Researchers describe how biofuels can achieve cost parity with petroleum fuels

by Emily Scott, Lawrence Berkeley National Laboratory

Credit: CC0 Public Domain

Biofuels are an important part of the broader strategy to replace petroleum-based gasoline, diesel, and jet fuels that we use today. However, biofuels have so far not reached cost parity with conventional petroleum fuels.

One strategy to make biofuels more competitive is to make plants do some of the work themselves. Scientists can engineer plants to produce valuable chemical compounds, or bioproducts, as they grow. Then the bioproducts can be extracted from the plant and the remaining plant material can be converted into fuel. When produced in the plant itself, bioproducts can help reduce the cost of the resulting biofuel.

But one important part of this strategy has remained unclear—exactly how much of a particular bioproduct would plants need to make in order to make the process economically feasible?

Now researchers at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and the Department of Energy's Joint BioEnergy Institute (JBEI), which is managed by Berkeley Lab, have provided the first definition of this amount. Their study, jointly led by Corinne Scown and Patrick Shih, was published recently in the Proceedings of the National Academy of Sciences.

The researchers first gathered information on a group of well-studied bioproducts that plants can already effectively produce—ranging from flavors and fragrances to biodegradable plastic. Making a valuable bioproduct would help offset the cost of making biofuels and make the whole process cheaper.

"It's a really elegant solution, to be able to engineer a plant to directly accumulate a valuable bioproduct," said Scown, a researcher in JBEI and Berkeley Lab's Energy Technologies Area.

They then designed and simulated what it would take to extract these bioproducts from plant material in the context of an ethanol biorefinery. In this setting, valuable bioproducts would be extracted from the plant, while the remaining plant material would be converted into ethanol.

This helped them answer two important questions: what amount of bioproduct the plant needs to produce in order to make the process of extracting it worthwhile, and what amount needs to be made in order to reach the target ethanol selling price of $2.50 per gallon.

To their surprise, their results showed that the amount plants need to make is actually quite feasible. For example, they calculated that when accumulated at 0.6% of the biomass dry weight, a compound such as limonene—used in flavor and fragrance—would offer net economic benefits to biorefineries. In other words, if they can harvest 10 dry metric tons of sorghum biomass from an acre of land, they need to recover only around 130 pounds of limonene from that biomass.

"The researchers in our Feedstocks Division were surprised by how modest the target levels were," Scown said. "The levels we need to accumulate in plants to offset the cost of bioproduct recovery and drive down the price of biofuels are well within reach."

Their results show that this strategy for reducing the cost of biofuels is feasible—but scientists shouldn't put all of their eggs in one basket, because the market for each high-value product is limited in size. Their analysis suggests that just five commercial-scale biorefineries could support the entire projected 2025 market demand for limonene. Scown said crops need to be engineered to produce a broad range of products to make sure the industry is diversified and the market is not flooded for any one product.

"With techno-economic models, this research provides new insights into the role of bioproducts in improving the economics of biorefineries," said Minliang Yang, a postdoctoral researcher at JBEI and lead author of the study.

Scown said the biggest impact of the paper is that it offers the first quantitative basis to actually implement this cost-saving strategy, providing a starting point for scientists who are attempting to engineer or breed plants that create bioproducts on their own and offset the cost of making biofuels as a result.

"I think this research is just the first step to demonstrating the future potential of engineered bioenergy feedstock crops," said Shih, Director of Plant Biosystems Design at JBEI. "I would imagine that our findings will help motivate future efforts to make biofuels economically viable."Researchers demonstrate that jet fuels made from plants could be cost competitive with conventional fossil fuels

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More information: Minliang Yang et al, Accumulation of high-value bioproducts in planta can improve the economics of advanced biofuels, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2000053117

Journal information: Proceedings of the National Academy of Sciences

Researchers give yeast a boost to make biofuels from discarded plant matter

The new system streamlines the process of fermenting plant sugar to fuel by helping yeast survive industrial toxins

WHITEHEAD INSTITUTE FOR BIOMEDICAL RESEARCH

Research News

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IMAGE: WHITEHEAD INSTITUTE MEMBER GERALD FINK STANDING IN FRONT OF A FIELD OF THE GRASS MISCANTHUS GIGANTEUS, WHICH IS ANOTHER POTENTIAL SOURCE OF CELLULOSE THAT COULD BE CONVERTED TO ETHANOL.... view more 

CREDIT: PHOTO COURTESY OF FELIX LAM

More corn is grown in the United States than any other crop, but we only use a small part of the plant for food and fuel production; once people have harvested the kernels, the inedible leaves, stalks and cobs are left over. If this plant matter, called corn stover, could be efficiently fermented into ethanol the way corn kernels are, stover could be a large-scale, renewable source of fuel.

