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The Ethanol Forum
A Closer Look at Fuel Ethanol Issues

Energy Balance
Energy and Greenhouse Gas Emissions Impacts of Fuel Ethanol [PowerPoint presentation] Michael Wang, August 2005
 
Argonne National Laboratory researcher Michael Wang presented research at the National Press Club confirming that ethanol fuel substantially helps reduce fossil fuel and petroleum use compared with gasoline. Wang found that ethanol produced from corn achieves moderate reductions in greenhouse gases and that ethanol produced from grass and other cellulosic biomass sources can achieve much greater energy and greenhouse gas benefits. The research dismisses an ongoing academic argument about the amount of energy needed to produce ethanol (see paper by Pimentel and Patzek  below). Wang concludes that:
  • Energy balance value alone is not meaningful in evaluating the benefit of ethanol or any other energy product. For proper evaluation, a product's energy balance must be compared with that of the product it replaces.
  • Compared to gasoline, any type of fuel ethanol substantially helps reduce fossil energy and petroleum use.
  • Ethanol produced from corn can achieve moderate reductions in greenhouse gas emissions.
  • Ethanol produced from "cellulosic" plants, such as grass and weeds, can achieve much greater energy and greenhouse gas benefits.
 


 
The 2001 Net Energy Balance of Corn-Ethanol [24 kb PDF] Hosein Shapouri, James Duffield, Andrew McAloon and Michael Wang, 2004
 
This report estimates the net energy balance of corn ethanol utilizing the latest survey of U.S. corn producers and the 2001 U.S. survey of ethanol plants. The results indicate that corn ethanol has a positive energy balance, even before subtracting the energy allocated to by-products. The net energy balance of corn ethanol adjusted for byproduct credits is 27,729 and 33,196 Btu per gallon for wet- and dry- milling, respectively, and 30,528 Btu per gallon for the industry. The study results suggest that corn ethanol has an energy output/input ratio of 1.67.
 



 
Net Energy Yield  (link)
 
The Governors' Ethanol Coalition firmly agrees with mainstream science that ethanol production has a positive energy yield. The Coalition is concerned by the continuing inaccurate statements that ethanol production has a negative net energy yield and believes those statements cannot withstand close scrutiny. The Coalition makes both sides of this argument available for open and public consideration.
 


 
 
Pimentel and Patzek conclude that the energy outputs from ethanol produced using corn, switchgrass and wood biomass are less than the fossil energy inputs and that the same is true for producing biodiesel using soybeans and sunflower. They conclude that ethanol production using corn grain required 29 percent more fossil energy than the ethanol fuel produced,that ethanol production using wood biomass required 57 percent more fossil energy than the ethanol fuel produced and that biodiesel production using soybeans required 27 percent more fossil energy than the biodiesel fuel produced.
 



 
Ethanol Energy Balances [PDF] by David Andress & Associates, November 2002.
 
In the last twenty years, significant advances in farming techniques and improvements in ethanol production have occurred, and recent studies have concluded that the energy balances for ethanol production are now positive.
 
The "net energy gain" is the difference between the energy in the fuel product (output energy) and the energy needed to produce the product (input energy). The net energy gain is often expressed as a percent of the input energy. Using the latest energy data for agricultural requirements and ethanol plant use, several studies released in 2002 estimated that the net energy gain for corn ethanol is between 21 and 34 percent. Further improvements in agricultural practices and improvements made to ethanol plants could lead to an increase in the net energy gain in the near future.
 
By comparison, there is a net energy loss in the production of gasoline of between 19 and 20 percent for gasoline. The net energy loss for MTBE is about 33 percent.
 
Fuel ethanol in the United States is currently produced from starch-based crops like corn, but scientists are working on ways to develop more efficient and economical methods for converting cellulosic matter to ethanol. As this technology matures, the nation’s vast reservoir of agricultural residues, and eventually energy crops, will serve as the feedstocks to significantly expand ethanol production. In 2004, the corn ethanol industry reached a production capacity of about 3.3 billion gallons per year. However, expanding ethanol production past 6 to 8 billion gallons per year will require a transition to cellulosic ethanol.
 
