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 ------- 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- ------- 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 ------- 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. ------- "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 ------- |