"Stover is produced in huge amounts, on the scale of petroleum," said Whitehead Institute Member and Massachusetts Institute of Technology (MIT) biology professor Gerald Fink. "But there are enormous technical challenges to using them cheaply to create biofuels and other important chemicals."

And so, year after year, most of the woody corn material is left in the fields to rot.

Now, a new study from Fink and MIT chemical engineering professor Gregory Stephanopolous led by MIT postdoctoral researcher Felix Lam offers a way to more efficiently harness this underutilized fuel source. By changing the growth medium conditions surrounding the common yeast model, baker's yeast Saccharomyces cerevisiae, and adding a gene for a toxin-busting enzyme, they were able to use the yeast to create ethanol and plastics from the woody corn material at near the same efficiency as typical ethanol sources such as corn kernels.

Sugarcoating the issue

For years, the biofuels industry has relied on microorganisms such as yeast to convert the sugars glucose, fructose and sucrose in corn kernels to ethanol, which is then mixed in with traditional gasoline to fuel our cars.

Corn stover and other similar materials are full of sugars as well, in the form of a molecule called cellulose. While these sugars can be converted to biofuels too, it's more difficult since the plants hold onto them tightly, binding the cellulose molecules together in chains and wrapping them in fibrous molecules called lignins. Breaking down these tough casings and disassembling the sugar chains results in a chemical mixture that is challenging for traditional fermentation microorganisms to digest.

To help the organisms along, workers in ethanol production plants pretreat high-cellulose material with an acidic solution to break down these complex molecules so yeast can ferment them. A side effect of this treatment, however, is the production of molecules called aldehydes, which are toxic to yeast. Researchers have explored different ways to reduce the toxicity of the aldehydes in the past, but solutions were limited considering that the whole process needs to cost close to nothing. "This is to make ethanol, which is literally something that we burn," Lam said. "It has to be dirt cheap."

Faced with this economic and scientific problem, industries have cut back on creating ethanol from cellulose-rich materials. "These toxins are one of the biggest limitations to producing biofuels at a low cost." said Gregory Stephanopoulos, who is the Willard Henry Dow Professor of Chemical Engineering at MIT.

Lending yeast a helping hand

To tackle the toxin problem, the researchers decided to focus on the aldehydes produced when acid is added to break down tough molecules. "We don't know the exact mechanism by which aldehydes attack microbes, so then the question was, if we don't really know what it attacks, how do we solve the problem?" Lam said. "So we decided to chemically convert these aldehydes into alcohol forms."

The team began looking for genes that specialized in converting aldehydes to alcohols, and landed on a gene called GRE2. They optimized the gene to make it more efficient through a process called directed evolution, and then introduced it into the yeast typically used for ethanol fermentation, Saccharomyces cerevisiae. When the yeast cells with the evolved GRE2 gene encountered aldehydes, they were able to convert them into alcohols by tacking on extra hydrogen atoms.

The resultant high levels of ethanol and other alcohols produced from the cellulose might have posed a problem in the past, but at this point Lam's past research came into play. In a 2015 paper from Lam, Stephanopoulos and Fink, the researchers developed a system to make yeast more tolerant to a wide range of alcohols, in order to produce greater volumes of the fuel from less yeast. That system involved measuring and adjusting the pH and potassium levels in the yeast's growth media, which chemically stabilized the cell membrane.

By combining this method with their newly modified yeast, "we essentially channeled the aldehyde problem into the alcohol problem, which we had worked on before," Lam said. "We changed and detoxified the aldehydes into a form that we knew how to handle."

When they tested the system, the researchers were able to efficiently make ethanol and even plastic precursors from corn stover, miscanthus and other types of plant matter. "We were able to produce a high volume of ethanol per unit of material using our system," Fink said. "That shows that there's great potential for this to be a cost-effective solution to the chemical and economic issues that arise when creating fuel from cellulose-rich plant materials."

Scaling up

Alternative fuel sources often face challenges when it comes to implementing them on a nationwide scale; electric cars, for example, require a nationwide charging infrastructure in order to be a feasible alternative to gas vehicles.

An essential feature of the researchers' new system is the fact that the infrastructure is already in place; ethanol and other liquid biofuels are compatible with existing gasoline vehicles so require little to no change in the automotive fleet or consumer fueling habits. "Right now [the US produces around] 15 billion gallons of ethanol per year, so it's on a massive scale," he said. "That means there are billions of dollars and many decades worth of infrastructure. If you can plug into that, you can get to market much faster."

And corn stover is just one of many sources of high-cellulose material. Other plants, such as wheat straw and miscanthus, also known as silvergrass, can be grown extremely cheaply. "Right now the main source of cellulose in this country is corn stover," Lam said. "But if there's demand for cellulose because you can now make all these petroleum-based chemicals in a sustainable fashion, then hopefully farmers will start planting miscanthus, and all these super dense straws."