Because most of the energy requirements associated with cellulosic ethanol production are derived from renewable sources, the conversion process uses virtually no fossil fuels. Cellulosic ethanol can reduce fossil energy consumption relative to gasoline by 88 to more than 100 percent, depending on the type of feedstock. Reductions of fossil energy by more than 100 percent come from a co-product credit for the sale of excess electricity from cellulosic ethanol plants. The cellulosic ethanol fuel cycle has an added benefit of emitting virtually no net greenhouse gases.
 

 
Fossil Energy Use in the Manufacture of Corn Ethanol [PDF] by Michael Graboski, August 2002.
 
Environmentalists and policy makers have expressed concern about the energy efficiency of corn ethanol production and its potential impact on petroleum use. Energy efficiency is important to climate change as well. This study quantified the total fossil energy and petroleum energy used to produce ethanol from corn for the current industry as well as the future industry that would result from an expansion of production to 5 billion gallons per year of ethanol in 2012.
 
Ethanol is produced in wet mills and dry mills. In 2000, wet mills accounted for about 54% of the grain based capacity in the United States. Since the vast majority of new capacity is in the form of dry mills, it is projected that dry mills will account for 80% of US capacity in 2012.
 
The energy basis used in this study is the total net heating value, or total lower heating value (LHV) per gallon of 200 proof ethanol. The primary LHV represents the useful energy that can be extracted from fuel in conventional combustion systems. The total LHV energy includes the primary energy plus the extraction, manufacturing and transportation energy required to bring it to its end use. Only fossil energy is considered in the energy analysis. Thus, energy supplied by solar and nuclear sources is not included, but the fossil energy to recover and process uranium is included. Solar sources include energy captured by corn, as well as hydroelectric and biomass fired electric power.
 
The total fossil energy input to produce corn accounts for about one-third of the total fossil energy in ethanol. In corn agriculture, fertilizers, particularly nitrogen, account for more than 40% of the total energy input per acre of corn harvested. Ethanol conversion is the most significant energy input to the total energy input. Only small amounts of energy are required for corn and ethanol transportation and distribution.
 
The net energy is the sum of the energy content of ethanol and avoided energy related to co-products less the energy of all inputs. The energy ratio is the output energy in ethanol divided by the input energy corrected for the co-product credit. A positive net energy indicates a process that contains more product energy than inputted fossil energy. A net energy ratio greater than one suggests a process that produces more energy out in liquid fuel than is consumed as fossil fuel.
 
The study found that without credit for co-products, dry mills exhibit a positive net energy while wet mills yield a negative net energy. However, with co-products, the overall net energy of the current ethanol industry is 13,300 BTU/gallon and the corresponding energy ratio is 1.21.
 

 
The Energy Balance of Corn Ethanol: An Update [PDF] By Hosein Shapouri, James A. Duffield and Michael Wang. US Department of Agriculture, Office of the Chief Economist, Oregon Department of Energy Policy and New Uses. Agricultural Economic Report No. 814, July 2002.
 
In this study published by the USDA in 2002, researchers conclude that the energy balance for corn-ethanol is positive when fertilizers are produced by modern processing plants, corn is converted in modern ethanol facilities and farmers achieve average corn yields. The report includes a review of past energy balance studies and shows that the energy requirements for producing a gallon of ethanol have fallen over time. One of the primary factors for this increase in energy efficiency is the increase in corn yields in the United States.
 
The study estimates that for every Btu dedicated to producing ethanol there is a 34-percent energy gain. Ethanol production utilizes domestic energy feedstock, such as coal and natural gas, to convert corn into a premium liquid fuel. Thus, producing ethanol from domestic corn stocks achieves a net gain in a more desirable form of energy, which helps the United States to reduce its dependence on imported oil.
 
Only about 17 percent of the energy used to produce ethanol comes from liquid fuels, such as gasoline and diesel fuel. For every 1 Btu of liquid fuel used to produce ethanol, there is a 6.34 Btu gain.
 

 
Life-Cycle Analysis of Ethanol from Corn Stover [PDF] by John Sheehan, NREL Report No. PO-510-31792, National Renewable Energy Laboratory, 2002.
 
