OCR error (C:\Conversion\JobRoot\00000CEG\tiff\20013N7A.tif): Unspecified error
-------
AEERL-P-842a
TECHNICAL REPORT DATA
(Please read Inunctions on the reverse before complel
1. REPORT NO
EPA/600/J-92/046
3.
PB92-15061U
4. TITLE AND SUBTITLE
Fuel Cell Energy Recovery from Landfill Gas
5. REPORT DATE
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
G. J. Sandelli (IFC) and R. J. Spiegel (EPA)
I. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
International Fuel Cells Corporation
195 Governors Highway
South Windsor, Connecticut 06074
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-0008
12. SPONSORING AGENCY NAME AND ADDRESS
EPA, Office of Research and Development
Air and Energy Engineering Research Laboratory
Research Triangle Park-, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Journal article; 1-9/91
14. SPONSORING AGENCY CODE
EPA/600/13
is.SUPPLEMENTARY NOTES AEERL projectofficer is RonaldJ< Spiegel. MailDroP63. 919/
541-7542. Journal of Power Sources, 37 (1992), 255-264.
i6. ABSTRACTThe paper discusses Phase I results of an EPA-sponsored program to
demonstrate energy recovery from landfill gas using a commercial phosphoric acid
fuel cell power plant. 3PA is interested in fuel cells for this application because it
is the cleanest energy conversion technology available. Phase I is a conceptual de-
sign, cost, and evaluation study. The conceptual design of the fuel energy recovery
concept is described and its economic and environmental feasibility is projected.
Phase II covers the construction and testing of a landfill gas pretreatment system
which will render l«\ndfill gas suitable for use in the fuel cell. Phase III is the demon-
stration of the energy recovery concept.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS
c. COSATl Field/Group
Pollution
Fuel Cells
Gases
Earth Fills
Energy
Phosphoric Acids
Pollution Control
Stationary Sources
Landfill Gas
Energy Recovery
13 B
10B
07D
13C
14G
07B
8. DISTRIBUTION STATEMENT
Release to Public
19. St-CURITY CLASS (This Report)
Unclassified
21. NO. OF PAGtS
IX
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (3-73)
REPRODUCED BY
U.S. DEPARTMENT OF COMMERCE
NATIONAL TECHNICAL
INFORMATION SERVICE
SPRINGFIELD. VA 22161
-------
PB92-15061U
EPA/600/J-92/046
Journal <•/ Amvr Source. 37 (I'WJT. 255-2(i4
255
,,c*
Fuel cell energy recovery from landfill gas
G. J. Sandelli
International Fuel Cells Corporation, 195 Governor, Highway. South Windsor. CT 06074 (USA)
R. J. Spiegel"
U.S. Environmental Protection Agency, Air and Energy Engineering Research Laboratory,
Research Triangle Park, NC 27711 (USA)
Abstract
International Fuel Cells Corporation is conducting a US Environmental Protection Agency
(EPA) sponsored program to demonstrate energy recovery from landfill gas using a commercial
phosphoric acid fuel cell power plant. The US EPA is interested in fuel cells for this
application because it is the cleanest energy conversion technology available. Thfs paper
discusses the results of Phase I, a conceptual design, cost, and evaluation study. The
conceptual design of the fuel cell energy recovery concept is described and its economic
and environmental feasibility is projected. Phase II will include construction and testing
of a landfill gas pretrcatmcnt system which will render landfill gas suitable for use in the
fuel cell. Phase III will be a demonstration of the energy recovery concept. •,
Introduction
The US Environmental Protection Agency (EPA) has proposed standards and
guidelines [1] for the control of air emissions from municipal solid waste (MSW)
landfills. Although not directly controlled under the proposal, the collection and disposal
of waste methane, a significant contributor to the greenhouse effect, would result from
the emission regulations. This EPA action will provide an opportunity for energy
recovery from the waste methane that could further benefit the environment. Energy
produced from landfill gas could offset the use of foreign oil, and air emissions affecting
global warming, acid rain, and other health and environmental issues.
