A Penn State led team of international researchers has taken the first step in converting methane directly to electricity using bacteria, in a way that could be done near natural gas drilling sites.

Thomas K. Wood, holder of the biotechnology endowed chair and professor of chemical engineering at Penn State explains one motive, “Currently, we have to ship methane via pipelines. When you ship methane, you release a greenhouse gas. We can’t eliminate all the leakage, but we could cut it in half if we didn’t ship it via pipe long distances.”

There are other motives as well, such as making use of gas that is stranded away from pipelines.

The team’s research paper reporting the results of their work has been published in Nature Communications.

Micrograph of a synthetic bacterium that manufactures the chemical needed to capture electrons.  Image Credit: Thomas K. Wood / Penn State University. Click image for the largest view.

The researchers’ goal is to use microbial fuel cells to convert methane into electricity near the wellheads, eliminating long-distance transport. That goal is still far in the future, but they now have created a bacteria-powered fuel cell that can convert the methane into small amounts of electricity.

Wood said, “People have tried for decades to directly convert methane. But they haven’t been able to do it with microbial fuel cells. We’ve engineered a strain of bacteria that can.”

Microbial fuel cells convert chemical energy to electrical energy using microorganisms. They can run on most organic material, including wastewater, acetate and brewing waste. Methane, however, causes some problems for microbial fuel cells because, while there are bacteria that consume methane, they live in the depths of the ocean and are not currently culturable in the laboratory.

“We know of a bacterium that can produce an energy enzyme that grabs methane. We can’t grow them in captivity, but we looked at the DNA and found something from the bottom of the Black Sea and synthesized it,” he said.

The researchers actually created a consortium of bacteria that produces electricity because each bacterium does its portion of the job. Using synthetic biological approaches, including DNA cloning, the researchers created a bacterium like those in the depths of the Black Sea, but one they can grow in the laboratory.

This bacterium uses methane and produces acetate, electrons and the energy enzyme that grabs electrons. The researchers also added a mixture of bacteria found in sludge from an anaerobic digester – the last step in waste treatment. This sludge contains bacteria that produce compounds that can transport electrons to an electrode, but these bacteria needed to be acclimated to methane to survive in the fuel cell.
“We need electron shuttles in this process,” said Wood. “Bacteria in sludge act as those shuttles.”

Once electrons reach an electrode, the flow of electrons produces electricity. To increase the amount of electricity produced, the researchers used a naturally occurring bacterial genus – Geobacter, which consumes the acetate created by the synthetic bacteria that captures methane to produce electrons.

To show that an electron shuttle was necessary, the researchers ran the fuel cell with only the synthetic bacteria and Geobacter. The fuel cell produced no electricity. They added humic acids – a non-living electron shuttle – and the fuel cells worked. Bacteria from the sludge are better shuttles than humic acids because they are self-sustaining.

The researchers have filed provisional patents on this process.

“This process makes a lot of electricity for a microbial fuel cell,” said Wood. “However, at this point that amount is 1,000 times less than the electricity produced by a methanol fuel cell.”

That’s an honest comparison that we don’t often see. But let’s not overlook the breakthrough aspects of the work. This is methane straight to electricity. Methane is abundant, cleaner than many fuels and often found way out there where the economics for pipelining is uneconomic. That makes further pursuit worth the effort, which is a lot better than still looking for an method that works. Congratulations are in order with encouragement for more development. Cohabitating bacteria is an idea that has quite interesting potentials.

UCLA chemists have developed a new technique to convert carbon-hydrogen bonds into carbon-carbon bonds using catalysts made of silicon and boron, both abundant and inexpensive elements.

When scientists develop the chemical formulas for new products such as fuels and medications, they often must first create molecules that haven’t previously existed. A basic step toward creating new molecules is selectively breaking and re-forming the chemical bonds that connect the atoms that make them up. One of the chief challenges is that the bond between carbon and hydrogen atoms – the building blocks of many molecules – is exceptionally strong, so chemists often have to resort to using rare and expensive chemicals like iridium to convert it into other, more useful types of chemical bonds. Scientists refer to this process as “functionalizing” the bonds.

In what may prove to be a breakthrough, a team of UCLA chemists has developed a new technique for breaking carbon-hydrogen bonds and making carbon-carbon bonds. The approach uses catalysts made of two abundant and inexpensive elements, silicon and boron.

The team’s research paper has been published in Science in a collaboration on the study with UCLA graduate students Brian Shao, Alex Bagdasarian and Stasik Popov.

A new technique created by Brian Shao, Alex Bagdasarian, Stasik Popov and Hosea Nelson (from left) allows complex molecules to be assembled in fewer steps than previously possible.  Image Credit: Penny Jennings, UCLA. Click image for the largest view.

