United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-94/008 March 1994
EPA Project Summary
Proceedings: The 1992
Greenhouse Gas Emissions and
Mitigation Research Symposium
Sue Philpott, Compiler
The report documents results of the
1992 Greenhouse Gas Emissions and
Mitigation Research Symposium, spon-
sored by the U.S. Environmental Pro-
tection Agency's Air and Energy Engi-
neering Research Laboratory (EPA-
AEERL), and held in Washington, D.C.,
on August 18-20,1992. The symposium
provided a forum of exchange of tech-
nical information on global change
emissions and potential mitigation tech-
nologies. The primary objectives of the
meeting were dissemination of techni-
cal information and education in recent
research. Oral papers along with an
international panel discussion,
overheads, slides, and a GloED dem-
onstration proved for lively exchanges
in the following areas: activities in EPA,
U.S. Department of Energy (DOE), and
Electric Power Research Institute (EPRI)
on greenhouse gas emissions and miti-
gation research, and AEERL's global
emissions and technology databases;
international activities of selected in-
dustrialized and developing countries;
carbon dioxide (CO2) emissions and
their control, disposal, and reduction
through conservation and energy effi-
ciency, and carbon sequestration in-
cluding utilization of waste CO2; meth-
ane (CH4) emissions and mitigation
technologies including such topics as
coal mines, the natural gas industry,
key agricultural sources, landfills and
other cookstove emissions and control
approaches; and solar and renewable
energy sources, including renewable
energy options, alternative biomass fu-
els, advanced energy systems, solar
energy developments, and woodstove
emissions and mitigation. The proceed-
ings contain 34 submitted papers.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
The 1992 Greenhouse Gas Emissions
and Mitigation Research Symposium,
sponsored by the U.S. Environmental Pro-
tection Agency's Air and Energy Engineer-
ing Research Laboratory (EPA/AEERL)
and Acurex Environmental Corporation
was held August 18-20, 1992, in Wash-
ington, DC. Thirty-four speakers presented
papers on recent research on global
change emissions and potential mitigation
technologies. The symposium Chairper-
son was Robert P. Hangebrauck of EPA/
AEERL. This project summary includes
abstracts of the papers presented at the
symposium. The six sessions were:
I. Overview
II. International Activities
III. CO2, Emissions, Control, Disposal,
and Utilization
IV. Emissions and Mitigation of Meth
ane and Ozone Precursors
V. Biomass Emission Sources and
Sinks
VI. Energy Sources/Solar/Renewable
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Session I
Overview
(Frank T. Princiotta, EPA, Session
Chairperson)
"Greenhouse Warming: The Mitigation
Challenge," Frank T. Princiotta, EPA)
This paper describes the symposium as
a forum to discuss the state-of-the-art and
research opportunities associated with the
sources and mitigating releases of green-
house gases. Essential to discussing miti-
gation opportunities is the understanding
of fundamental driving forces for releases
of these gases, relating projected emis-
sions to anticipated global warming, ex-
amining the important greenhouse gases
and their relative contributions, and un-
derstanding the penalties associated with
delaying implementation of a mitigation
program.
"Methane Reductions are a Cost-
Effective Approach for Reducing
Emissions of Greenhouse Gases,"
Kathleen B. Hogan and Dina W.
Kruger, EPA
Methane reductions can play a large
role in providing low cost, if not profitable,
opportunities for reducing greenhouse gas
emissions, in addition to other benefits for
the atmosphere. This paper reports on
opportunities for reducing emissions of
methane that have been examined through
a number of EPA efforts and activities
developed by the Intergovernmental Panel
on Climate Change. The paper concludes
that efforts to encourage methane reduc-
tions will require identification and removal
of a number of barriers that hinder the
implementation of available technologies.
"Climate Change and Related
Activities," Kenneth Freidman, DOE
This report is a brief discussion of the
U.S. Department of Energy's (DOE's) ac-
tivities in scientific research, technology
development, policy studies, and interna-
tional cooperation that are directly related
to or have some bearing on the issue of
global climate change. Part I describes
DOE's major activities: 1) developing com-
puter models to predict rate and magni-
tude of global and regional climate change,
2) understanding the systems that control
the current and past climates of the Earth,
and 3) exchanging and communicating
data and modeling results with other cli-
mate researchers around the world. Part
II focuses on DOE's related activities in-
cluding scientific research; transportation;
alternative fuels development; residential,
commercial, and industrial efficiency; ap-
pliance and equipment efficiency; indus-
trial process technologies; industrial waste
minimization; electricity generation and
use; and policy analysis.
"EPRI's Greenhouse Gas Emissions
Assessment and Management
Research Program," D.F. Spencer and
G.M. Hidy, EPRI
This paper briefly reviews the rationale
and need for an electric utility greenhouse
gas emissions assessment and manage-
ment research program, as well as poten-
tial cost implications to society of short-
term control requirements. The balance of
the paper focuses on EPRI's directly re-
lated R&D program and its key elements,
namely: a) model development and model
evaluation activities, b) ecological effects,
c) management/mitigation research, and
d) development of an integrated assess-
ment framework. EPRI's directly related
greenhouse gas research program, includ-
ing co-funding, is expected to expend ap-
proximately $60 million over the next 4
years to address key aspects of this sig-
nificant environmental issue.