In the future, the researchers hope to investigate the potential of modifying yeasts with these anti-toxin genes to create diverse types of biofuels such as diesel that can be used in typical fuel-combusting engines. "If we can [use this system for other fuel types], I think that would go a huge way toward addressing sectors such as ships and heavy machinery that continue to pollute because they have no other electric or non-emitting solution," Lam said.

CAPTION

In a new paper, researchers present a method to more efficiently produce biofuels from woody plant materials such as corn residues and some grasses.

CREDIT

Markus Distelrath/Pixabay

Engineered yeast could expand biofuels' 

reach

By making the microbes more tolerant to toxic byproducts, researchers show they can use a wider range of feedstocks, beyond corn.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY

Research News

 

CAMBRIDGE, MA - Boosting production of biofuels such as ethanol could be an important step toward reducing global consumption of fossil fuels. However, ethanol production is limited in large part by its reliance on corn, which isn't grown in large enough quantities to make up a significant portion of U.S. fuel needs.

To try to expand biofuels' potential impact, a team of MIT engineers has now found a way to expand the use of a wider range of nonfood feedstocks to produce such fuels. At the moment, feedstocks such as straw and woody plants are difficult to use for biofuel production because they first need to be broken down to fermentable sugars, a process that releases numerous byproducts that are toxic to yeast, the microbes most commonly used to produce biofuels.

The MIT researchers developed a way to circumvent that toxicity, making it feasible to use those sources, which are much more plentiful, to produce biofuels. They also showed that this tolerance can be engineered into strains of yeast used to manufacture other chemicals, potentially making it possible to use "cellulosic" woody plant material as a source to make biodiesel or bioplastics.

"What we really want to do is open cellulose feedstocks to almost any product and take advantage of the sheer abundance that cellulose offers," says Felix Lam, an MIT research associate and the lead author of the new study.

Gregory Stephanopoulos, the Willard Henry Dow Professor in Chemical Engineering, and Gerald Fink, the Margaret and Herman Sokol Professor at the Whitehead Institute of Biomedical Research and the American Cancer Society Professor of Genetics in MIT's Department of Biology, are the senior authors of the paper, which appears today in Science Advances.

Boosting tolerance

Currently, around 40 percent of the U.S. corn harvest goes into ethanol. Corn is primarily a food crop that requires a great deal of water and fertilizer, so plant material known as cellulosic biomass is considered an attractive, noncompeting source for renewable fuels and chemicals. This biomass, which includes many types of straw, and parts of the corn plant that typically go unused, could amount to more than 1 billion tons of material per year, according to a U.S. Department of Energy study -- enough to substitute for 30 to 50 percent of the petroleum used for transportation.

However, two major obstacles to using cellulosic biomass are that cellulose first needs to be liberated from the woody lignin, and the cellulose then needs to be further broken down into simple sugars that yeast can use. The particularly aggressive preprocessing needed generates compounds called aldehydes, which are very reactive and can kill yeast cells.

To overcome this, the MIT team built on a technique they had developed several years ago to improve yeast cells' tolerance to a wide range of alcohols, which are also toxic to yeast in large quantities. In that study, they showed that spiking the bioreactor with specific compounds that strengthen the membrane of the yeast helped yeast to survive much longer in high concentrations of ethanol. Using this approach, they were able to improve the traditional fuel ethanol yield of a high-performing strain of yeast by about 80 percent.

In their new study, the researchers engineered yeast so that they could convert the cellulosic byproduct aldehydes into alcohols, allowing them to take advantage of the alcohol tolerance strategy they had already developed. They tested several naturally occurring enzymes that perform this reaction, from several species of yeast, and identified one that worked the best. Then, they used directed evolution to further improve it.

"This enzyme converts aldehydes into alcohols, and we have shown that yeast can be made a lot more tolerant of alcohols as a class than it is of aldehydes, using the other methods we have developed," Stephanopoulos says.

Yeast are generally not very efficient at producing ethanol from toxic cellulosic feedstocks; however, when the researchers expressed this top-performing enzyme and spiked the reactor with the membrane-strengthening additives, the strain more than tripled its cellulosic ethanol production, to levels matching traditional corn ethanol.

Abundant feedstocks

The researchers demonstrated that they could achieve high yields of ethanol with five different types of cellulosic feedstocks, including switchgrass, wheat straw, and corn stover (the leaves, stalks, and husks left behind after the corn is harvested).

"With our engineered strain, you can essentially get maximum cellulosic fermentation from all these feedstocks that are usually very toxic," Lam says. "The great thing about this is it doesn't matter if maybe one season your corn residues aren't that great. You can switch to energy straws, or if you don't have high availability of straws, you can switch to some sort of pulpy, woody residue."

The researchers also engineered their aldehyde-to-ethanol enzyme into a strain of yeast that has been engineered to produce lactic acid, a precursor to bioplastics. As it did with ethanol, this strain was able to produce the same yield of lactic acid from cellulosic materials as it does from corn.