Hosea Nelson, a UCLA assistant professor of chemistry and biochemistry and senior author of the study, said the energy industry has been interested in taking very simple hydrocarbon molecules like methane and turning them into new fuels. “This new method will enable scientists to incorporate methane into bigger molecules,” he said.

Another potential application would be converting methane, one of the primary components of natural gas, into something that’s denser and easier to contain after it has been produced from reservoirs. The current process is complicated because methane, a light gas, tends to escape into the atmosphere.

The researchers used their new technique to create a compound similar to a phenyl cation, a chemical substance that has been studied theoretically but rarely investigated in actual laboratory experiments. They then used the compound to slice through carbon-hydrogen bonds in methane and benzene, which allowed them to insert other atoms and form carbon-carbon bonds, which are the basic building blocks of molecules that make up living organisms, as well as fuels and pharmaceuticals.

Besides demonstrating that phenyl cation-like compounds exist, the new technique allows complex molecules to be assembled in far fewer reaction steps than was previously possible, which could save chemical and pharmaceutical manufacturers time and money. Another advantage of the method is that, unlike previous approaches, it can be performed at temperatures and gas pressures that are easily attainable in a laboratory.

The process could also be used to alter the molecules in existing pharmaceuticals to make them more effective, safer or less addictive.

The chemists have tested their technique using very small samples of reactants – far less than a gram. But Nelson is hopeful that the methodology can be scaled up to be useful for a broad range of real-world chemical reactions.

This is sure to get the attention of research chemists an process engineers. Where it could lead is simply mind boggling.

University of Wisconsin-Madison’s professor James Dumesic has developed a new process that triples the fraction of biomass converted to high-value products to nearly 80 percent. The development also triples the expected rate of return for an investment in the technology from roughly 10 percent (for one end product) to 30 percent.

Technologies for converting non-edible biomass into chemicals and fuels traditionally made from petroleum exist in surprising number. But when it comes to attracting commercial interest, these technologies compete financially with a petroleum-based production pipeline that has been perfected over the course of decades.

UW-Madison researchers and collaborators have developed a new ‘green’ technology for converting non-edible biomass into three high-value chemicals that are the basis for products traditionally made from petroleum.  Image Credit: Graphic courtesy UW-Madison, by Phil Biebl. Click image for the largest view.

Winning that competition – or at least leveling the economic playing field – requires a huge leap forward. And by developing a new process for obtaining not one, but three high-value products from biomass in one fell swoop, University of Wisconsin-Madison engineers and their collaborators have now made that huge leap.

The researchers published their results in the journal Science Advances.

David Martin Alonso, the study’s first author and a researcher in chemical and biological engineering at UW-Madison said, “When a technology is new and risky, proving its economic feasibility and profit potential is critical for attracting investors. That’s why we are very excited about its 30-percent internal rate of return.”

Alonso is also director of research and development at Glucan Biorenewables, a UW-Madison spinoff company co-founded in 2012 by biomass conversion technology pioneer Dumesic.

Dumesic’s discovery is the magic key for turning all three components – cellulose, hemicellulose and lignin – of lignocellulosic (non-edible) biomass into distinct high-value products. Its gamma valerolactone (GVL), a solvent that is derived from plant material and has several highly appealing properties.

Alonso said, “GVL is very effective at fractionating the biomass. But it is also much more stable than other solvents, allowing us to reuse 99 percent of it in a closed-loop process. Until now, solvent loss had been a major bottleneck for making a renewable and carbon-efficient bio-refinery economically feasible.”

It also explains why the new technology is so “green.” It starts with renewable biomass, has a very high solvent-recycling rate, needs miniscule amounts of acid, and uses all three fractions of biomass, minimizing waste. And the list of GVL’s advantages goes on.

Ali Hussain Motagamwala, Dumesic’s doctoral student and a co-author on the paper takes the information release further, “GVL is also feedstock-agnostic. We have demonstrated that it works on corn stover, switchgrass, hardwood trees like white birch and poplar, and softwood trees like loblolly pine. In fact, we have shown that it is an effective solvent for more than 30 types of biomass.”

Several industry sectors may benefit from the new technology. Pulp and paper mills can turn two currently unused biomass fractions – hemicellulose and lignin – into commercial products, in addition to making paper from cellulose. With an additional step that increases its purity, they can also spin cellulose into fibers to produce textiles.

Car manufacturers can convert plant-derived lignin into carbon foam and fibers, avoiding the sulfur smell that reduces the appeal of lignin derived from other sources. Scientists at the University of Tennessee, who are co-authors on the study, demonstrated that lignin can also be used to make battery anodes, traditionally made from more expensive graphite.

Last, but not least, the new technology converts hemicellulose into furfural, a chemical intermediate that is the basis for a variety of plastics, polymers and fuels. Too expensive to be produced by U.S. companies, furfural is imported from China.

