[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.]
BAL scientists engineer yeast to produce ethanol from brown seaweed; brown seaweed biorefinery
December 03, 2013
An international team of researchers from Bio Architecture Labs, a synthetic biology and enzyme design company focused on the production of biofuels and biochemicals from macroalgae (seaweed) (earlier post), reports the development of a synthetic yeast platform based on Saccharomyces cerevisiae that can efficiently produce ethanol from brown seaweed; the paper is published in the journal Nature.
In January 2012, BAL scientists reported the engineering a strain of Eschericia coli that could break down and then ferment alginate—one of the most abundant sugars in brown algae, but a sugar that industrial microbes can’t metabolize—into ethanol. That paper was featured on the cover of the journal Science. (Earlier post.)
NREL study probes emissions impact of butanol-gasoline blends in light-duty vehicles
November 26, 2013
|Summary of significant emissions results from the fuel testing. Credit: ACS, Ratcliff et al. Click to enlarge.|
Results of a study led by a team from the National Renewable Energy Laboratory on the impact of butanol-gasoline blends on light-duty vehicle emissions suggest that widespread deployment of n-butanol or i-butanol in the gasoline pool could result in changes to the estimated emissions of alcohols and carbonyls in the emissions inventory. Given equivalent deployment of butanols and ethanol, the results suggest emissions of unburned alcohols would decrease, but carbonyl emissions would increase; some of these compounds have poorly understood health effects, they note.
The carbonyls acetaldehyde and formaldehyde are classified as carcinogens or probable carcinogens by the National Institute for Occupational Safety and Health (NIOSH), International Agency for Research on Cancer, and the EPA. NIOSH considers butyraldehyde to have similar reactivity and mutagenicity to acetaldehyde.
EPA proposes reduction in cellulosic biofuel and total renewable fuel standards for 2014
November 15, 2013
The US Environmental Protection Agency (EPA) is proposing a reduction in the cellulosic biofuel and total renewable fuel standards (RFS) for 2014. Once the proposal is published in the Federal Register, it will be open to a 60-day public comment period.
Specifically, EPA is proposing a total renewable fuel target of 15.21 billion gallons; the final 2013 overall volumes and standards require 16.55 billion gallons; the original target as specified in the Clean Air Act is 18.15 billion gallons. (Earlier post.) EPA is setting the troublesome cellulosic biofuel target at 17 million gallons—significantly lower than the Clean Air Act (CAA) target of 1.75 billion gallons—but an increase from the 6.0 million gallons specified for 2013. This reflects EPA’s current estimate of the amount of cellulosic biofuel that will actually be produced in 2014, but EPA will consider public comments before setting the final cellulosic standard.
Researchers explore ethanol-diesel dual-fuel combustion for reduction in engine-out emissions
November 14, 2013
|Effect of ethanol energy fraction and PFI position on CO, NOx, HC, and opacity emissions. Credit: ACS, Padala et al. Click to enlarge.|
Researchers at the University of New South Wales (Australia) have demonstrated the potential for ethanol use in diesel engines with dual-fuel combustion, in which ethanol is injected into the intake manifold and diesel is directly injected into the engine cylinder. A paper on their work is published in the ACS journal Energy & Fuels.
The goal of such an approach is effectively to address some of the drawbacks of conventional diesel combustion, such as higher in-cylinder soot formation associated with locally rich mixtures and high flame temperatures and engine-out emissions of NOx.
LanzaTech-Shougang joint venture in China earns RSB certification for waste steel mill gas to biofuel process
November 05, 2013
Beijing Shougang LanzaTech New Energy Science & Technology Co., Ltd. has earned the Roundtable on Sustainable Biomaterials Services Foundation’s (RSB’s) sustainability certification for the joint venture’s facility that converts waste steel mill gases to sustainable biofuels. LanzTech and the Shougang Group signed the joint venture agreement in September 2011.
The facility, which utilizes LanzaTech’s waste gas fermentation technology (earlier post), is the first RSB-certified biofuel plant in China, and the first of its kind anywhere to receive this key certification for industrial carbon capture and utilization. The RSB is a global sustainability standard and certification system for biofuels and biomaterials production.
Univ. of Illinois team argues that renewable fuel standard needs to be modified, not repealed
October 16, 2013
A policy analysis by two University of Illinois researchers argues that Congress should minimally modify, not repeal, the Renewable Fuel Standard (RFS). In the study, law professor Jay P. Kesan and Timothy A. Slating, a regulatory associate with the Energy Biosciences Institute, argue that RFS mandates ought to be adjusted to reflect current and predicted biofuel commercialization realities; that its biofuel categories be expanded to encompass all emerging biofuel technologies; and that its biomass sourcing constraints be relaxed.
In the paper, to be published in the NYU Environmental Law Journal, Kesan and Slating contend that the RFS can serve as a “model policy instrument” for the federal support of all types of socially beneficial renewable energy technologies.
NREL review of E15 effects on MY2001 and later cars finds no meaningful differences with E10
October 13, 2013
A review of 43 studies of the effects of E15 (15% ethanol blends) on Model Year 2001 and newer cars by the National Renewable Energy Laboratory (NREL) found that the studies reviewed showed no meaningful differences between E15 and E10 in any performance category.
The NREL study, commissioned by the Renewable Fuels Association, included 33 unique research studies, as well as 10 related reviews. The study does not address engines that EPA has not approved for use with E15, such as pre-2001 cars, marine, snowmobile, motorcycle, and small non-road engines.
Butamax and Highwater Ethanol break ground on biobutanol retrofit project
October 04, 2013
|Converting a corn ethanol plant to produce biobutanol requires changes to the fermentation step (mainly a new microorganism) and to alcohol recovery from the fermentation. Source: Butamax. Click to enlarge.|
Butamax Advanced Biofuels LLC, the biobutanol technology company formed as a joint venture between DuPont and BP, and Highwater Ethanol LLC, a producer of first-generation corn ethanol, have begun to retrofit Highwater’s ethanol plant in Lamberton, Minnesota for the production of bio-isobutanol.
Butamax’s technology package will include the installation of novel corn oil separation technology. Butamax and Highwater have entered into definitive agreements for license of Butamax’s patented corn oil separation technology, which is an integral part of a full retrofit to biobutanol production and can also be installed independently as a first phase of the conversion.
Study finds HTL algal biofuels offer 50-70% lifecycle CO2 reduction compared to petroleum fuels; EROI and GHG comparable to or better than other biofuels
September 20, 2013
A new life cycle analysis by a team led by researchers at the University of Virginia has concluded that biofuel produced from algae via hydrothermal liquefaction (HTL) can reduce life cycle CO2 emissions by 50 to 70% compared to petroleum fuels, and also has energy burdens and GHG (greenhouse gas) emission profiles that are comparable to or better than conventional biofuels, cellulosic ethanol and soybean biodiesel.
HTL algae-derived gasoline has a considerably lower GHG footprint and a better EROI relative to conventional ethanol made from corn on a per MJ basis, the team found. The data suggest that a shift to algae-derived gasoline could have immediate climate benefits even using existing technologies, the authors noted. In addition, given expected technological improvements, the benefits of algae-derived gasoline will likely improve.
European Parliament backs 6% cap on land-based biofuels, switchover to advanced biofuels; no mandate
September 11, 2013
In a vote on draft legislation, the European Parliament has backed a cap on the use of biofuels produced from starch-rich crops, sugars, oil and other crops grown on land and a speedy switchover to new biofuels from alternative sources such as seaweed and waste. The measures aim to reduce greenhouse gas emissions that result from the turnover of agricultural land to biofuel production.
According to current legislation, member states must ensure that renewable energy accounts for at least 10% of energy consumption in transport by 2020. In the adopted text, MEPs (Members of the European Parliament) say land-based biofuels should not exceed 6% of the final energy consumption in transport by 2020. (The proposal by the European Commission on which the draft legislation was based had suggested an even lower 5% cap.)
EPA grants Aemetis’ sorghum ethanol and biogas the D5 advanced biofuel RIN category
September 03, 2013
The US Environmental Protection Agency (EPA) has granted Aemetis, an advanced fuels and renewable chemicals company formerly known as AE Biofuels, approval to produce ethanol using grain sorghum and biogas at its converted corn ethanol plant to generate D5 Advanced Biofuels Renewable Identification Numbers (RINs).
Until now, the D5 Advanced Biofuels RIN portion of the RFS (Renewable Fuel Standard) has been mostly met by imported Brazilian sugarcane ethanol or by substituting D4 biodiesel RINs due to a lack of advanced ethanol production.
DEMA consortium targeting direct production ethanol from algae at less than $2/gallon
The EU-funded project DEMA (Direct Ethanol from MicroAlgae) is working to produce bioethanol directly from cyanobacteria—a microalgae found in almost every terrestrial and aquatic habitat, including in oceans, lakes and damp soil, and on rocks—for less than €0.40/liter (US$2.00/gallon).
The conversion of solar energy, H2O and CO2 into ethanol will be carried out by a metabolically engineered strain of the cyanobacterium, Synechocystis sp. PCC 6803. The DEMA team will develop and demonstrate the technology.
Viable exhaust-driven on-board ethanol reforming for improvements in fuel economy and emissions
August 20, 2013
|Schematic diagram of the successful “shoebox” reformer design and a picture of the core, after insertion of the catalyst. Credit: ACS, Sall et al. Click to enlarge.|
A team at Monsanto and colleagues at AVL Powertrain have successfully designed and demonstrated an onboard low-temperature ethanol reformer that can be driven by exhaust heat. A paper on their work is published in the ACS journal Energy & Fuels.
The low-temperature ethanol-reforming pathway, catalyzed by copper-nickel powder catalysts, transforms ethanol into a mixture of H2, CO, and CH4 at temperatures between 300 and 350 °C. Blending 25-50% of this low-temperature ethanol reformate with ethanol or E85 fuels enables dilute engine operation, resulting in substantial improvements in fuel economy and emissions.
EPA sets 2013 percentages for Renewable Fuel Standard; anticipating adjustments to 2014 volume requirements
August 06, 2013
The US Environmental Protection Agency (EPA) finalized the 2013 percentage standards for four fuel categories that are part of the Renewable Fuel Standard (RFS) program. The final 2013 overall volumes and standards require 16.55 billion gallons of renewable fuels to be blended into the US fuel supply (a 9.74% blend).
The 2013 standard specifically requires: biomass-based diesel (1.28 billion gallons; 1.13%); advanced biofuels (2.75 billion gallons; 1.62%); and cellulosic biofuels (6.00 million gallons; 0.004%). These standards reflect EPA’s updated production projections. All volumes are ethanol-equivalent, except for biomass-based diesel which is actual volume.
Advanced Biofuels USA introduces “E30 Capable” high-octane fuels concept in EPA Tier 3 comments
July 02, 2013
Biofuel advocacy group Advanced Biofuels introduced the concept of “E30 Capable” vehicles as part of its comments to the the US Environmental Protection Agency’s (EPA’s) recently proposed Tier 3 motor vehicle fuel and emission rulemaking. (Earlier post.)
As part of the Tier 3 requirements, EPA proposes allowing vehicle manufacturers to request approval for an alternative certification fuel—such as a high-octane 30% ethanol by volume (E30) blend—for vehicles they might design or optimize for use on such a fuel. (Earlier post.) Advanced Biofuels suggests that “E30 Capable” vehicles can serve a practical key to transitioning to higher percentage blends of affordable renewable transportation fuels. Elements of the proposal include:
Siemens and LanzaTech sign 10-year agreement to transform steel mill off-gases into bioethanol
June 19, 2013
Siemens Metals Technologies and LanzaTech, a producer of low-carbon fuels and chemicals from waste gases, have signed a ten-year co-operation agreement to develop and market integrated environmental solutions for the steel industry worldwide. The collaboration will utilize the fermentation technology developed by LanzaTech transforming carbon-rich off-gases generated by the steel industry into low carbon bioethanol and other platform chemicals. (Earlier post.)
Siemens and LanzaTech will work together on process integration and optimization, and on the marketing and realization of customer projects. In December 2012, LanzaTech and Baosteel, a leading steel producer in China, announced the success of their 100,000 gallon per year (300 tons) pre-commercial plant located at one of Baosteel’s steel mills outside Shanghai, China. (Earlier post.)
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.