International Fuel Cells Corporation (IFC) was awarded a contract by the US
EPA to demonstrate energy recovery from landfill gas using a commercial phosphoric
acid fuel cell. IFC is conducting a three-phase program to show that fuel cell energy
recovery is economically and environmentally feasible in commercial operation. Work
was initiated in Jan. 1991. This paper discusses the results of Phase I, a conceptual
design, cost, and evaluation study, which addressed the problems associated with landfill
gas as the feedstock for fuel cell operation.
'The research described in this article has been reviewed by the Air and Energy Engineering
Research Laboratory of the US EPA and approved for publication. Approval docs not necessarily
reflect the view and policy of the Agency nor does mention of trade names or commercial
products constitute endorsement or recommendation for use.
"Author to whom correspondence should be addressed.
NTIS is authorized to reproduce and sell this
report. Permission lor further reproduction
must be obtained from the copyright owner.
1992 - Elsevicr Sequoia. V\ll rights reserved
> '
-------
Phase II ol the piourain includes construction and testing i>l the landfill JMS
prelrcatmciil module to be used in the demonstration. Its objective will be lo determine
the cll'ectiveiiess ot the pretrcalmenl system design lo remove critical fuel cell catalyst
poisons such as sulfur and lialides. A challenge test is planed to show the feasibility
of using the pretreatment process at any landfill in conjunction with the fuel cell
cncigy recovery concept. A preliminary description of the gas pretieater is presented
here.
Phase III of this program will be a demonstration of the fuel cell energy recovery
concept. The demonstrator will operate at Pcnrosc station, an existing landfill gas-to-
cncrgy facility owned by Pacific Energy in Sun Valley, CA. Pcnrosc Station is an 8.9
MW internal combustion engine facility supplied with landfill gas from four landfills.
The electricity produced by the demonstration will be sold to the electric utility grid.
Phase II activities began in Sept. 1991 and Phase III activities are i-chedulcd to
begin in Jan. 1993.
Landfill gas
Availability
The MSW landfills in the US were evaluated to determine the potential power
output which could be derived using a commercial 200 kW fuel cell. Each fuel cell
would consume 100000 SCFD of landfill gas to generate 200 kW, assuming a heating
value of 500 Btu per cubic foot.
The potential power generation mavket available for fuel cell energy recovery was
evaluated using an EPA estimate of methane emissions in the year 1992 [2aj. An
estimated 4370 M\V of power could be generated from the 7480 existing and closed
sites identified. The largest number of potential sites greater than 200 kW occurs in
the 400 to 1000 kW range. This segment represents a market of 1700 sites or 1010
MW.
The assessment concluded that these sites are ideally suited to the fuel cell
concept. The concept can provide a generating capacity tailored to the site because
of the modular nature of the commercial fuel cell. Sites in this range arc also less
well served by competing options, especially Rankinc and Brayton Cycles which exhibit
poorer emission characteristics at these power ratings.
As a result of the assessment, the conceptual design of the commercial concept
was required to be modular and sized to have the broadest impact on the market.
Characteristics
The available information on landfill gas compositions was evaluated to determine
the range of gas characteristics which a fuel cell landfill gas-to-cnergy power plant
will encounter. This information was used to set the requirements for the gas pretreatment
and fuel cell power plant designs.
A summary of landfill gas characteristics is shown in Table 1. The heating value
of the landfill gas varies from 350 to 600 Btu per cubic foot, with a typical value of
500 Btu per cubic foot. The major non-methane constituent of landfill gas is carbon
dioxide. The carbon dioxide ranges from 40 to 55% by volume of the gas composition
with a typical value of 50%. Other diluent gases include nitrogen and oxygen, which
arc indicative of air incursion into the well (most frequently in perimeter wells).
Nitrogen concentrations can range as high as 15% but typical values arc 5% or less.