This demonstration suggests that it could be feasible to engineer aldehyde tolerance into strains of yeast that generate other products such as diesel. Biodiesels could potentially have a big impact on industries such as heavy trucking, shipping, or aviation, which lack an emission-free alternative like electrification and require huge amounts of fossil fuel.

"Now we have a tolerance module that you can bolt on to almost any sort of production pathway," Stephanopoulos says. "Our goal is to extend this technology to other organisms that are better suited for the production of these heavy fuels, like oils, diesel, and jet fuel."

###

The research was funded by the U.S. Department of Energy and the National Institutes of Health.

Written by Anne Trafton, MIT News Office

GREENWASHING

Waste-to-ethanol biofuels plant in Edmonton closes 11 years ahead of schedule

CBC
Thu, February 1, 2024 

The Enerkem waste to to biofuels facility was set back by delays and produced a fraction of the fuel it set out to do in 2010. (Enerkem - image credit)

A state-of-the-art biofuels plant in northeast Edmonton has shut down production, 14 years after the City of Edmonton and Enerkem Alberta Biofuels struck a deal to turn waste into ethanol.

Under the initial 25-year agreement signed in 2010, the city supplied garbage that couldn't be recycled or composted and Enerkem would use its proprietary technology to turn it into biofuels.

When it closed this week, the plant had produced five million litres of biofuels, far less than the 36 million litres a year Enerkem had projected it would generate.

On Thursday, Enerkem's executive vice president of technology and commercialization Michel Chornet said it was a bittersweet day.

"We felt we had reached our main objectives which was to demonstrate this technology at commercial scale," Chornet said in an interview with CBC News. "Now we are retiring this facility,"

The Edmonton plant was once touted as the world's first industrial-scale biofuels project to use municipal solid waste as feedstock.

The $80 million facility was projected to generate biofuels to supply over 400,000 cars per year running on a five per cent ethanol blend, the company's news release said.

Deal ends

The city says with the plant closing at the Edmonton Waste Management Centre, its agreement with Enerkem is also ending.

Enerkem's facility was built and operated at their expense and will be dismantled at their expense, said Denis Jubinville, branch manager of waste services at the City of Edmonton.

"While this innovative project did not fully achieve the desired waste diversion, we have gained important learnings that will inform future waste diversion strategies," Jubinville said in an email to CBC News this week.

The city invested about $45 million into its own refuse-derived fuel (RDF) facility that turns waste into a low-carbon fuel that can be used for energy production.

This facility is still operational and will continue to produce RDF, he added.

"The closure will not have significant impacts on the city's day-to-day waste management activities," he said.

The city doesn't plan to replace or expand the Enerkem plant but is establishing new partnerships to divert waste from landfill using waste-to-energy, Jubinville noted.

Dampened by delays

The operation encountered technical obstacles in producing ethanol and had adjusted equipment along the way.

"Each phase had some specific milestones," Chornet said. "Once they were achieved, we added more equipment on and on, so the phasing induced some delays that may have been perceived."

This week, former city councillor Ben Henderson said he was disappointed the plant didn't turn out to be a long-term solution to Edmonton's waste disposal.

"The hope was that it was going to take the majority of our non-organic non-recyclable waste and turn it into something useful."

He said if things had gone according to plan, the plant would have been running at full steam for quite a number of years already.

Edmonton impact 

"It was a difficult week," Chornet told CBC News. "We had 56 employees in Edmonton — great employees, dedicated, passionate and very professional. So my thoughts are with them."

Henderson said he is happy that the city walks away with some technological advantage.

"I would hate to see us stopping to try new things and to try new solutions," Henderson said. "If no one is prepared to do that, then we're not going to be able to make any kind of progress on what's a really significant problem with what to do with their solid waste."

Montreal-based Enerkem Inc., founded in 2000, develops and commercializes its gasification technology, transforming non-recyclable waste into biofuels, low-carbon fuels and circular chemicals for hard-to-abate sectors, including sustainable aviation and marine fuels.

The Alberta government contributed $4.5 million from its Technology Innovation and Emissions Reduction Regulation program, set up to help industrial facilities find innovative ways to reduce carbon emissions.

Do biofuels harm the planet more than gasoline?
A new study suggests that biofuels can mitigate only 37 percent of the CO2 released by burning the biofuel.

Janet S. Carter/AP/File

Corn kernels peer out from the husk of an ear of corn in a North 

Carolina cornfield. Biofuel is made from the stalks and leaves of corn.

August 27, 2016
By Rowena Lindsay Staff CHRISTIAN SCIENCE MONITOR

Corn ethanol and biodiesel biofuels may be more environmentally damaging than petroleum gasoline, according to a new study from the University of Michigan Energy Institute (UMEI),

The surprising finding comes after the research team, led by UMEI researcher John DeCicco, analyzed the amount of carbon dioxide (CO2) absorbed as the crops grow and then released when they are burned as biofuel. They calculated that the aggregate US crop yield can remove only 37 percent of the CO2 that burning biofuel releases into the air.

