PA
yes
mass burn
Wheelabrator Falls
Wheelabrator Falls Inc.
Morrisville
PA
yes
mass burn
York County Resource Recovery Center
Covanta York Renewable Energy LLC
York
PA
yes
mass burn
Alexandria/Arlington Resource Recovery Facility
Covanta Arlington/Alexandria, Inc.
Alexandria
VA
yes
mass burn
Flampton-NASA Steam Plant
City of Hampton
Hampton
VA
No. The steam is used directly by NASA
mass burn
1-95 Energy/Resource Recovery Facility (Fairfax)
Covanta Fairfax, Inc.
Lorton
VA
yes
RDF
Wheelabrator Portsmouth
Wheelabrator Portsmouth Inc.
Portsmouth
VA
yes
Mass Burn
Spokane Waste-to-Energy Facility
City of Spokane
Spokane
WA
yes
Modular
Truman Barron County Waste-to-Energy & Recycling Facility
Almena
WI
No. The steam goes to Saputo Cheese
69
-------
Assessment ofMSW Energy Recovery Technologies
technology
type
Site name
Operator
City
State
Included as a WTE facility in the US
EIA 2017 Electric Generator Report
RDF
French Island Generating Station
Northern States Power Co - Minnesota
La Crosse
WI
No. Categorized as combusting
wood/wood waste biomass.
Facilities that have recently closed
RDF
Great River Energy - Elk River Station
Great River Energy
Maple Grove
MN
Yes. Closed 201979
mass bum
Covanta Warren Energy Resource Facility
Covanta Warren Energy Resource Co.
Oxford
N.T
Yes. Closed 2019.80
mass bum
Commerce Refuse-to-Energy Facility
Sanitation District of Los Angeles
Commerce
CA
Yes, but then closed June 2018
mass bum
Davis Energy Recovery Facility
Wasatch Integrated Waste Management
Layton
UT
No. Closed May 2017
79 EE Online. Great River Energy: Elk River project stops operations, prepares for closure. Feb. 25, 2019.
https://electricenergvonline.com/article/energv/categorv/biofuel/83/750958/elk-river-proiect-stops-operations-prepares-for-closure.html
811 Leliighvalleylive.com Covanta has shut down its Warren County trash incinerator. But it might not be permanent. 4 April 2019.
https://www.leliighvallevlive.com/warren-countv/2019/04/covanta-has-shut-down-its-warren-countv-trash-incinerator-but-it-might-not-be-pennanent.html
70
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Attachment B:
Listing of Stand-Alone and Co-Digestion Facilities in the US
Stand-Alone Facilities
Location
Multi-Source
(MS)/lndustry-Dedicated
(ID)/Other*
Facilities currently operating
Ralphs Recovery System
Compton, CA
ID
Fairfield Brewery BTS
Fairfield, CA
ID
MillerCoors Brewery
Irwindale, CA
ID
Zero Waste Energy -Monterey
Marina, CA
MS
North State Rendering Co. Inc./John S. Ottone
Oroville, CA
MS
Gills Onions
Oxnard, CA
ID
CleanWorld SATS
Sacramento, CA
MS
Kompogas SLO LLC
San Luis Obispo, CA
MS
Zero Waste Energy Development Company
San Jose, CA
MS
Blue Line Biogenic CNG Facility
South San Francisco, CA
MS
LA BTS
Van Nuys, CA
ID
Quantum Biopower
Southington, CT
MS
Harvest Power Orlando
Bay Lake, FL
MS
Jacksonville BTS
Jacksonville, FL
ID
Cartersville BTS
Cartersville, GA
ID
City of Waterloo Anaerobic Lagoon
Waterloo, IA
OTHER
Waste No Energy, LLC
Monticello, IN
MS
Stop & Shop Freetown Distribution Center
Assonet, MA
ID
Garelick Farms
Franklin, MA
ID
CRMC Bioenergy Facility
New Bedford, MA
OTHER
Generate Fremont Digester, LLC
Fremont, Ml
MS
Hometown BioEnergy
Le Sueur, MN
MS
St. Louis BTS
St. Louis, MO,
ID
Full Circle Recycle
Zebulon, NC
MS
Merrimack BTS
Merrimack, NH
ID
Newark BTS
Newark, NJ
ID
Lassonde Pappas
Seabrook, NJ
ID
AB-lnbev Baldwinsville
Baldwinsville, NY
ID
Buffalo BioEnergy
West Seneca, NY
MS
Generate Niagara Digester
Wheatfield, NY
MS
Emerald BioEnergy
Cardington, OH
MS
Collinwood BioEnergy
Cleveland, OH
OTHER
Central Ohio BioEnergy
Columbus, OH
MS
Columbus BTS
Columbus, OH
ID
Dovetail Energy
Fairborn, OH
MS
Campbell Soup Supply Company
Napoleon, OH
ID
Three Creek BioEnergy, LLC
Sheffield Village, OH
MS
Buckeye Biogas, LLC
Wooster, OH
MS
Zanesville Energy, LLC
Zanesville, OH
MS
Stahlbush Island Farms
Corvallis, OR
OTHER
Yuengling Beer Company
Pottsville, PA
ID
71
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Assessment of MSW Energy Recovery Technologies
Stand-Alone Facilities
Location
Multi-Source
(MS)/lndustry-Dedicated
(ID)/Other*
Bush Brothers and Company Process Water Recovery
Dandridge, TN
ID
Houston BTS
Houston, TX
ID
Magic Hat Resource Recovery Center
South Burlington, VT
MS
FCPC Renewable Generation
Milwaukee, Wl
MS
Urban Dry Digester - UW Oshkosh
Oshkosh, Wl
MS
Facilities Under Development
CleanWorld/UC Davis Renewable Energy Anaerobic
Davis, CA
Temporary Shut-Down
Agromin Organic Recycling Compost Facility
Oxnard, CA
Planning stage; Design
Organic Energy Systems (OES)
San Bernardino, CA
Procurement
Tajiguas Resource Recovery Project
Santa Barbara, CA
Planning stage; Design
Turning Earth LLC
Southington, CT
Fully permitted, seeking
BTS Biogas LLC-Maryland Food Center
Jessup, MD
Under Construction
Orbit Energy Charlotte
Charlotte, NC
Start-up Mode
Linden Renewable Energy
Linden, NJ
Planning stage; Design
Gloucester City Organic Recycling
Marlton, NJ
Under Construction
Point Breeze Renewable Energy
Philadelphia, PA
Planning stage; Design
Orbit Energy Rhode Island
Johnston, Rl
Start-up Mode
Freestate Farms Integrated Facility
Manassas, VA
Planning stage; Design
Facilities That Have Ceased Operations
Heartland Biogas
LaSalle, CO
CR&R
Perris, CA
Garelick Farms
Lynn, MA
* "OTHER" represents two industry dedicated digesters that accept outside feedstocks periodically.
1. Source: US EPA, 2019
On-Farm Digesters Co-Digesting Food Waste
Location
Facilities Currently Operating
Green Cow Power
Goshen, IN
BioTown Ag
Reynolds, IN
Rutland AD1
Rutland, MA
Exeter Agri-Energy/Stonyvale Farm
Exeter, ME
Patterson Farms Inc.
