Preliminary Test Report Shows No Significant Change in Vehicle Emissions from Intermediate Ethanol Blends
07 October 2008
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| Average percentage change in criteria emissions and fuel economy for all vehicles compared to E0 fuel on the LA92 cycle. Bars show average for all vehicles, while discrete data points show the change for each vehicle tested. Click to enlarge. |
A preliminary report released by the US Department of Energy’s (DOE) National Renewable Energy Laboratory (NREL) and Oak Ridge National Laboratory (ORNL) on the use of intermediate E15 and E20 ethanol blends (15% and 20% ethanol respectively) in 13 vehicles and 28 small non-road engines found that most of the regulated vehicle emissions from E15 and E20 use were within the normal test variation. No statistically significant change was detected.
The E10 (10% ethanol) blend market in the US will likely be saturated (at less than 15 billion gallons per year) in the next few years, possibly as soon as 2010. At the same time, the Renewable Fuel Standard (RFS) calls for 36 billion gallons of renewable fuel by 2022. The DOE says that while it remains committed to expanding the E85 infrastructure, that market represented less than 1% of the ethanol consumed in 2007 and will not be able to absorb projected volumes of ethanol in the near-term. Given this reality, DOE and others have begun assessing the viability of using intermediate ethanol blends as a way to accommodate growing volumes of ethanol. (Earlier post.)
In August 2007, the US Department of Energy (DOE) initiated a test program to assess the potential impacts of higher intermediate ethanol blends on conventional vehicles and other engines that rely on gasoline. The test program focuses specifically on the effects of intermediate blends of E15 and E20 on emissions, catalyst and engine durability, drivability or operability, and materials associated with these vehicles and engines.
In the study described in the report, an initial group of 11 vehicles was selected primarily to span evolution in emission control system technology and focused on two model years, 2003 and 2007. Five additional popular model vehicles were selected from a set of vehicles identified as particularly likely to be sensitive to increased ethanol content in gasoline. These five vehicles included three 1999 models, one 2001 model, and one 2004 model. The initial report describes results from 13 of the 16 vehicles.
All of the vehicles were tested on federal certification gasoline (E0), E10, E15, and E20. Due to time constraints in obtaining match-blended fuels, splash blends were used in this study&madsh;i.e., the E0 certification fuel was diluted with appropriate amounts of fuel grade ethanol. Match-blended and splash-blended fuels have different hydrocarbon and volatility characteristics. The report notes that while the different fuel characteristics were not expected to have significant impact on the temperature measurements, the emissions results may have been influenced slightly due to unintended changes in the vehicle cold start and warm up.
Vehicle results include the following when E15 and E20 were compared with traditional gasoline:
All 13 vehicles exhibited a loss in fuel economy commensurate with the energy density of the fuel. (Ethanol has about 67% of the energy density of gasoline on a volumetric basis.) With E20, the average reduction in fuel economy (i.e., the reduction in miles per gallon) was 7.7% compared to E0. Limited evaluations of fuel with as much as 30% ethanol were conducted, and the reduction in miles per gallon continued as a linear trend with increasing ethanol content.
Tailpipe emissions were similar. As ethanol content increased, NOx and NMOG showed no significant change; NMHC and CO emissions dropped slightly on average, although CO did not change appreciably from E10 to E20; ethanol emissions increased; acetaldehyde emissions increased; formaldehyde emissions increased slightly; and benzene and 1,3-butadiene were expected to decrease due to dilution, but measurements were only conducted on a subset of the vehicles and have not been thoroughly analyzed to date.
At closed-loop operating conditions, catalyst temperatures were cooler or unchanged with higher levels of ethanol. Seven of the 13 tested vehicles adjusted fueling with increased ethanol content to maintain a consistent fuel:air equivalence ratio† at wide-open throttle (WOT). In these cases, the catalyst temperatures at equivalent operating conditions were lower or unchanged with ethanol.
Six of the 13 tested vehicles ran leaner (albeit still rich) with E20 fuel than with E0 fuel at WOT. For these vehicles catalyst temperatures were between 29ºC and 35ºC higher at E20 relative to E0.
No operability or driveability issues were identified using any of the ethanol blends during the limited time of the project. Each vehicle accumulated at least 100 miles on each ethanol blend, and at least 200 miles on gasoline (E0 fuel). Mileage accumulations for the vehicles ranged from 500–1,200 due to additional tests on some of the vehicles.
