Biomass resources represent a renewable carbon and energy source that can be utilized in many ways such as conversion to liquid fuel for transportation, or as a solid, liquid or gaseous fuel for residential heating and cooking. The talks in this session will illustrate the role of LCA as a valuable decision support tool that can help to identify the preferred routes for biomass utilization in a particular geographical region.
Key Discussion Points:
- Impact of biofuel conversion efficiency on their LCA outlook
- The impact of co-product allocation on the life cycle impact of biofuels
- Non-GHG impacts of biomass utilization
- Geographic variability in bioenergy LCA outcomes
- Social implications of fuel choices that are not considered in LCA
|13:30||Binod Neupane, Sharon Klein and M. Clayton Wheeler
Life Cycle Energy and Greenhouse Gases Emissions Assessment of Drop-in Biofuel Production in Maine
ABSTRACT. As concerns over climate, energy security and economic development grow, the search for alternative energy sources intensifies. Many alternative energy sources are known today. However, developing liquid fuels that can replace petroleum transportation fuels is particularly challenging. While ethanol from corn is a well-established technology, recent efforts have focused on drop-in biofuels that would be compatible with existing transportation infrastructure. Among biomass feedstocks that have been explored for drop-in biofuels, biomass from forest resources (eg. forest residue) has garnered much support because of its domestic availability and its ability to provide solutions in regard to the issues debated in corn-based ethanol. We assess the energy and greenhouse gas (GHG) emissions of an infrastructure compatible drop-in biofuel produced from forest residues via a Thermal DeOxygenation (TDO) pathway, which was developed at the University of Maine. The results are then compared with the conventional petroleum counterpart. The TDO drop-in fuel pathway is an advanced drop-in fuel production technology, which requires a lower quantity of externally supplied hydrogen to upgrade oil to diesel-range fuels. A life cycle assessment model was developed in R-software using TDO process data and data from The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Results reveal that depending on the bio-char handling scenario, the TDO drop-in diesel shows approximately 68- 118% of GHG reductions compared to that of its conventional diesel counterpart. Similarly, the TDO drop-in diesel has 73-111% less fossil fuel energy consumption in comparison to conventional diesel. We have developed different scenarios to assess the energy and emissions tradeoffs across the fuel supply chain. Our LCA model can be adapted to assess similar technologies and supply chains in other geographic regions.
|13:45||Erik Budsberg, Jordan Crawford, Rick Gustafson, Renata Bura and Maureen Puettmann
Ethanologens vs. Acetogens: Environmental impacts of two bioethanol fermentation pathways.
ABSTRACT. Bioconversion production of bioethanol from cellulosic feedstock is generally proposed to use direct fermentation of sugars to ethanol. Another potential route for ethanol production is fermentation of sugars to acetic acid followed by hydrogenation to convert the acetic acid into ethanol. The advantage of the acetogen pathway is an increased ethanol yield; however, using an acetogen requires the additional hydrogenation, which could substantially affect the life cycle global warming potential of the process. Assuming a poplar feedstock, a cradle to grave Life cycle assessment (LCA) is used to evaluate the environmental impacts of an acetogen based fermentation pathway. An LCA of a fermentation pathway that uses ethanologen fermentation is developed for comparison. It is found that the ethanologen and acetogen pathways have Global Warming Potentials (GWP) that are 97 % and 50 % lower than the GWP of gasoline, respectively. When the absolute GWP reduction compared to gasoline is calculated using a unit of land basis, the benefit of the higher ethanol yield using the acetogen is observed as the two pathways achieve similar GWP savings. The higher ethanol yield in the acetogen process plays a crucial role in choosing a lignocellulosic ethanol production method if land is a limited resource.