Auburn, NY
Noblehurst Green Energy
Linwood, NY
Oregon Dairy Farm LLC
Lititz, PA
Reinford Farms
Mifflintown, PA
Oak Hill Farm
Nottingham, PA
Chaput Family Farms
North Troy, VT
Vermont Technical College Anaerobic Digester
Randolph Center, VT
Vander Haak Dairy
Lynden, WA
Qualco Energy
Monroe, WA
Holsum Elm Dairy
Hilbert, Wl
Holsum Irish Dairy
Hilbert, Wl
Allen Farms
Oshkosh, Wl
Facilities That Have Ceased Operations
Zuber Farms
Byron, NY
72
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Assessment of MSW Energy Recovery Technologies
On-Farm Digesters Co-Digesting Food Waste
Location
George Deruyter Dairy
Outlook, WA
Wild Rose Dairy
LaFarge, Wl
Source: US EPA, 2019
Co-Digestion at WWTP Facilities
Location
Facilities Currently Operating
Fourche Creek Water Reclamation Facility
Little Rock, AR
Wildcat Hill Wastewater Treatment Plant
Flagstaff, AZ
Delta Diablo WWTP
Antioch, CA
Bakersfield Wastewater Treatment Plant # 2
Bakersfield, CA
Bakersfield Wastewater Treatment Plant # 3
Bakersfield, CA
Hill Canyon Wastewater Treatment Plant
Camarillo, CA
Encina Wastewater Authority (EWPCF)
Carlsbad, CA
Joint Water Pollution Control Plant
Carson, CA
Sacramento Regional Wastewater Treatment Plant
Elk Grove, CA
Fairfield-Suisun Sewer District
Fairfield, CA
Fresno-Clovis RWRF
Fresno, CA
City of Hayward Water Pollution Control Facility
Hayward, CA
Napa Sanitation District
Napa, CA
East Bay Municipal Utility District Main Wastewater Treatment Plant
Oakland, CA
Silicon Valley Clean Water
Redwood City, CA
Oro Loma Sanitary District
San Lorenzo, CA
Central Marin Sanitation Agency
San Rafael, CA
El Estero WWTP
Santa Barbara, CA
Santa Rosa Regional Water Reuse Plant (Laguna Treatment Plant)
Santa Rosa, CA
Victor Valley Wastewater Reclamation Authority
Victorville, CA
City of Watsonville WWTP
Watsonville, CA
Santa Rita Wastewater Reclamation Plant (City of Durango WWTP)
Durango, CO
South Cross Bayou Advanced Water Reclamation Facility
St. Petersburg, FL
Thomas P Smith Water Reclamation Facility (TPS Treatment Plant)
Tallahassee, FL
F. Wayne Hill Water Resources Center
Buford, GA
South Columbus Water Treatment Facility
Columbus, GA
Lower Poplar Street Water Reclamation Facility
Macon, GA
Ames Water Pollution Control Plant
Ames, IA
Davenport Water Pollution Control Plant
Davenport, IA
Des Moines Metropolitan Wastewater Reclamation Authority
Des Moines, IA
Dubuque Water & Resource Recovery Center
Dubuque, IA
Downers Grove Sanitary District Wastewater Treatment Center
Downers Grove, IL
Rock River Water Reclamation District
Rockford, IL
Urbana & Champaign Sanitary District
Urbana, IL
West Lafayette Wastewater Treatment Facility
West Lafayette, IN
DLS Middle Basin Wastewater Treatment Plant
Overland Park, KS
Greater Lawrence Sanitary District
North Andover, MA
Lewiston-Auburn Water Pollution Control Authority
Lewiston, ME
Delhi Charter Township Wastewater Treatment Plant
Holt, Ml
Flint Biogas Plant
Flint, Ml
St. Cloud Nutrient, Energy and Water Recovery Facility
St. Could, MN
73
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Assessment of MSW Energy Recovery Technologies
Co-Digestion at WWTP Facilities
Location
City of Springfield Southwest Wastewater Treatment Plant
Springfield, MO
Joint Meeting of Essex & Union Counties
Elizabeth, NJ
Rahway Valley Sewerage Authority
Rahway, NJ
Landis Sewerage Authority
Vineland, NJ
Newtown Creek Wastewater Resource Recovery Facility
Brooklyn, NY
LeRoy R. Summerson Wastewater Treatment Facility
Cortland, NY
Gloversville Johnstown Joint Wastewater Treatment Facility
Johnstown, NY
City of London Wastewater Treatment Plant
London, OH
City of Wooster Water Resource Recovery Facility
Wooster, OH
Gresham Wastewater Treatment Plant
Gresham, OR
City of Pendleton Wastewater Treatment Facility
Pendleton, OR
Clean Water Services -Durham Advanced Wastewater Treatment Facility
Tigard, OR
Hermitage Municipal Authority
Hermitage, PA
Derry Township Municipal Authority
Hershey, PA
Milton Regional Sewer Authority
Milton, PA
New Castle Sanitation Authority
New Castle, PA
Mauldin Road Water Resource Recovery Facility
Greenville, SC
Southside Wastewater Treatment Plant
Dallas, TX
Waco Metro -Area Regional Sewage System
Waco, TX
North River Wastewater Treatment Facility
Mt. Crawford, VA
Opequon Water Reclamation Facility
Winchester, VA
Village of Essex Junction Water Resource Recovery Facility
Essex Junction, VT
Appleton Wastewater Treatment Plant
Appleton, Wl
Fond du Lac Regional Wastewater Treatment & Resource Recovery Facility
Fond du Lac, Wl
City of Kiel Wastewater Facility
Kiel, Wl
MMD South Shore Water Reclamation Facility
Oak Creek, Wl
City of Port Washington Wastewater Treatment Plant
Port Washington, Wl
City of Rice Lake Wastewater Treatment Plant
Rice Lake, Wl
Stevens Point Wastewater Treatment Plant
Stevens Point, Wl
City of West Bend Wastewater Treatment Plant
West Bend, Wl
Wisconsin Rapids Wastewater Treatment Facility
Wisconsin Rapids, Wl
Facilities Under Development
South Slope Wastewater Treatment Plant
Planning stage; Design stage;
Moline, IL
Kinross Township Wastewater Treatment Plant
Under Construction
Kincheloe, Ml
Western Lake Superior Sanitary District
Planning stage; Design stage;
Duluth, MN
Empire Wastewater Treatment Plant
Under Construction
Farmington, MN
Village of Ridgewood Water Pollution Control Facility
Temporary Shut-down
Glen Rock, NJ
Rome Water Pollution Control Facility
Planning stage; Design stage;
Rome, NY
City of Newark Wastewater Treatment Plant
Temporary Shut-down
Newark, OH
Green Bay Metropolitan Sewerage District
Under Construction
Green Bay, Wl
Facilities That Have Ceased Operations
Hyperion Treatment Plant
Playa Del Rey, CA
Metropolitan Syracuse Wastewater Treatment Plant
Syracuse, NY
Struthers Wastewater Treatment Plant
Struthers, OH
Janesville Wastewater Treatment Plant
Janesville, Wl
Sheboygan Wastewater Treatment Plant
Sheboygan, Wl
Source: US EPA, 2019
74
-------
Assessment of 'MSW Energy Recovery Technologies
Attachment C:
Definitions
Anaerobic Digestion (AD) - decomposition of biodegradable waste in oxygen depleted conditions to
biogas and solid residue (digestate)81
Conversion technologies - waste treatment technologies that do not directly combust MSW feedstock
but rather convert it via partial-oxygen or oxygen absent thermochemical or biological processes. The
resulting gases can be combusted to produce electricity or further processed into a liquid fuel or chemical
commodity product.