None of the vehicles displayed a malfunction indicator light (MIL) as a result of the ethanol content of the fuel. No fuel filter plugging symptoms were observed. No cold start problems were observed in 75°F and 50°F laboratory conditions. No fuel leaks or conspicuous degradation of the fuel systems were observed.
Small non-road engine results include the following when E15 and E20 were compared with traditional gasoline:
Regulated emissions remained largely unchanged;
Engine and exhaust temperatures increased;
Engine performance was inconsistent, even with traditional gasoline;
Commercial engines, as well as more sophisticated residential engines, exhibited no particular sensitivity to ethanol from a durability perspective; and,
The effect of E15 and E20 on the durability of smaller, less expensive residential engines (e.g., line trimmers) was not clear given that a number of these engines failed regardless of fuel type.
Other studies currently underway on the use of intermediate ethanol blends in addition to the work reported on in this study include:
Emissions of various gasoline and ethanol blends. Performed in collaboration with EPA and CRC (Coordinating Research Council), this study will assess the impacts of varying Reid vapor pressure (RVP), T50, T90, and aromatic content of gasoline and different ethanol/gasoline fuel blends on tailpipe emissions and performance of 19 new and 3 in-use vehicles. About 30 different match-blended fuels will be used to collect emissions data on criteria pollutants [HC, CO, NOx, and particulate matter], ethanol, and carbonyl compounds. Co-funding from CRC will support blending and testing of two of the fuels. Detailed HC speciation data will be collected for all vehicles tested in this task. Detailed PM and semivolatile organic compound data will be collected for a subset of the fuels.
Evaporative emissions. This study, being conducted in collaboration with CRC will measure evaporative emissions associated with testing gasoline fuels of varying RVP (volatility) and ethanol blends on eight vehicles. Five fuels with defined vapor pressures and ethanol content ranging from 0 to 20% will be tested on four Tier-2 near-zero low-emission vehicles and four “enhanced” 1996–2001 model year vehicles. Static permeation, running loss, hot soak, and diurnal emissions will be measured.
Catalyst durability. This task will assess the impact of intermediate ethanol blends on the full useful life of the catalyst system. In Phase I, the study will initially screen 25 vehicles for catalyst performance and key temperatures during open-loop (WOT) operation. Full-life (120,000 miles) studies on about 10 engine families will follow in Phase II. For each engine family, eight vehicles will be tested—with a pair dedicated to one of four fuels ranging from E0 to E20. A total of 80 vehicles will be tested (10 models × 4 fuel types × 2 vehicles per pair). Engines will have compression and leakdown checks performed at each emissions testing interval. Any operational issues observed will also be reported.
Driveability. This study evaluates impacts of intermediate blends on the driveability of six late-model non-FFVs and of various E85 fuels in 20 FFVs. The standard driveability test, developed by CRC, was used. Fuels tested in the study include E0, E15, and E20 with prescribed vapor pressures.
Materials compatibility. This will evaluate the durability of wetted components of fuel systems in non-FFVs when exposed to E10 and E20. This study will measure effects on all materials found in the fuel system, including plastics, elastomers, O-rings, and hose materials.
Specialty engines. This task will consider the effects of intermediate ethanol blends on various other non-automotive engine types (e.g., marine, motorcycles, snowmobiles). Preliminary planning meetings have been held with industry representatives to guide the development of test plans for these engines.
Resources
Brian West, Keith Knoll, Wendy Clark, Ronald Graves, John Orban, Steve Przesmitzki, Timothy Theiss (2008) Effects of Intermediate Ethanol Blends on Legacy Vehicles and Small Non-Road Engines, Report 1 (NREL/TP-540-43543, ORNL/TM-2008/117)
We have the E10 cr@p here in Dallas, every time I go home to Austin and use real gas I get ~5 mpg more than the E10 they sell up herei should know I keep every receipt for fuel and mark the mileage. I have 30000 miles of fuel economy data and go home every 3 weeks so the difference from summer to winter blends is apparent too. What stings even more is that E10 is more per gallon too.
Posted by: Dallasite | 07 October 2008 at 02:08 PM
"All 13 vehicles exhibited a loss in fuel economy commensurate with the energy density of the fuel."
and I'm sure that the price will not be reduced to reflect this loss if anything the price will go up to cover the additional cost of blending and transport of the ethanol. so yet again the consumer gets the hose.
