Interesting New 57% Efficient Solid Oxide Fuel Cell

Fuel cells can burn a wide range of fuels: from hydrogen to biomass to methane to diesel. They are also more efficient than internal combustion engines. This makes them practical for both stationary power generation facilities, and for mobile power generation in electric-powered vehicles. Below we have republished two excerpts from stories reporting on important developments in solid oxide fuel cell (SOFC) design and development, which makes SOFCs more efficient and practical.

GCC

Researchers at the Pacific Northwest National Laboratory report on a highly efficient, small-scale solid oxide fuel cell system featuring PNNL-developed microchannel technology in combination with adiabatic, external steam reforming and anode gas recirculation. The heat and water required for the endothermic reforming reaction are provided by the recirculated anode gas emerging from the SOFC stack. They refer to this as adiabatic steam reforming because external heat sources, such as a combustor or an electric-resistance heater, are not necessary to support the reaction.

The new fuel cell system achieves up to 57% efficiency—significantly higher than the 30 to 50% efficiencies previously reported for other solid oxide fuel cell systems of its size—according to a study published in this month’s issue of the Journal of Power Sources. The pilot system generates about 2 kW of electricity; the PNNL team designed it to be scaleable to produce between 100 and 250 kW. _GCC

NewEnergyandFuel

The PNNL SOFC system has been streamlined to make it more efficient and scalable by using PNNL-developed microchannel technology in combination with processes called external steam reforming and fuel recycling. PNNL’s system includes fuel cell stacks developed earlier with the support of Department of Energy’s Solid State Energy Conversion Alliance.

The big numbers for the efficiency of this small SOFC system is the use of a PNNL-developed microchannel technology in the system’s multiple heat exchangers. Instead of having just one wall that separates the two gases, PNNL’s microchannel heat exchangers have multiple walls created by a series of tiny looping channels that are narrower than a paper clip. This increases the surface area, allowing more heat to be transferred and making the system more efficient. PNNL’s microchannel heat exchanger was designed so that very little additional pressure is needed to move the gas through the turns and curves of the looping channels. Even more interesting is the second unique aspect of the system – it recycles the heat. _NewEnergyandFuel

SOFCs using heat recycling fuel reformers, should eventually be able to use a wide range of carbonaceous fuels -- including biomass. So much for the collapse of civilisation when crude oil is abandoned as a primary fuel.

More on biomass fuel cells (PDF)

Here is a "kinder, gentler" way of turning biomass into energy. As we have predicted, the conversion of cellulose to energy and fuels is likely to follow a rough trajectory over various processes. The "brute force" thermal and thermochemical approaches are more practical initially. As better organisms and enzymes are engineered, the biological approach is likely to grow more efficient. Finally, as nanotechnological bio-mimics improve, the greater robustness of inorganic nanotech-catalysts should facilitate their use in place of more fragile bio-based catalysts. In the background, the movement of more advanced societies to safe, clean, reliable, and affordable gen III and gen IV nuclear reactors at various scales, is likely to increase the energy and fuel production choices of societies almost exponentially.

The Quest for Bioenergy Enzymes: Novozymes

Danish company Novozymes is investing $200 million in a Nebraska enzyme plant. That is a significant investment for the company -- particularly in an economic downturn. But the best way to be ready for higher prices for a commodity like oil is to be first in line with an economical substitute.

...Novozymes is the world's biggest enzyme maker, and its products account for about 60 percent of the market in the biofuel industry.

Enzymes are strings of protein that can serve as catalysts in many natural and manmade processes. Those include breaking down starch in corn - a vital step in ethanol production.

Novozymes is also a player in the emerging cellulosic ethanol business, and it is working with the nation's largest ethanol company, Poet LLC, on a pilot cellulosic ethanol plant in Emmetsburg, Iowa, that is expected to begin operating in 2011.

Cellulose is the woody material in branches and stems that makes plants hard, and the ethanol industry is developing ways to produce fuel from cellulose economically. Once the costs of cellulosic ethanol are similar to corn-based ethanol, companies will be able to produce ethanol from straw, corn stalks, wood pulp and other inedible agricultural leftovers.

Hansen said Novozymes has 150 researchers working to improve the enzymes it produces to break down cellulose and reduce their cost. Novozymes has reduced the cost of cellulosic ethanol enzymes to about $1 per gallon, and the company expects to cut that cost to about 50 cents per gallon next year.

Hansen predicted the technology will be ready to produce cellulosic ethanol by the end of 2010... _Bioeneryg

Enzymes can turn cellulose into more than just ethanol. But since the US government is currently backing ethanol as a gasoline additive, it makes sense to invest in EtOH -- for a start. Long term, butanol and other fuels and valuable chemicals makes more sense.

What is the advantage of the enzyme approach over the gasification / pyrolysis / torrefaction approach? Potentially higher efficiencies and profits. It is always about efficiency and profit.