Motagamwala said, “Depending on furfural from China, and on petroleum from OPEC countries, means that the market is volatile. But since biomass is something every country has, bio-refineries may create a more stable market.”

Dumesic says the next challenge is to de-risk the technology.

“Now that we have proven that GVL is very effective at separating the three biomass fractions without diminishing their value, we see a path forward to becoming cost-competitive with a petroleum refinery,” he said. “Our next goal is to demonstrate that this new kind of bio-refinery can deliver a wide range of advanced biofuels and commodity chemicals as end products.”

Larry Clarke, Glucan Biorenewables’ CEO, will use his company’s platform to scale up the process and help realize its market potential.

Clarke said, “Since this simple, yet elegant and robust technology provides multiple value chain options, I believe it has the potential to transform the global biomass industry.”

The research is also widely based. Study collaborators include Troy Runge, a UW-Madison professor of biological systems engineering and an expert in biomass fractionation; Christos Maravelias, a UW-Madison professor of chemical and biological engineering who performed the techno-economic modeling; the U.S. Forest Service; and the University of Tennessee’s Center for Renewable Carbon.

This research looks to have legs. There are feedstock producers with motive, markets for the output and the anti agitators are mostly non U.S.

Its a long way to thousands or a million barrels of equivalent per day. The corn guys did it, maybe this technological breakthrough can get it done too.

A team from the University of Pittsburgh and the University of Oklahoma investigated the full life cycle impact of one promising ‘second-generation biofuel’ produced from short-rotation oak. The study found that second-generation biofuels made from managed trees and perennial grasses may provide a sustainable fuel resource.

This is a schematic showing the stages modeled in the biomass-to-fuel life cycle assessment. The image first appeared in the Royal Society of Chemistry journal Energy & Environmental Science, Issue 5, 2017.
Image Credit: Vikas Khanna. Click image for the largest view.

Over the years numerous studies have raised critical concerns about the promise of corn ethanol’s ability to mitigate climate change and reduce dependence on fossil fuels. Some of the studies have suggested that after a full life cycle assessment – meaning an analysis of environmental impact throughout all stages of a product’s life – biofuels like corn ethanol may not offer any greenhouse gas emissions reductions relative to petroleum fuels. The assertion remains a dubious allegation after nearly thirty years of experience.

Meanwhile, this team’s study results have been published in the Royal Society of Chemistry journal Energy & Environmental Science.

The study titled, “Multistage Torrefaction and In Situ Catalytic Upgrading to Hydrocarbon Biofuels: Analysis of Life Cycle Energy Use and Greenhouse Gas Emissions” took a novel approach to the production of second-generation biofuel while also comprehensively accounting for all of the steps involved in the full supply chain.

Vikas Khanna, assistant professor of civil and environmental engineering at the University of Pittsburgh and corresponding author of the study said, “Corn ethanol environmental impacts weren’t really studied until after its commercialization. The great thing about this project is it addresses full life cycle sustainability questions of new fuel sources before they come up later down the road.”

In 2007, the United Nations called for a five-year moratorium on food-based (or first-generation) biofuels because of concerns that they would consume farmland and lead to worldwide food shortage. It was an idea that went essentially nowhere.

Dr. Khanna and his team’s study used wood from oak trees, as they can be harvested year-round and reduce the need for large-scale storage infrastructure.

Dr. Khanna explained, “Second-generation biofuels differ from first generation biofuels because they don’t come directly from food crops like corn and soy. They include woody crops, perennial grasses, agricultural and forest residues, and industrial wastes.”

A significant metric for determining the efficacy of fuel is the Energy Return on Investment (EROI) ratio. The EROI of petroleum crude production remains high at about 11:1, meaning an investment of one unit of energy will yield 11 units of energy. However, the EROI has been steadily decreasing since 1986 and will continue to worsen as fossil fuels become more scarce and difficult to access.

When researchers study potentially promising energy sources, they look for a ratio greater than 1:1. Corn derived ethanol, for example, has a EROI of 1.3:1. The study found the median EROI for multistage second-generation biofuel systems ranges from 1.32:1 to 3.76:1. This is another construct rife with opportunities to mislead. The assertion that America’s record 15 billion+ bushel corn crop last year, producing nearly a million barrels a day of ethanol for about 40% of the crop and the other 60% going to feed and chemical products would suggests the American corn crop alone is a huge part of industrial petroleum use. EROI is a good idea that gets turned into nonsensical assertions.

The Energy Independence and Security Act of 2007 states that cellulosic biofuels, like the ones used in the study, must outperform the greenhouse gas emissions of fossil fuels by reducing relative emissions by 60 percent to receive economic incentives from the government. The study surpassed minimum requirements and showed an 80 percent reduction in greenhouse gas emissions relative to baseline petroleum diesel. Additionally, there was a 40 percent reduction in hydrogen consumption relative to a single-stage pyrolysis system.

Now it gets interesting.