"Global Emissions Database (GloED)
Software," Lee Beck, EPA
The EPA Office of Research and De-
velopment has developed a powerful soft-
ware package called the Global Emissions
Database (GloED). GloED is a user-friendly,
menu-driven tool for storage and retrieval
of emissions factors and activity data on a
country-specific basis. Data can be se-
lected from databases resident within
GloED and/or imputed by the user. The
data are used to construct emissions sce-
narios for the countries and sources se-
lected. References are linked to the data
to ensure clear data pedigree. The sce-
nario outputs can be displayed on the-
matic global maps or other graphic out-
puts such as bar or pie charts. In addition,
data files can be exported as Lotus 1-2-3,
dBase, or ASCII files, and graphics can
be saved as a PCX file or exported to a
printer. This paper describes GloED and
how it works. It also presents future plans
for software enhancements and populat-
ing the databases.
Session II
International Activities
(Jane Leggett, EPA, Session
Chairperson)
"Beyond Rio," Hans van Zijst, Royal
Netherlands Embassy
This brief narrative explores the Dutch
perspective on the future of research and
policies on climate change. Current policy
goals and measures taken by the Dutch
government are examined, which include
issues such as energy savings, fuel con-
sumption, traffic and transport, and the
waste sector. The paper emphasizes the
strong need for international cooperation
in implementing the Convention on Cli-
mate Change.
Session III
CO2, Emissions, Control,
Disposal, and Utilization
(Ken Freidman, DOE, Session
Chairperson)
"Carbon Dioxide Sequestration,"
Robert P. Hangebrauck, Robert H.
Borgwardt, and Christopher D. Geron,
EPA
Mitigation of global climate change will
require the stabilization of atmospheric
concentration of greenhouse gases, es-
pecially carbon dioxide (CO2). CO2 can be
sequestered by flue-gas and fuel CO2 se-
questration or by atmospheric CO2 fixa-
tion/utilization. Flue-gas sequestration in-
volves separation/concentration, transport,
and either disposal or use. Disposal op-
tions are either land or ocean based. Utili-
zation is by either chemical or biological
utilization (recycling). Flue-gas-oriented
techniques in general have high economic
and energy costs, but a few areas show
potential and warrant research and devel-
opment (R&D) attention, especially those
holding promise of combined CO/sulfur
dioxide (SO2)/nitrogen oxides (NOx) con-
trol and the integrated gasification com-
bined cycle approaches. CO2 disposal is
neither a "sure thing" nor a permanent
solution, with options needing further en-
vironmental assessment. Near term, some
CO2 recycling is possible, and R&D to
examine longer-term prospects seems
warranted. Atmospheric CO2 fixation/utiliza-
tion involves either enhanced terrestrial or
marine fixation with utilization of the biom-
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ass in some cases. Atmospheric fixation
approaches which seem most attractive
are those involving enhanced biomass CO2
sequestration combined with utilization of
the biomass for energy to displace fossil
fuel. Of these, the most attractive for R&D
appear to be advanced direct combustion
using biomass and use of biomass as a
source of hydrogen to leverage fossil fuel
use for methanol production (Hydrocarb
process).
"The NOAA Carbon Sequestration
Program," Peter Schauffler, National
Oceanic and Atmospheric
Administration
Increasing attention is being given to
oceanic techniques for sequestering car-
bon in various molecular forms as part of
an overall global-change strategy. EPRI,
through a Caltech contract, is looking at
the formation and semi-permanent reten-
tion of CO2 hydrates at ocean depths of
1,000 m or so. Similar investigations are
being actively pursued by the Japanese.
EPRI and NOAA, assisted by Caltech and
George Washington University, are re-ex-
amining the feasibility of large-scale farm-
ing of microalgae as a way of collecting
CO2 from the atmosphere and upper ocean
layers, sequestering it in liquid or hydrate
form in the deep ocean and/or locking up
the carbon in the farm structure, and us-
ing the farm-produced methane and per-
haps methanol as a CO2-neutral fossil fuel
substitute.
"The Role of DOE Energy Efficiency
and Renewable Energy Programs in
Reducing Greenhouse Gas
Emissions," Eric Peterson, DOE
This presentation illustrates DOE's pro-
grams in energy conservation and energy
efficiency, and renewable, nuclear and fos-
sil energy technology research and devel-
opment. The history and the mission of
the Office of Conservation and Renew-
able Energy is described. Also, overviews
of other DOE-initiated programs such as
the Wind Energy Program are given.
"Fuzzy Logic Control of AC Induction
Motors to Reduce Energy
Consumption," R.J. Spiegel and P.
Chappell, EPA; J.G. Cleland, Research
Triangle Institute; and B.K. Bose,
University of Tennessee
Fuzzy logic control of electric motors is
being investigated under sponsorship of
EPA to reduce energy consumption when
motors are operated at less than rated
speeds and loads. Electric motors use
60% of the electrical energy generated
in the U.S. An improvement of 1% in
operating efficiency of all electric motors
could result in savings of 17 x 109 kWh/yr
in the U.S.. New techniques are required
to extract maximum performance from
modern motors. This paper describes
EPA's research program, as well as early
stages of work, to implement fuzzy logic
to optimize the efficiency of alternating
current (AC) induction motors.