“What we found is that when you actually look at how quickly crops like corn and soybeans pull CO2 from the air and compare that with the emissions that occur when the biofuels like ethanol and biodiesel are burned, you find out that they are not carbon neutral like everyone has been assuming,” Dr. DeCicco tells The Christian Science Monitor.




That's a flawed premise, argues Daniel Schrag, a geology professor at Harvard who advises the EPA on bioenergy climate impacts. He says that biofuels don't have to be carbon neutral to be an environmentally preferable alternative to petroleum gasoline.

“For about 10 years there have been very careful studies of corn ethanol and all of the fossil carbon that is used to make it ... and those studies have gotten a range of answers, but it is about a 20 percent reduction of net emissions relative to gasoline,” says Professor Schrag in an interview with the Monitor. “Nobody ever thought corn ethanol was carbon neutral, because there are lots and lots of fossil inputs to it.”

The biofuel debate has raged for years, with critics worried about the impact of the additional land deforested to convert to corn fields, and proponents arguing for biofuel as a green alternative to gasoline. Another group says that it is really too soon to tell.

The conversation has generally been dictated by the food vs. fuel debate. This focuses on the indirect consequences of biofuel crop production, such as land use and deforestation, which create a ripple effect felt by the entire global food market.

DeCicco decided to question the basic life cycle analysis model that previous studies relied on, some of which had assumed that biofuel is carbon neutral and that only production-related greenhouse gas emissions need to be taken into account when comparing biofuel to fossil fuels.


Whether you burn biofuel ethanol or petroleum gasoline, he argues, the same amount of CO2 is released into the atmosphere. So comparing the fuels' environmental impacts comes down to how efficiently that carbon can be removed from the air, he says – and forests are better at that than cornfields.

"The United States uses 40 percent of its corn harvest to make ethanol, but that does not mean mean we eat 40 percent less corn-based products," DeCicco tells the Monitor.

DeCicco explains that as cropland once used for food is transferred to fuel use, food must be produced elsewhere, meaning that more grasslands and forests are converted to production. However, grasslands and forests can neutralize more carbon dioxide than crops, he says.

Schrag says that this ignores the long-term perspective, when biofuels make up for carbon loss from forests.

“In their approach time scale does not come into it,” he tells the Monitor. “They are looking at crop yield data and assuming that you should balance the carbon cycle based on how much crops you produce.”

Michael Wang, a researcher at the Argonne National Laboratory, tells the Monitor that he also questions the study's carbon accounting, arguing that the study does not properly account for the carbon uptake or that corn production for both ethanol and for food increased over the period of the study.

“The carbon uptake by the US farming systems is calculated based only on grain harvest," Dr. Wang tells the Monitor. "Carbon uptake embedded in above- and below-ground biomass is ignored in the paper with a simple assumption that carbon in these biomass sources are oxidized back to the air."

Additionally, the research received funding from the American Petroleum Institute, which critics say is grounds for skepticism, but the UMEI researchers stated that “the analysis, results and conclusions presented [in their study] are those of the authors alone.”

Other experts have come out in support of the research. Tim Searchinger, a researcher at the Science, Technology, and Environmental Policy Program at Princeton University, said that the research was very narrow, but useful.

“This article is saying that if you think the reason biofuels are helping to solve climate change is because the US is increasing its production of crops and that increased production of crops offsets the carbon release from burning the biofuels, you’re wrong. That is not what is happening,” Mr. Searchinger tells the Monitor. “What reduces carbon in the atmosphere is not the biofuel, it is the plant growth.”

DeCicco says that the solution is not to make biofuel more efficient, but to invest in reforestation.

“We should not be trying to make biofuels at all, any time soon,” DeCicco tells the Monitor. “It is much better to reforest and restore ecosystems.... Reforestation is a much better way to remove CO2 than anything we can do with biofuels.”

Corn-based ethanol is environmentally damaging in the short run

Science Apr 21, 2014 3:40 PM EDT

It turns out production of corn-based ethanol has a tremendous environmental cost, according to a new $500,000 government-funded study released on Sunday.

While corn-based ethanol proves better in the long-run, the study, published in peer-reviewed journal Nature Climate Change, says the biofuel initially produces seven percent more greenhouse gases at first than conventional gasoline. This conclusion challenges the Obama administration’s stance for corn-ethanol policies — which calls cellulosic ethanol a better, low-polluting alternative to petroleum.

The Environmental Protection Agency passed the Energy Independence and Security Act in 2007 to include specific volume standards for renewable fuel as well as renewable fuel categories. It also specifies criteria for both renewable fuels and for the feed stocks used to produce them. The recent study basically argues that biofuels won’t meet the standards in this law to qualify as renewable fuel.