Oxygen concentrations are monitored closely and held low for safety reasons.
-------
257
TAW.I: I
Larullill g.is ch.ic.i(.tcriNtiCM
Characteristic
Healing value
(111 IV) (Lilu/ll1)
CII4 (%)
CO, (%)
N; (%)
0, (%)
Sulfur as H:S (ppmv)
Halulcs (ppnivj
Non-methane organic compounds
(NMOCs) (ppmv)
Range
350-600
35-58
40-55
0-15'
0-2.5'
1-700
N/A
237-14000
Typical
500
50
45
5
< [% (for safety)
21
132
2700
"Highest values occur in perimeter wells.
Landfill gas constituent compounds reported by EPA [2b] indicate a typical value
for the total non-methane organic compounds (NMOCs) of 2700 ppmv (expressed as
hcxanc). The NMOC concentration in the landfill gas is an important measure of the
total capacity required in the gas prctreatment system, while the specific individual
analyses provide a basis for gas pretreatmcr.t subcomponent sizing. The specific
contaminants in the landfill gas, of interest to the fuel cell, are sulfur and halidcs
(chiefly chlorides and fluorides). The sulfur level ranges from 1 to 700 ppmv, with a
typical value in the order of 21 ppmv. Sufficient data were not available to assess the
range of the halidcs, but a typical value of 132 ppmv was calculated for this contaminant
[2e]. The range of contaminant values varies not only from site to site, but also at
any given site with time due to seasonal weather or moisture content. These characteristics
require the prctreatment system design to be capable of handling these gas quality
variations to avoid expensive site specific engineering of the prctrcatmcnt design which
would alTcct the marketability and economics of the concept.
Emissions requirements
Existing US regulations do not address methane emissions from landfills directly.
Proposed new EPA regulations [1] would control NMOCs from large landfills (150
Mg per year and up) and hence would indirectly control methane emissions.
Landfill gas emission requirements are primarily determined at the state and local
level. State requirements arc generally limited to controlling explosion hazards, typically
limiting methane concentrations to below 25% of the lower explosion limit. An evaluation
of state regulations revealed that collection and control requirements generally necessitate
venting, or the use of a flare. However, Federal Clean Air Act requirements arc
driving the state and local air quality rules, especially in areas identified as non-
attainment regions. For instance, non-attainment regions for ozone may lead to strict
requirements for secondary emissions including NO,, carbon monoxide and NMOCs.
The best known cxampl: of strict local emission requirements is the South Coast Air
Quality Management District (SCAQMD) in southern California.
-------
25S
Commercial fuel coll lanillHl gas to energy system conceptual design
This section describes the commercial fuel cell landfill gas to energy system
conceptual design. The design is based on providing a modular, packaged, energy
conversion system which can operate on landfill gases with a wide range of compositions
as typically found in the US. The complete system incorporates the landfill gas collection
system, a fuel gas pretrcalmcnt system and a fuel cell energy conversion system. In
the fuel gas pretrcatment section, the raw landfill gas is treated to remove contaminants
to a level suitable for the fuel cell energy conversion system. The fuel cell energy
conversion system converts the treated gas to electricity and useful heat.
Landfill gas collection systems are presently in use in over 100 MSW landfills in
the US. These systems have been proven effective for the collection of landfill gas.
Therefore these design and evaluation studies were focused on the energy conversion
concept.
Overall system description
The commercial landfill gas to energy conversion system is illustrated in Fig. 1.
The fuel prctreatmcnt system has provisions for handling a wide range of gas con-
taminants. Multiple prctreatmcnt modules can be used to accommodate a wide range
of landfill sizes. The wells and collection system collect the raw landfill gas and deliver
it at approximately ambient pressure to the gas prctreatmcnt system. In the gas
prctreatmcnt system the gas is treated to remove NMOCs including trace constituents
which contain halogen and sulfur compounds.
