Math Path to Ideal Algae Biorefineries

A joint research team from the Chemical and Biological Sciences Department, Universidad Autónoma de Sinaloa, and the Chemical Engineering Department of Universidad Michoacana de San Nicolás de Hidalgo, both located in Mexico, have discovered a way to produce biofuels from algae that also removes CO2 emissions from the environment. The findings were published in a recent edition of Industrial & Engineering Chemistry Research journal.

Researchers developed a mathematical model to calculate how to efficiently produce biofuel from algae. Credit: MiguelUrbelz/iStock/ThinkStock

Researchers developed a mathematical model to calculate how to efficiently produce biofuel from algae. Photo Credit: MiguelUrbelz/iStock/ThinkStock

To address the issue of cost and energy barriers to the success of algae-based biorefineries, Eusiel Rubio-Castro and colleagues developed a mathematical model to determine the optimal design of an algae-based biorefinery where flue gases from different industrial facilities are used as raw materials. A basic algae biorefinery just needs nutrients, water, sunlight and CO2 to operate.

The team developed a mixed integer non-linear programming (MINLP) model and applied it to a case study in Mexico. Their model determined that using flue gases as a source of CO2 reduced costs associated with the algae-growing stage of the process — the most expensive part — and reduced all other costs by almost 90 percent. Using water recycled within the biorefining process also reduced fresh water needs by about 83 percent. However, as the technology stands, the researchers say that the costs are still too high to justify an algae-based biorefinery on its own. Instead, they say that producing cleaner, algae-based fuels should be seen as a necessary expense in the global effort to reduce and capture carbon emissions.

U of York Team Aids in Biofuel Enzyme Research

A global research team is working together to help develop more efficient production methods for biofuel production. Scientists at the University of York are part of this team looking at how natural occurring enzymes can be used to degrade microbe-resistant biomass. The research is part of ongoing study of a recently discovered family of enzymes produced by fungi and bacteria, which are able to break down tough cellulose-based materials such as plant stems. The hope is that by understanding how the naturally occurring enzymes work, they can then be improved for industrial purposes, principally the production of biofuels from sustainable sources.

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Photo credit: Julia Walton

Professor Paul Walton and Professor Gideon Davies of the Department of Chemistry at York, two members of the team recently presented the first published molecular structure of one of the key enzymes (lytic polysaccharide monooxygenases or LPMOs) involved in these processes. The paper appeared in Nature Chemical Biology.

The research shows how the ‘active site’ of the enzyme changes when it binds to plant cell wall cellulose, and this knowledge, say the scientists, is important in advancing understanding of the reaction chemistry.

“LPMOs have overturned our thinking about biomass degradation in biology; they are also essential components in the commercial production of bioethanol from cellulosic feedstocks,” said Professor Walton. This new structure will help chemists and biochemists improve the efficiencies of these important enzymes.”

Professor Davies added, “When we can understand structure and chemistry we can improve environmentally-friendly processes for the benefit of all. This work, by a combined European team, gives us unparalleled molecular insight into one of the key reactions catalysed by fungi. It is truly exciting.”

The new research resulted from a European consortium project entitled Critical Enzymes for Sustainable Biofuels from Cellulose (CESBIC) involving York and the Universities of Copenhagen and Cambridge, CNRS Aix-Marseille Université, France, Chalmers University of Technology, Sweden, and industrial partner Novozymes A/S in Denmark.

Berkeley Lab’s Enzyme Reduces Plant Lignin

One of the barriers to efficient second generation biofuels is creating a better way to break down the lignin in plants that is then converted to the sugars that create the building blocks of biobased products such as cellulosic ethanol, biomaterials and biochemicals. But this hurdle may be getting lower with research out of Lawrence Berkeley National Laboratory. Scientists have demonstrated an enzyme that can be tweaked to reduce lignin in plants.