Gang of 15 Fungal Cellulases Open the Bio-Gate

The bio-gateway to abundant energy and wealth was just opened a crack. Cellulose is one of nature's favourite ways of storing solar energy. But human machines and power systems do not run well on cellulose. Naturally, a conversion from cellulose to high density liquid, solid, and gaseous forms of energy storage is vital. But, how to do it? Using clever and efficient enzymes can be a good way, but single enzymes lack the power and versatility to do everything necessary. Hence, the "gang of 15 enzymes" working together.

Researchers at the California Institute of Technology (Caltech) led by Frances H. Arnold, the Dick and Barbara Dickinson Professor of Chemical Engineering and Biochemistry at Caltech, and gene-synthesis company DNA2.0 have developed a new group of 15 highly stable fungal enzyme catalysts that efficiently break down cellulose into sugars at high temperatures for conversion into a variety of renewable fuels and chemicals.

Previously, fewer than 10 such fungal cellobiohydrolase II (CBH II) enzymes were known. In addition to their remarkable stabilities, Arnold’s enzymes degrade cellulose over a wide range of conditions. A paper on the work was published 23 March in the early edition of the Proceedings of the National Academy of Sciences.

This is a really nice demonstration of the power of synthetic biology. You can rapidly generate novel, interesting biological materials in the laboratory, and you don’t have to rely on what you find in nature. We just emailed DNA2.0 sequences based on what we pulled out of a database and our recombination design, and they synthesized the DNA. We never had to go to any organism to get them. We never touched a fungus.
—Dr. Frances Arnold

...Arnold and Caltech postdoctoral scholar Pete Heinzelman created the 15 new enzymes using a process called structure-guided recombination. Using a computer program to design where the genes recombine, the Caltech researchers mated the sequences of three known fungal cellulases to make more than 6,000 progeny sequences that were different from any of the parents, yet encoded proteins with the same structure and cellulose-degradation ability.

By analyzing the enzymes encoded by a small subset of those sequences, the Caltech and DNA2.0 researchers were able to predict which of the more than 6,000 possible new enzymes would be the most stable, especially under higher temperatures (a characteristic called thermostability). _GCC

Very clever. And this is just the beginning.

We are living in a biological world. When we start working with biology to get more of the things we want, we can begin building a veritable cornucopia of riches.

Genetic Re-Shuffling For Abundant Energy

Codexis develops novel industrial biocatalysts, including enzymes and microbes, for use in the energy and pharmaceutical industries. The Codexis directed evolution platform (“MolecularBreeding”) uses DNA shuffling to generate a library of novel genes or genomes via recombination of selected starting or parental genes or genomes.

Codexis then screens the encoded library of novel enzymes or strains for those possessing desirable and improved properties and repeats the process until the resulting enzymes or strains meet or exceed the desired efficiency benchmark. _GCC

Royal Dutch Shell is working with Codexis and Iogen Energy Corporation to move beyond mere cellulosic ethanol to cellulosic hydrocarbons such as diesel, jet fuel, and gasoline. New catalysts hold the potential to greatly reduce the energy costs of such processing -- thus improving profitability and viability in tough economic times. More at the link above.

Iowa State University is taking the thermochemical route to cellulosic ethanol, concentrating on a new burner and new catalysts:

The burner....Gasifying biomass releases the fixed nitrogen as ammonia in the generated gases. Improperly burning gases containing ammonia could produce nitrogen oxide emissions. Kong’s goal is to develop a burner that will minimize the emission of such pollutants while maximizing combustion efficiency.

A conventional gas burner now at the Iowa Energy Center’s Biomass Energy Conversion Facility in Nevada will provide baseline data to develop computer models of the burner’s performance. Those models will test new designs that optimize the combustion of producer gas from biomass, and lead to the construction and testing of a prototype.

The catalyst. Victor Lin, a professor of chemistry, director of Iowa State’s Center for Catalysis, director of Chemical and Biological Sciences for the US Department of Energy’s Ames Laboratory and founder of Catilin Inc., an Ames-based company that produces catalysts for biodiesel production is leading the development of a new catalyst for ethanol production. Lin says it may be possible to efficiently produce liquid fuel directly from synthesis gas.

The key will be carbon-based nanoparticles just a few billionths of a meter wide. The particles are made from graphite and carry a transition metal that produces a chemical reaction. That reaction converts synthesis gas to ethanol.

Lin said there is an existing chemical catalyst that can convert synthesis gas to ethanol. But that catalyst has a very low yield of ethanol, produces greenhouse gases such as methane, needs heat up to 540 °F (282 ° C) and requires high pressures.

Lin said the new catalyst should work at lower temperatures and pressures while delivering a higher yield of ethanol. _GCC

These are just two of the many dozen well-financed approaches to producing cellulosic fuels. If you add in the efforts to develop biomass fuel cells, biomass gasification (IGCC, CHP) power plants, boost the growth of biomass, and synthesise high value chemicals from biomass, you begin to see that this is not your grandfather's botany or chemistry. To say nothing of DNA shuffling.