The benefits of ethanol depend heavily on how it is made and from what. One issue is whether ethanol saves energy compared to gasoline. A closely related issue is how much reduction in greenhouse gas emissions results from using ethanol in lieu of gasoline. Life-cycle analyses conducted at NREL suggest that making ethanol from nontraditional sources of biomass uses far less fossil energy to deliver a mile of travel than does gasoline. For example, NREL has studied the use of agricultural residues to make ethanol. They have found that the amount of fossil energy that is required to make and use E85 (an 85% blend of ethanol in gasoline) in a flex-fueled car is only 20% of that used when the same car burns gasoline.
 

 
Well-to-Wheel Energy Use and Greenhouse Gas Emissions of Advanced Fuel/Vehicle Systems – North American Analysis by Center for Transportation Research, Argonne National Laboratory, June 2001.
 
In a massive study commissioned by General Motors and reviewed by BP, ExxonMobil, and Shell, the Argonne National Laboratory analyzed the energy efficiency of 75 different fuel pathways using the GREET model. The fuel pathways analyzed included conventional gasoline and ethanol, as well as natural gas, diesel, hydrogen and others.
 
The GREET model uses the following calculation of "well-to-tank" energy efficiency:
Efficiency = 1,000,000/(1,000,000 + total energy use)
In this equation, the 1,000,000 in the numerator is 1 million Btu of a given fuel available in a vehicle tank."Total energy use" is the total energy used to produce and deliver the 1 million Btu of fuel to the vehicle tanks (in Btu per million Btu of fuel available in the vehicle tank).
 
Energy Efficiency of Gasoline
 
For conventional gasoline, the study found that it takes about 241,000 Btu to produce and deliver 1 million Btu to a gas tank in the form of gasoline (50% probability values are reported here). The efficiency calculation is 1,000,000/(1,000,000 + 241,000) or about 81%.
 
To deliver 1 million Btu in the form of gasoline takes 241,000 Btu for recovering crude oil from the well, transporting the crude to a refinery, refining crude oil to gasoline and finally transporting the gasoline to a service station. The energy expended in exploration for crude oil is not included in this calculation.
 
In other words, each Btu of gasoline energy requires about 1.2 Btu of energy input, which includes the energy contained in crude oil plus the energy consumed in converting crude to gasoline.
 
Energy Efficiency of Ethanol Produced from Corn
 
For ethanol produced at a dry-mill plant, with co-product credits calculated on a "displacement" basis, corn-based ethanol efficiency is 63%.
 
An adjustment for "co-product credits" is necessary because corn-based ethanol plants produce other products in addition to ethanol. Distillers´ grains and solubles (DGS) is a CO-product of dry-mill corn ethanol production. DGS is used in animal feed. To properly account for the energy used to produce fuel, the total energy used at a dry mill ethanol plant must be allocated between the fuel produced and the co-products. Two methods of allocating the energy inputs are the "displacement" method and the "market value" method. The displacement method is the more conservative approach (lower credit given). The displacement method starts by estimating the amount of CO-products produced. Second, the products to be displaced in the marketplace by the CO-products are identified. Third, the displacement ratios between CO-products and the displaced products are determined. Finally, an estimate is made of the energy that would be needed to product displaced products. This estimated amount of energy represents the "energy credit" of the CO-products
 
The energy efficiency of corn ethanol as described for this pathway is 63% (based on 50% probability values). It takes about 587,000 Btu in total energy to produce and deliver 1 million Btu of ethanol fuel to a vehicle fuel tank.
 
According to this study, it takes more energy to produce and deliver ethanol to a fuel tank than it does to produce and deliver gasoline. Every Btu of energy in ethanol requires about 1.6 Btu of energy input, which includes the energy consumed in the production and transportation of fertilizer and other agri-chemicals, farming corn, transportation of corn to the ethanol production facility, production of ethanol and transportation of the fuel to a fueling station.
 
However, there is an important difference between gasoline and ethanol motor fuels. The Btus in corn or other biomass feedstock are renewable, unlike the Btus in crude oil. The calculation of efficiency based on total energy input is therefore less meaningful for renewable source-based fuels. A better indicator of the energy balance for renewable biofuels is the ratio between the energy content of the fuel and the fossil energy used for production. If the public is concerned about reducing the use of fossil fuel (and reducing the associated emissions of carbon dioxide into the atmosphere), then the focus should be on how much fossil energy is consumed.
 