Posted by: sickofgovtmeddling | 07 October 2008 at 02:11 PM
It's good to see NREL do a study on this (instead of corn industry supported studies that in the past have claimed increased MPG from certain mixtures like E30). Here they clearly show that E10,15,20 and 30 show ever decreasing fuel economy, as expected based on fuel density.
Since they showed the bad effect on MPG, the emissions also need to be corrected for that, since E blends cause you to burn more fuel for a given distance. If you correct for decreased MPG, then it seems like there IS an increase in NMOG and NOx emissions.
I really hope the cellulosic ethanol process can be scaled up (they've got a few demonstration facilites now). Corn ethanol is an environmental DISASTER! (oil based fertilizers, water usage, fertilizer run-off, etc).
Also, I really hope the industry will be forced to label how much ethanol is in their gasoline. Right now they get away with anywhere from 0-10% without any labeling.
Posted by: | 07 October 2008 at 02:25 PM
It's good to see NREL do a study on this (instead of corn industry supported studies that in the past have claimed increased MPG from certain mixtures like E30). Here they clearly show that E10,15,20 and 30 show ever decreasing fuel economy, as expected based on fuel density.
Since they showed the bad effect on MPG, the emissions also need to be corrected for that, since E blends cause you to burn more fuel for a given distance. If you correct for decreased MPG, then it seems like there IS an increase in NMOG and NOx emissions.
I really hope the cellulosic ethanol process can be scaled up (they've got a few demonstration facilites now). Corn ethanol is an environmental DISASTER! (oil based fertilizers, water usage, fertilizer run-off, etc).
Also, I really hope the industry will be forced to label how much ethanol is in their gasoline. Right now they get away with anywhere from 0-10% without any labeling.
Posted by: Karkus | 07 October 2008 at 02:25 PM
One reason for a smaller than expected improvement in emissions is that the test engines were efficient types running cleanly and in good condition to start with.
Some extra benefits may apply if those conditions were not met.(though the authors seem to be thoughtful in this respect)
This maybe the five vehicles that were expected to give higher benefits.
One may hope to see better results from modern closed loop engines that are engineered with alcohol fuels in mind.
Methodology seems good so the results are a real world disappointment.
It would be good to see similar testing on diesel.
At lest we can get a laugh at this bit.
The effect of E15 and E20 on the durability of smaller, less expensive residential engines (e.g., line trimmers) was not clear given that a number of these engines failed regardless of fuel type.
Posted by: arnold | 07 October 2008 at 02:26 PM
I don't recall anyone ever making claims that ethanol would be a lower tailpipe emitter.
Its all about reducing foreign oil and minimizing the embodied energy in a non-petroleum additive. PHEVs connected to your ethanol in the future will reduce costs and give advanced mileage.
Posted by: Jer | 07 October 2008 at 03:32 PM
I don't recall anyone ever making claims that ethanol would be a lower tailpipe emitter.
Its all about reducing foreign oil and minimizing the embodied (full life cycle) energy in a non-petroleum additive. PHEVs connected to your ethanol in the future will reduce costs and give advanced mileage.
Posted by: Jer | 07 October 2008 at 03:35 PM
I don't recall anyone ever making claims that ethanol would be a lower tailpipe emitter.
Its all about reducing foreign oil and minimizing the embodied (full life cycle) energy in a non-petroleum additive. PHEVs connected to your ethanol in the future will reduce costs and give advanced mileage.
Posted by: Jer | 07 October 2008 at 03:36 PM
I accept the research as written. But why was it needed?
Ethanol blends could have been definitively studied decades ago. I certainly used some gasohol long ago. I remember it about 1993 in Morro Bay, CA.
Newer vehicles have different fuel systems, emission systems, engines, and catalysts. So testing is still useful. But come on, they didn't know how ethanol blends performed?
Posted by: K | 07 October 2008 at 07:18 PM
The tests of converter life and other components is good. This shows that more oxygenate is probably not needed for cleaner air and denying a waiver to California was mostly about corn and farmers.
Posted by: sjc | 07 October 2008 at 08:13 PM
“denying a waiver to California was mostly about corn and farmers.”