Administration officials and the EPA, however, criticized the study as flawed. In a statement, EPA spokeswoman Liz Purchia argued that the study “does not provide enough information relevant to the life cycle greenhouse gas emissions from corn stover ethanol.”

An EPA spokeswoman, Liz Purchia, said in a statement that the study “does not provide useful information relevant to the life cycle greenhouse gas emissions from corn stover ethanol”

Biofuels Have a Big, Big Problem Nobody Talks About

2 Feb 2022,  Florin Amariei 

 Think of economically viable alternatives to traditional fuels like gas and diesel. Nothing makes more immediate sense than biofuels. They use waste, produce fewer emissions, and lower the supply of untreated fuels needed everywhere else.

The United States alone is a powerhouse in the cultivation of corn – an ingredient that has now become extremely important for biofuels. When driving across the Upper Midwest, you will be met by vast corn fields stretching to the horizon in either direction. This agricultural giant was the bedrock of the American diet. Corn flower, corn bread, corn meal – all staples of traditional American food – are now being actively forgotten. Farmers and companies are pivoting toward the energy industry. Today, nearly half of all corn production is used for making ethanol. Mixing this liquid with gasoline results in a reduction for the carbon footprint of all those commuting.

For most Americans today, the gasoline they use is composed by up to 10% of ethanol and farmers are making more than ever because of the government mandate. Moreover, the current administration is being lobbied to up the percentage of ethanol found in fuels.Why this is happening
There is nothing inherently wrong with burning fuel as long as we develop a method to capture its products. Unfortunately, we have become like the yeast trapped in a brewer`s vat: we are using the fuel provided and releasing toxic byproducts. At some point, the alcohol produced reaches a concentration that is extremely harmful. Here, survival is no longer an option. Moreover, nobody is interested in investing in a dying economic sector like hydrocarbons. But, for us humans, biofuels try to address this imbalance before it`s too late or, you know, before EVs completely take over.

The theoretical cycle of biofuels is comprised of the theory that they can be restored over a short period of time, unlike fossil fuels. You take the corn, you ferment it and, voila, you have fuel that can be burned, can release CO2 and it will all be taken back by next year`s crop.

According to the U.S. Energy Information Administration, in 2019 only 5% of the total energy was biomass. Almost half of that has been ethanol. The primary method of producing this liquid is from yeast. Without oxygen and with the help of bacteria, it uses anaerobic respiration where it converts sugar into energy and ethanol. The U.S. is the largest producer of ethanol, and the quantity made is growing yearly.What we will face
Given the fact that it`s being requested to double the percentage of ethanol in fuels and turning them into biofuels, the land needed to plant corn only will amass over 30,000,000 hectares. One fifth of the U.S. farmland will be used only for producing ethanol.

Farmers are getting more cash for their crops and the need for larger quantities of corn will only encourage the use of land in this direction. Croplands are expanding at an explosive rate: over 1,000,000 acres per year! Therefore, natural habitats are suffering in the U.S.

Food prices have also risen because of this growing interest in ethanol. Corn is being used for chickens, cows, and other animals, so, naturally, the prices of eggs and milk are now much higher than ever before. This vicious cycle will continue, and the average U.S. citizen will pay even more.

On top of all that, one liter of ethanol contains only 5.130 kcal, and to make it you need 6.600 kcal of energy. This means that from the start there is a loss of 22,3%. It is a negative process. This is not a green technology because, in reality, photosynthesis is also a very inefficient way to turn sunlight into usable energy. On average, plants can capture and convert about 1% of sunlight, while humans can use up to 20% of the sunlight with photovoltaic cells. Corn is even worse at this than your average plant – 0,25%.Growing plants for food is a necessity, growing plants for power is irrational
Corn also needs a lot of water to grow properly and is, as stated above, inefficient. Water is incredibly scarce, and its absence is already causing havoc in some parts of the world, not only U.S. Using it for that part of the agriculture that in the end produces biofuels is wrong. The water footprint of biomass energy is 72 times higher than that of fossil fuels and 240 times more than solar! More, over 80% of freshwater is already being used for agriculture in the States. Increasing crops for biofuels will just raise this percentage to an unsustainable level.

That is one of the reasons why the E.U. already put a mild stop to this since 2014.

Nonetheless, the government will keep subsidizing this sector just because it represents over 300,000 jobs, which cannot be lost under any administration that wants a second term.Viable alternatives
Batteries are still heavy and still short ranged for heavy duty vehicles or planes.

The precious freshwater can be preserved by using algae. This, however, is expensive. The cost is now somewhere between $300 and $2600 per barrel. It has great potential and that is why researchers like those at the Pacific Northwest National Laboratory are already working on it to make it as cheap as possible. They are trying to create new strains of algae because it has a greater fat content, which can be turned into green crude oil that can eventually become fuels for transportation.