Energy recovery ~ conversion of waste materials into usable heat, electricity, or fuel through a variety of
processes, including combustion, gasification, pyrolysis, anaerobic digestion and landfill gas recovery.
Gasification -thermal decomposition of waste in a controlled oxygen environment that converts any
material containing carbon - such as coal, petroleum or biomass - into synthesis gas (syngas) composed
of hydrogen and carbon monoxide. The syngas can be then burned to produce electricity or further
processed to produce vehicle fuel.82
Mass burn combustion (or waste to energy) -burning of MSW in a confined and controlled
environment, typically in a single combustion chamber under conditions of excess air, to produce steam
that is used to generate electricity or combined heat and power83. Mass burn often includes recovery of
ferrous and other metals prior to disposal of combustion ash.
Material Recovery Facility: a facility where comingled recycling streams and/or solid waste is sorted to
recover materials for recycling.84
MSW Landfill: an entire disposal facility in a contiguous geographical space where household waste is
placed in or on land. An MSW landfill may also receive other types of RCRA Subtitle D wastes (§ 257.2
of this title) such as commercial solid waste, nonhazardous sludge, conditionally exempt small quantity
generator waste, industrial solid waste and coal combustion residuals.
Municipal Solid Waste: discards from residential and commercial sources that include durable and
nondurable goods including paper, plastic glass, metal, food scraps, yard trimmings, and other inorganic
and organic materials. MSW does not contain regulated hazardous wastes. (MSW = Residential +
Commercial), U.S. EPA National Measurement Workgroup, 2013.85
Organic Materials: the remains, residues or waste products of any organic materials that are components
of the solid waste disposal stream. Such materials may include but are not limited to food residuals; yard
debris; and wood, plant or paper products. This term does not include metals, glass, or petroleum-based
plastic (U.S. EPA National Measurement Workgroup, 2013).
81 Gershman, Brickner & Bratton, Inc. Presentation for Arizona Tribal Energy Association on Waste to Energy
Technologies. January 2018
82 EPA Webpage https://www.epa.gov/smm/energv-recoverv-combustion-municipal-solid-waste-msw
83 EPA Webpage https://www.epa.gov/smm/energv-recoverv-combustion-municipal-solid-waste-msw
84 UC Berkeley School of Law. "Wasting Opportunities: How to Secure Environmental & Clean Energy Benefits
from Municipal Solid Waste Energy Recovery." May 2016
85 US EPA. State Measurement Template Definitions, https://www.epa.gov/sites/production/files/2015-
09/documents/smp definitions.pdf
75
-------
Assessment of 'MSW Energy Recovery Technologies
Pyrolysis - an endothermic process, also referred to as cracking, using heat to thermally decompose
carbon-based material in the absence of oxygen, into pyrolysis oil, syngas, and other byproducts (such as
char, tar or flue gas).86
Refuse-derived fuel -mechanically shredded MSW that is processed to separate out non-combustible
materials and produce a combustible mixture in loose or pelletized form that is suitable as a fuel in a
dedicated furnace or as a supplemental fuel in a conventional boiler system.87
Syngas - synthesis gas, produced by gasification or pyrolysis, which is composed of hydrogen, carbon
monoxide and carbon dioxide.88
86 UC Berkeley School of Law. "Wasting Opportunities: How to Secure Environmental & Clean Energy Benefits
from Municipal Solid Waste Energy Recovery." May 2016.
87 EPA Webpage https://www.epa.gov/smin/energv-recoverv-combustion-municipal-solid-waste-msw
88 UC Berkeley School of Law. "Wasting Opportunities: How to Secure Environmental & Clean Energy Benefits
from Municipal Solid Waste Energy Recovery." May 2016.
76
-------
Assessment of MSW Energy Recovery Technologies
Attachment D:
Pyrolysis Life Cycle Inventory Data Compiled from the Literature
77
-------
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Input
n/a
Aggregate
kg
11.6
11.6
11.6
Input
n/a
Air
kg
400
400
400
Input
n/a
Aluminium
kg
0.0016
0.0016
0.0016
Input
n/a
Calcium oxide
kg
46.0
46.0
46.0
Input
n/a
Chromium
kg
0
0
0
Input
n/a
Clay
kg
3.95
3.95
3.95
Input
n/a
Copper
kg
0.0015
0.0015
0.0015
Input
n/a
Electricity
MJ
0.21
810
1,620
Input
n/a
Fossil energy
MJ
1,040
2,872
3,910
Input
n/a
Iron
kg
0.0091
0.0091
0.0091
Input
n/a
Limestone, calcium carbonate
kg
10.9
10.9
10.9
Input
n/a
Manganese
kg
0
0
0
Input
n/a
Naphtha
MJ
131
131
131
Input
n/a
Ni catalyst
kg
0.19
0.19
0.19
Input
n/a
Nickel
kg
0
0
0
Input
n/a
Pyrite
kg
0
0
0
Input
n/a
Rock
kg
65.7
65.7
65.7
Input
n/a
Sand
kg
0.0099
4.25
8.50
Input
n/a
Sodium chloride
kg
0.010
0.010
0.010
Input
n/a
Soil
kg
0.24
0.24
0.24
Input
n/a
Water
kg
0
1,271
3,300
Input
n/a
Zeolite
kg
1.20
1.20
1.20
Input
n/a
Zinc
kg
0
0
0
Output
(blank)
Calcium chloride
kg
17.0
17.0
17.0
Output
(blank)
Calcium oxide
kg
40.0
40.0
40.0
Output
air
Ammonia
kg
0
0
0
Output
air
Argon
kg
11.7
11.7
11.7
78
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
air
Butadiene
kg
0.67
0.67
0.67
Output
air
Butane
kg
1.88
1.88
1.88
Output
air
Butene
kg
0.80
0.80
0.80
Output
air
Carbon dioxide
kg
370
730
1,090
Output
air
Carbon monoxide
kg
0.18
14.8
29.5
Output
air
Ethane
kg
0.94
0.94
0.94
Output
air
Formic acid
kg
3.2E-05
3.2E-05
3.2E-05
Output
air
GHG, biogenic (C02 eq)
kg
1,035
1,035
1,035
Output
air
GHG, fossil (C02 eq)
kg
230
240
250
Output
air
Hydrocarbons, unspecified
kg
5.5E-05
5.5E-05
5.5E-05
Output
air
Hydrogen
kg
0
1.34
2.68
Output
air
Hydrogen sulphide
kg
0.012
0.012
0.012
Output
air
Iron
kg
1.6E-05
1.6E-05
1.6E-05
Output
air
Lead
kg
5.0E-06
5.0E-06
5.0E-06
Output
air
Manganese
kg
6.1E-06
6.1E-06
6.1E-06
Output
air
Mercury
kg
1.3E-06
1.3E-06
1.3E-06
Output
air
Methane