More evidence that folks in California like to talk about renewable energy but neither want to produce renewable energy California nor pay for it.
Poor California, everybody is picking on them.
Posted by: Kit P | 08 October 2008 at 06:29 AM
Would the results be better with butanol-gasoline blends?
Butanol has more (per volume) energy than ethanol, i.e. almost the same as gasoline. The mpg should be about the same. As for emissions? who knows?
Posted by: HarveyD | 15 October 2008 at 06:30 AM
Louisiana Enacts the Most Comprehensive Advanced Biofuel Legislation in the Nation
__________________
Advanced Biofuel Industry Development Initiative Benefits Consumers, Farmers and Gas Station Owners with Localized “Field-to-Pump” Strategy
Tampa, FL (October 31, 2008) – Governor Bobby Jindal has signed into law the Advanced Biofuel Industry Development Initiative, the most comprehensive and far-reaching state legislation in the nation enacted to develop a statewide advanced biofuel industry. Louisiana is the first state to enact alternative transportation fuel legislation that includes a variable blending pump pilot program and a hydrous ethanol pilot program.
Field-to-Pump Strategy
The legislature found that the proper development of an advanced biofuel industry in Louisiana requires implementation of the following comprehensive “field-to-pump” strategy developed by Renergie, Inc.:
(1) Feedstock Other Than Corn
(a) derived solely from Louisiana harvested crops;
(b) capable of an annual yield of at least 600 gallons of ethanol per acre;
(c) requiring no more than one-half of the water required to grow corn;
(d) tolerant to high temperature and waterlogging;
(e) resistant to drought and saline-alkaline soils;
(f) capable of being grown in marginal soils, ranging from heavy clay to light sand;
(g) requiring no more than one-third of the nitrogen required to grow corn, thereby reducing the risk of
contamination of the waters of the state; and
(h) requiring no more than one-half of the energy necessary to convert corn into ethanol.
(2) Decentralized Network of Small Advanced Biofuel Manufacturing Facilities
Smaller is better. The distributed nature of a small advanced biofuel manufacturing facility network reduces feedstock supply risk, does not burden local water supplies and provides for broader based economic development. Each advanced biofuel manufacturing facility operating in Louisiana will produce no less than 5 million gallons of advanced biofuel per year and no more than 15 million gallons of advanced biofuel per year.
(3) Market Expansion
Advanced biofuel supply and demand shall be expanded beyond the 10% blend market by blending fuel-grade anhydrous ethanol with gasoline at the gas station pump. Variable blending pumps, directly installed and operated at local gas stations by a qualified small advanced biofuel manufacturing facility, shall offer the consumer a less expensive substitute for unleaded gasoline in the form of E10, E20, E30 and E85.
Pilot Programs
(1) Advanced Biofuel Variable Blending Pumps - The blending of fuels with advanced biofuel percentages between 10 percent and 85 percent will be permitted on a trial basis until January 1, 2012. During this period the Louisiana Department of Agriculture and Forestry Division of Weights & Measures will monitor the equipment used to dispense the ethanol blends to ascertain that the equipment is suitable and capable of producing an accurate measurement.
(2) Hydrous Ethanol - The use of hydrous ethanol blends of E10, E20, E30 and E85 in motor vehicles specifically selected for test purposes will be permitted on a trial basis until January 1, 2012. During this period the Louisiana Department of Agriculture and Forestry Division of Weights & Measures will monitor the performance of the motor vehicles. The hydrous blends will be tested for blend optimization with respect to fuel consumption and engine emissions. Preliminary tests conducted in Europe have proven that the use of hydrous ethanol, which eliminates the need for the hydrous-to-anhydrous dehydration processing step, results in an energy savings of between ten percent and forty-five percent during processing, a four percent product volume increase, higher mileage per gallon, a cleaner engine interior, and a reduction in greenhouse gas emissions.
Act No. 382, entitled “The Advanced Biofuel Industry Development Initiative,” was co-authored by 27 members of the Legislature. The original bill was drafted by Renergie, Inc. Representative Jonathan W. Perry (R - District 47), with the support of Senator Nick Gautreaux (D - District 26), was the primary author of the bill. Reflecting on the signing of Act No. 382 into law, Brian J. Donovan, CEO of Renergie, Inc. said, “I am pleased that the legislature and governor of the great State of Louisiana have chosen to lead the nation in moving ethanol beyond being just a blending component in gasoline to a fuel that is more economical, cleaner, renewable, and more efficient than unleaded gasoline. The two pilot programs, providing for an advanced biofuel variable blending pump trial and a hydrous ethanol trial, established by the State of Louisiana should be adopted by each and every state in our country.”