The commercial energy conversion system shown in Fig. 1 consists of four fuel
cell power plants. These power plants arc designed to provide 200 kW output when
operating on landfill gas with a heating value of 500 Btu per standard cubic foot and
for accommodating higher contaminant concentrations. The output from the fuel cell
is utility grade a.c. electric power. It can be transformed and put into the electric
grid, used directly at nearby facilities, or used at the landfill itself. The power plants
arc capable of recovering co-generation heat for nearby use or rejecting it to air.
800 KW FUEL CELL POWER PLANT
OPERATING ON LANDFILL GAS
LANDFIIX CAS WEliS
AND COLLECTION
SYSTEM
OmCF. AND
BLOWER
MULTIPLE
FUEL CELL
POWER PLANTS
CAS PRETREATMENT
SYSTEM
Fig. 1. Fuel cell energy rccoveiy commercial concept.
-------
As configured) in l;ig. 1, the commercial system c;m process ;ipproximately 18000
standard cubic (cut per liour of landfill gas (mitigate 9050 SCFH of methane) with
minimum environmental impact in terms of liquids, solids or air pollution. Details of
the individual sub-elements in the energy conversion system follow this discussion.
Fuel prcttcatmcnt system
A block diagram of the landfill gas pretrcMmcnt system is shown in Fig. 2. The
fuel prelrealnicnt system incorporates two stages of refrigeration combined with three
rcgenerablc adsorbent steps. The use of staged refrigeration provides tolerance to
varying landfill gas constituents. The first stage significantly reduces the water content
and removes the bulk of the heavier hydrocarbons from the landfill gas. This step
provides flexibility to accommodate varying landfill characteristics by delivering a
relatively narrow cut of hydrocarbons for the downstream beds in the prctrcatmcnt
system. The second refrigeration step removes additional hydrocarbons by a proprietary
process and enhances the effectiveness of the activated carbon and molecular sieve
beds, which remove the remaining volatile organic compounds and hydrogen sulfide
in the landfill gas. This approach is more flexible than utilizing dry bed adsorbents
alone and has built-in flexibility for the wide range of contaminant concentrations
which can exist from site to site and even within a single site varying with time.
The three adsorbents are rcgenerzted by using heated gas from the process stream.
Each step consists of two beds in parallel. In operation, one bed is adsorbing while
the parallel bed is being regenerated. The regeneration path and sequence are shown
as dashed lines in Fig. 2. A small portion of the treated landfill gas (approximately
8%) is heated by regeneration with the incinerator gases and then passes through the
beds in the sequence shown. After exiting the final bed, the regeneration gas is fed
into the low NO, incinerator where it is combined with the vaporized condcnsatcs
from the refrigeration processes and the mixture is combusted to provide 98% destruction
of the NMOCs from the raw landfill gas. The exhaust from the incinerator is essentially
CO2 and water. The pretrcatmcnt system design provides treated gas to the fuel cell
power plant in an efficient, economic, and environmentally acceptable manner.
The prctrcatmcnt system design provides flexibility for operation on a wide range
of landfill gas compositions, it has minimal solid wastes, high thermal efficiency, and
low parasite power requirements. The pretreatment system is based upon modification
of an cxistjji« system and utilizes commercially available components. The process
train and opciating characteristics need to be validated by demonstration. Key dem-
REOCNCIUriON OAS
fllTEH fr>>)
7
.AND
rrnsT BTAQC ftfocNfRA£L£ L
BfRIOf flATKW -*S WOC SltVE PS
CONOCHSCA >"^ DCHVOAAItON \r
UJW
PRESSURE
•LOWER
nu
\
\
I
CECX>NO 1
RCOCNEHABLC 1
1
_ 1
COWOCN SATES
'BCQCN
1 c,
1
T
LDWWO* J
(NCtNCRATOfl |
Tig. 2. Simplified block diagram of commercial landfill gas prctrcatr.icnt system.