This illustration shows the molecular structure of HCT that was derived at Berkeley Lab’s Advanced Light Source. The purple and green areas are two domains of the enzyme, and the multi-colored structures between the two domains are two molecules (p-coumaryl-shikimate and HS-CoA) in the binding site. New research shows this binding site is indiscriminate with the acceptor molecules it recruits, including molecules that inhibit lignin production. (Credit: Berkeley Lab)

This illustration shows the molecular structure of HCT that was derived at Berkeley Lab’s Advanced Light Source. The purple and green areas are two domains of the enzyme, and the multi-colored structures between the two domains are two molecules (p-coumaryl-shikimate and HS-CoA) in the binding site. New research shows this binding site is indiscriminate with the acceptor molecules it recruits, including molecules that inhibit lignin production. (Credit: Berkeley Lab)

Lignin is essential to plant health. It resides in a plant’s cell walls and surrounds and traps the sugars inside. In order to extract the sugars, the lignin must first be broken down through chemical pretreament. Thus, the less lignin there is, the less expensive the pretreatment step becomes.

The research was published in Plant & Cell Physiology and focuses on an enzyme called HCT that plays a key role in synthesizing lignin in plants and has been found to be indiscriminate with what molecules it binds with. With this discovery, the researchers introduced another molecule to the enzyme that occupies the binding site usually occupied by the lignin-producing molecule. This swap inhibits the enzyme’s ability to support lignin production. Initial tests showed a decrease in lignin content by 30 percent while increasing sugar production, without weakening the plant.

“Our goal is to tune the process so that lignin is reduced in a plant where we want it reduced, such as in tissues that produce thick cell walls, and when we want it reduced, such as later in a plant’s development,” said Dominique Loque, a plant biologist with the Joint BioEnergy Institute (JBEI), a DOE Bioenergy Research Center led by Berkeley Lab, which pursues breakthroughs in the production of cellulosic biofuels. “This would result in robust bioenergy crops with more sugar and less lignin, and dramatically cheaper pretreatment costs.”

Next the researchers want to learn how to adjust the temporal and spatial specificity of the enzyme’s lignin-reduction abilities in plants. They also want to further study the Advanced Light Source-derived enzyme structures to see if HCT can be modified to be even more attractive to the new molecules.

University of Illinois Identifies Ideal Bioenergy Crops

New research from the University of Illinois has identified what bioenergy crops are best for certain regions while minimizing effects on water quantity and quality. The study was based on replacing current vegetation with crops for ethanol production and looked at how each crop would impact water quantity and quality in soils.

“We expect the outcome of this study to support scientifically sound national policy decisions on bioenergy crops development especially with regards to cellulosic grasses,” wrote Atul Jain, professor of atmospheric sciences at University of Illinois, regarding a paper published by the journal Environmental Science & Technology.

This figure shows how much water is used to produced one unit of ethanol (defined as water use intensity) for each energy crop. (Image courtesy of Atul Jain.)

This figure shows how much water is used to produced one unit of ethanol (defined as water use intensity) for each energy crop. (Image courtesy of Atul Jain.)

Today, corn is the primary feedstock for ethanol production in the U.S. Prior research has found that several bioenergy grasses such as Miscanthus and switchgrasses such as Alamo and Cave-in-Rock causes less nitrogen loss as compared to corn. Nitrogen is an important nutrient for crops and a key ingredient in fertilizer, but nitrogen often washes away into rivers and other bodies of water where it is detrimental to aquatic ecosystems.

Researchers argue that another advantage bioenergy grasses and switchgrasses have over corn is their deep root system that allows them to draw water and nutrients from deeper soil levels and enables them to be more resilient in poor growing seasons.