"Evaluation of Methanol Production
from Hydrogen and Waste Carbon
Dioxide," Stefan Unnasch and Dan
Luscher, Acurex Environmental
Corporation
The production of methanol from waste
carbon dioxide (CO2) and hydrogen was
evaluated. Using recycled CO2 in metha-
nol fuel would reduce the emissions of
CO2 into the atmosphere. We investigated
the cost and technical status of potential
non-fossil hydrogen production technolo-
gies and CO2 recovery technologies. The
primary focus for hydrogen production was
an photovoltaic (PV) power sources.
Methanol can be produced from CO2 and
hydrogen by reacting CO2 with hydrogen
to form carbon monoxide (CO) and water.
The CO is then reacted with hydrogen to
form methanol. Producing 1.0 Ib of metha-
nol with this approach would require 4.37
kWh of electrical power for the production
of hydrogen and capture of CO2. The
methanol would cost over $3.00/gal if the
power were derived from current PV tech-
nology; about 85% of this cost is associ-
ated with hydrogen production. This cost
could be reduced by 70% with improve-
ments in PV technology that are expected
to be feasible with large scale production
and projected advances in technology. Al-
most all of the carbon in a coal gasifica-
tion system can be converted to methanol
with the addition of hydrogen. Producing
1.0 Ib of methanol from coal would require
only 1.89 kWh of electric power.
Session IV
Emissions and Mitigation of
Methane and Ozone Precursors
(M.J. Shearer, Global Change
Research Center, Session
Chairperson)
"Global Atmospheric Methane: Trends
of Sources, Sinks and
Concentrations," M.A.K. Khalil, R.A.
Rasmussen, and M.J. Shearer, Global
Change Research Center
The global cycle of methane is driven
by emissions around 550 Tg/yr from both
natural and sources related to anthropo-
genic activities, particularly the production
of food and energy. Major sources are
rice agriculture, domestic ruminants, and
wetlands. Methane is removed from the
atmosphere mostly by reacting with OH
radicals. Some methane is removed by
the soils. Over the past decade methane
concentrations have been increasing at
about 1%/yr or 16 ppbv/yr. A record of
atmospheric methane extending back
150,000 years has been constructed from
the analysis of polar ice cores. It shows
that, during this time, methane concentra-
tions have never been more than half of
present levels. The recent increase of
methane was probably caused by increas-
ing emissions. Recent changes in the trend
of methane may also be attributed to
changing levels of OH. This paper deals
with the changes in global methane con-
centrations in the past, the causes of in-
creased levels at present, and the future
of atmospheric methane. The present un-
derstanding of the global methane bud-
get provides critical facts for policies re-
lated to controlling anthropogenic sources.
"Coal Mine Methane Emissions and
Mitigation," David A. Kirchgessner,
EPA; and Stephen D. Piccot, Science
Applications International Corporation
Estimates of methane (CH4) emissions
from coal mines range from 25 to 45 Tg/yr
with a recent estimate as high as 65 Tg/
yr. At 46 Tg/yr, the estimate produced by
this project, coal mines contribute about
10% of anthropogenic CH4 emissions and
may contribute significantly to the global
change phenomenon. Although emissions
from underground mines are now believed
to be adequately characterized, virtually
no data are available on emissions from
surface mines, and data are totally lack-
ing on emissions from abandoned/inac-
tive mines and coal handling operations.
The methodology developed to calculate
emissions from underground mines is
briefly described, as is the Fourier trans-
form infrared spectroscopy technique be-
ing employed for measuring emissions
from surface mines. A nitrogen-flooding
technique for enhancing the recovery of
CH4 from coalbeds in advance of mining
is described as a possible measure for
mitigating CH4 emissions from under-
ground mines.
"Emissions and Mitigation of Methane
from the Natural Gas Industry," Robert
A. Lott, Gas Research Institute
The Gas Research Institute and EPA
are co-funding and co-managing a pro-
-------
gram to evaluate methane emissions from
U.S. natural gas operations. The purpose
of the program is to provide an emissions
inventory accurate enough for global cli-
mate modeling and for addressing the
policy question of "whether encouraging
the increased use of natural gas is a vi-
able strategy for reducing the U.S. contri-
bution to global warming." The program is
comprised of three phases: Scoping, Meth-
ods Development, and Implementation.
The purpose of Phase I was to define
the problem. Phase II of the program con-
centrated on developing techniques for
measuring steady state or fugitive emis-
sions and for calculating the highly vari-
able unsteady emissions from the variety
of sources that comprise the gas industry.
Because of the large number of sources
within each source type, techniques were
also developed for extrapolating emissions
data to similar sources within the industry.
Phase III of the program was started in
early 1992 and should be completed in
early 1994. The purpose of the current
phase of the program is to collect suffi-
cient data to achieve the accuracy goal of
determining emissions to within + 0.5% of
production.
Based on the limited amount of data
collected to date, methane emissions from
the U.S. gas industry appear to be in the
range of 1% of production.
"Emissions and Mitigation at Landfills
and Other Waste Management
Facilities," Susan A. Thorneloe, EPA
Landfills and other waste management
sources of methane are amenable to
cost-effective control. Consequently, these
sources have been given a high priority
for clarification of their emission potential.