-------
onstr;iuons in Phase II will include: Ihc achievement of low total halide contaminant
levels in i lie neatctl gas; elleclivencssot the regeneration cycle as a Heeled by regeneration
time and temperature; durability of the regenerable beds; and low cnviionmental
emissions.
The fuel pretieatment system described above was analyzed to estimate the overall
thermal efficiency, internal electric power requirements and maintenance characteristics.
The estimated thermal efficiency is 92% with the balance of thermal energy used for
regeneration, vaporization of the condensate and incineration of regeneration gases.
Electric power is used for pumping the gases and the refrigeration stages and is
accounted for as a parasite power characteristic of the system. Maintenance requirements
consist of maintaining and adjusting controls and valves in the regeneration system
and replacement of fully regenerated spent bed materials on an annual basis.
The pretrcatment system was evaluated to define anticipated air emissions, and
liquid and solid effluents. The incinerator is designed for 98% destruction of all NMOCs
and NC), emissions of less than 0.06 pounds per million Btu of fuel consumed. There
is no liquid effluent from the system since all condensates are vaporized and subsequently
incinerated. Solid disposal involves removing spent regenerable bed materials at the
factory and treatment by an approved reclamation processor.
cell power plant
The commercial landfill gas energy conversion conceptual design incorporates four
200 kW fuel cell power units. Since each of the four units in the concept is identical,
this discussion will focus on the design issues for a single 200 kW power unit.
A preliminary design of a fuel cell power plant was established to identify the
design requirements which allow optimum operation on landfill gas. Three issues
specific to landfill gas operation were identified which reflect a departure from a
design optimized for operation on natural gas. A primary issue is to protect the fuel
cell from sulfur and halidc compounds not scrubbed from the gas in the fuel pretrcatmcnt
system. An absorbent bed was incorporated into the fuel cell fuel preprocessor design
which contains both sulfur and halide absorbent catalysts. A second issue is to provide
mechanical components in the reactant gas supply systems to accommodate the larger
flow rates that result from use of dilute methane fuel. The third issue is an increase
in the heat rate of the power plant by approximately 10% above that anticipated from
operation on natural gas. This is a result of the inefficiency of using the dilute methane
fuel. The inefficiency results in an increase in heat recoverable from the power plant.
Because the effective fuel cost is relatively low, this decrease in power plant efficiency
will not have a significant impact on the overall power plant economics.
The landfill gas power plant design provides a packaged, truck transportable, self-
contained fuel cell power plant with a continuous electrical rating of 200 kW. It is
designed for automatic, unattended operation, and can be remotely monitored. It can
power electrical loads cither in parallel with the utility grid or isolated from the grid.
In summary, a landfill gas fueled power plant can be designed to provide 200
kW of electric output without need for technology developments. The design would
require selected components to increase reactant flow rates with a minimum pressure
drop. To implement the design would require non-recurring expenses for system and
component design, verification testing of the new components, and system testing to
verify the power plant performance and overall system integration.
Environmental and economic assessment of the fuel cell energy conversion system
The commercial application of the concept to the market described previously
was assessed. For the purpose of the evaluation, a site capable of supporting four
-------
tucl cell pi me I modules wax selected 'I'hc site cti.irude[istics .issiniK'il are the typical
values disused earlier. The site would produce appioximatcly -13-4 (100 standard cubic-
led ol landfill gas per day. The gas contains approximately 50% i;ielh;iiie with ;i
healing v;ilue of 500 Bin per standard cubic loot.
The analysis dt the environmental impact shows that both the fuel cell and the
Hare system can be designed to eliminate the methane and the NMOCs from the
landfill gas system. For the example site considered, the methane elimination is
essentially complete for both systems and V89c of the NMOCs are destroyed. Trace
amounts of SO, and NO, will be emitted in each case. With the fuel cell system,
however, significant reductions of NO, and SO, will be achieved due to the fuel cell
energy generation. This analysis assumes an 80% capacity factor for the fuel cell and
otlsetting emissions from electric utility power generation using a coal-fired plant
meeting New Source Performance Standards. For the example site, the fuel cell energy
conversion system provides 5.6 million kW h of electricity per year, with a net reduction
of NO, of 35.2 tons per year and a reduction of SO, of 16.8 tons per year. These
reductions can be used as environmental offsets, particularly in critical areas such as
California or other locations with severe environmental restrictions.