Finally, we need alternative technologies, and we should invest in them. Unfortunately, we don`t. Biofuels obtained from ethanol and fossil fuels are not at all green or sustainable. 

GREENWASHING

Biofuel on the road to energy, cost savings

Peer-Reviewed Publication

DOE/ARGONNE NATIONAL LABORATORY

Argonne collaborates with U.S. laboratories on research to identify promising biofuels for different engine types.

Biofuel is closer to becoming a cost-competitive, climate-friendly solution for slashing carbon emissions in cars and trucks, according to two new studies.

The U.S. Department of Energy’s (DOE) Argonne National Laboratory  collaborated with the DOE’s National Renewable Energy Laboratory (NREL), Pacific Northwest National Laboratory (PNNL) and Idaho National Laboratory (INL) on the research. Results showed that biofuel combined with advanced engine design can reduce greenhouse gas (GHG) emissions by roughly 60% while improving fuel efficiency or reducing tailpipe emissions.

Argonne energy system analyst Pahola Thathiana Benavides,  NREL process engineer Andrew W. Bartling and PNNL engineer Steven Phillips were lead analysts for the two studies published in ACS Sustainable Chemistry & Engineering.

“The idea is to develop new biofuels blended with conventional fuels to improve engine performance. This means a gasoline car or truck could go further on the same amount of fuel or a diesel vehicle could meet more stringent emissions standards.” — Troy Hawkins, Argonne’s group manager, Fuels and Products Group

Biofuel has significant advantages over petroleum gasoline. But the engines themselves are also critical to energy efficiency. Designing low-carbon fuels and engines to work together can maximize energy use and vehicle performance.

“We are at the intersection of new innovations in both engines and biofuel,” said Troy Hawkins, Argonne’s group manager, fuels and products group, an author on both ACS Sustainable Chemistry & Engineering studies. ​“Our goal was to develop new biofuels blended with conventional fuels to improve engine performance. This means a gasoline-powered car or truck could go further on the same amount of fuel. Or a diesel vehicle could meet more stringent emissions standards.”

In both studies, Argonne scientists worked with other national labs to identify promising fuels for different engine types. Researchers considered cost, environmental impact and potential for expanding to commercial markets.

The research is supported by the Co-Optimization of Fuels & Engines (Co-Optima) initiative jointly led by DOE’s Office of Energy Efficiency and Renewable Energy, Bioenergy Technologies Office and Vehicle Technologies Office.

Argonne is part of Co-Optima’s consortium of nine national laboratories and over 20 university and industrial partners. The consortium studies how simultaneous innovations in fuel and engines can boost fuel economy and vehicle performance while reducing emissions.

Scientists and experts at every DOE laboratory played an important role in each phase of the research, Hawkins said.

“This research is a really good example of how laboratories can work together to help the DOE accomplish its mission,” Hawkins said.

Finding biofuel pathways

Co-Optima’s research builds on the goal to identify and understand bioblendstocks, or biofuel. Biofuel is produced from biomass — organic materials including plants, agricultural waste and wet waste. Biofuel can be blended with conventional fuel to reduce emissions and improve fuel and engine performance.

Collaborating with Co-Optima fuel experts, researchers used a screening process to develop a list of biofuels for their research, Benavides said.

Argonne scientists developed the list of biofuels working with experts including PNNL technical team manager and Co-Optima Leadership Team member Daniel Gaspar, NREL senior scientist Gina Fioroni, NREL senior research fellow Robert McCormick, and Anthe George, senior manager at DOE’s Sandia National Laboratories (SNL).

“We worked with other experts to use specific criteria to narrow many biofuel candidates down to a short list for our research. This list was developed based on the required properties and the engine’s combustion mode,” Benavides said.

Converting biomass to biofuel is a complex process involving variables in feedstock, conversion technologies and fuel types. It is especially challenging finding biofuel pathways that also meet economic, technology and energy goals.

One study was co-first-authored by Benavides. The team assessed 12 biofuel production pathways for optimizing multimode internal combustion engines. Multimode engines can deliver greater efficiency and cost savings by using different methods of ignition, combustion and/or fuel-preparation, depending on driving demands.

Researchers used renewable biomass feedstock found in forestry byproducts such as wood waste and agricultural byproducts such as corn stover. They used conversion technologies including either fermentation, catalysis under high heat and pressure, or a combination of both.

“We found that not only can seven biofuels be produced cost-competitively, but that these seven are varied in terms of feedstock used and conversion technology,” Bartling said. ​“This means that biorefineries can be more flexible in choosing where and how to build their facilities.”

NREL and PNNL researchers did a techno-economic assessment of the biofuel production pathways, analyzing cost and technology performance.

“Our findings showed that many of the biofuels are competitive with the current cost of petroleum fuel,” Phillips said.