When you burn gasoline in your car you are consuming the fossil energy required to produce and distribute the gasoline plus the fossil energy contained in the crude oil from which the gasoline was made. Production and distribution of corn-based ethanol requires more fossil energy than production and distribution of gasoline. However, when you burn a gallon of ethanol in your car, your consumption of fossil energy is only the fossil energy used in production and distribution. The feedstock is renewable biomass, not crude oil.
 
By considering only the fossil energy inputs, the energy efficiency of corn-based ethanol is 170%. Every Btu of energy in ethanol fuel consumes about 0.6 Btu of fossil energy. In comparison, every Btu of energy in gasoline consumes about 1.2 Btu of fossil energy.
 
With renewable biofuels, you get more fuel energy in your tank than the amount of fossil energy used to get it there. This calculation provides some indication of the enhancement effect of renewable fuel production in helping to stretch out the use of limited nonrenewable resources.
 
Energy Efficiency of Ethanol Produced from Lignocellulosic Biomass
 
For ethanol produced from woody biomass rather than corn, the total energy efficiency is only 39%. Every Btu of energy in wood-based ethanol requires 2.6 Btu of energy input.
However, with woody biomass, not only are you starting from a renewable biomass source, but one of the byproducts of ethanol, the lignin, can be used as a fuel for the conversion process, displacing the use of fossil energy.
 
By considering only the fossil energy inputs, the energy efficiency of wood-based ethanol is 7,840%. Not only do you produce a renewable fuel for motor vehicle use, but you offset electric generation from other fossil sources, such as natural gas or coal. Every Btu of energy in wood-based ethanol fuel consumes only about 0.01 Btu of fossil energy.
 

 
Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions [PDF] by Michael Wang, Christopher Saricks and D. Santini, Center for Transportation Research, Energy Systems Division, Argonne National Laboratory, January 1999.
 
Fuel-Cycle Fossil Energy Use and Greenhouse Gas Emissions of Fuel Ethanol Produced from US Midwest Corn [PDF] by Michael Wang, Christopher Saricks and May Wu, Center for Transportation Research, Argonne National Laboratory, December, 1997.
 
Michael Wang has studied the energy balance of ethanol based on a model developed by the Argonne Laboratory. The model evaluates energy and emission impacts of vehicle technologies by assessing both the fuel cycle and the vehicle cycle. Sponsored by the US Department of Energy´s Office of Transportation Technologies, Argonne has developed a fuel-cycle model called GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation). It allows researchers to evaluate various engine and fuel combinations on a consistent fuel-cycle basis.
 
Wang´s research has shown that the net energy balance for ethanol is positive. An energy balance is calculated by starting with the energy contained in a gallon of ethanol (76,000 Btu) and subtracting the energy required to produce the gallon of ethanol. The energy requirement includes energy in petroleum, natural gas and coal used in producing ethanol. Wang found that corn-based ethanol has a net energy balance of 20,000 to 25,000 Btu per gallon. Cellulosic ethanol has a net energy balance of over 60,000 Btu per gallon.
 
The positive net energy balance for corn ethanol is attributable to the improvements in corn farming and corn-to-ethanol conversion that have been achieved in the last 20 years. The large positive net energy balance for cellulosic ethanol is largely attributable to two factors: the fact that little fossil energy is used in biomass farming and cellulosic ethanol conversion and, to a lesser extent, to the assumption that the extra electricity generated in cellulosic ethanol plants will be exported into the electric grid to displace electric generation in electric power plants.

Sustainability
Food, Feedstocks and Ethanol Production [PowerPoint] by Mike Penner, Food Science and Technology Department, Oregon State University (delivered at the Oregon Ethanol Forum, May 2001).
 
About 85 percent of fuel ethanol produced in the United States is made from corn. To substantially increase the production of ethanol in the future, other feedstock will be needed. Lignocellulosic feedstock (LCF) such as wood waste and agricultural residues could be used. The technology for converting LCF to ethanol has been demonstrated on a pilot scale, but it has yet to be demonstrated commercially.
 
Ethanol production does not appear to be a factor in worldwide food security. A World Bank policy study in 1986 defined "food security" as access by all people at all times to enough food for an active, healthy life. Although there are widespread areas of food deprivation, there is a plentiful supply of food being produced. Economic and political factors are the major causes of food shortages. Reducing the use of grain for ethanol production would do little to solve these problems.