EPA is conducting research to determine
the emission potential and mitigation op-
portunities for cost-effective control for the
major sources of greenhouse gases. EPA/
AEERL is responsible for developing more
reliable global and country-specific esti-
mates for the major sources of green-
house gases including waste management,
coal mines, natural gas production/distri-
bution, energy usage, cookstoves, and bio-
mass combustion. AEERL has gathered
data that have resulted in the develop-
ment of more reliable estimates for land-
fills. Research has been initiated to char-
acterize the methane potential of other
waste management facilities including
wastewater treatment lagoons, septic sew-
age systems, and livestock waste.
AEERL is also documenting the current
state of technology for utilization projects.
Currently, 114 landfill gas-to-energy
projects are occurring in the U.S. and
about 200 worldwide. Technology trans-
fer/technical assistance programs have
been initiated to help encourage the utili-
zation of waste methane and to help imple-
ment the upcoming Clean Air Act (CAA)
regulations for municipal solid waste land-
fills. For example, AEERL is working with
a consortium of local government repre-
sentatives to explore the application of
EPA research on methane/energy recov-
ery from municipal solid waste landfills.
AEERL also serves on the International
Energy Agency Expert Working Group on
Landfill Gas and the Steering Committee
for the Solid Waste Association of North
America. AEERL is also responsible for
demonstrating innovative approaches to
the control of waste methane such as the
application of fuel cell technology to re-
cover energy from landfills gas and di-
gester gas.
This paper describes the emission po-
tential for waste management sources and
the mitigation opportunities. It also pro-
vides an overview of some of the barriers
in the U.S. that affect methane utilization.
This research is funded through EPA's
Global Climate Change Research Pro-
gram.
"Fuel Cell Power Plant Fueled by
Landfill Gas," R.J. Spiegel, EPA, and
G.J. Sandelli, IFC
International Fuel Cells Corporation
(IFC), a subsidiary of United Technolo-
gies Corporation, is conducting an EPA-
sponsored program to demonstrate meth-
ane control from landfill gas using a com-
mercial phosphoric acid fuel cell power
plant. This is the world's first commercial-
scale demonstration to control methane
emissions from landfills using a fuel cell
energy recovery system. EPA is interested
in fuel cells for this application because it
is potentially the cleanest energy conver-
sion technology available. This paper dis-
cusses the project in general and describes
some results to date, with emphasis on
the landfill gas pretreatment system.
"Methane Emissions from Rice
Agriculture," M.A.K. Khalil, M.J.
Shearer, and R.A. Rasmussen, Global
Change Research Center
Rice agriculture has long been recog-
nized as a major source of methane (CH4).
Global budgets of methane have gener-
ally included emissions of about 100 Tg/yr
(Tg = 1012 g) from rice agriculture (range
of 50-300 Tg/yr) and constituting about
20% of emissions from all sources (range
14-40%).
During the last decade, a number of
systematic experiments have been re-
ported on methane emissions from rice
fields. Seasonal averages range from 0 to
40 mg/m2/hr. Factors affecting the flux of
methane include irrigation regime, fertil-
izer, soil temperature, and soil type.
The most recent global estimates put
the emissions from rice paddies at 50 to
100 Tg/yr. The major cause of increasing
methane emissions from rice paddies over
the past 50 years appears to be the tre-
mendous increase in area planted to rice.
Emissions appear to have stabilized over
the past decade. Future increases in meth-
ane emissions from rice will probably de-
pend on access to irrigation and the use
of organic fertilizer.
"Livestock Methane: Sources and
Management Impacts," Donald E.
Johnson, T. Mark Hill, and G.M. Ward,
Colorado State University
Herbivorous animals, particularly rumi-
nants, have a digestive tract that facili-
tates extensive symbiotic microbial diges-
tion of dietary structural plant carbohy-
drates. A by-product of this symbiotic mi-
crobial process is an estimated 70 Tg of
methane globally per year, primarily from
cattle and buffalo. Cattle methane emis-
sions equal 6 +/- 0.5% of their diet energy
(2% by wt) for most global conditions stud-
ied. Emissions by U.S. feedlot cattle are
uniquely lower at about 3.5% of diet en-
ergy. A major lack of information on size,
diet, class distribution and percentage loss
from developing country livestock pre-
cludes accurate definition of this source,
which is about 65% of global. Manure
disposal from livestock may produce an
additional 12 Tg globally, primarily through
anaerobic lagoons. Possible ameliorative
strategies include the decreased use of
lagoon disposal or the capture of this meth-
ane. General efforts should concentrate
on improving productivity of beef and dairy
cattle production systems, which will sec-
ondarily reduce methane.