kg
0.14
6.77
13.4
Output
air
Methane, biogenic
kg
3.0E-05
3.0E-05
3.0E-05
Output
air
Nickel
kg
2.8E-06
2.8E-06
2.8E-06
Output
air
Nitrogen
kg
310
310
310
Output
air
Nitrogen dioxide
kg
3.7E-05
3.7E-05
3.7E-05
Output
air
Nitrogen monoxide
kg
0
0
0
Output
air
Nitrogen oxides
kg
0.39
0.39
0.39
Output
air
Nitrogen, atmospheric
kg
4,350
4,350
4,350
Output
air
Nitrogentriflouride
kg
0
0
0
Output
air
Nitrous oxide
kg
0
0
0
Output
air
NMVOC
kg
0.016
0.016
0.016
79
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
air
Oxygen
kg
60.0
3,925
7,790
Output
air
Particles
kg
0.013
0.013
0.013
Output
air
PM 10
kg
4.9E-04
4.9E-04
4.9E-04
Output
air
PM 2.5
kg
3.3E-04
3.3E-04
3.3E-04
Output
air
Propane
kg
1.88
1.88
1.88
Output
air
Propene
kg
1.34
1.34
1.34
Output
air
Selenium
kg
4.7E-06
4.7E-06
4.7E-06
Output
air
Steam
kg
330
330
330
Output
air
Sulphur
kg
0
0
0
Output
air
Sulphur dioxide
kg
0.44
0.44
0.44
Output
air
Tin
kg
4.1E-06
4.1E-06
4.1E-06
Output
air
Titanium
kg
9.1E-06
9.1E-06
9.1E-06
Output
air
Vanadium
kg
6.4E-06
6.4E-06
6.4E-06
Output
air
VOC, unspecified
kg
0
0
0
Output
air
Water
kg
240
240
240
Output
air
Zinc
kg
9.1E-06
9.1E-06
9.1E-06
Output
energy
Steam
MJ
1,480
1,480
1,480
Output
fresh water
Aluminium
kg
0.74
0.74
0.74
Output
fresh water
Ammonia
kg
1.2E-04
1.2E-04
1.2E-04
Output
fresh water
Ammonium
kg
0
0
0
Output
fresh water
Antimony
kg
0.017
0.017
0.017
Output
fresh water
Barium
kg
1.1E-04
1.1E-04
1.1E-04
Output
fresh water
BOD
kg
1.17
1.17
1.17
Output
fresh water
Boron
kg
190
190
190
Output
fresh water
Bromate
kg
0
0
0
Output
fresh water
Bromine
kg
1,870
1,870
1,870
Output
fresh water
Calcium
kg
0.67
0.67
0.67
80
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
fresh water
Carbon disulphide
kg
0
0
0
Output
fresh water
Carbonate
kg
4.9E-04
4.9E-04
4.9E-04
Output
fresh water
Chlorate
kg
0
0
0
Output
fresh water
Chloride
kg
0.16
0.16
0.16
Output
fresh water
Chlorine, dissolved
kg
3.7E-04
3.7E-04
3.7E-04
Output
fresh water
Chromium
kg
0.011
0.011
0.011
Output
fresh water
Copper
kg
0.0098
0.0098
0.0098
Output
fresh water
DOC
kg
1.41
1.41
1.41
Output
fresh water
Fluoride
kg
32,600
32,600
32,600
Output
fresh water
Heavy metals
kg
0.019
0.019
0.019
Output
fresh water
Iron
kg
0.011
0.011
0.011
Output
fresh water
Lead
kg
0.0028
0.0028
0.0028
Output
fresh water
Magnesium
kg
0.052
0.052
0.052
Output
fresh water
Manganese
kg
0.0010
0.0010
0.0010
Output
fresh water
Nitrate
kg
15,100
15,100
15,100
Output
fresh water
Nitrogen
kg
0
0
0
Output
fresh water
Nitrogen, organic bounded
kg
1.5E-04
1.5E-04
1.5E-04
Output
fresh water
Particles
kg
0.034
0.034
0.034
Output
fresh water
Phosphate
kg
481
481
481
Output
fresh water
Phosphorus
kg
0
0
0
Output
fresh water
Potassium
kg
366,000
366,000
366,000
Output
fresh water
Sodium
kg
338,000
338,000
338,000
Output
fresh water
Sodium hypochlorite
kg
0
0
0
Output
fresh water
Sodium sulphate
kg
0
0
0
Output
fresh water
Solids, suspended
kg
3.37
3.37
3.37
Output
fresh water
Strontium
kg
0
0
0
Output
fresh water
Sulphate
kg
316,000
316,000
316,000
81
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
fresh water
Sulphide
kg
0
0
0
Output
fresh water
Tin
kg
0.0010
0.0010
0.0010
Output
fresh water
TOC
kg
1.41
1.41
1.41
Output
fresh water
Vanadium
kg
0.0020
0.0020
0.0020
Output
fresh water
Zinc
kg
0.023
0.023
0.023
Output
product
Char
kg
200
200
200
Output
product
Diesel
L
30.3
30.3
30.3
Output
product
Gasoline
L
30.3
252
363
Output
product
Hydrogen
L
23.3
23.3
23.3
Output
product
Residue
kg
448
448
448
Output
product
Gases
kg
147
147
147
Output
product
Liquid (Naphtha, light fraction)
MJ
265
265
265
Output
sea water
Inorganic emissions
kg
0.030
0.030
0.030
Output
sea water
Organic emissions
kg
0.0011
0.0011
0.0011
Output
sea water
Other emissions
kg
1,560
1,560
1,560
Output
sea water
Particles
kg
0.0037
0.0037
0.0037
Output
waste
Sand
kg
76.0
76.0
76.0
Output
waste
Wax
kg
46.0
46.0
46.0
Output
water
Wastewater
L
472
472
472
DOC,; GHG, greenhouse gas; n/a, not applicable; non-methane volatile organic compounds (NMOC), PM (particulate matter); TOC (total organic carbon); DOC
(dissolved organic compounds)
82
-------
Attachment E:
Gasification Life Cycle Inventory Data Compiled from the Literature
83
-------
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Input
n/a
Aggregate
kg
3.36
19.6
35.8
Input
n/a
Aluminium
kg
0.0050
0.0095
0.014
Input
n/a
Chromium
kg
0.0015
0.0058
0.010
Input
n/a
Clay
kg
0.020
4.28
12.3
Input
n/a
Copper
kg
0.0031
0.0095
0.016
Input
n/a
Electricity
MJ
0.11
727
1,221
Input
n/a
Fossil energy
kg
0.0014
3.00
9.00
Input
n/a
Hydrogen
kg
11.0
11.0
11.0
Input
n/a
Iron
kg
0.044
0.11
0.18
Input
n/a
Limestone, calcium carbonate
kg
53.0
61.6
70.2
Input
n/a
Manganese
kg
0
0.0012
0.0025
Input
n/a
Nickel
kg
0.0027
0.013
0.024
Input
n/a
Pyrite
kg
0
0.095
0.19
Input
n/a
Rock
kg
105
165
225
Input
n/a
Sand
kg
0.049
7.47
14.9
Input
n/a
Sodium chloride
kg
11.0
43.0
74.9
Input
n/a
Soil
kg
1.18
1.52
1.85
Input
n/a
Steam
MJ
112
112
112
Input
n/a
Water
kg
8,780
69,890
131,000
Input
n/a
Zinc
kg
0
0.0019
0.0039
Input
n/a
Natural gas
MJ
4,620
4,620
4,620
Input
n/a
Calcium carbonate
kg
1.00
3.81
6.61
Input
n/a
Solid waste
m3
0.040
0.040
0.040
Input
n/a
Land use
m2
0.20
0.20
0.20
Input
n/a
Urea
kg
4.60
4.60
4.60
Input
n/a
Hydrated lime
kg
6.50
6.50
6.50
Input
n/a
Activated carbon
kg
0.50
0.50
0.50
84
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Input
n/a
Coke
kg
49.0
49.0
49.0
Input
n/a
Steel
kg
6.97
6.97
6.97
Input
n/a
Alkyd paint
kg
0.080
0.080
0.080
Input
n/a
Wood
m3
0.0030
0.0030
0.0030
Input
n/a
LDPE
kg
0.30
0.30
0.30
Input
n/a
Gravel
kg
0.39
0.39
0.39
Input
n/a
Brick
kg
0.46
0.46
0.46
Input
n/a
Cement
kg
0.040
0.040
0.040
Input
n/a
Anhydrite
kg
0.080
0.080
0.080
Input
n/a
Plaster
kg
0.11
0.11
0.11
Output
(blank)
Calcium chloride
kg
4.10
4.10
4.10
Output
(blank)
Residue
kg
66.0
66.0
66.0
Output
(blank)
Hydrogen chloride
