[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
EIA: US fuel ethanol production capacity little changed in past year
May 20, 2013
|US fuel ethanol production capacity, 1 January 2013. Source: EIA. Click to enlarge.|
US fuel ethanol production capacity was 13.852 billion gallons per year (903,000 barrels per day), as of 1 January 2013, according to the latest annual report released by the US Energy Information Administration (EIA). The report shows a 0.9% increase in the total capacity of operating ethanol plants compared to 1 January 2012 (13.728 billion gallons/year). A total of 193 ethanol plants were operating as of 1 January 2013, compared to 194 plants operating a year earlier.
Most of the existing fuel ethanol capacity (about 91%) is located in the Midwest (PAD District 2). Total nameplate capacity in PADD 2 is 12.6 billion gallons per year (822,000 barrels per day). The number of plants in this report includes plants that were idled or temporarily shut down during 2012.
Researchers propose evaluating alt fuel efficiency based on energy rather than volume; impact of ethanol on vehicle efficiency and GHGs
May 17, 2013
|Relative changes in vehicle energy efficiency (VEE) (km/MJ) on ethanol/gasoline blends over those on gasoline for different blending levels. Credit: ACS, Yan et al. Click to enlarge.|
In a policy analysis in the ACS journal Environmental Science & Technology, researchers from the Universities of Cambridge, Exeter and Oxford argue that, due to the increased emphasis on alternative fuels with drastically differing energy densities, vehicle efficiency should be evaluated based on energy rather than volume.
With that as a premise, they go on to show that the efficiency of existing vehicles can be both positively and negatively affected by ethanol content, ranging from −15% to +24%. As a result, they conclude, uncertainties in the net greenhouse gas (GHG) effect of ethanol, particularly when used in a low-level blend with gasoline, are considerably larger than previously estimated. Standard deviations increase by >10% and >200% when used in high and low blends, respectively.
Ford / AVL study concludes mid-level ethanol blend attractive as a long-term future fuel for use in optimized engines in US
April 19, 2013
A study by a team from Ford Motor Company and AVL has concluded that a mid-level ethanol blend—greater than E20 but less than E40—appears to be attractive as a long-term future fuel for the US for use in engines optimized for the higher octane blend. The team presented a paper on their work at the 2013 SAE World Congress in Detroit. Ford engineers also presented two other papers evaluating the effects of low to mid-level ethanol blends in spark-ignited engines at the conference.
In the face of increased regulatory stringency (e.g., US CAFE, California LEV 3 and pending US Tier 3), the combustion engine community is gearing up for an intensified push to deliver higher efficiency engines with lower fuel consumption and emissions. One of the many emerging possible technology pathways to achieve those goals is the use of a future high-octane fuel in optimized, higher-compression-ratio engines. (Earlier post.) The study by the Ford / AVL team provides an overview of the effects of such a future ethanol-gasoline blend in such an engine.
New catalysts convert ethanol to butanol with high selectivity; potential low-cost upgrade for ethanol plants
April 11, 2013
Researchers at the University of Bristol (UK) have developed a new family of catalysts that enables the conversion of ethanol into n-butanol—a higher alcohol with better characteristics for transportation applications than ethanol—with selectivity of more than 95% at good conversion. The team presented a pair of papers on their work at the Spring meeting of the American Chemical Society this week in New Orleans.
While butanol has emerged as a potential sustainable liquid fuel replacement for gasoline, development of biosynthetic pathways for its synthesis are challenged by very low conversion and modest selectivity, they noted. Although catalytically upgrading the more readily available bioethanol to butanol is theoretically attractive, this has been hampered by modest selectivity in most cases.
EIA: US consumption of alt fuels up 13% in 2011; E85 second behind natural gas; medium-duty vans had greater impact than LDVs
April 09, 2013
|Consumption of alternative fuels by vehicle type, 2011. Replacement fuels—i.e., E10 and biodiesel—are categorized separately. Source: EIA. Click to enlarge.|
Overall consumption of alternative transportation fuels in the US increased almost 13% in 2011 to a total of 515,920 thousand gasoline-equivalent gallons, compared to 457,755 thousand gasoline-equivalent gallons in 2010, according to the latest Alternative Fuel Vehicle Data from the US Energy Information Administration (EIA).