State Agencies Must Purchase or Lease Vehicles That Use Alternative Fuels
Louisiana’s Advanced Biofuel Industry Development Initiative further states, “The commissioner of administration shall not purchase or lease any motor vehicle for use by any state agency unless that vehicle is capable of and equipped for using an alternative fuel that results in lower emissions of oxides of nitrogen, volatile organic compounds, carbon monoxide, or particulates or any combination thereof that meet or exceed federal Clean Air Act standards.”
Advanced Biofuel Price Preference for State Agencies
Louisiana’s Advanced Biofuel Industry Development Initiative provides that a governmental body, state educational institution, or instrumentality of the state that performs essential governmental functions on a statewide or local basis is entitled to purchase E20, E30 or E85 advanced biofuel at a price equal to fifteen percent (15%) less per gallon than the price of unleaded gasoline for use in any motor vehicle.
Economic Benefits
The development of an advanced biofuel industry will help rebuild the local and regional economies devastated as a result of hurricanes Katrina and Rita by providing:
(1) increased value to the feedstock crops which will benefit local farmers and provide more revenue to the local community;
(2) increased investments in plants and equipment which will stimulate the local economy by providing construction jobs initially and the chance for full-time employment after the plant is completed;
(3) secondary employment as associated industries develop due to plant co-products becoming available at a competitive price; and
(4) increased local and state revenues collected from plant operations will stimulate local and state tax revenues and provide funds for improvements to the community and to the region.
“Representative Perry and Senator Gautreaux have worked tirelessly to craft comprehensive advanced biofuel legislation which will maximize rural development, benefit consumers, farmers and gas station owners while also protecting the environment and reducing the burden on local water supplies,” said Donovan. “Representative Perry, Senator Gautreaux, and Dr. Strain, Commissioner of the Louisiana Department of Agriculture and Forestry, should be praised for their leadership on this issue.”
About Renergie
Renergie was formed on March 22, 2006 for the purpose of raising capital to develop, construct, own and operate a network of ten ethanol plants in the parishes of the State of Louisiana which were devastated by hurricanes Katrina and Rita. Each ethanol plant will have a production capacity of five million gallons per year (5 MGY) of fuel-grade ethanol. Renergie’s “field-to-pump” strategy is to produce non-corn ethanol locally and directly market non-corn ethanol locally. On February 26, 2008, Renergie was one of 8 recipients, selected from 139 grant applicants, to share $12.5 million from the Florida Department of Environmental Protection’s Renewable Energy Technologies Grants Program. Renergie received $1,500,483 (partial funding) in grant money to design and build Florida’s first ethanol plant capable of producing fuel-grade ethanol solely from sweet sorghum juice. On April 2, 2008, Enterprise Florida, Inc., the state’s economic development organization, selected Renergie as one of Florida’s most innovative technology companies in the alternative energy sector. By blending fuel-grade ethanol with gasoline at the gas station pump, Renergie will offer the consumer a fuel that is more economical, cleaner, renewable, and more efficient than unleaded gasoline. Moreover, the Renergie project will mark the first time that Louisiana farmers will share in the profits realized from the sale of value-added products made from their crops.
Posted by: Brian J. Donovan | 31 October 2008 at 05:14 PM
The use of ethanol in fuel is about decreasing the use of oil, so we should all be interested in the effect of E20 or E30 on non-FFV because we may be having to use it in the near future. Other fuels are being investagated like butanol, but that is more expensive to produce. The most resent complaint about ethanol is that it increases the price of corn, but like the cost of crude the resent price run is more due to speculation than actual shortage. I do agree that overall corn produced ethanol is in a way a loss-loss situation due to more energy being used to produce the corn, expecially with the farmers super satuating the fields with furtilizer to produce 200+ bushels/acre, but as other feed stock starts being used the fuel will lessen our use on oil. Of course the biggest in reducing fuel usage is to use less in the first place.
Posted by: Larry Bevard | 07 November 2008 at 04:15 PM