Greenhouse Gas Emissions
Well-to-Wheel Energy Use and Greenhouse Gas Emissions of Advanced Fuel/Vehicle Systems – North American Analysis by Center for Transportation Research, Argonne National Laboratory, June 2001. (see links above )
 
In addition to the analysis of energy efficiciency discussed above, this study compares the life-cycle greenhouse gas emissions of different fuel pathways. The results for 30 fuel pathways are presented, including three ethanol fuel pathways (wet-mill corn-ethanol, herbaceous cellulose and woody cellulose).
 
The study found that all three ethanol pathways have negative greenhouse gas emissions because of carbon uptake sequestration during growth of corn plants, trees and grass. Corn ethanol has a smaller greenhouse gas benefit, compared to cellulosic ethanol, because the use of fossil fuels during corn farming and in ethanol plants offsets some of the carbon dioxide sequestered during growth of corn plants. All the carbon sequestered during biomass growth is released back to the air during combustion of ethanol in vehicles.
 

 
Greenhouse Gas Emissions and Ethanol [PowerPoint] by Gary Whitten, ICF Consulting(delivered at the Oregon Ethanol Forum, May 2001)
 

 
Assessment of Net Emissions of Greenhouse Gases from Ethanol-Blended Gasolines in Southern Ontario [PDF] by Don O´Connor, (S&T)2 Consulting, and Levelton Engineering Ltd., Agriculture and Agri-Food Canada (January 2000).
 
Assessment of Net Emissions of Greenhouse Gases from Ethanol-Blended Gasolines in Canada: Lignocellulosic Feedstocks [PDF] by Levelton Engineering Ltd. in consultation with (S&T)2 Consulting, Agriculture and Agri-Food Canada (January 2000).
 
These two studies assess the life-cycle impact of ethanol produced from corn and lignocellulosic feedstock (LCF). The studies examine greenhouse gas and criteria air contaminant emissions. The studies use an analytical model that calculates energy balances and life-cycle greenhouse gas emissions for a variety of fuels and engines. Life-cycle analysis considers all steps of production, distribution and end-use of the fuel, including:
  • Vehicle operation
  • Fuel dispensing at the retail level
  • Fuel storage and distribution at all stages
  • Fuel production
  • Feedstock transport
  • Feedstock production and recovery
  • Fertilizer manufacture
  • Land use changes and cultivation associated with biomass derived fuels
  • Leaks and flaring of greenhouse gases associated with production of oil and gas
  • Carbon in fuel from air
  • Emissions displaced by CO-products of alternative fuels
  • Vehicle assembly and transport
  • Materials used in the vehicles
 
Among the findings, the studies conclude that gasoline blended with 10-percent ethanol made from LCF could reduce greenhouse gas emissions in Ontario by 5.8 to 6.7 percent. A 10-percent blend of ethanol made from corn reduces greenhouse gas emissions by 3.9 percent. The advantage of LCF ethanol compared to corn ethanol is due almost entirely from using lignin as fuel for the conversion process.
 

 
Effects of Fuel Ethanol Use on Fuel-Cycle Energy and Greenhouse Gas Emissions [PDF] by Michael Wang, Christopher Saricks and D. Santini, Center for Transportation Research, Energy Systems Division, Argonne National Laboratory, January 1999.
 
In addition to the results showing a positive energy balance discussed above, this study estimated fuel-cycle greenhouse gas emissions of conventional gasoline and 10-percent (E-10), 85-percent (E-85) and 95-percent (E-95) ethanol blends. The study concluded that using ethanol to fuel motor vehicles helps reduce greenhouse gas emissions. To address the evolving technology of ethanol production, estimates were made for the following cases: (1) a current case with current technologies for production of ethanol from corn; (2) a near-future case, which assumed improvements in corn ethanol production technologies and near-term cellulosic ethanol production technologies; and (3) a future case, which assumed improvements in cellulosic ethanol production technologies.
 
In the current technology case, the study estimated a 19-percent reduction (compared to gasoline) in greenhouse gas emissions for E-85 produced from corn by dry-milling. The near-future case showed a 26-percent reduction in greenhouse gas emissions for E-85.
 