“Growing bioenergy grasses, in general, can mitigate nitrogen leaching across the United States,” said Yang Song, a graduate student and the study’s lead author. “However, the greatest reduction in nitrogen leaching occurs when bioenergy crops displace other cropland or grassland, because energy crops consume more water and less nitrogen fertilizer than the crops and grasses that they replace, resulting in less water runoff and nitrogen loss.” Continue reading

U of Illinois Miscanthus Research Breakthrough

University of Illinois researchers have studied genetic markers of miscanthus to identify early developmental traits that will improve yield. According to the researchers, “this study begins to establish links between reproducible genetic markers and a number of key agronomic traits in Miscanthus sinensis.” The research paper was published in GCB Bioenergy, “Mapping the genome of Miscanthus sinensis for QTL associated with biomass productivity.”

Miscanthus_1Over a period of three years, researchers measured developmental and biomass traits over a period of three establishment years in the offspring of a cross between Miscanthus sinensis cultivars ‘Grosse Fontaine’ and ‘Undine.’ It can take three-four years for a miscanthus crop to have a reliable yield. Next, the team extracted DNA from the plants and examined the resulting single nucleotide polymorphisms, or SNPs, to develop a genetic map. The technique improves upon older types of genetic markers that were not as tightly linked to particular genes controlling important biomass traits.

“It represents one of the very first maps that was made and it’s also one of the first times we were able to map a number of genes associated with biomass productivity, and determine the locations of those genes in the Miscanthus genome,” said U of I geneticist Jack Juvik.

On a practical level, the researchers saw strong positive correlations between biomass yield and plant basal circumference, height, and tiller (stem) number, suggesting that plants that are able to grow taller and produce more tillers in the first few years may achieve higher yields in the long term. They also found negative correlations between flowering time and yield, with early flowering individuals producing less biomass. The researchers breeders could make use of that information to improve early selection of plants with enhanced biomass productivity to accelerate the breeding program.

“The advantage to marker-assisted breeding is that you can grow seedlings, collect DNA, and probe for a large suite of DNA markers that are linked to genes that confer the characteristics you want. That can save a lot of time, because you can identify potential phenotypes without having to wait 3-4 years to get a mature plant,” explained Juvik. “The value of this kind of system in Miscanthus is substantial in terms of breeding progress.”

In addition to saving time and providing breeders with specific traits to look for in high-yielding plants, the techniques used in the study and the initial results establish a jumping-off point for future work.

Juvik notes, “This is the starting point. We’ve continued this work and applied it to other populations and to other questions about breeding Miscanthus. This sets up the foundation for moving into a range of different applications.”

Research Looks Into Gas Prices

Your eyes do not deceive. I paid $1.40 per gallon for ethanol-blended fuel on Thursday, February 18, 2106 in Fairfield Glade, TN. Photo credit: Joanna Schroeder

Your eyes do not deceive. I paid $1.40 per gallon for ethanol-blended fuel on Thursday, February 18, 2106 in Fairfield Glade, TN. Photo credit: Joanna Schroeder

As I pulled into a gas station in Fairfield Glade, Tennessee last week I couldn’t believe the price per gallon of fuel with ethanol. After nearly $5.00 per gallon of gas a few years ago in states such as California, I never thought I’d see prices drop below $2.00. But they have and continue to stay. While this is great news for drivers, Big Oil is not too happy about the billions of dollars they are losing with cheap oil. Crude Oil prices have fallen 23 percent in 2016, and 70 percent in the last 20 months – prices the world hasn’t seen in more than a decade.

According to AAA, the national average for gas this week is $1.70 per gallon – 55 cents less than this time last year. Interestingly, anti-biofuel advocates are using cheap oil as a call to end the Renewable Fuel Standard (#RFS) and stop blending corn-based ethanol into our nation’s fuel supply.

Professor Bruce Babcock of Iowa State University says oil companies are making “thoroughly outrageous claims” about what it would cost them, and you, to keep up with the plan to reduce greenhouse emissions. In his paper “Compliance Path and Impact of Ethanol Mandates on Retail Fuel Market in the Short Run,” co-authored by Sébastien Pouliot of Iowa State, Babcock found the impact on consumer prices is “close to zero.” This paper was recently selected to be published in the American Journal of Agricultural Economics.