In alternative-fueled vehicles, consumption of ethanol (E85) increased 52% from the prior year’s consumption, an increase from 90,323 thousand gasoline-equivalent gallons in 2010 to 137,165 thousand gasoline-equivalent gallons in 2011. EIA attributed this to the increase in overall inventory of E85-capable vehicles. In 2011, E85 became the second-most consumed alternative fuel, behind natural gas (220,247 thousand-gasoline-equivalent gallons), and outpacing LPG (124,457 thousand-gasoline-equivalent gallons).
Navigant forecasts global 6% CAGR for biofuels to 2023
March 29, 2013
|Total Biofuels production by fuel type, world markets: 2013-2023. Source: Navigant. Click to enlarge.|
Navigant Research forecasts global biofuels production will grow at a compound annual growth rate (CAGR) of 6% between 2013 and 2023, despite slower than expected development of advanced biofuels pathways (such as cellulosic biofuels); an expected expansion in unconventional oil production in key markets such as the United States; and a decline in global investment for biofuels in recent years.
In contrast, Navigant expects the CAGR for fossil-based gasoline, diesel, and jet fuel to be 3.1% over the forecast period. The research firm projects that total biofuels production will reach 62 billion gallons by 2023 or 5.9% of global transportation fuel production from fossil sources.
California ARB considering four new low-carbon fuel pathways; Neste renewable diesel and sugarcane molasses ethanol
March 20, 2013
California Air Resources Board (ARB) staff has posted four new Low Carbon Fuel Standard (LCFS) pathways to the LCFS web site. (Earlier post.) Among the new pathways to be considered is the production of renewable diesel from Australian tallow at Neste Oil’s Singapore plant. Others are sugarcane molasses ethanol from Guatemala; mixed feedstock to biodiesel from Texas; and a new ARB-staff-developed pathway for North American landfill gas.
The Low Carbon Fuel Standard, approved in April 2009, requires that suppliers of transportation fuels meet an average declining standard of carbon intensity (CI) —expressed in grams of CO2 equivalent per megajoule of fuel energy (g CO2e/MJ)—that will provide a 10% reduction in greenhouse-gas emissions for all fuels used in California by 2020. The CI of a fuel is determined by the sum of all greenhouse gas emissions associated with the production, transportation, processing and consumption of a fuel (its pathway).
Study explores impact of alcohol-gasoline blends with early inlet valve closing at low and moderate loads on EGR tolerance
A team from Brunel University, MAHLE Powertrain and University College London studied the combined effects of different inlet valve operating strategies on combustion, performance and emissions with different ethanol and 1-butanol blends with gasoline in a single-cylinder spark-ignition research engine equipped with a fully variable valvetrain. Their paper is published in the journal Fuel.
The focus was to better quantify the effects of alcohol content and Early Inlet Valve Closing (EIVC) operation on EGR tolerance under the lowest speed-load conditions typically encountered (e.g., engine idle) while also quantifying the changes in optimum valvetrain settings at moderate speeds and loads where the effects of varying EGR tolerance were less dominant.
UTS study details efficiency benefits of combining ethanol direct injection with gasoline port injection
February 25, 2013
|Variation of indicated thermal efficiency with increased EER at 3500 rpm and light load. Zhuang and Hong, 2013. Click to enlarge.|
A new study by researchers at the University of Technology, Sydney (Australia) is contributing more detail on the leveraging effect of combining ethanol direct injection with gasoline port injection (EDI + GPI) to reduce gasoline consumption in a spark ignition engine while retaining performance. (The EDI + GPI concept was proposed by MIT researchers in 2005. Earlier post.)
Existing methods of using ethanol fuel—e.g., in blends with gasoline or neat—do not make the best use of ethanol’s potentials in improving engine performance, they noted in a paper on their work in the journal Fuel. Ethanol possesses a higher octane number and latent heat of vaporization, which allow the use of higher compression ratios and consequently can lead to the increased thermal efficiency. Ethanol fuel’s higher combustion velocity could also help increase the combustion efficiency and minimize the energy loss.
SAE High Octane Fuels Symposium: Is a new high-octane fuel a pragmatic pathway for higher engine efficiency in the US? (part 2)
February 06, 2013
As highlighted at the 2013 SAE International High Octane Fuels Symposium (HOF) last week, high octane fuels—combined with optimized engines—are viable enablers to higher efficiency operation. When ethanol is used as the octane enhancer, there is an added benefit due to the latent heat of vaporization of that fuel. (Earlier post.)