kg
5.00
5.00
5.00
Output
air
Aluminium
kg
4.0E-04
4.0E-04
4.0E-04
Output
air
Ammonia
kg
0
0
0
Output
air
Argon
kg
0
5.15
10.3
Output
air
Carbon dioxide
kg
7.18
666
1,000
Output
air
Carbon monoxide
kg
0.022
0.53
1.46
Output
air
Copper
kg
1.1E-05
1.1E-05
1.1E-05
Output
air
Hydrocarbons, unspecified
kg
7.2E-05
7.8E-05
8.3E-05
Output
air
Hydrogen
kg
0
0.11
0.23
Output
air
Hydrogen sulphide
kg
0
0.0079
0.016
Output
air
Iron
kg
4.3E-05
8.8E-05
1.3E-04
Output
air
Lead
kg
9.1E-06
9.2E-05
2.4E-04
Output
air
Manganese
kg
8.5E-06
1.7E-05
2.6E-05
Output
air
Mercury
kg
3.4E-06
3.7E-05
7.0E-05
Output
air
Methane
kg
0.51
0.95
1.38
85
-------
Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
air
Methane, biogenic
kg
7.8E-05
2.4E-04
4.0E-04
Output
air
Nickel
kg
4.2E-06
2.3E-05
4.0E-05
Output
air
Nitrogen
kg
3,180
3,180
3,180
Output
air
Nitrogen monoxide
kg
0
0
0
Output
air
Nitrogen oxides
kg
0.074
0.37
0.78
Output
air
Nitrogen, atmospheric
kg
0
0
0
Output
air
Nitrogentriflouride
kg
0
0.10
0.20
Output
air
Nitrous oxide
kg
0
0
0
Output
air
NMVOC
kg
0.019
0.020
0.020
Output
air
Oxygen
kg
0.56
262
674
Output
air
Particles
kg
0.0035
0.019
0.038
Output
air
Selenium
kg
6.2E-06
9.0E-06
1.2E-05
Output
air
Sulphur
kg
0
0.31
0.62
Output
air
Sulphur dioxide
kg
0.012
0.18
0.43
Output
air
Tin
kg
5.5E-06
7.3E-06
9.1E-06
Output
air
Titanium
kg
2.5E-06
5.3E-06
8.1E-06
Output
air
Vanadium
kg
8.8E-06
3.5E-05
6.2E-05
Output
air
VOC, unspecified
kg
0
0.0028
0.011
Output
air
Zinc
kg
1.6E-05
1.3E-04
3.3E-04
Output
air
Hydrogen chloride
kg
0.032
0.032
0.032
Output
air
Nitrogen (atmospheric)
kg
3,700
3,700
3,700
Output
air
Carbon dioxide, biogenic
kg
618
618
618
Output
air
Carbon dioxide, fossil
kg
612
612
612
Output
air
Cadmium
kg
6.0E-06
6.5E-06
6.9E-06
Output
air
Hydroflouric acid
kg
8.4E-04
8.4E-04
8.4E-04
Output
air
Hydrochloric acid
kg
0.013
0.013
0.013
Output
air
Dioxins and furans
kg
3.1E-12
2.6E-11
4.8E-11
86
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Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
air
Hydrogen flouride
kg
3.4E-04
3.4E-04
3.4E-04
Output
air
Arsenic
kg
6.0E-05
6.0E-05
6.0E-05
Output
air
PCBs
kg
0
0
0
Output
fresh water
Aluminium
kg
0.018
1.16
2.30
Output
fresh water
Ammonia
kg
0
1.3E-04
2.6E-04
Output
fresh water
Ammonium
kg
1.1E-04
0.0017
0.0033
Output
fresh water
Antimony
kg
0
0.027
0.054
Output
fresh water
Barium
kg
0
0
0
Output
fresh water
BOD
kg
0.0020
1.83
3.66
Output
fresh water
Boron
kg
216
222
227
Output
fresh water
Bromate
kg
0
4.2E-04
8.4E-04
Output
fresh water
Bromine
kg
0
2,910
5,820
Output
fresh water
Calcium
kg
0.87
1.46
2.05
Output
fresh water
Carbon disulphide
kg
0
0
0
Output
fresh water
Carbonate
kg
7.2E-04
0.0010
0.0013
Output
fresh water
Chlorate
kg
0
0.0032
0.0064
Output
fresh water
Chloride
kg
498,000
4,239,000
7,980,000
Output
fresh water
Chlorine, dissolved
kg
4.5E-04
6.1E-04
7.7E-04
Output
fresh water
Chromium
kg
0
0.017
0.035
Output
fresh water
Copper
kg
0
0.015
0.031
Output
fresh water
DOC
kg
0.0025
2.10
4.20
Output
fresh water
Fluoride
kg
46,400
56,650
66,900
Output
fresh water
Heavy metals
kg
0.022
0.042
0.061
Output
fresh water
Iron
kg
0
0.017
0.033
Output
fresh water
Lead
kg
0
4.19
8.38
Output
fresh water
Magnesium
kg
0.098
0.13
0.15
Output
fresh water
Manganese
kg
0.0029
0.0053
0.0078
87
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Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
fresh water
Nitrate
kg
2,230
6,865
11,500
Output
fresh water
Nitrogen
kg
0
1.2E-04
2.5E-04
Output
fresh water
Nitrogen, organic bounded
kg
2.3E-04
3.5E-04
4.6E-04
Output
fresh water
Particles
kg
0.063
0.14
0.22
Output
fresh water
Phosphate
kg
1,000
2,655
4,310
Output
fresh water
Phosphorus
kg
0
1.5E-04
3.0E-04
Output
fresh water
Potassium
kg
8,170
574,085
1,140,000
Output
fresh water
Sodium
kg
483,000
733,500
984,000
Output
fresh water
Sodium hypochlorite
kg
0
4.8E-04
9.6E-04
Output
fresh water
Sodium sulphate
kg
0
0.0036
0.0072
Output
fresh water
Solids, suspended
kg
0.19
5.34
10.5
Output
fresh water
Strontium
kg
0
0.0014
0.0028
Output
fresh water
Sulphate
kg
18.0
468,509
937,000
Output
fresh water
Sulphide
kg
0
1.9E-04
3.9E-04
Output
fresh water
Tin
kg
0
0.0016
0.0032
Output
fresh water
TOC
kg
0.0025
2.21
4.42
Output
fresh water
Vanadium
kg
0
0.0031
0.0062
Output
fresh water
Zinc
kg
1.7E-09
0.036
0.072
Output
product
Electricity
MJ
2,466
2,466
2,466
Output
product
Syncrude
kg
822
822
822
Output
product
Gases
kg
90.0
90.0
90.0
Output
sea water
Inorganic emissions
kg
0.046
0.073
0.099
Output
sea water
Organic emissions
kg
9.0E-04
9.9E-04
0.0011
Output
sea water
Other emissions
kg
2,010
2,280
2,550
Output
sea water
Particles
kg
0.0052
0.0079
0.011
Output
waste
Solid waste
kg
50.0
50.0
50.0
Output
soil
Residue
kg
120
120
120
88
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Assessment ofMSW Energy Recovery Technologies
Flow Type
Release
Compartment
Material
Unit per
tonne
Min of Sum of
Quantity,
Harmonized Units
Average of Sum of
Quantity,
Harmonized Units
Max of Sum of
Quantity,
Harmonized Units
Output
soil
Solid waste
kg
71.1
71.1
71.1
Avoided
n/a
Electricity
MJ
1,620
1,620
1,620
Reuse
n/a
Metals
kg
36.0
36.0
36.0
Reuse
n/a
Slag
kg
206
206
206
BOD, biological oxygen demand; DOC, dissolved organic compound; n/a, not applicable; TOC, total organic carbon
89
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Assessment of MSW Energy Recovery Technologies
Attachment F:
Decision Makers Guide for Assessing Municipal Solid Waste
Energy Recovery Technologies
90
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Assessment of 'MSW Energy Recovery Technologies
Decision Makers Guide for Assessing Municipal Solid Waste
Energy Recovery Technologies
Waste Management Hierarchy
Source Reduction & Reuse
Recycling / Composting
Energy Recovery
W
Sustainable materials management (SMM) is a systemic
approach to using and reusing materials more