"Ozone and Global Warming," Robert
P. Hangebrauck and John W. Spence,
EPA
Changes in several trace substances in
the Earth's atmosphere are affecting glo-
bal radiative forcing. Those substances
that seem to be in the greatest state of
change now and projected into the future
are carbon dioxide, ozone (and its precur-
sors and depleters), and aerosols. Con-
ceivably, countervailing changes in the ra-
diative forcing effects of these substances,
-------
especially ozone and aerosols, may be
temporarily hiding or at least changing the
"greenhouse signal"—an unfortunate cir-
cumstance, particularly if the overall im-
pacts that will eventually occur are unpre-
dictable or difficult to reverse quickly. If in
fact the greenhouse signal is partially be-
ing obscured at present, there is also po-
tential for this effect becoming less signifi-
cant in the decades ahead because of 1)
a continuation of increases in greenhouse
gas emissions, 2) saturation of the tropo-
spheric aerosol effect plus controls on sul-
fur emissions, and 3) increasing tropo-
spheric ozone. The substantial complexi-
ties in factors affecting ozone and aero-
sols are discussed with emphasis on ozone
and its precursors, including methane, non-
methane hydrocarbons, carbon monoxide,
and nitrogen oxides. Quantifying radiative
forcing is of substantial importance. EPA
is undertaking research to enhance the
ability to estimate indirect factors contrib-
uting to forcing, including measures such
as Global Warming Potentials. Many of
the important but difficult factors to re-
solve are of the indirect type. A number of
potential indirect forcing effects are identi-
fied along with an estimate of direction
(sign).
"Overview of Methane Energy and
Environmental Research Programs in
the United Kingdom," Suzanne A.
Evans, Anton van Santen, Paul S.
Maryan, Caroline A. Foster, Keith M.
Richards, Harwell Laboratory
The biofuels program of research and
development forms an important part of
the UK Department of Energy's renew-
able energy program. This program be-
gan in the mid-1970s as a response to
the oil crisis of that time and was part of a
much wider look at alternative energy sup-
plies. The initial driving force for biofuels
and other renewables research was the
prospect of greater diversity, and hence
security of energy supply for the nation.
More recently, concerns over the environ-
ment and the need for sustainable sources
of energy have added further strength to
the case for using "environmentally
friendly" renewables. This paper reviews
the history of the biofuels program, its
present content, and considers where fu-
ture emphasis might lie.
Session V
Biomass Emission Sources and
Sinks
(Robert Dixon, EPA, Session
Chairperson)
"The Carbon Balance of Forest
Systems: Assessing the Effects of
Management Practices on Carbon
Pools and Flux," Robert K. Dixon and
Jack K. Winjum, EPA, and Paul E.
Schroeder, ManTech Environmental
Technology, Inc.
Forests play a major role in the Earth's
carbon cycle through assimilation, stor-
age, and emission of CO2. Establishment
and management of boreal, temperate,
and tropical forest and agroforest systems
could potentially enhance sequestration of
carbon in the terrestrial biosphere. A bio-
logic and economic analysis of forest es-
tablishment and management options from
94 nations revealed that forestation,
agroforestry, and silviculture could be em-
ployed to conserve and sequester 1
gigaton (Gt) of carbon annually over a 50-
year period. The marginal cost of imple-
menting these options to sequester 55 Gt
of carbon would be approximately $107
ton.
"Global BIOME (BlOspheric Mitigation
and adaptation Evaluation) Program,"
Robert K. Dixon and Jack K. Winjum,
EPA
Preliminary assessments suggest that
forests and agroecosystems can be man-
aged to conserve and sequester carbon,
thereby reducing the accumulation of
greenhouse gases in the atmosphere. Bio-
mass utilization is a necessary compo-
nent of a sustained terrestrial carbon se-
questration effort. The Global BIOME
(BlOspheric Mitigation and adaptation
Evaluation) Program will consist of a) tech-
nical assessments of effectiveness of ter-
restrial biosphere management options and
biomass fuel technology in reducing at-
mospheric accumulation of greenhouse
gases, b) demonstration projects to as-
sess the technical and economic feasibil-
ity of applying agricultural and forest man-
agement options and biomass fuel substi-
tution, c) regional, national, and global
assessments of effectiveness of terrestrial
biosphere management and adaptation
options, and d) assessment of practices
and technologies that, if implemented,
could facilitate adjustment of forest and
agroecosystems to global climate change.
The Global BIOME initiative is a compo-
nent of EPA's Office of Research and
Development national Global Change Re-
search Program. The research is man-
aged by the Agency's laboratories: ERL-A,
ERL-C, AEERL, and AREAL. Research is
conducted by EPA scientists in coopera-
tion with universities, other federal agen-
cies and laboratories, and contractors.
"Agricultural Management and Soil
Carbon Sequestration: An Overview of
Modeling Research," Robert B.
Jackson IV and Thomas O. Barnwell
Jr., EPA; Anthony S. Donigian Jr. and
Avinash S. Patwardhan, Aqua Terra
Consultants; and Kevin B. Weinrich
and Allen L. Rowel I, Computer
Sciences Corporation
Soil carbon fluxes and pools are pro-
foundly affected by agricultural manage-
ment, which is in turn affected by national
and international agricultural policies. This
paper briefly describes the framework and
some details of a computer modeling re-
search strategy that is being implemented
at the Athens Environmental Research
Laboratory (AERL). The objective of the
research is to determine the potential for
U.S. agroecosystems to accumulate and
sequester carbon as a means of slowing
the global increase in atmospheric carbon
dioxide.
"Assessment of the Biogenic Carbon
Budget of the Former Soviet Union,"
Tatyana P. Kolchugina and Ted S.