The environmental impact of application of the fuel cell concept to the potential
market is shown in Table 2. The data show that both the Hare and (he fuel cell
mitigate methane and NMOCs under the proposed standards and guidelines [2].
However, the flare merely converts these emissions lo CO2, and rain and other unhealthy
pollutants. The fuel cell can provide a net reduction in global pollution by offsetting
energy production from coal.
Economically the fuel cell energy system has the potential for.deriving revenues
from electric sales, thermal sales and emission offsets credits. These revenues can be
used to offset the investment cost associated with gas collection, gas prctrcatmcnt and
fuel cell power units. The level of these revenues depends upon the value of the
electricity, the amount and value of ihe heat used, and the value of ihe emissions
offsets.
Economics
Electric rates vary considerably with geographic location and the purchaser of
the electric energy. Commercial rates are applicable where the electricity can be used
at the landfill or in nearby commercial facilities. Commercial rates vary from a high
of 13.68 cents per kW h to a low of 2.71 cents per kW h. The median rale in Ihe
US is approximately 7 cents per kW h. The rates charged to industry arc generally
TAHLE2
Emissions impact of fuel cell energy recovery from landfill gas
Abatement Global warming Acid rain and health
technology
Methane NMOC CO2 SO2 NO, CO
(Mg/yr.) (Mg/yr.) (Mg/yr.) (Mg/yr) (Mg/yr.) (Mg/yr.)
Venting [2] 1 8x 107 52100
only
Flare 0 -10200 +4.94x10' +2972 +29720 +14860
Fuel cell 0 -10200 -6.45x10' -53500 -259000 -8620
-------
lower and are closer 10 the fully burdened avoided eost for the uli'ity These rates
range from 10.0 ccnis per kW h to a low of 1.64 cents per kW h with the mean value
of approximately 5 cents per k\V h. In general, both the commercial and industrial
rates are higher in locations with high population density and/or with air emissions
problems. These locations are ideal for the use of the fuel cell energy conversion
system with its favorable environmental impact. Since the rates vary considerably, the
analysis in this section is done on a parametric basis for a wide range of electric rates.
The fuel cell energy conversion system was studied to establish the net revenues
or costs for processing landfill gas to mitigate methane emissions. For the purposes
of the analysis it was assumed that the fuel cell energy conversion system and the
flare system would have an overall annual capacity factor of 80%. For this analysis,
two levels of fuel cell installed costs were considered. The lower level represents a
fully mature cost when the power plant has been accepted into the marketplace, and
is routinely produced in large quantities. The upper level represents a price level when
the power plant is being introduced >nto the marketplace, and is produced on a
moderate and continuous basis.
Figure 3 shows the fuel cell revenues for the most stringent application situation
(no emission credits or thermal energy utilization). In this case, the fuel cell receives
revenues only from the sale of electricity. Although the emissions arc lower fiom the
fuel cell, no specific credit or value is attached to them for this example. Under these
conditions the fuel cell is still the economic choice for most locations at the mature
product installed cost. At the entry cost the fuel cell is economical in those areas
where the value of electricity is 9 cents per kW h or higher. This would primarily be
areas such as California, New York, and other parts of New England. With the potential
for revenue from thermal energy or emission offset credits, the economics become
more comp-titive. Thus the applicability of the concept would become attractive to
a broader market.
Other energy conversion systems could also produce electric and/or thermal energy.