As articulated by Dr. Jim Szybist from Oak Ridge National Laboratory (ORNL), one vision of a high-octane ethanol fuel infrastructure and distribution system could include a standardized high ethanol/high octane fuel with ethanol content probably in the E20-E50 range. Refiners would continue to produce two high volume products in the gasoline boiling range: the Exx BOB (Blendstock for Oxygenate Blending) would have a low octane requirement (e.g., RON ~85), and be inexpensive for refiners to produce. Gasoline or E10 BOB would be premium-grade fuel for total coverage of legacy fleet.
2013 SAE International High Octane Fuels Symposium: the potential for high octane fuels (Part 1)
January 31, 2013
The 2013 SAE International High Octane Fuels Symposium (HOFS) this week in Washington, DC, explored the pros and the cons of high octane fuels, with a particular focus on using ethanol as the source of the octane improvement.
The “obvious driver” for the consideration of a high octane fuel (HOF), said MIT Prof. Emeritus John Heywood, one of the speakers, is that higher octane fuels would lead to higher compression ratios which would lead to more efficient engines and reduced fuel consumption. With the spread of turbocharged gasoline engines, he added, there is a double benefit: higher compression ratios and increased boost.
CRC study finds that fuel systems in some modern vehicles fail with E15 use
January 30, 2013
A newly completed study (CRC Project No. AVFL-15a) by the Coordinating Research Council, a non-profit organization created and supported by the petroleum and auto industries, has found that some fuel systems in modern vehicles survive testing in mid-blend ethanol fuels, while others will experience complete failures that would prevent operation.
The fuel pumps and level senders that failed or exhibited other effects during testing on E15 and E15a are used on a substantial number of the 29 million 2001 – 2007 model year vehicles represented by the components evaluated in the report.
New Argonne lifecycle analysis of bioethanol pathways finds corn ethanol can reduce GHG emissions relative to gasoline by 19-48%; long-term, cellulosic offers the most benefits
January 22, 2013
|Well-to-wheels results for greenhouse gas emissions in CO2e for six pathways. Source: Wang et al. Click to enlarge.|
A new lifecycle analysis of five bioethanol production pathways by a team from Argonne National Laboratory led by Dr. Michael Wang found that, relative to petroleum gasoline, ethanol from corn; sugarcane; corn stover; switchgrass; and miscanthus can reduce lifecycle greenhouse gas (GHG) emissions [P10-P90 (P50)] by 19–48% (34%); 40–62% (51%); 90–103% (96%); 77–97% (88%); and 101–115% (108%), respectively when including land use change emissions. They researchers reported similar trends with regard to fossil energy benefits for the five bioethanol pathways. An open access paper on the study in published in the journal Environmental Research Letters.
While the results for cellulosic ethanol (stover, switchgrass and miscanthus) are in line with recent studies, and the findings for sugarcane ethanol are only slightly lower than other similar studies, the results for corn ethanol are in sharp contrast to other studies predicting that corn ethanol would have a greater life-cycle GHG impact than gasoline, the authors noted.
Spatially explicit life cycle assessment of 5 sun-to-wheels pathways finds photovoltaic electricity and BEVs offer land-efficient and low-carbon transportation
January 04, 2013
A new spatially-explicit life cycle assessment of five different “sun-to-wheels” conversion pathways—ethanol from corn or switchgrass for internal combustion vehicles (ICVs); electricity from corn or switchgrass for battery-electric vehicles (BEVs); and photovoltaic electricity for BEVs—found a strong case for PV BEVs.
According to the findings by the team from the University of California, Santa Barbara and the Norwegian University of Science and Technology, published in the ACS journal Environmental Science & Technology, even the most land-use efficient biomass-based pathway (i.e., switchgrass bioelectricity in US counties with hypothetical crop yields of more than 24 tonnes/ha) requires 29 times more land than the PV-based alternative in the same locations.
EPA denies waiver of Renewable Fuels Standard
November 16, 2012
The US Environmental Protection Agency (EPA) announced that it has not found evidence to support a finding of severe “economic harm” that would warrant granting a waiver of the Renewable Fuels Standard (RFS). The decision is based on economic analyses and modeling done in conjunction with the US Departments of Agriculture (USDA) and Energy (DOE).