“One of the reasons for writing this paper was to debunk the myths for justifications of getting rid of the RFS,” Babcock said. “This takes one of the justifications away.”

UNCTAD Report: Advanced Biofuels Here Now

Screen Shot 2016-02-25 at 9.16.21 AMSecond generation biofuels made from non-food biomass are here right now according to a new report from UNCTAD. “Second-Generation Biofuel Markets: State of Play, Trade and Developing Country Perspectives,” finds these biofuels are a commercial reality in the context of advanced technologies, economic pressures and a political will to act on climate change. The report focuses on the role advanced biofuels can play in meeting global climate and energy goals and how to make the technology available in developing countries.

With a specific focus on cellulosic ethanol, the report provides a wide-ranging review of the second-generation biofuels sector, maps selected cellulosic ethanol projects, and details recent policy developments from around the world. A key factor in decreasing costs for the industry has been process improvements that have allowed the market to expand, the report finds.

The United States has the largest installed capacity for cellulosic ethanol production and the greatest number of working second-generation biofuel facilities, the report found, followed respectively by the People’s Republic of China, Canada, the European Union (EU) and Brazil. As of 2015, there were no cellulosic ethanol projects on the African continent and in Latin America (excluding Brazil); however, progress has been made in bagasse-fired electricity co-generation and biomass cook stoves in these regions.

The report finds two main strategies have given traction to the growth of advanced biofuels. The first is a market-segmentation strategy in conventional/advanced cellulosic biofuels used in the U.S., and more recently in the EU with the adoption of limits for conventional biofuels, resulting in premium pricing. The second is the availability of national development bank loans that have reduced risk and promoted growth in the industry, especially in China and Brazil. Low interest rates and a venture-capital culture have also played a role in advancing the position of second-generation biofuels.

The report concludes with five suggestions for the responsible development of the second-generation global biofuels industry and is an update from a similar UNCTAD report published in 2014.

Cellulosic Ethanol Prices Hinges on Feedstocks

A new study from Lux Research finds innovation is still needed to make advanced biofuels competitive. The report cites six cellulosic ethanol facilities online and finds Raizen has the lowest projected minimum ethanol selling price of $2.17 per gallon. Abengoa’s $500 million Hugoton plant has the highest price of $4.55 with feedstock cost as the most critical variable. (It should be noted the study was conducted before the Hugoton plant was taken offline due to Abengoa’s financial troubles.)

“Improving feedstock aggregationlux research cellulosic ethanol price per gallon and lowering feedstock cost is critical in cellulosic ethanol achieving cost parity, as feedstock cost can impact total cost by 40%,” said Yuan-Sheng Yu, Lux Research Analyst and lead author of the report titled, “Uncovering the Cost of Cellulosic Ethanol Production.”

Lux Research built a comprehensive cost model based on six cellulosic feedstocks and three pre-treatment technologies. Among their findings:

  • Feedstock cost is a key differentiator. Two companies with the lowest projected minimum ethanol selling price – GranBio and Raizen – both utilize the cheapest cellulosic feedstocks. Sugarcane straw and sugarcane bagasse cost $40 and $38 per dry metric ton (MT), respectively, compared with corn stover ($90) used by Abengoa and POET-DSM and wheat straw ($75) used by Beta Renewables.
  • Bigger is far from better. Abengoa’s Hugoton facility cost $500 million but despite getting economic credits for a 21 MW on-site generation unit, it is projected to have the highest projected selling price for ethanol of $4.55 per gallon.
  • DuPont creates new economics. Even without electricity credits, DuPont has a projected selling price of $3.31 per gallon, similar to Beta Renewables and POET-DSM, at its 30 MGY plant. It uses improved feedstock aggregation processes, reducing corn stover from $90 per dry MT to $52 per day MT.