Master-Stroke by Researchers Yields One-Step Super Yeast for Cellulosic Ethanol

Japanese researchers have succeeded in integrating cellulolytic enzyme genes from koji mould, into a sake yeast. This yeast now has the the cellulolytic enzyme prominently sprinkled over its cell membrane, where it can break down cellulose from biomass, while the sake yeast itself ferments the resulting simple sugars into ethanol.

To create the super yeast that produces the bioethanol, koji mold genes that produce cellulolytic enzymes were integrated into sake yeast using cell surface engineering so that the enzymes are densely displayed on the surfaces of the yeast cells. Because super yeast combines the capabilities of koji mold, which converts the cellulose starch (cellooligosaccharide) into sugar (glucose), with that of yeast, which ferments sugar (glucose), it can produce ethanol by itself from cellulose pretreated with subcritical water

The combination of subcritical water treatment with super yeast enables clean and easy pretreatment, and simple and efficient ethanol production, which means that small-scale plants could be built and operated in many different rural locations where the plant materials are produced.

Gekkeikan Research Institute has already demonstrated at the experimental level that the new process can effectively produce ethanol from paddy straw and chaff, and it is now working to refine the process for commercial production through research aimed at boosting alcohol yield and integration with various other technologies. _Gekkeikan_via_Japanfs_via_autobloggreen

This one step process utilising a hybrid yeast w/mould genes, is just the beginning of the clever use of biotechnology for meeting the basic needs of human society. Consider it a humble, though important, beginning.

Butanol from Cellulose: Better Fuel, Better Feedstock

The California Institute of Technology has spawned a bio-energy startup, Gevo. Gevo has recently acquired new financing to pursue its goal of efficient production of cellulosic bio-butanol. Butanol is a superior fuel for gasoline engines than ethanol, blending better with gasoline and causing much less corrosion than ethanol. Progress in the efficient and economical production of bio-butanol would be much welcomed.

Gevo, the Pasadena, Calif., based developer of synthetic biofuels just wrapped up a $17 million third round of funding. New investors Burrill & Co. and Malaysian Life Sciences Capital Fund joined cleantech regulars Khosla Ventures and Virgin Green Fund; the biofuel start-up has already raised over $30 million since the beginning of last year.

Like competitors LS9, OPX Biotechnologies and Amyris, Gevo is trying to change the face of the biofuel industry by using synthetic biology to engineer enzymes and microorganisms to convert cellulosic crops and waste into advanced biofuels like isobutanol and butanol. Butanol, the company claims, is superior to first-generation biofuels like corn ethanol in several respects: It has a higher energy content; does not absorb water and can easily be transported through the existing gas infrastructure; and — perhaps most importantly — can be directly pumped into current vehicles.

Gevo says its metabolic and process engineering techniques will facilitate the commercial-scale production of second-generation biofuels and bring costs down to compete with current biofuels, like corn ethanol. The cost of producing cellulolytic enzymes hovers around 20 - 50 cents per gallon of ethanol produced; the cost of producing a gallon of corn ethanol, on the other hand, is only about 3 - 4 cents. __CheckBiotech

Termites to the Rescue--Secrets of Cellulosic Ethanol and Butanol

Metagenomics is the clever art of stealing DNA from one species to use for the benefit of another--namely, us. Presently, humans need a good way to convert cellulose--from plant waste and prolific grasses and woods--into sugars for fermentation to useful alcohols such as butanol and ethanol. Termites have been hosting bacteria that perform that conversion for millions of years. Perhaps we could learn something from termite guts?

Scientists are sequencing the genomes of entire microbial communities in the hope of uncovering new genes and organisms that can create fuel, mine metals, or clean up superfund sites. Known as metagenomics, the field relies on studying bits of DNA from a variety of organisms that live in the same place. Thanks to ever-improving sequencing methods, the number of metagenome projects is growing, giving scientists myriad new genes to explore.

...Converting cellulose in trees and grasses into the simple sugars that can be fermented into ethanol is a very energy-intensive process. "If we had better enzymatic machinery to do that, we might be better able to make sugars into ethanol," Bristow says. "Termites are the world's best bioconverters."

Researchers at the Joint Genome Institute, which sequenced some of the human genome and is now largely devoted to metagenomics, have just finished sequencing the microbial community living in the termite gut. They have already identified a number of novel cellulases--the enzymes that break down cellulose into sugar--and are now looking at the guts of other insects that digest wood, such as an anaerobic population that eats poplar chips. The end result will be "basically a giant parts list that synthetic biologists can put together to make an ideal energy-producing organism," says Hugenholtz.

Source.

So you see, metagenomics may help to break the chokehold of petroleum on the modern global economic infrastructure. And much, much, more.