In August, in light of drought conditions affecting the country, governors from several states requested a waiver of the national volume requirements for the renewable fuel standard program (RFS). EPA said that while it recognizes that this year’s drought has created significant hardships in many sectors of the economy, particularly for livestock producers, its analysis made clear that Congressional requirements for a waiver have not been met. Further, it found, waiving the RFS would have little, if any, impact on ethanol demand or energy prices over the time period analyzed.
Brazilian biofuels with LUC may have much higher non-GHG emissions than conventional gasoline and diesel
September 24, 2012
|Comparisons of life-cycle emissions from LUC phase for (a) sugar cane ethanol and (b) soybean biodiesel. Credit: ACS, Tsao et al. Click to enlarge.|
When including Land Use Change (LUC) factors, Brazilian sugar cane ethanol and soybean biodiesel have much larger life-cycle emissions than conventional gasoline and biodiesel for six regulated, non-greenhouse gas (GHG) air pollutants, according to a study led by a team from the University of California, Merced. The pollutants are NMHC, CO, NOx, TPM, PM2.5 and SOx.
Even with the application of the “Green Ethanol Protocol”—which will eliminate sugar cane pre-harvest burning in the future—Brazilian biofuels including sugar cane ethanol and soybean biodiesel are still likely to have higher air pollution impacts than conventional fossil fuels due to the LUC effects if the LUC occurs as projected through 2020, according to the researchers. A paper on their work is published in the ACS journal Environmental Science & Technology.
Researchers report on potential long-range atmospheric emissions impacts of increased ethanol fuel use in North America
July 28, 2012
A study by a team of researchers from the University of Minnesota; University of Colorado, Boulder; National Center for Atmospheric Research; and NASA Ames Research Center have used an ensemble of aircraft measurements combined with the GEOS-Chem chemical transport model to to gauge potential long-range emissions impacts of increased ethanol fuel use in North America. Their paper is published in the ACS journal Environmental Science & Technology.
Ethanol is emitted to the atmosphere by both natural and anthropogenic processes; examples of the latter include industrial processes, biomass combustion and use as a biofuel mixed with gasoline. (Terrestrial plants are thought to be the dominant global source of atmospheric ethanol.) In the atmosphere, ethanol is a precursor of acetaldehyde (CH3CHO) and peroxyacetyl nitrate (PAN).
Pertamina to collaborate with Celanese to develop fuel ethanol projects using Celanese TCX process in Indonesia; use of lower-rank coal
July 19, 2012
|Celanese TCX production process. Click to enlarge.|
Celanese Corporation has entered into a Joint Statement of Cooperation to advance the development of fuel ethanol projects with Pertamina, the state-owned energy company of Indonesia. Pertamina will collaborate exclusively with Celanese jointly to develop synthetic fuel ethanol projects in the Republic of Indonesia utilizing Celanese’s proprietary TCX ethanol process technology. (Earlier post.)
TCX builds on Celanese’s acetyl platform and integrates new technologies to produce ethanol using basic hydrocarbon feedstocks—natural gas, coal and pet coke now, with biomass and waste planned for the future. So far, Celanese has been targeting the industrial ethanol market as part of its acetyl business. The customers are the same, and the supply chain is the same. However, the company last year created a different business unit to help orchestrate and organize a potential fuel ethanol new line of business. (Earlier post.)
MIT/UC Davis professors challenge claims that ethanol production decreased gasoline prices in 2010 and 2011
July 17, 2012
Two professors from MIT and UC Davis have released a paper challenging the recent claims by the Renewable Fuel Association (RFA) and US Secretary of Agriculture Vilsack that ethanol production decreased gasoline prices by $0.89 and $1.09 in 2010 and 2011, respectively.
Those estimates are based on a series of papers by University of Wisconsin and Iowa State University economists Xiaodong Du and Dermot Hayes, who used monthly regional data to estimate the relationship between ethanol production and the proﬁt margin for oil refiners. The paper by Prof. Christopher Knittel at MIT and Assoc. Professor Aaron Smith at UC Davis tests the validity of the statistical work underlying the claims and concludes that the results are driven by implausible economic assumptions and “spurious” correlations—correlations that are the result of the fact that over the sample the ratio of gas prices to oil prices fell while, at the same time, ethanol production increased.