productively over their entire life cycles. It represents a
change in how our society thinks about the use of natural
resources and environmental protection. The United
States Environmental Protection Agency (EPA) has
established a Non-Hazardous Materials and Waste
Management Hierarchy, which prioritizes and ranks the
various management strategies from most to least
environmentally preferred. The hierarchy places
emphasis on reducing, reusing, and recycling as key to
sustainable materials management. Some communities
are also interested in assessing energy recovery
alternatives for non-recyclable materials in municipal
solid waste (MSW).
Current energy recovery from MSW in the US is
primarily the result of landfill gas recovery and waste-to-energy (WTE) or refuse-derived energy (RDF) plants.
New and emerging technologies for managing MSW are of interest and include anaerobic digestion, gasification
and pyrolysis. These technologies are considered as "emerging" because they do not have the same level of
operational experience or commercialization in the US as historically used technologies such as mass-burn WTE
and landfill facilities. These technologies are also referred to as "conversion technologies" because they seek to
convert portions of MSW into energy and/or commodity products via thermal, chemical, and/or biological
processes.
Conversion technologies can help to advance EPA's SMM goals and provide economic opportunities and
environmental benefits to your community. However, these technologies are complex systems that will require
significant capital investment and a robust supporting environment (e.g., policies, new market development) to
ensure the technology is successful and sustainable. Implementing a new conversion technology may also entail
changes that align collection and sorting infrastructure and procedures to the provide specific feedstock
requirements for the facility.
As with any proposed MSW management strategy or technology, it is important to ask questions and to complete
a thorough evaluation of these emerging conversion technologies. The purpose of this guide is to provide a
structured approach for evaluating MSW energy recovery technologies to help community leaders make informed
decisions on the potential solutions to managing waste that best meets the needs and goals of their communities.
Planning and decision making among alternative waste management technology options is complex, but we can
approach it in five steps:
1
A
Step 1
Define
MSW goals
Assess MSW
feedstock
Identify
technologies
Evaluate cost
and impacts
Select best fit
option(s)
91
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Assessment of 'MSW Energy Recovery Technologies
Define your MSW management and sustainability goals
Well-defined and meaningful goals serve as a guide for navigating varied and complex options for how best to
manage waste within your community. EPA's waste management hierarchy provides a strong starting point when
setting goals for it ranks waste management strategies from the most to least environmentally preferred. The
hierarchy prioritizes source reduction and reuse, recycling, and composting. Many communities have already
established goals related to sustainability and waste management, typically in strategic planning documents such
as environmental plans, zero waste plans, or integrated waste management plans. As a first step, review existing
goals and consider whether they are relevant and meaningful, or need to be revised.
Key goals questions to ask
> What are the current MSW management goals and policies?
> What are the broader community sustainability (e.g., LEED [Leadership in Energy
and Environmental Design]) goals and policies?
> How does energy recovery from MSW advance these goals and policies?
Understand your available MSW feedstock
MSW energy recovery technologies have different requirements (or constraints) for feedstock quantity and
composition. To identify energy recovery technologies that are best suited to your community's MSW feedstock,
it is important to understand the types and amounts of MSW that are generated by your community and that are
available. Many communities have performed waste characterization studies. With respect to energy recovery
technologies, it will be particularly important to understand the detailed types (e.g., organic or plastic materials
types rather than bulk mixed amounts) and amounts of post-recycled material available.
Key feedstock questions to ask
> What is the quantity and composition of post-recycled MSW available?
> How is the MSW currently collected and processed (i.e., sorted)?
> Who currently controls the waste and for how long?
Identify suitable energy recovery technology options
The suitability of any energy recovery technology will depend on the quantity and composition of available
feedstock and the manner in which it has been collected—that is, is it a mixture of materials or source segregated.
Landfill and WTE facilities typically accept unprocessed MSW or residuals from other recycling or treatment
processes. Advanced energy recovery technologies—such as AD, gasification and pyrolysis—typically accept
only certain materials and/or have feedstock preprocessing requirements. These preprocessing requirements can
include sorting, size reduction, washing and drying. In general, gasification can accept minimally processed MSW
whereas pyrolysis and AD will require more robust separation and/or processing as their accepted materials can
be more limited. Any preprocessing can occur as part of collection and separation (e.g., MRF [materials recovery
facility]) system and/or as a part of the energy recovery technology. Figures 1 to 3 illustrate possible management
pathways for different types of MSW feedstock: unsegregated MSW, food waste and plastic waste.