Yuan-Sheng Yu added, “Improvements in pre-treatment yield, enzyme performance and price, and fermentation efficiency potentially reduce costs by up to 16%.”

Goat’s Guts Lead to Better Biofuels

New research finds that some day your gas tanks could be filled up by horses, sheep and goat’s guts. Researchers looked at how the anaerobic gut fungi, as compared to engineered fungi, were able to convert plant material into sugars that could be converted into advanced biofuels and other biobased materials.

Fungi found in the guts of goats, horses and sheep help them digest stubborn plant material. A team of researchers report in the journal Science that these fungi could potentially lead to cheaper biofuel and bio-based products. Professor of chemical engineering at the University of California, Santa Barbara Michelle O’Malley, was the lead author of the paper. She explained, “Nature has engineered these fungi to have what seems to be the world’s largest repertoire of enzymes that break down biomass.”

Fungi found in the guts of goats, horses and sheep help them digest stubborn plant material. A team of researchers report in the journal Science that these fungi could potentially lead to cheaper biofuel and bio-based products. Image courtesy of Daniele Faieta/Flickr

Fungi found in the guts of goats, horses and sheep help them digest stubborn plant material. A team of researchers report in the journal Science that these fungi could potentially lead to cheaper biofuel and bio-based products. Image courtesy of Daniele Faieta/Flickr

These enzymes — tools made of protein — work together to break down stubborn plant material. The researchers found that the fungi adapt their enzymes to wood, grass, agricultural waste, or whatever they were fed. The findings suggest that gut fungi could be modified so the produce better enzymes that will outperform even the best ones on the market today. With a more effective way to break down biomass, it should led to the development of less expensive biofuels and bioproducts.

O’Malley and her colleagues knew the fungi’s hyphae excrete proteins, or enzymes, break down plant material. The researchers understood that like tools in a toolbox, the more diverse the enzymes, the better the fungi can take apart plants and turn them into food. So the goal was to help develop this fungi toolbox for the bioindustry to use to better break down biomass.

“Despite their fascinating biology, anaerobic gut fungi can be difficult to isolate and study,” said Scott Baker, EMSL’s science theme lead for Biosystem Dynamics and Design, one of the agencies that collaboratively participated in the research. “By utilizing the cutting-edge scientific capabilities at EMSL and JGI, O’Malley showed how the huge catalog of anaerobic gut fungi enzymes could advance biofuel production.”

New BIO-Yeast Could Improve Biofuels Production

Quinn Dickinson, research specialist at the University of Madison’s Wisconsin Energy Institute who also works with the Great Lakes Bioenergy Research Center (GLBRC), has helped to design a new strain of yeast that he believes holds great promise in improving the efficiency of making biofuel from biomass such as switchgrass.

Dickinson’s goal is to solve a problem in the biomass to biofuels conversion process, namely that in some cases, solvents are so good at breaking down biomass that they often hinder the next critical step of the process, fermentation.

GLBRC assistant research specialist Quinn Dickinson picks a colony of a new yeast strain that could reduce the cost of biofuels produced with ionic liquids.

GLBRC assistant research specialist Quinn Dickinson picks a colony of a new yeast strain that could reduce the cost of biofuels produced with ionic liquids.

The precursor to this finding was research Dickinson was conducting with fellow GLBRC colleague, Jeff Piotrowski, who is now a principal scientist at Yumanity Therapeutics in Massachusetts. The two were working on ionic liquids, solvents that can deconstruct different kinds of biomass into relatively pure streams of the plant’s sugar but which are also toxic to the kind of microorganisms that ferment those sugars into fuel.

“Ionic liquids are a particularly promising technology for deconstructing biomass, but their toxicity to fermentative microbes has posed a challenge,” said Piotrowski. “To really harness the power of this solvent — and to enable a bio-based economy — we need microbes specifically tailored to tolerate the specific toxicity of ionic liquids.” Continue reading