MSU team develops consolidated bioprocessing platform for efficient production of ethanol and hydrogen from biomass with a microbial electrolysis cell
July 10, 2012
Researchers at Michigan State University have developed a method for the consolidated bioprocessing (CBP) of corn stover pretreated by ammonia fiber expansion (AFEX-CS) to produce ethanol and hydrogen with a microbial electrolysis cell (MEC) using the ethanol-producing bacterium Cellulomonas uda in partnership with the exoelectrogenic bacterium Geobacter sulfurreducens.
The synergistic activities of the ethanol-producing and electricity-producing bacteria resulted in substantial energy recoveries from ethanol production alone (ca. 56%). (G. sulfurreducens removes waste fermentation byproducts that can inhibit ethanol production.) The cogeneration of H2 in the MEC further increased the energy recoveries to ca. 73%.
EPA approves first company plans for E15 misfueling mitigation; E15 may be lawfully introduced to market
June 15, 2012
The US Environmental Protection Agency (EPA) approved the first plans from individual companies for satisfying the misfueling mitigation conditions of the E15 partial waivers. Approved companies have now met all Clean Air Act requirements related to E15 and may legally—for CAA requirements—introduce E15 into the marketplace. However, noted EPA, other federal, state and local requirements and practical concerns must also be addressed.
For example, dispenser and tank compatibility with E15 must be considered by marketers of E15. (EPA has issued guidance and a proposed rule on tank compatibility.) Since a number of states restrict the sale of some gasoline-ethanol blends, state law changes may also be needed before E15 may be sold in those states. Industry stakeholders are also preparing an E15 public education campaign to provide consumers with additional information about the proper use of E15 and to help them avoid misfueling. EPA is participating in that effort.
Ethanol thermal stratification as a means to extend the high-load limit of HCCI engines
|The effect of increasing levels of fuel stratification on observed pressure. Increased stratification leads to longer combusstion duration, no stratification results in the highest PRR. Krisman et al. Click to enlarge.|
Researchers from the University of New South Wales (Australia) and Sandia National Laboratories in the US report that ethanol fuel thermal stratification has the potential to reduce significantly the pressure-rise rate (PRR) and so to extend the high-load limit of homogeneous-charge compression-ignition (HCCI) engines.
In a simulation study, published in the journal Fuel, the team developed and applied a multi-zone model of thermal stratification to assess the potential of ethanol fuel stratification to reduce PRR in HCCI engines and to understand the possible trade-off with increased NOx formation.
California Energy Commission awards more than $23M to encourage use of alternative transportation fuels
June 14, 2012
The California Energy Commission (CEC) approved funding of $23,110,015 for projects that will advance the development of green fuels, and the installation of fueling stations. The awards are provided through the Energy Commission’s Alternative and Renewable Fuel and Vehicle Technology Program, created by Assembly Bill 118.
The program provides approximately $100 million annually to encourage the development and use of alternative and renewable fuels and new vehicle technologies. By leveraging outside funding, many of these projects also attract additional investment in clean energy technology. The award recipients are:
Researchers argue crop-based biofuels only show GHG savings because of LCA accounting flaw; the need for “additional” biomass
June 11, 2012
In an invited opinion paper published in the journal GCB Bioenergy, Kevin Smith from the University of Edinburgh and Tim Searchinger from Princeton University argue that current Life Cycle Analysis (LCA) models indicate that crop-based biofuels generate greenhouse gas (GHG) savings compared with fossil fuels only because the models ignore the emissions of CO2 from vehicles burning the biofuels without determining if the biomass is “additional”.
Additional biomass is biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy. The models also underestimate the ultimate emissions of N2O from nitrogen fertilizer use, the authors suggest.
California Energy Commission awards more than $35M for green transportation in California
June 01, 2012
The California Energy Commission unanimously approved funding of $35,031,310 to projects that will accelerate the development of green fuels and technology in California. This set of awards supports a diversity of alternative fuel and vehicle types, including biodiesel production, natural gas vehicle technologies and incentives, hybrid and plug-in vehicles, and E85 fueling stations.
These awards are provided through the Energy Commission’s Alternative and Renewable Fuel and Vehicle Technology Program. The program, created by Assembly Bill 118, provides approximately $100 million annually to encourage the development and use of new vehicle technologies and alternative fuels to help the state fulfill its pioneering climate change policies.