Implications of ethanol-based fuels for greenhouse gas emissions
- Oak Ridge National Lab., TN (United States)
- Univ. of California, Davis, CA (United States). Inst. of Transportation Studies
- National Renewable Energy Lab., Golden, CO (United States)
The US Environmental Protection Agency has proposed a rule which would mandate that 30% of the oxygen content of reformulated gasoline be provided by renewable oxygenates. The rule would essentially require that biomass-based ethanol, or ETBE derived from ethanol, be used to supply 30% of the oxygen in reformulated gasoline. This short statement addresses the very narrow question, ``Would this rule result in a net decrease in greenhouse gas emissions?`` The challenge then is to determine how much greenhouse gas is emitted during the ethanol fuel cycle, a fuel cycle that is much less mature and less well documented than the petroleum fuel cycle. In the petroleum fuel cycle, most of the greenhouse gas emissions come from fuel combustion. In the ethanol fuel cycle most of the greenhouse gas emissions come from the fuel production processes. Details of corn productivity, fertilizer use, process efficiency, fuel source, etc. become very important. It is also important that the ethanol fuel cycle produces additional products and the greenhouse gas emissions have somehow to be allocated among the respective products. With so many variables in the ethanol fuel cycle, the concern is actually with ethanol-based additives which will be produced in response to the proposed rule, and not necessarily with the average of ethanol which is being produced now. A first important observation is that the difference between standard gasoline and reformulated gasoline is very small so that when differences are drawn against alternative fuels, it makes little difference whether the contrast is against standard or reformulated gasoline. A second observation is that for this base case comparison, emissions of CO{sub 2} alone are roughly 13% less for the ethanol fuel cycle than for the reformulated gasoline cycle.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC05-84OR21400
- OSTI ID:
- 10138066
- Report Number(s):
- CONF-940269-1; ON: DE94009171; TRN: AHC29408%%33
- Resource Relation:
- Conference: Governors` ethanol coalition,Lincoln, NE (United States),14 Feb 1994; Other Information: PBD: 14 Feb 1994
- Country of Publication:
- United States
- Language:
- English
Similar Records
Health concerns fuel EPA study of ETBE and TAME
Environmental, economic, and energetic costs and benefits of biodiesel and ethanol biofuels