Vinson, Oregon State University
A framework was created to quantify
the natural terrestrial carbon cycle of the
former Soviet Union (FSU). The organiza-
tion of the carbon cycle parameter and
georeferenced database, which supports
the framework and the calculations, which
are required to establish the carbon bud-
get, are performed with personal com-
puter hardware and commercially avail-
able spreadsheet software. Based on the
framework, net primary productivity (NPP)
-------
for the FSU was estimated at 6.2 +/- 1.7
GT (109 tons) C/yr, the vegetation carbon
pool at 118.1 +/- 28.5 GT C, the litter
carbon pool at 18.9 + 4.4 GT C, and total
soil carbon pool at 404.0 +/38.0 2GT C.
The components of the carbon budget
obtained with the framework were in good
agreement with estimates from other pub-
lished sources. The framework will allow
the role of the FSU in the global carbon
cycle to be assessed. The extent of forest
and agricultural ecosystems within the FSU
that can be technically managed on a
sustainable basis to conserve and seques-
ter carbon may also be determined with
the framework.
"Household Fuels in Developing
Countries: Global Warming, Health,
and Energy Implications," Kirk R.
Smith, Program on Environment, and
Susan A. Thorneloe, EPA
Although individually small, the wide-
spread and daily use of household stoves
with poor combustion efficiency in devel-
oping countries raises questions about
possible global warming and other envi-
ronmental implications of their airborne
emissions. To explore the possible utility
of efforts to measure the emissions from
representative samples of these devices,
a small pilot study of greenhouse gas
emissions of biomass and fossil-fuel stoves
was undertaken in Manila. The results,
although based on only a few measure-
ments, indicate that such stoves may have
a significant role in global greenhouse gas
inventories; be subject to substantial im-
provement through alternative technolo-
gies; and that policy measures should con-
sider energy and health implications as
well. As a consequence, a larger set of
studies is being planned for India, China,
Thailand, and Brazil. This research is
funded through EPA's Global Climate
Change Research Program. Research on
emissions and mitigation of major sources
of greenhouse gases is being conducted
by EPA/AEERL.
"The Potential for Energy Crops to
Reduce Carbon Dioxide Emissions,"
R.L. Graham, Oak Ridge National
Laboratory
Energy crops are herbaceous or woody
plants grown specifically to produce biom-
ass for combustion and production of elec-
tricity or for conversion to fuels such as
ethanol. When grown intensively, such
crops can yield up to 43 dry Mg biomass/
ha/yr in the temperate zone although yields
of 10 to 20 Mg are more typical.
By substituting sustainably grown biom-
ass for fossil fuels, CO2 emissions from
energy consumption can be reduced sig-
nificantly. Although biomass fuels are net
emitters of CO2, because fossil fuels are
used in the production of energy crops
(e.g., fertilizers, transportation), biomass
fuels emit much less CO2than fossil fuels
per unit of energy produced. A hectare of
U.S. farmland on the average could pro-
duce sufficient biomass to reduce annual
CO2 emissions by 5 Mg C if such biomass
were used to produce electricity that would
otherwise be produced with coal.
Within the U.S., at least 131 million
hectares of farmland could support en-
ergy crop production. Much of this land
lies in the midwest although the southeast
also contains considerable acreage. More
acreage can support herbaceous energy
crops than woody crops as there are her-
baceous crops that can tolerate drier con-
ditions than any woody crop.
The potential for energy crops to re-
duce CO2 emissions will depend on how
much land can be profitably dedicated to
energy crops. Farmers will adopt energy
crops when it is economically advanta-
geous for them to do so. Power compa-
nies will adopt biomass energy when the
cost of energy from fossil fuels exceeds
that from biomass. Government policies
and regulations affect both these relation-
ships. Currently biomass crops must com-
pete with subsidized agricultural crops
thereby inflating the price of biomass to
an energy facility. On the other hand, pol-
lution regulations can favor energy crops
as a fuel source since biomass crops can
burn cleaner than coal.
Session VI
Energy Sources/Solar/
Renewable
(Robert Williams, Princeton
University, Session Chairperson)
"Roles for Biomass Energy in
Sustainable Development," Robert H.
Williams, Princeton University
Biomass (plant matter) accounts for
15% of world energy use and 38% of
energy use in developing countries. But
most biomass is used inefficiently, mainly
for cooking and heating in rural areas of
developing countries, and often in much
the same way it has been used for millen-
nia. Biomass can also be converted into
modern energy carriers such as gaseous
and liquid fuels and electricity that can be
widely used in more affluent societies. The
most promising options are biomass-integrated
gasifier/gas turbine power systems as an al-
ternative to coal-based power plants and
biofuels for fuel-cell vehicles as an alternative
to gasoline for internal-combustion-engine ve-
hicles. The prospects are good that these
technologies could be competitive with con-
ventional fossil fuel technologies at present
world energy prices.
The large-scale utilization of biomass
for energy can provide a basis for rural
development and employment in develop-
ing countries, thus helping to curb urban
migration. In addition, if biomass is grown
sustainably, its production and use cre-
ates no net buildup of carbon dioxide (CO2)
in the atmosphere, because the CO2 re-
leased during combustion is offset by the
CO2 extracted from the atmosphere dur-
ing photosynthesis.
Biomass for energy can be obtained
from residues of ongoing agricultural and
forest product industries, from harvesting
forests, and from dedicated plantations.