Transition from corn ethanol to cellulosic ethanol achieves significantly greater greenhouse gas emissions benefits. In the near-future case, E85 produced from woody biomass reduces greenhouse gas emissions by an estimated 102%. The greater-than-100% reduction is due to emissions offsets in electric power generation.
 
Under the future case, the greenhouse gas emissions benefits of woody cellulosic ethanol are less than those for the near-future case because of substantial reductions in electricity credits for future cellulosic ethanol plants. Improvements in ethanol yields in cellulosic ethanol plants over time, because they are accompanied by reduced electricity credits, do not result in greater emissions and energy benefits.
 

 
Alternatives to Traditional Transportation Fuels 1994, Volume 2, Greenhouse Gas Emissions [PDF] Energy Information Administration, January 1996.
 
This report provides information on greenhouse gases as required by Section 503 a(4) and b(3) of the Energy Policy Act of 1992 (EPACT). Section 503 requires the Secretary of Energy to estimate greenhouse gas emissions resulting from the use of alternative transportation fuels over the entire fuel cycle rather than only those produced from combustion. The Energy Information Administration uses the life-cycle methodology developed by Mark Delucchi (Institute of Transportation Studies, University of California) because "it offers the best framework for adhering to the EPACT requirements."
 
The greenhouse gas data are in Volume 2. Volume 1 contains estimates of the number of alternative-fueled vehicles in use and estimates of alternative and replacement fuel consumption. About two-thirds of the alternative-fueled vehicles in use in 1996 were vehicles designed to operate on liquefied petroleum gases. Only about 8 percent of such vehicles were designed to for blends of ethanol meeting the alternative-fuel definition.
 
The report concludes that alcohol fuels emit less carbon dioxide in the vehicle stage than gasoline, and the total carbon dioxide emissions per vehicle mile traveled (VMT) for the fuel cycle from corn-based ethanol (about 326 grams) is smaller than from gasoline (about 347 grams). Ethanol from corn produces the lowest amount of carbon dioxide emissions in the pre-vehicle stage at 0.56 moles (24.4 grams) per vehicle mile traveled due to the sequestration carbon. The report did not study the life-cycle emissions for ethanol produced from lignocellulosic feedstock.

 
Greenhouse Gas Emissions from Ethanol and MTBE: A Comparison [PDF] by Irshad Ahmed and David Morris, Institute for Local Self-Reliance (Draft, June 1994).
 
The use of ethanol can reduce greenhouse gases. This study found the percentage of greenhouse gas reduction (compared to gasoline) varied, depending on the feedstock used and the source of energy used in the conversion process. The study found that ethanol produced from corn using coal-fired power as an energy source reduced greenhouse gases by up to 35 percent. Ethanol produced from lignocellulosic feedstock, using biomass as an energy source, reduced greenhouse gases by 60 percent to 70 percent, compared to emissions from gasoline.

Health Impacts
Air Quality and GHG Emissions Associated With Using Ethanol in Gasoline Blends [PDF] by David Andress, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy (May 2000).
 
Estimating the impact of emissions on air quality involves gathering data on tailpipe and evaporative emissions from each vehicle for each type of fuel used, estimating vehicle fleet characteristics and population driving patterns and incorporating the effects of meteorological and geographic conditions. From this data, researchers can project the persistence of primary and formation of secondary emissions in the atmosphere.
 
The principal air quality concerns arising from gasoline-powered mobile-source emissions are ozone, toxic air pollutants and carbon monoxide. Most toxic air pollutants and other pollutants decrease when ethanol is added to gasoline, primarily through dilution. Adding ethanol to gasoline decreases emissions of CO, a product of incomplete combustion, in both conventional gasoline and reformulated gasoline. In conventional gasoline, evaporative volatile organic compounds increase due to the higher vapor pressure of the ethanol mixture, and NOx emissions may increase because of the added oxygen. However, this does not happen in RFG, because VOC and NOx emissions must be controlled to meet RFG standards.
 

 
Ethanol Blend Fuels Affects on Health and the Environment [PowerPoint] by Howard Haines, Montana Department of Environmental Quality (delivered at the Oregon Ethanol Forum, May 2001).
 