92
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Assessment of MSW Energy Recovery Technologies
Mechanical
or Chemical
Plastics
Recycles
Markets
Compost
Product
to Market
Mixed MSW
Compost
Mixed MSW
" MRF
Non-
Recyclable
Residuals
Feedstock
Preprocessing*
i
Conversion via
Pyrolysls,
Gasification "
or Digestion
Dige state
Application
Non-
Compostable
Residuals
Landfill
t
Residuals
Waste to Energy
nil
MSW - Municipal Solid Waste MRF - Material Recovery Facility
Preprocessing can Include shredding, screening, washing and/or drying depending on feedstock type, quality and
conversion technology requirements. Note that preprocessing may not be required In all oases prior to conversion and
processes may be cu-located with the conversion facility.
Figure 1. Technology pathways unsegregated MSW.
Note: Although technically feasible to compost mixed MSW feedstock, there are no known operating MSW compost facilities in
the US probably due to the heterogeneity of the MSW feedstock. This approach has been tried and not found to be successful.
93
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Assessment of MSW Energy Recovery Technologies
Compost
Product to
Market
Residuals
Compost
Non-Compostable
Residuals
Feedstock
Preprocessing*
Residuals
Conversion via
Anaerobic
Digestion
Dlgestate
Application
Residuals
Landfill
Waste to Energy
MSW - Municipal Solid Waste
•Preprocessing can Include shredding, screening, and/or washing depending on feedstock quality and process requirements. Note that
preprocessing may not be required in all cases prior to conversion and processes may be co-located with the conversion facility.
Figure 2. Pathways for food waste.
94
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Assessment ofMSW Energy Recovery Technologies
&>t i
plastics*
in Mixed
Recyclables
Mechanical
or Chemical
Plastics
Recyciers
Markets
MRF
Non-
Recyclable
Plastics
Non-
Recyclable
Plastics
Feedstock
Preprocessing*
Conversion via
Pyrolysis/
Gasification
m A
Residuals
Landfill
Waste to Energy
MSW - Municipal Solid Waste MRF - Material Recovery Facility
'Preprocessing can Include shredding, screening, and/or washing depending on feedstock quality and process requirements. Note
that preprocessing may not be required in all cases prior to conversion and processes may be co-located with the conversion facility.
Figure 3. Pathways for plastic waste.
95
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Assessment of 'MSW Energy Recovery Technologies
Descriptions and key characteristics
for MSW energy recovery
technologies are presented in
Attachment A. These technologies
differ in terms of their "readiness/'
Landfill and WTE are well established
options. AD has grown rapidly in
recent years with currently more than
Lab
Technology ReadinessScale
Pilot
Demo
Serially
Commercial Commercialized
25 stand-alone facilities that accept / \
multi-source facilities that process
food and other organic fractions of MSW. There are a number of gasification and pyrolysis technologies in
various stages of research and development. However, there are currently only one gasification and two pyrolysis
facilities operating at a commercial scale in the US using fractions of MSW as feedstock.
In additional to consideration of what technology is most suitable to your available feedstock and the readiness of
the technologies, it is important to consider what the primary end product (e.g., electrical energy, liquid fuel,
biogas) is from each technology option. Community needs and market viability for these end products will differ
by location.
Key technology Questions to ask
> What are the accepted feedstocks and any preprocessing requirements of the technology?
> What are the minimum and maximum capacities of the technology?
> What is the main energy product generated by the technology?
> What is the technical readiness of the technology?
Cost associated with energy recover from MSW will vary by technology and region. Tipping fees for landfills89
and WTE9" plants are readily available with landfills tipping fees ranging from $30 to $155 per ton and WTE
ranging from $65-75 per ton in the US. Cost and/or tipping fee data for newer AD, gasification and pyrolysis
technologies is limited and often anecdotal. Ultimately, the cost will be location specific and depend on multiple
factors such as the specific technology facility costs, permitting, feedstock segregation and processing,
operational costs, market prices for products and disposal or management costs for residuals such as ash or
digestate. A broader range of economic benefits may also include job creation and local economic development.
From an environmental perspective AD, gasification and pyrolysis are considered "energy recovery"' and
preferable to "treatment and disposal" on EPA's waste management hierarchy. However, the ability to draw life
cycle environmental performance conclusions between these newer technologies and conventional energy
recovery via WTE and landfill gas recovery is limited due to the general lack of newer technology operational
history, experience and available long term data (more than 5 years) to establish environmental performance over
time.
All energy recovery technology options will generate gaseous, liquid and solid emissions that require additional
treatment or disposal. The literature data suggest that gasification and pyrolysis can result in carbon equivalent
emissions comparable to WTE and landfills (see US EPA, 2020). This is due to the carbon emissions associated
with the combustion of the syngas or synfuel product, which is considered, or partially considered, to be fossil-
89 https://erefdn.org/product/analvsis-msw-landfill-tipping-fees-2/
911 https://www.usi.edu/recvcle/solid-waste-landfill-facts/
96
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Assessment of MSW Energy Recovery Technologies
based fuel. Conversely, the use of biogenic (i.e., organic) feedstock in either conventional or conversion
technologies will result in a biogenic energy product that is considered carbon neutral. For example, AD of food
waste will create biogenic energy that is considered carbon neutral. Likewise, landfills also produce biogenic
energy and the organic fraction of waste combusted in a WTE plant (or gasification or pyrolysis) is considered
biogenic with respect to carbon accounting.
All energy recovery technologies produce solid
residuals that sometimes include hazardous waste
streams (e.g., ash, char, wax, slag, and digestate) and
will require additional treatment via combustion or
disposal in solid or hazardous waste landfill.
Technology process by-products may also require
treatment or disposal if a viable end-use or market
cannot be found. The data available from the literature
show that advanced energy recovery technologies of
AD, gasification and pyrolysis will generally produce
as much or higher amounts of residuals as
conventional WTE, or approximately 5-15 percent of
feedstock volume. The exact amounts of solid
residuals generated will be dictated by the feedstock
composition and the level of acceptable contamination
by specific technology. In general, it could be
expected that a mixed feedstock (e.g., bulk MSW, materials recovery facility |MRF] residuals) will generate
greater amounts solid residuals than a source segregated feedstock (e.g., plastics, food waste).
Key cost/benefit Questions to ask
p What is the full cost and revenue potential for the technology?
> What are the local employment opportunities?
r What is the net energy balance for the technology?
ip What would be the air and water emission levels and how would residual waste be managed?
P Does the technology have any significant resource requirements (e.g., water)?
Identify best-fit technology options
Ultimately, identifying an energy recovery technology
that is best matched to your specific community will take
into account and align several factors including your
community goals; quantify, type and availability of
consistent feedstock; technology options and their
suitability to available feedstock and technology
readiness; technology product(s) type and local/regional
needs and access to end markets; and cost and benefits.