The harvesting of forests for biomass is
likely to be limited by environmental con-
cerns. Over the next couple of decades
new bioenergy industries will be launched
primarily using residues as feedstocks.
Subsequently, the industrial base will shift
to plantations, the largest potential source
of biomass.
The most promising sites for planta-
tions are deforested and otherwise de-
graded lands in developing countries and
excess croplands in the industrialized
countries. Revenues from the sale of bio-
mass crops grown on plantations estab-
lished on degraded lands can help finance
the restoration of these lands. Establish-
ing plantations on excess croplands can
be a new livelihood to farmers who would
otherwise abandon their land because of
foodcrop overproduction. In either case,
biomass plantations can, with careful plan-
ning, substantially improve these lands
ecologically relative to their present uses.
But a substantial and sustained research
and development effort is needed to en-
sure the realization and sustainability of
high yields under a wide range of growing
conditions. Moreover, the establishment
and maintenance of biomass plantations
must be carried out in the framework of
sustainable economic development in
ways that are acceptable to the local
people.
Ultimately, land and water resource con-
straints will limit the contributions that bio-
mass can make as an energy source in
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advanced societies. But biomass energy
can make major contributions to sustain-
able development before these limits are
reached, if biomass is grown productively
and sustainably and efficiently converted
to modern energy carriers that are used in
energy efficient end-use technologies.
"An Analysis of the Hydrocarb Process
for Methanol Production from
Biomass," Yuanji Dong and Meyer
Steinberg, Hydrocarb Corporation, and
Robert H. Borgwardt, EPA
A pilot plant is being designed to evalu-
ate the technical feasibility of producing
transportation fuel from biomass by the
Hydrocarb process. As a basis for that
design, computer simulations and experi-
mental studies have been carried out to
establish optimum process conditions for
a range of feedstocks that are anticipated
for pilot plant tests. This paper discusses
the results of simulations to determine the
operating parameters and performance
when using urban wastes such as
greenwaste and sewage sludge as feed-
stocks. The simulations were used to con-
figure the process steps for maximum fuel
(methanol) production, to determine feed
rates, and to estimate thermal efficiency.
The results indicate that about 77 kg of
methanol can be produced from 79 kg of
dry greenwaste when sludge and digester
gas are fed as co-feedstocks in a ratio of
0.2. The optimum system pressure is found
to be 50 atm (5 MPa). Temperatures of
900°C for gasification and 1000°C for
methane pyrolysis are recommended on
the bases of thermodynamics, kinetics,
and the limitations of materials of con-
struction. Thermal efficiency at these con-
ditions is estimated to be 74%.
"Alternative Fuels from Biomass,"
Charles E. Wyman, National
Renewable Energy Lab
Substitution of biofuels derived from cel-
lulosic biomass for conventional fuels
would reduce the accumulation of carbon
dioxide in the atmosphere and the possi-
bility of global climate change, improve
our energy security and trade deficit, revi-
talize rural and farm economies, and ad-
dress urban air pollution and waste dis-
posal problems. The major fractions of
biomass, cellulose and hemicellulose, can
be broken down into sugars that can be
fermented into ethanol. Through technol-
ogy advances for producing ethanol, the
projected cost at the plant gate has been
reduced from about $3.60/gal 10 years
ago to $1.27/gal, and opportunities have
been identified to further drop the price to
$0.67/gal, a price competitive with gaso-
line from oil at $25/bbi, within 10 years.
Through anaerobic digestion, a consor-
tium of bacteria can break down cellulosic
biomass to generate a medium-Btu gas
that can be cleaned up for pipeline-quality
methane. The cost of this methane has
been reduced to about $4.50/MBtu (106
Btu) for municipal solid waste (MSW) feed-
stocks, and technology advances could
drop the price to about $2.00/MBtu. Algae
could consume carbon dioxide from power
plants and produce lipid oil that can be
converted into a diesel fuel substitute. Pro-
jected costs for this biodiesel have dropped
from almost $18.00/gal to about $3.50/gal
now, with a target of $1.00/gal. Biomass
can also be gasified to a mixture of car-
bon monoxide and hydrogen for catalytic
conversion into methanol. Currently,
methanol from biomass is projected to
cost about $0.85/gal, and with improved
technology, a cost of $0.50/gal could be
realized. Catalytic processing of pyrolytic
oils from biomass produces a mixture of
olefins that can be reacted with alcohols
to form ethers such as methyl tertiary bu-
tyl ether (MTBE) for use in reformulated
gasoline to reduce emissions. Costs could
be competitive today for olefins from MSW.
Because biofuels technologies require little
if any fossil fuel inputs, carbon is recycled
through their use, reducing substantially
the net amount of carbon dioxide released
to the atmosphere.
"Co-production of Methanol and
Power," William Weber, EPRI; Arden B.
Walters, Florida Power & Light
Company; and Samuel S. Tarn, Bechtel
Group, Inc.
Integrated Coal Gasification Combined
Cycle (IGCC) is one of the emerging tech-
nologies for electric power generation from
coal. Under contract with Florida Power &
Light (FPL) and Electric Power Research
Institute (EPRI), Bechtel is to design an
IGCC/methanol co-production plant that is
suitable for utility operation of a base-
loaded power plant. The potential benefits
of methanol co-production in an IGCC plant
are identified and quantified.