One advantage of ethanol blended fuel is the reduction of air emissions without the potential adverse effects on water quality associated with the use of the additive MTBE. MTBE has been found in almost all Oregon gasoline. Some MTBE is used to increase octane but it also contaminates other gasoline during transport. MTBE has a high affinity for water. It makes water taste bad (at levels of 20 to 40 PPM). It has been linked to cancer in rats and has been shown to cause illness in humans in levels as low as 2 PPB.
 
Howard Haines has analyzed the benefits of a 10-percent ethanol blend in gasoline (E-10). His findings are based on actual data and field work experience. The use of E-10 reduces emissions of  fine particulate matter (PM 2.5), hydrocarbons, carbon monoxide, volatile organic compounds and air toxics especially in SUVs, RVs, light duty vehicles and 2-stroke engines. 
 

 
Air Quality and Ethanol [PowerPoint] by Gary Whitten, ICF Consulting (delivered at the Oregon Ethanol Forum, May 2001).
 
Air Quality and Ethanol in Gasoline [PDF] by Gary Whitten, Smog Reyes (Presented at the 9th Annual National Ethanol Conference: Policy & Marketing, February 16-18, 2004).
 
The use of ethanol in motor fuel reduces emissions of carbon monoxide by 3 percent compared to gasoline blended with MTBE and by 10 percent in "aggressive driving" tests. Reduction of carbon monoxide is important in reducing the creation of ozone, because carbon monoxide is the biggest single contributor to ozone formation. In addition, ethanol can reduce benzene by 30 percent in gasoline. Although emissions of acetaldehyde are increased with the use of ethanol, several studies show this is not a problem. Ethanol can significantly reduce the emissions of particulate matter. Studies show that primary PM2.5 emissions (emissions directly from vehicles) are reduced by 50 percent using 10-percent blends of ethanol in gasoline. Ethanol is the only motor fuel component that can reduce greenhouse gases.

Ethanol Economics
The Economics of Fuel Ethanol: "Costs and Benefits of a Biomass-To-Ethanol Production Industry in California" [PowerPoint] by Mike McCormack, Transportation Technology Office, California Energy Commission (delivered at the Oregon Ethanol Forum, May 2001).
 
Costs and Benefits of a Biomass-To-Ethanol Production Industry in California (PDF), Transportation Technology Office, California Energy Commission (March 2001).
 
The Transportation Technology Office at the California Energy Commission (CEC) provides advice to the California Governor and Legislature on next steps regarding the use of ethanol in California. This report concluded that California could develop a 200-million gallon per year industry that would produce benefits of $1 billion over 20-year period, assuming state government investment in incentives totaling $500 million. Ethanol production would provide California rice growers with an alternative to plowing rice straw into the ground to meet air quality regulations. Cellulosic ethanol production from forest biomass could reduce the frequency and intensity of forest fires and improve forest health while reducing emissions from wildfires and agricultural burning. 
 
The report recommended that the state should provide technical and financial support for one or more biomass-to-ethanol production projects to verify technical and economic performance of commercial scale demonstration facilities. The state should fund activities to enhance the availability and quality of cellulose resources for ethanol production. The report, further, recommended that California legislature should direct the CEC to explore means to increase the state’s ethanol import options, balance ethanol demand growth with available supplies and limit ethanol price fluctuations.

About the Forum
"Biofuels for Sustainable Transportation" logo
 
The Oregon Department of Energy hosted the Oregon Ethanol Forum on May 8, 2001, in Eugene, Oregon. The Forum explored five key issues that shape public opinion about the use of ethanol fuel.  The issues - energy, sustainability, environment, health and economics - are at the heart of what makes a suitable alternative fuel or gasoline additive. The information on this web page is an outgrowth of the Forum. It includes information presented at the event and summaries of other recent reports on the same topics.
 
The Oregon Ethanol Forum was co-sponsored by the Oregon Department of Energy and the US Department of Energy Regional Biomass Energy Program. The Forum was part of a series of state workshops—Biofuels for Sustainable Transportation—sponsored by the USDOE Office of Fuels Development to educate key public officials and the general public about ethanol as a transportation fuel. Planning and event arrangements for the ethanol workshop series were provided by BBI International.

 
Page updated: August 01, 2007

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