|14:00||Rebe Feraldi, Sarah Cashman, Susan Thorneloe, Melissa Huff, Anne Marie Molen, Molly Rogers, Beverly Sauer and Shelly Schneider
Comparative Life Cycle Assessment of Cooking Fuel Options in China and India
ABSTRACT. In both China and India, about half of each country’s population currently uses traditional cookstove fuels and over a million annual premature deaths are attributed to Household Air Pollutants (HAPs). Consumption of these traditional cookstove fuels, e.g., coal and wood, combined with rapid rates of urbanization and industrialization, has contributed to the countries’ resource depletion, deforestation, desertification, and biodiversity loss. The U.S. Environmental Protection Agency (EPA) is working in collaboration with the United Nation Foundation’s Global Alliance for Clean Cookstoves (GACC) and other international partners to conduct research and provide tools to inform decisions in the clean cookstoves sector in these countries. Toward this end, this study scope includes a life cycle assessment (LCA) comparing the environmental footprint of current and possible fuels used for cooking within China and India.
Detailed LCI profiles for the following cooking fuels in each country have been compiled on the basis of 1 Gigajoule (GJ) of useful energy delivered to and used by consumers: electricity; natural gas; liquefied petroleum gas (LPG); coal; kerosene; biomass (crop residue, dung, charcoal, firewood, wood pellets); biogas; sugarcane ethanol; and dimethyl ether (DME). The profiles for current fuel mix used are compared to scenarios of projected differences in and/or cleaner cookstove fuels. The results for the comparisons are reported by life cycle stage (feedstock production, fuel processing, distribution, and cookstove use) for a suite of relevant life cycle impact assessment (LCIA) mid-point indicators: global climate change, energy demand, fossil depletion, water input, particulate matter formation, acidification, eutrophication and photochemical smog formation.
Data for this study are developed from existing literature and LCI sources. The primary intended use of this study is to provide comparative data to inform policy decisions, i.e., a more holistic analysis of correlations between changes in cookstove fuel scenarios to those in potential local and global environmental impacts. EPA will make these data available to the public in order to support their efforts to improve and facilitate access to data and information on emissions from a wide range of cookstove fuel types and use-scenarios in China and India.
|14:15||Seema Patel, Sarah Cashman, Raynee Chiang, Daniel Ertis, Rebe Feraldi, Melissa Huff, Carlie Knope and Molly Rodgers
Guide for Sustainable Cookstove Fuel Production, Distribution and Use in Developing Countries
ABSTRACT. The use of traditional cookstoves in developing countries affects millions of lives on a daily basis with far-reaching health, environmental, and economic impacts. The United Nation Foundation’s Global Alliance for Clean Cookstoves (GACC) is working towards providing access to credible information on cookstove fuel production, distribution and use to facilitate communication of the full impacts of commonly used and potentially cleaner fuels.
The study scope covers fuels for cooking in Nigeria, Uganda, Ghana, Kenya, India, China, Bangladesh, and Guatemala. The focus is fuels currently used in these target countries: ethanol (from sugarcane and sawdust), non-carbonized and carbonized briquettes (from wood, bamboo, and crop residue), biomass pellets, wood chips, whole wood, biogas from anaerobic digestion of organic waste (from crop residues and cattle dung), and LPG stored in canisters.
GACC is completing a comprehensive LCA of these country and fuel combinations by evaluating a suite of environmental impact categories: global climate change, energy demand, water input, black carbon emissions, particulate matter formation, acidification, eutrophication and smog formation. The economic and social impacts of cookstove fuel choices are equally important to the environmental considerations, with economic and social sustainability being imperative to achieve adoption of cleaner fuels. The full life cycle costs, as well as affordability, employment and training, existing infrastructure and trade, and current fuel production and use are assessed. Social indicators covering the potential increase in skills for women, government policies, challenges for distributing fuels, reliability of acquiring fuels, time savings in the household, and the safety of household members are described qualitatively and through case studies.
Data for this study is developed from existing literature sources and extensive communication with GACC’s partner organizations and enterprises within each of the countries. A key project component is to effectively communicate the information collected to a variety of audiences ranging from policy-makers, researchers, enterprises, donors and investors, and others. GACC is doing this through development of a web-based comparative fuel analysis tool. The tool will be publicly accessible via GACC’s website. Access to such data will allow local governments, ground level enterprises, and higher level strategic planners to make informed decisions for transitioning to cleaner and safer fuels that are economically viable and socially responsible.