Shell and Dow gasifiers are selected for
this study only to illustrate the potential
effects of the dry-feed and slurry-feed gas-
ification process on methanol production.
The combined-cycle power plant features
the GE Model MS-7001F gas turbines,
heat recovery steam generation (HRSG)
with steam reheat, and duct firing. The
fuel-grade methanol plant design is based
on Chem Systems' Liquid Phase Metha-
nol (LPMEOH) Process. Two operating
modes of the methanol plant are consid-
ered: the recycle mode (RM) and the
once-through mode (OTM).
Results from cases with the slurry-feed
gasifiers and OTM plant are presented in
this paper. They have indicated that metha-
nol co-production can increase the equiva-
lent availability of an IGCC plant to that
for a natural gas fueled combined cycle
plant. Methanol co-production can also re-
duce the risk of the lower than anticipated
gasifier availability.
"EPA's Cost-shared Solar Energy
Program," Ronald J. Spiegel, EPA
The objective of this program is to es-
tablish and demonstrate solar energy
cost-shared commercialization projects to
demonstrate how they can be used to
displace fossil fuels. The program will also
have a major impetus to validate the abil-
ity of solar energy to be used as a pollu-
tion mitigation technology. Further, the
demonstrations will assist in removing ob-
stacles to the marketplace for solar tech-
nologies by assisting in quantifying envi-
ronmental concerns. This paper discusses
a project that has just commenced in the
area of photovoltaic demand-side power
supplies. Additional discussion is provided
relative to future projects that are being
contemplated.
"Photovoltaic Developments," Jack L.
Stone, National Renewable Energy
Laboratory
Photovoltaics, the direct conversion of
sunlight to electricity, is an environmen-
tally pristine, renewable energy option cur-
rently used in a large number of interna-
tional applications, principally non-
grid-connected in remote locations. Ex-
amples include water pumping, communi-
cations, vaccine refrigeration, and village
power. Over the past 15 years, a very
aggressive research and development pro-
gram carried out by DOE has continued
to improve photovoltaic performance and
reliability and has contributed to lower pro-
duction costs. Along with these improve-
ments have come a large number of new,
cost-effective uses, including larger power
installations in a utility environment. This
technical and economic progress is re-
viewed to represent the current status of
this renewable energy option. Near-term
plans for large-scale installations in the
U.S. are discussed along with the required
costs for competitiveness with conventional
electricity generation options.
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"Advanced Energy Systems Fueled
from Biomass," Carol R. Purvis and
Keith J. Fritsky, EPA
The concentration of CO2, a greenhouse
gas, is increasing by an estimated 0.5%
per year. CO2 emissions from fossil fuel
combustion quadrupled between 1950 and
1980. Conversion of renewable biomass
to energy is CO2, neutral and produces
lower SO2 and NOx emissions than fossil
fuel combustion.
EPA/AEERL is studying two biomass
conversion technologies: conventional
combustion in a boiler coupled with a
steam turbine system and gasification in a
gasifier coupled with an aero derivative tur-
bine system. In-house research is address-
ing the problems encountered in conven-
tional systems with regard to emissions,
tube fouling, bed agglomeration, and low
thermal efficiency. Extramural research is
addressing the problems of advanced sys-
tems with regard to fixed/fluidized-bed gas-
ifiers, alkali/particulate cleanup, gas com-
patibility with turbines, and system effi-
ciency. The results will provide data for
owner/operators to improve system per-
formance and for designer/developers to
demonstrate advanced systems. This re-
search will help promote biomass-for-energy
as a global warming mitigation strategy
by focusing on a need to maximize biom-
ass resources through increased utiliza-
tion efficiency.
"Programs and Policy Impacts
Attributable to Regional Biomass
Program Woodstove Research
Efforts," Stephen Morgan, EPA
The decision by the CONEG Policy Re-
search Center in the spring of 1985 to
embark upon a field evaluation of
woodstoves led to an ambitious and so-
phisticated 6-year research program that
has had profound impacts on the evolu-
tion of the industry. The initial interest in
exploring the claims of manufacturers
about the efficiency, particulate emissions,
and creosote buildup in catalytic, catalytic
add-on, and non-catalytic "high tech"
woodstove models readily expanded to
undergird much of the conceptual thinking
that informed the EPA's participatory regu-
lations negotiations process engaging the
industry, the Agency and environmental-
ists. Since the publication of the EPA cer-
tification standards in 1987 and the labo-
ratory testing methodology utilized to sup-
port the standard, the Northwest Regional
Biomass Program (NRBP)-sponsored re-
search has moved on to test the field
durability of certified stoves. The early,
disappointing findings in that field testing
identified structural, design and materials
flaws that have directly contributed to im-
proved stove designs in the second gen-
eration of certified stoves.
Sue Philpott is with Acurex Environmental Corp., Durham, NC 27713.
Keith J. Fritsky is the EPA Project Officer (see below).
The complete report, entitled, "Proceedings: The 1992 Greenhouse Gas Emissions
and Mitigation Research Symposium," (Order No. PB94-132180/AS; Cost:
$61.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U. S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-94/008
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