Researchers also analyzed environmental impact. A life cycle analysis of the pathways using Argonne’s GREET® (Greenhouse Gases, Regulated Emissions, and Energy used in Technologies) model showed impressive results. Ten biofuels have the potential to reduce GHG emissions by 60% compared to petroleum gasoline. The list includes alcohols, furan mixtures and olefins.

Biofuel promising for diesel engines

The second study was co-first-authored by Bartling. Researchers analyzed 25 pathways for producing biofuel optimized to improve combustion for mixing-controlled compression ignition engines. These are a type of diesel engine mainly used for freight transportation.

To develop biofuel production pathways, researchers used feedstocks ranging from plant materials such as wood chips or corn stover, to oils from soybean and cuphea, to wet wastes and recycled grease. They used conversion technologies including fermentation, gasification, and hydrothermal liquefaction.

“The diverse set of biomass resources available in the U.S. has great potential to replace a portion of fuels and chemicals that now come from petroleum,” said Damon Hartley, INL’s Operations Research and Analysis Group lead. ​“However, one of the largest barriers is the wide variability in quality in the raw materials. This can have a large impact on how the material performs in conversion.”

As with the first study, most of the technologies performed well. Most of the biofuels were cost-competitive with current gas prices.

In terms of environmental impact, GHG emissions were reduced more than 60% in 12 of the 25 pathways, according to the GREET life cycle analysis.

“We evaluated the life cycle GHG emissions for each mixing-controlled compression ignition engine pathway. This included not only the tailpipe emissions but also upstream emissions resulting from biomass cultivation, feedstock transportation, biofuel production and biofuel distribution,” Hawkins said.

Creating a biofuel playbook

Researchers did not intend to produce a definitive list of biofuels, Benavides said. Instead, the studies offer a guide for stakeholders on selecting biofuel pathways that best meet their needs.

“We provide researchers and industry guidance on assessing biofuels based on a number of complex variables,” Benavides said. ​“The life cycle and techno-economic analysis is important in guiding stakeholders as early as possible. We can’t tell stakeholders what choices to make. But these tools can point them in the right direction from the beginning.”

While many of these biofuel pathways could potentially be cost-competitive, it is too soon to lock in prices in a constantly fluctuating gas market. ​“The challenge is providing cost-competitive prices in the long term,” Hawkins said.

While these biofuel production pathways target cars and diesel trucks, Argonne researchers are also studying the potential for using these pathways in hard-to-electrify sectors like aviation and maritime industries. The goal is to bring biofuel to market across a range of industries as quickly as possible.

“DOE is constantly working on sustainable solutions for decarbonizing the transportation sector. Biofuel is a big piece of that,” Hawkins said. ​“We will continue to expand on Co-Optima’s important work.”

Along with Argonne, ORNL, NREL, PNNL, INL, and SNL, other U.S DOE national labs in the Co-Optima Initiative are Los Alamos, Lawrence Berkeley, and Lawrence Livermore national laboratories.

ACS Sustainable Chemistry & Engineering research authors:

“Identification of key drivers of cost and environmental impact for biomass-derived fuel for advanced multimode engines based on techno-economic and life cycle analysis”: Pahola Thathiana Benavides, Argonne, Andrew W. Bartling, NREL, Steven D. Phillips, PNNL, Troy R. Hawkins, Argonne, Avantika Singh, NREL, George G. Zaimes, Argonne, Matthew Wiatrowski, NREL, Kylee Harris, NREL, Pralhad H. Burli, INL, Damon Hartley, INL, Teresa Alleman, NREL, Gina Fioroni, NREL, Daniel Gaspar, PNNL.

“Environmental, economic, and scalability considerations of selected bio-derived blendstocks for mixing-controlled compression ignition engines”: Andrew W. Bartling, NREL, Pahola Thathiana Benavides, Argonne, Steven D. Phillips, PNL, Troy Hawkins, Argonne, Avantika Singh, NREL, Matthew Wiatrowski, NREL, Eric C. D. Tan, NREL, Christopher Kinchin, NREL, Longwen Ou, Argonne, Hao Cai, Argonne, Mary Biddy, NREL, Ling Tao, NREL, Andrew Young, NREL, Kathleen Brown, NREL, Shuyun Li, PNNL, Yunhua Zhu, PNNL, Lesley J. Snowden-Swan, PNNL, Chirag R. Mevawala, PNNL, Daniel J. Gaspar, PNNL.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.

The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://​ener​gy​.gov/​s​c​ience.

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JOURNAL

ACS Sustainable Chemistry & Engineering

DOI

10.1021/acssuschemeng.2c00944 

ARTICLE TITLE

Identification of Key Drivers of Cost and Environmental Impact for Biomass-Derived Fuel for Advanced Multimode Engines Based on Techno-Economic and Life Cycle Analysis

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