Dr. Khanna said, “Pyrolysis is the process of heating biomass to high temperatures in the absence of oxygen to and create biofuel. If it’s done quickly, in one stage, a lot of carbon will be lost. Our research showed that a multistage, lower temperature system of pyrolysis can increase the carbon chain length, create more liquid fuel and improve the energy output of the entire process.”

This is easily one of the leading bewildering press releases your humble writer has seen. The gem is the innovations in pyrolysis, of which very little is said. These innovations are likely the most important part of the team’s work and yet, is a minor part of the press release.

On the other hand, corn and sugar cane ethanol are both raging successes with decades of experience and improvements, billions invested worldwide and a nemesis to OPEC and oil companies. For this team though, there is not a huge crop with large amounts going to waste and producers in deep financial trouble to drive a new use and market.

The team instead, is faced with a new crop, with little existing market, if any, hardly any motivated producers and would be yet another nemesis. Moreover, for those familiar with working woods, handling a saw or axe with popular or aspen is one thing, tearing up oak for processing is a whole other matter.

We can hope the team has a broader view than seen in the press release. There are likely raw materials in abundant supply, looking for new markets with a motivated producer base that will irritate the petroleum industry in a big way. That’s when their low temp pyrolysis could get going. Perhaps the team will pyrolysis cook some other things and they’ll start getting somewhere.

Helmholtz-Zentrum Berlin für Materialien und Energie scientists have fabricated a nanomaterial made from nanoparticles of a titanium oxide compound for lithium sulfur battery cathodes. The titanium oxide, Ti4O7 is characterized by an extremely large surface area, and was tested as a cathode material in lithium sulfur batteries.

The porous structure of the nanoparticles is visible under the electron microscope. Image Credit: HZB. Click image for the largest view.

Presently lithium batteries are one of the best solutions for storing electrical power in a small space. Lithium ions in these batteries migrate from the anode pole to the opposite electrical cathode pole during the discharge cycle. The anode and cathode generally consist of heavy-metal compounds that are expensive and toxic.

One interesting alternative is the lithium sulfur battery. A lithium sulfur cathode does not consist of heavy metals, but instead its sulfur, an economical and widely available material. As lithium ions migrate to the cathode during the discharge cycle, a reaction takes place there that forms lithium sulfide (Li2S) via various intermediate lithium polysulfides. During cycling, dissolution of lithium polysulfides causes the battery’s capacity to decline over the course of multiple charging cycles via the so-called “shuttle effect.” For this reason, researchers the world over are working to improve cathode materials that would be able to chemically or physically confine or encapsulate polysulfides, such as with nanoparticles made of titanium dioxide (TiO2), for example.

The scientific paper explaining the research has been published in Advanced Functional Materials.

The HZB team headed by Professor Yan Lu has now fabricated a cathode material that is even more effective. Here as well, nanoparticles provide confinement of the sulfur. However, they do not consist of titanium dioxide, but instead of Ti4O7 molecules arranged on a porous spherical surface. These porous nanoparticles bind polysulfides substantially more strongly than the usual TiO2 nanoparticles.

Yan Lu explained, “We have developed a special fabrication process to generate this complex, three-dimensionally interconnected pore structure.” Yan Lu first fabricates a template made of a matrix of tiny polymer spheres that have porous surfaces. This template is prepared in additional steps, then submerged in a solution of titanium isopropoxide. A layer of Ti4O7 is formed on the porous spheres and remains after thermal treatment, which decomposes the underlying polymer. Compared with other cathode materials made of titanium oxides, the Ti4O7 nanosphere matrix possesses an extremely large surface area. 12 grams of this material would cover a football field.

X-ray spectroscopy measurements (XPS) at the CISSY experiment of BESSY II show that sulfur compounds bind strongly to the surface in the nanomatrix.

This also accounts for the high specific capacity per gram (1219 mAh) at 0.1 C (1 C = 1675 mA g-1). The specific capacity also declines very little during repeated charge/discharge cycles (0.094 per cent per cycle). By comparison, the specific capacity of cathode materials made of TiO2 nanoparticles is 683 mAh/g. To increase the conductivity of this material, it is possible to apply a supplementary coating of carbon to the nanoparticles. The highly porous structure remains intact after this process.

Yan Lu said, “We have been working to improve the repeatability of this synthesis for over a year. Now we know how to do it. Next, we will work on fabricating the material as a thin-film.” And the best part: in this case, what has been successful in the laboratory can also be transferred to commercial manufacturing. This is because all the processes, from the colloid chemistry to the thin-film technology, are scalable.

Its a great month for lithium sulfur battery breakthroughs. Last week we saw an impressive innovation for the liquid electrolyte and now, the cathode. That fundamentally leaves the anode to go. And figuring out how to get these or other technologies together to offer the market a vastly superior battery at lower cost..


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