The University of Texas at Austin

EPA: XA-83379501-0

Analysis of Innovative Feedstock Sources & Production Technologies for Renewable Fuels Cockrell School of Engineering, Center for Energy and Environmental Resources
The Center for Energy and Environmental Resources (CEER) researchers in cooperation with the Center for Electromechanics (CEM) and the Department of Mechanical Engineering (ME) completed an assessment of non-traditional biofuel feedstocks. (Download full report) (26 Mb)

Suggested Citation:

Murphy, C.F., O’Donnell, M., Alhajeri, N., McDonald-Buller, E., Strank, S., Liu, M.H-P., Webber, M., Allen, D.T., Hebner, R. Analysis of innovative feedstock sources and production technologies for renewable fuels, EPA Project Number XA-83379501-0, Final Report to EPA, 2010

Life Cycle Assessment Methodology for Transportation Fuels
David T. Allen, Cynthia F. Murphy - Chapter 2 - (PDF)
Lifecycle assessment (LCA) is a system-level view of a process that considers all material and energy flows (inputs and outputs) associated with a process or product. This study focused on the process of LCA for greenhouse gas (GHG) emissions associated with fuel production.

Sugarcane

Sugarcane Ethanol - Cynthia F. Murphy - Chapter 3 - (PDF)
Sugarcane has been viewed as a significant success in Brazil and is the second most likely source of starch-based ethanol (after corn). But this is not a problem-free solution. As currently practiced in the US, the cultivation of sugarcane is extremely water intensive and a significant portion occurs on organic soils in the Everglades. Burning is used to facilitate harvesting and to increase sugar content, and thus yield, but it also contributes to emissions.

Citrus Waste Ethanol - Cynthia F. Murphy - Chapter 4 - (PDF)
Citrus waste is a potential source of ethanol that if not used for a beneficial source of material would normally contribute to the food waste stream. However, the total available supply does not support volumes necessary to meet demand so this will likely be at best a niche market. Moreover, like cellulosic ethanol, the process to convert the citrus waste to ethanol is not mature.

Cotton

Cottonseed Oil Biodiesel - Cynthia F. Murphy - Chapter 5 - (PDF)
Cottonseed, although usable for future cotton crops or as a source of cooking oil or animal feed, is generally less valuable than cotton fiber. Expansion of cotton growth to meet demands for fuel is likely problematic. Even with the advent of genetically modified seed, cotton cultivation tends to require significant amounts of pesticides. While there is a strong correlation between irrigation and yield (irrigation of cotton can double the yield), only slightly more than one-third of US cotton is currently irrigated. However, increased demand for cotton products would likely encourage greater amounts irrigation, which would have a negative impact on aquifers. Growing cottonseed for fuel production is also land-intensive. If all available land in the southern US (approximately two-thirds of the total) were converted to growing cotton, less than 20% of the current demand for petroleum motor diesel could be met by cottonseed biodiesel. In addition, the amount of lint created by meeting cottonseed demand for biodiesel demand could unbalance the commercial cotton market

  Algal Oil Biodiesel - Cynthia F. Murphy - Chapter 6 - (PDF)
Algal biofuel is currently of interest due to algae’s rapid growth, ability to prosper in water of poor quality, and possible higher productivity than any other plant-based source of fuel. This study shows algae growth can require significant amounts of water, energy to move water and high value nutrients. Consequently, synergies such as those with waste water treatment or agricultural runoff, ocean-based systems, or heterotrophic growth are being investigated.

Algae Fields

Gasoline and Petroleum Diesel - Maureen Kaplan, Cynthia F. Murphy, David T. Allen - Chapter 10 - (PDF)
This section addresses the use of water associated with gasoline and petroleum diesel. For analysis of greenhouse gases the authors defer to the National Energy Technology Laboratory report from 2008.  This work provides an important perspective for similar considerations in emerging biofuels for which data are limited.

Environmental Impact of Fuel Use -  David T. Allen, Elena McDonald-Buller, Nawaf Alhajeri, Hsing-Pang Liu, Shannon Strank, Cynthia F. Murphy,  - Chapter 11 - (PDF)
Regional emission scenarios are addressed in this chapter, which considers the impact of replacing conventional fuels with biofuels in vehicles at rates of 30%, 50%, and 100%, using emission characteristics published in the literature. In addition, to provide a check on the emissions characteristics measurements were performed using an engine simulator. None of these scenarios showed a significant impact on air quality.

Barriers to Biofuel Transitions - Michael J. O'Donnell, Michael Webber, David T. Allen, Cynthia F. Murphy - Chapter 12 - (PDF)
This study examines several historical trends in fuel transitions, including the transition from leaded to unleaded gasoline and low to ultralow sulfur for petroleum diesel. There are always unintended consequences and massive changes in usage patterns, energy consumption, and other areas. This work provides useful insight on substitution processes and likely transition durations.

Summary - Cynthia F. Murphy - Chapter 14 - (PDF)

For further information contact:

Cynthia F. Murphy, CEER

David T. Allen, CEER

Michael Webber, ME

Robert T. Hebner, CEM

If there are questions or comments about the studies, you are invited to contact the team leaders. These studies are being offered to provide a better community understanding of the key concerns about and impediments to the adoption of biofuels.

 

 

EPA SealAlthough the research described on this web site has been funded by the United States Environmental Protection Agency through cooperative agreement XA-83379501-0, it has not been subjected to the Agency's required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred.