Obstacles to Commercial Development of Cellulosic Ethanol

Written by Claudio Muñoz on

August 21, 2016

Technological immaturity and high cost are two key barriers to cellulosic ethanol at present. Making this fuel competitive in the marketplace will require more experience and significantly reduced production costs, including capital costs. If the costs of cellulosic ethanol production come down as the technology matures, this fuel will still face some, although not all, of the obstacles that corn-based ethanol currently faces.




Flex-fuel vehicle deployment

Recent research indicates that current passenger vehicles may be capable of running on fuel blends containing up to 20 percent ethanol by volume (E20). Higher-level blends (up to E85) can be used by flex-fuel vehicles. Flex-fuel modifications are relatively inexpensive when made during vehicle production (estimated to be $50 - $100 per vehicle), but retrofitting existing vehicles could be costly. As of 2008, an estimated 7.3 million light-duty E85 vehicles, or roughly 3 percent of the roughly 250 million passenger vehicles currently registered in the United States, were flex-fuel vehicles. Higher-level blends also require dedicated pumps to dispense the fuel. Currently most of the 1,600 stations with E85 dispensing capability are concentrated in the Midwest, where most ethanol production occurs.


Infrastructure requirements

Ethanol cannot be shipped in existing crude oil or petroleum fuel pipelines, because ethanol can absorb water and other impurities that accumulate in these pipes, affecting fuel quality, and because ethanol’s corrosiveness can shorten pipeline lifetime. Instead, ethanol is currently transported via rail (60 percent of domestic ethanol shipped), truck (30 percent), and barge (10 percent). Currently in the United States, cellulosic feedstocks can be most easily grown in the Midwest and Southeast, but much of the demand for transportation fuels is along the coasts. Thus, large volumes of ethanol may need to be shipped long distances to reach areas of high demand in the future. Without substantial infrastructure investment, increased ethanol shipping could result in significant bottlenecks on both rail and highway networks. These problems could be reduced by encouraging the use of high-level ethanol blends (i.e., E85) regionally instead of low-level blends (E10) on a national basis. Distributing and using ethanol close to where it is produced – i.e., in the Midwest and Southeast – would also minimize the GHG emissions associated with transporting ethanol.


Food versus fuel

Unlike corn ethanol (or ethanol produced from sugarcane), cellulosic ethanol does not necessarily compete with food markets for feedstock directly. However, the production of cellulosic crops is constrained by land availability, which is a limited resource. To decrease competition with other agricultural crops, cellulosic feedstocks could be grown on degraded or marginal farmland unsuitable for production of food crops. However, doing so can decrease yields or increase input energy and fertilizer requirements, which could result in higher feedstock prices and increased GHG emissions.


Land use change

The production of fuels from biomass feedstocks has direct and indirect impacts on land use. For example, clearing grasslands or forests to plant biofuel crops are direct land use changes that result in releases of carbon stored in soils and vegetation. Indirect land use change refers to the land use changes that result from the impacts on land and biomass prices due to increased demand for biomass for biofuel production and the interactions with ongoing demand for food, feed, and fiber products. Accounting for indirect land use changes is particularly challenging and relies upon a number of estimates and assumptions. Recent studies have shown that the GHG impacts of indirect land use changes could significantly affect the overall life-cycle GHG emissions of biofuels. Both direct and indirect land-use change remain important areas of concern and a topic of continued scientific research.


Technological immaturity and high cost are two key barriers to cellulosic ethanol at present. Making this fuel competitive in the marketplace will require more experience and significantly reduced production costs, including capital costs. If the costs of cellulosic ethanol production come down as the technology matures, this fuel will still face some, although not all, of the obstacles that corn-based ethanol currently faces.




Flex-fuel vehicle deployment

Recent research indicates that current passenger vehicles may be capable of running on fuel blends containing up to 20 percent ethanol by volume (E20). Higher-level blends (up to E85) can be used by flex-fuel vehicles. Flex-fuel modifications are relatively inexpensive when made during vehicle production (estimated to be $50 - $100 per vehicle), but retrofitting existing vehicles could be costly. As of 2008, an estimated 7.3 million light-duty E85 vehicles, or roughly 3 percent of the roughly 250 million passenger vehicles currently registered in the United States, were flex-fuel vehicles. Higher-level blends also require dedicated pumps to dispense the fuel. Currently most of the 1,600 stations with E85 dispensing capability are concentrated in the Midwest, where most ethanol production occurs.


Infrastructure requirements

Ethanol cannot be shipped in existing crude oil or petroleum fuel pipelines, because ethanol can absorb water and other impurities that accumulate in these pipes, affecting fuel quality, and because ethanol’s corrosiveness can shorten pipeline lifetime. Instead, ethanol is currently transported via rail (60 percent of domestic ethanol shipped), truck (30 percent), and barge (10 percent). Currently in the United States, cellulosic feedstocks can be most easily grown in the Midwest and Southeast, but much of the demand for transportation fuels is along the coasts. Thus, large volumes of ethanol may need to be shipped long distances to reach areas of high demand in the future. Without substantial infrastructure investment, increased ethanol shipping could result in significant bottlenecks on both rail and highway networks. These problems could be reduced by encouraging the use of high-level ethanol blends (i.e., E85) regionally instead of low-level blends (E10) on a national basis. Distributing and using ethanol close to where it is produced – i.e., in the Midwest and Southeast – would also minimize the GHG emissions associated with transporting ethanol.


Food versus fuel

Unlike corn ethanol (or ethanol produced from sugarcane), cellulosic ethanol does not necessarily compete with food markets for feedstock directly. However, the production of cellulosic crops is constrained by land availability, which is a limited resource. To decrease competition with other agricultural crops, cellulosic feedstocks could be grown on degraded or marginal farmland unsuitable for production of food crops. However, doing so can decrease yields or increase input energy and fertilizer requirements, which could result in higher feedstock prices and increased GHG emissions.


Land use change

The production of fuels from biomass feedstocks has direct and indirect impacts on land use. For example, clearing grasslands or forests to plant biofuel crops are direct land use changes that result in releases of carbon stored in soils and vegetation. Indirect land use change refers to the land use changes that result from the impacts on land and biomass prices due to increased demand for biomass for biofuel production and the interactions with ongoing demand for food, feed, and fiber products. Accounting for indirect land use changes is particularly challenging and relies upon a number of estimates and assumptions. Recent studies have shown that the GHG impacts of indirect land use changes could significantly affect the overall life-cycle GHG emissions of biofuels. Both direct and indirect land-use change remain important areas of concern and a topic of continued scientific research.


9th Biofuels International Conference – Ghent, Belgium

Written by Claudio Muñoz on

November 26, 2015

We are pleased to announce that the 9th Biofuels International Conference will be held in Ghent, Belgium, on 21-22nd September 2016.


As biofuel producers, regulators and experts come together in Ghent to discuss the industry's transition to advanced biofuels, where will you be?




With the 2 day conference focusing on the latest developments in biofuels policy, international biofuels trading, sustainability, solutions for first generation producers, progress in advanced biofuels and information on feedstock pricing and trends, it's a must attend industry event.


Be part of the industry's future and join us.


With a limited number of exhibition spaces available for companies to showcase their products and services to delegates, contact Matthew now to secure your company's place at this well respected event.


Interested in being part of the 2016 conference programme? Please send your contact details and a short abstract to: margaret@biofuels-news.com


We are pleased to announce that the 9th Biofuels International Conference will be held in Ghent, Belgium, on 21-22nd September 2016.


As biofuel producers, regulators and experts come together in Ghent to discuss the industry's transition to advanced biofuels, where will you be?




With the 2 day conference focusing on the latest developments in biofuels policy, international biofuels trading, sustainability, solutions for first generation producers, progress in advanced biofuels and information on feedstock pricing and trends, it's a must attend industry event.


Be part of the industry's future and join us.


With a limited number of exhibition spaces available for companies to showcase their products and services to delegates, contact Matthew now to secure your company's place at this well respected event.


Interested in being part of the 2016 conference programme? Please send your contact details and a short abstract to: margaret@biofuels-news.com


BIT’s 6th Annual World Congress of Bioenergy

Written by Claudio Muñoz on

November 24, 2015

The 6th Annual World Congress of Bioenergy will be held in KINTEX, Gyeonggi-do, South Korea from June 30 to July 03, 2016.


Bioenergy 2016 will showcase the bioenergy research in a global context and will bring together world-class researchers in bioenergy, including academia, policy makers, industrialists and other related stakeholders. It will include high profile plenary keynote speakers, subject-specific break-out sessions, workshops and poster presentations.




Join us in Gyeonggi-do, South Korea for the Bioenergy 2016. Over the three days of the conference, there will be many opportunities to learn more about the industry in Asia as well as the latest global trends in fibre supply, sustainability, products, technology, policies and other drivers of the future bioeconomy.


If you would like to give an oral presentation at this conference, please submit a proposal, including the title and brief (3-5 sentences) summary on your recent work in the area. For more information, please kindly check on http://www.bitcongress.com/wcbe2016/default.asp


The 6th Annual World Congress of Bioenergy will be held in KINTEX, Gyeonggi-do, South Korea from June 30 to July 03, 2016.


Bioenergy 2016 will showcase the bioenergy research in a global context and will bring together world-class researchers in bioenergy, including academia, policy makers, industrialists and other related stakeholders. It will include high profile plenary keynote speakers, subject-specific break-out sessions, workshops and poster presentations.




Join us in Gyeonggi-do, South Korea for the Bioenergy 2016. Over the three days of the conference, there will be many opportunities to learn more about the industry in Asia as well as the latest global trends in fibre supply, sustainability, products, technology, policies and other drivers of the future bioeconomy.


If you would like to give an oral presentation at this conference, please submit a proposal, including the title and brief (3-5 sentences) summary on your recent work in the area. For more information, please kindly check on http://www.bitcongress.com/wcbe2016/default.asp


Search for better biofuels microbes leads to the human gut

Written by Claudio Muñoz on

October 24, 2014

(By University of Illinois at Urbana-Champaign) - Scientists have scoured cow rumens and termite guts for microbes that can efficiently break down plant cell walls for the production of next-generation biofuels, but some of the best microbial candidates actually may reside in the human lower intestine, researchers report.



Their study, reported in the Proceedings of the National Academy of Sciences, is the first to use biochemical approaches to confirm the hypothesis that microbes in the human gut can digest fiber, breaking it down into simple sugars in order to ferment them into nutrients that nourish human cells. These findings have significance for human health but also for biofuels production, since the same sugars can be fed to yeast to generate ethanol and other liquid fuels. The human microbes appear to be endowed with enzymes that break down a complex plant fiber component more efficiently than the most efficient microbes found in the cow rumen, the researchers report.


Their work in cows led the researchers to the human microbes, said University of Illinois animal sciences and Institute for Genomic Biology professor Isaac Cann, who led the new analysis with his colleagues, animal sciences professor Roderick Mackie and M.D./Ph.D. student Dylan Dodd. Cann also is a microbiology professor and a principal investigator at the Energy Biosciences Institute. Dodd is now at Stanford University.


"In looking for biofuels microbes in the cow rumen, we found that Prevotella bryantii, a bacterium that is known to efficiently break down (the plant fiber) hemicellulose, gears up production of one gene more than others when it is digesting plant matter," Cann said.


When searching a database for similar genes in other organisms, the researchers found them in microbes from the human gut. The team focused on two of these human microbes, Bacteroides intestinalis and Bacteroides ovatus, which belong to the same bacterial phylum as Prevotella from the cow.


"We expressed the human gut bacterial enzymes and found that for some related enzymes, the human ones actually were more active (in breaking down hemicellulose) than the enzymes from the cow," Cann said.


When the researchers looked more closely at the structure of the human enzymes, they saw something unusual: many single polypeptide (protein) chains actually contained two enzymes, one of which was embedded in the other. Further analysis of the most important protein revealed that the embedded component was a carbohydrate-binding module (CBM), which, as its name implies, latches onto carbohydrates such as hemicellulose. This enzyme shreds the plant fiber hemicellulose so that other enzymes can work on it to break it down into its unit sugars.


Working with U. of I. biochemistry professor Satish Nair, the researchers also noticed that the CBM "put a kink" in the fiber when it bound to it. This bending action may bring the fiber close to the other enzyme in the protein so it can get to work breaking the bonds between the sugars. Further research is needed to confirm this hypothesis, Cann said.


The study points to human microbes as a potentially potent source of microbes that can aid in biofuels production, Cann said.


"In addition to finding microbes in the cow rumen and termite gut, it looks like we can actually make some contributions ourselves," he said. "And our bugs seem to have some enzymes that are even better than those in the cow rumen."


(By University of Illinois at Urbana-Champaign) - Scientists have scoured cow rumens and termite guts for microbes that can efficiently break down plant cell walls for the production of next-generation biofuels, but some of the best microbial candidates actually may reside in the human lower intestine, researchers report.



Their study, reported in the Proceedings of the National Academy of Sciences, is the first to use biochemical approaches to confirm the hypothesis that microbes in the human gut can digest fiber, breaking it down into simple sugars in order to ferment them into nutrients that nourish human cells. These findings have significance for human health but also for biofuels production, since the same sugars can be fed to yeast to generate ethanol and other liquid fuels. The human microbes appear to be endowed with enzymes that break down a complex plant fiber component more efficiently than the most efficient microbes found in the cow rumen, the researchers report.


Their work in cows led the researchers to the human microbes, said University of Illinois animal sciences and Institute for Genomic Biology professor Isaac Cann, who led the new analysis with his colleagues, animal sciences professor Roderick Mackie and M.D./Ph.D. student Dylan Dodd. Cann also is a microbiology professor and a principal investigator at the Energy Biosciences Institute. Dodd is now at Stanford University.


"In looking for biofuels microbes in the cow rumen, we found that Prevotella bryantii, a bacterium that is known to efficiently break down (the plant fiber) hemicellulose, gears up production of one gene more than others when it is digesting plant matter," Cann said.


When searching a database for similar genes in other organisms, the researchers found them in microbes from the human gut. The team focused on two of these human microbes, Bacteroides intestinalis and Bacteroides ovatus, which belong to the same bacterial phylum as Prevotella from the cow.


"We expressed the human gut bacterial enzymes and found that for some related enzymes, the human ones actually were more active (in breaking down hemicellulose) than the enzymes from the cow," Cann said.


When the researchers looked more closely at the structure of the human enzymes, they saw something unusual: many single polypeptide (protein) chains actually contained two enzymes, one of which was embedded in the other. Further analysis of the most important protein revealed that the embedded component was a carbohydrate-binding module (CBM), which, as its name implies, latches onto carbohydrates such as hemicellulose. This enzyme shreds the plant fiber hemicellulose so that other enzymes can work on it to break it down into its unit sugars.


Working with U. of I. biochemistry professor Satish Nair, the researchers also noticed that the CBM "put a kink" in the fiber when it bound to it. This bending action may bring the fiber close to the other enzyme in the protein so it can get to work breaking the bonds between the sugars. Further research is needed to confirm this hypothesis, Cann said.


The study points to human microbes as a potentially potent source of microbes that can aid in biofuels production, Cann said.


"In addition to finding microbes in the cow rumen and termite gut, it looks like we can actually make some contributions ourselves," he said. "And our bugs seem to have some enzymes that are even better than those in the cow rumen."


Ethanol Production Hits Record High

Written by Claudio Muñoz on

June 25, 2014

(Reuters) - U.S. ethanol production increased for the sixth week in a row to a record high, government data showed, as rising gasoline prices helped boost demand for the grain-based biofuel.



Ethanol production surged 28,000 barrels per day, or about 3 percent, to an average of 972,000 bpd in the week ending June 13, according to the U.S. Energy Information Administration. Production surpassed the previous record of 963,000 bpd reached in the last week of 2011.


Despite the higher output, strong demand squeezed stocks of ethanol, which fell 572,000 barrels to 17.85 million barrels, a three-week low.


Makers of the biofuel are earning near-record profits as prices for corn, the main feedstock used in ethanol production, hovered near a four-month low. Meanwhile, gasoline futures have maintained roughly a $1-per-gallon premium over ethanol futures throughout June, making ethanol attractive for fuel blenders during the early days of the summer driving season.


(Reuters) - U.S. ethanol production increased for the sixth week in a row to a record high, government data showed, as rising gasoline prices helped boost demand for the grain-based biofuel.



Ethanol production surged 28,000 barrels per day, or about 3 percent, to an average of 972,000 bpd in the week ending June 13, according to the U.S. Energy Information Administration. Production surpassed the previous record of 963,000 bpd reached in the last week of 2011.


Despite the higher output, strong demand squeezed stocks of ethanol, which fell 572,000 barrels to 17.85 million barrels, a three-week low.


Makers of the biofuel are earning near-record profits as prices for corn, the main feedstock used in ethanol production, hovered near a four-month low. Meanwhile, gasoline futures have maintained roughly a $1-per-gallon premium over ethanol futures throughout June, making ethanol attractive for fuel blenders during the early days of the summer driving season.