In addition to the key questions in steps 1-4, other
important questions to consider when making decisions
about potential MSW energy recovery technologies can
include:
Existing tools such as EPA's
Municipal Solid Waste
Decision Support Tool (MSW
DST) can help to assess the
cost and life-cycle
environmental performance of
MSW energy recovery
options. Since AD,
gasification and pyrolysis
technologies are more emerging in nature, there is a general
lack of operational history, experience and accompanying
data. Some technology test and model estimated data is
available from the literature and can be combined with the
collection processing and residuals treatment and disposal
options in tools like the MSW DST to assess cost and
environmental perfonnance (see US EPA, 2020).
m
97
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Assessment of'MSW Energy Recovery Technologies
> Geographic footprint (land requirement) and siting. Where would the facility be located and who would
likely be impacted91 by increased traffic, air emissions, noise, or odors?
> What level of public awareness and support is there for the technology?
> What are the relevant state and local regulations and laws, and is there a precedent for permitting the
technology?
> What is the capacity of the local/regional government agencies to facilitate permitting and to monitor and
enforce permit conditions?
> Is there a potential for infrastructure "lock in" (i.e., inability to change MSW management strategy or
programs in the future)?
Additional Resources:
US EPA. 2020. Assessment of Municipal Solid Waste Energy Conversion Technologies. [Forthcoming]
SWANA & NWRA. 2017. Briefing for Elected Officials Effective Responses to Emerging Waste Management
Technology Proposals. February 2017.
91 Use EPA's EJSCREEN to identify minority and/or low-income populations, potential environmental quality issues, and areas where a
combination of environmental and demographic indicators are greater than the norm.
98
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Assessment of 'MSW Energy Recovery Technologies
Attachment A: Descriptions and key information for MSW energy recovery technologies.
Technology
Description
MSW
Feedstocks
Accepted
Primary
Product and
End
Application(s)
Residual
Requiring
Disposal
(by weight)
Number of
Facilities
Operating in
the US
Anaerobic
Digestion (AD)
AD plants use a controlled anaerobic environment (i.e., absent of added
oxygen) to enhance the biochemical decomposition of organic matter by
microorganisms to create biogas. The process does not require external heat.
The biogas produced from an AD can be used directly, to generate electrical
energy, or additionally treated to allow injection into the pipeline. Byproducts
include air emissions, solid and/or liquid digestate. The solid and liquid
digestate can be land applied, composted, used as a soil amendment or
processed into fertilizer pellets. The liquid digestate can be further processed to
concentrate nitrogen or phosphorous chemicals. These chemicals can be sold
outright or added to fertilizers.
Food and yard
waste
Biogas used to
generate heat,
electricity or
fuels (e.g.,
CNG, LNG).
Digestate can be
used as fertilizer
Approximately
5-10%a
25+92
Gasification
Gasification plants use a thermal process that, in a controlled oxygen
environment, convert organic or fossil fuel carbon-containing material into
synthetic gas. The process is like pyrolysis, except that oxygen is added to
maintain a reducing atmosphere in the reactor. Inert materials such as glass and
metals are removed and then the feedstock is shredded to be a consistent size
and fed into the gasifier. In the gasitier the materials are heated to temperatures
of 1100 to 1800 degrees in a chamber with a controlled amount of oxygen
resulting in a chemical reaction that produces syngas and residues. The syngas
is cleaned to remove dust, ash, and tar and it may be further purified or
conditioned. Char and ash may be reused (if approved for reuse) or will require
disposal.
Carbon-
containing
materials in
MSW
Synthetic gas
used to generate
electricity, heat,
fuels, fertilizers
and chemical
products
Greater than
10%
2
Pyrolysis
Pyrolysis plants use heat to thermally decompose carbon-based material in the
absence of oxygen. The main products of pyrolysis include gaseous products
(syngas), liquid products (typically oils), and solids (char and any metals or
minerals that might have been components of the feedstock). Pyrolysis plants
generate synthetic oil which likely will require additional refining or cleaning
to meet market requirements. Byproducts include petroleum wax and char.
Wax produced (normally less than or equal to 10% by weight of feedstock)
may be a marketable commodity. Char is considered a hazardous waste and
approvals are often required for its disposal.
Plastics or
biomass
Synthetic oil
used to create
fuel products or
commodities
(e.g., waxes)
Greater than
10%
4
RDF
RDF plants use mechanical systems to sirred incoming MSW, separate out and
recycle non-combustible materials, and produce a combustible mixture that is
suitable as a fuel in a dedicated furnace or as a supplemental fuel in a
conventional WTE plant. The RDF can either be used as-is (shredded fluff) or
MSW
Steam used to
generate
electricity or
Combined Heat
Approximately
15-25%
13
92 https://www.epa.gOv/anaerobic-digestion/anaerobic-digestion-tools-and-resources#ADdata.
99
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Assessment of 'MSW Energy Recovery Technologies
Technology
Description
MSW
Feedstocks
Accepted
Primary
Product and
End
Application(s)
Residual
Requiring
Disposal
(by weight)
Number of
Facilities
Operating in
the US
compressed into pellets, bricks, or logs for transportation, storage or sale. Like
WTE, RDF facility combusts MSW in high heat, controlled conditions to
produce steam from the boiler that is used to generate electricity or utilized in a
combined heat and power system. It also produces combustion residues, or ash
that will require disposal.
and Power
(CHP)
WTE
WTE plants use mass bum combustion to bum waste to generate heat and
electricity. Mass bum combustion facilities take unsorted MSW - your trash -
from bin to burner. The facility combusts MSW in high heat, controlled
conditions to produce steam from the boiler that is used to generate electricity
or utilized in a combined heat and power system. Ferrous metal is typically
recovery from the ash and recycled. It also produces combustion residues, or
ash that will require disposal. WTE facilities need a lot of feedstock. The
smallest plant in the US has a capacity of 175 tons per a day.
MSW
Steam used to
generate
electricity or
CHP
Approximately
15-25%
73b
Landfill with
gas recovery
Landfills are large, outdoor engineered sites designed for the disposal of MSW
and other wastes - the trash and garbage that is thrown away every day at
home, work, and school. Hie design of landfills includes liners and other
materials like clay to prevent groundwater contamination. Monitoring is
required to determine if there is any groundwater contamination. Daily
operation of landfills includes compacting and covering waste with several
inches of soil or other cover material to reduce odor and litter as well as control
rodents and pests. Landfills can also be designed to collect landfill gas and
utilize this gas to generate energy products.
MSW
Biogas which
can be used to
generate heat,
electricity
and/or fuels
(e.g., CNG,
LNG)
0%
56493
AD, anaerobic digestion; CHP, combined heat and power; CNG, compressed natural gas; LNG, liquefied natural gas; MSW, municipal solid waste; RDF, refuse-derived fuel;
WTE, waste-to-energy
adoes not include digestate which typically is composted
bmost existing WTE plants in the US have been operating for more than 20 years. Only one new WTE facility has been built in the US since 1995.
93 https://www.epa.gov/lmop/landfill-gas-energy-proiect-data-and-landfill-teclinical-data
100
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vvEPA
United States
Environmental Protection
Agency
PRESORTED STANDARD
POSTAGE & FEES PAID
EPA
PERMIT NO. G-35
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Official Business
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$300
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