Both the internal combustion engine and the gas turbine engine have been suggested
as options for methane mitigation at landfill sites. For the landfill size selected for
o
UJ <3
s ri
z c
o g
er 5
u- 2
-------
this .in.ilvsis, ihc inicin.il combustion engine is more cllcclivc th.in the gas turbine
options lor cleanup. This is used .is the basis for the coinpansons provided here. The
internal combustion engine can provide both heat and electric energy while consuming
the methane at the landlill ;;as site. With the present state-of-the-art technology,
however. .1 lean-burn internal :ombustion engine has higher levels of NO, emissions
than a (uH cell unless special precautions arc taken to clean the exhaust. For our
analysis IAO cases were considered. The first case assumes no cleanup of the internal
combustion engine exhaust, and the second assumes that the exhaust is cleaned with
selective catalytic reduction (SCR). Since the SCR employs a catalyst in the cleanup
system, the landlill gas will have to be pretreated in a manner similar to the fuel cell
system. For those cases with a SCR cleanup system, a pretrcatment system has also
been included as part of the total system cost.
Figure 4 shows the results of the economic analysis for the fuel cell system and
the internal combustion engine system. Since both systems can provide electricity, the
comparison between the systems is based on the cost of electricity generated from
the energy conversion system with appropriate credit for thermal sales and/or emission
olTscts. The fuel cell is competitive at the full mature price when no exhaust cleanup
is required with the internal combustion engines. However, the operation of the internal
combustion engine at the landfill site would be quite dirty, and significant amounts
of NO, would be added to the ambient air. For many locations where the fuel cell
would be considered, such as California or other high emissions areas, the exhaust
cleanup option is required. Consequently, the fuel cell option would be fully competitive
with the internal combustion engine option for most cases where on-sitc cleanup of
the internal combustion engine is required. In areas where a SCR would be employed
to clean up an internal combustion engine exhaust, the fuel cell concept is competitive
at entry level cost.
Based on the analysis of both the Hare option and other energy conversion options,
the fuel cell power plant is fully competitive in all situations in the mature production
situation. For initial power plant applications with limited lot production, the lucl cell
power plant is competitive in areas with high electric rates and/or severe emissions
restrictions at the local landfill site.
• ELECTRICITY SALES
• THERMAL RECOVERY
• EMISSIONS OfTsETS
F
MATURE
RODUC
COST
WITH
SCR
EXHAUST
CLEANUP
T
NO
EXHAUST
CLEANUP
I
FUEL CELL IC.E.
ENERGY CONV. ENERGY CONV.
SYSTEM SYSTEM
Fig. 4. Comparison of fuel cell to internal combustion engine energy conversion system.
-------
Conclusions
Based on (lie environmental and economic evaluation of the commercial fuel cell
energy system, the t'ollosving conclusions can be made.
• The fuel cell landfill gas to energy conversion system provides a net reduction in
total emissions svhile simultaneously mitigating the methane from the landfill gas.
• Fuel cells will be competitive at initial product prices on landfill sites located in
high electric cost areas or where [he thermal energy can be utilized. The fuel cell
will also be attractive where there is a credit for the environmental impact of fuel
cell energy conversion.
• When the projected mature product price is achieved, fuel cells will be competitive
for most application scenarios. In many situations, fuel cells will provide net revenues
to the landfill owners. This could, in the long term, result in methane mitigation
without additional cost to the ultimate consumer.
References
1 (AS l-'edcral Register, May 30, 1991, Fart III Environmental Protection Agency, 40 CFR Parts
51. 52 .mil 60, Standards ol Performance for New Statiorary Sources and Guidelines tor
Control of pAistmj; Sources, Municipal Solid Waste Landfill!,; Proposed Rule, Guideline and
Nonce ot Puhhc Healing
2 Air emissions from municipal solid waste landfills — background information for proposed
si.md.irds .mil L'mdelmes. KP.-\-450l3-90-Olla (NTIS l'B91 -197061), Mar. l'J9l. (a) p 3-30.
(I)) p .i-_\ (O I'.ihles 3 6, p[i 3-2S to 3-2K
------- |