We humans are great at making ethanol from grains. We’ve been doing it for thousands of years to make beer and liquor, and our expertise is one reason that corn ethanol has been the biofuel of choice so far. But the biofuels of the future, experts say, will come not from the starch in corn but from the cellulose in grasses and other abundant green plants. There’s just one problem: We’re not good at breaking down the tough structure of cellulose to get at the sugars inside.
But cows are.
Cows, like termites and leafcutter ants, love to eat tough plant material, and host bacteria with the molecular machinery to do so in their guts. Scientists, in their attempts to get better at breaking down cellulose, have tried to copy nature by studying the enzymes that allow those grass-eating animals to do their thing. And now researchers say they have found a treasure trove of new microbe-produced enzymes inside a cow that could help them in their quest.
In a study published Thursday in the peer-reviewed journal Science, researchers described how they incubated bags of switchgrass inside cow rumens and from that found 27,755 “candidate genes” with the potential for efficiently breaking down plant cellulose into usable sugar that can then become ethanol. [MSNBC]
Eddy Rubin and his team executed this chemical excursion by surgically opening a hole into the first of the cow’s four stomachs.
In Washington D.C. today, the X-Prize foundation doled out $10 million in prize money for the Automotive X-Prize, its competition begun in 2008 to build cars that break 100 miles per gallon (or equivalent) and still resemble usable commercial vehicles. They raced at Michigan International Speedway; they underwent inspection by Consumer Reports and the Department of Energy. This morning’s winnings were divvied up among three teams:
1. Edison 2’s “Very Light Car”
Runs on: E85 ethanol
So named for weighing just more than 800 pounds—featherweight for a car—the vehicle from Edison 2 of Charlottesville, Virginia, took home the biggest slice of the prize money by winning the “mainstream” category.
In the “Mainstream” class, which offered the biggest cash prize, vehicles were required to have four wheels, seat four people and have a driving range of at least 200 miles. In other words, they had to offer the bare basics of a typical car [CNN].
The Very Light Car stayed light because it didn’t offer much more than that, though lead leader Oliver Kuttner says they did manage to squeeze in heater and basic ventilation.
The implants of the future will be powered by the energy sources already inside your body. Last week we saw scientists take a step toward this vision by developing a transistor that used the fuel from our cells (a molecule called ATP). And now, a French team has announced the development of a fuel cell that can use the glucose (sugar) inside an animal to produce electricity. Their paper is available free at the journal PLoS One.
The team surgically implanted the device in the abdominal cavity of two rats. The maximum power of the device was 6.5 microwatts, which approaches the 10 microwatts required by pacemakers [Technology Review].
Philippe Cinquin and his team created the cell, in which graphite electrodes are coated with enzymes that oxidize glucose to produce energy. Then connectors carry the electricity from the cell to whatever it’s powering.
The F/A-18 Super Hornet burns through more fuel than any other aircraft in the United States Navy, whose pilots have flown more than 400 of the jets. But with the week of Earth Day upon us, the Navy is trying to use the jet to show it can mend its fuel-guzzling ways. Tomorrow the “Green Hornet,” an F/A-18 running on a half-petroleum, half-biofuel blend, will make a test flight from Maryland.
Secretary of the Navy Ray Mabus has set a target that half of naval energy consumption will come from alternative sources by 2020. A “Great Green Fleet,” to sail by 2016, will include nuclear ships, as well as surface combatants with hybrid electric power systems using biofuel and biofuel-powered aircraft [National Geographic]. Before we can talk about ambitious deployment targets, however, the Navy has to prove that its “green” fighter has got what it takes, and so the experimental F/A-18 will try to break the sound barrier.
In a bid to go green, British Airways has announced that come 2014, part of its fleet would be powered by biofuel derived from household trash. The airlines announced Monday that it has inked a deal with U.S. company Solena Group to set up Europe’s “first sustainable jet-fuel plant.”
The plant will be located in east London, and it will take food and plant waste from the city’s homes and businesses and convert it to bio-fuel. The airline said in a statement that the plant “will convert 500,000 tonnes of waste per year into 16 million gallons of green jet fuel through a process that offers lifecycle greenhouse gas savings of up to 95 percent compared to fossil-fuel derived jet kerosene.” The aviation fuel will be produced from gasification of the waste into a so-called syngas which is then converted by the Fischer Tropsch process into liquid fuel [Reuters]. The biofuel would power part of the British Airways fleet flying out of London. The airline also says that diverting waste from landfills will curb the production of methane, a powerful greenhouse gas that is generated when garbage decomposes.
The move is part of a larger push by British Airways to get biofuels into the fuel tanks of its planes. BA plans to have biofuels make up 10 per cent of its total fuel usage by 2050, but not all will be derived from the Solena plant. Willie Walsh, BA chief executive, said the Solena partnership would pave the way for BA to cut net carbon emissions by 50 per cent by 2050 [Financial Times].
Now that many U.S. farmers have grown used to genetically modified (GM) soy and corn, the controversy surrounding GM crops may shift over to GM eucalyptus–a fast-growing Australian tree that, in its unmodified strains, dominates the tropical timber industry.
Two industry giants, International Paper Co. and MeadWestvaco Corp. have formed a biotech venture called ArborGen LLC that is looking to introduce this tree to the southeastern forests of the United States. The company is seeking greater governmental deregulation so it can roll out its plans of replacing native pines in southeastern plantation forests with the genetically engineered eucalyptus, which can survive freezing winter temperatures.
Unlike the pine trees used in Southern plantations — which have quietly helped displace tobacco in the region’s economy — eucalyptus can deploy a full canopy of leaves within a few years. It is greedy for carbon, and within 27 months can grow to 55 feet in height [The New York Times]. ArborGen points out that the high growth rate will allow the company to grow more wood on less land, which could provide a boost to the region’s timber exports. What’s more, the wood could potentially serve as a biofuel feedstock.
Most of us associate the bacteria E. coli with nasty stomach ailments. But a new study published in Nature magazine suggests E. coli can not just turn stomachs, but could potentially turn the wheels of your car, since a genetically engineered strain of the bacteria has produced clean, road-ready biodiesel.
The bacteria can work on any type of biomass, including wood chip, switchgrass, and the plant parts that are left behind after a harvest–all contain cellulose, a structural material that comprises much of a plant’s mass. Study coauthor Jay Keasling and his colleagues report engineering E. coli bacteria to synthesize and excrete the enzyme hemicellulase, which breaks down cellulose into sugars. The bacteria can then convert those sugars into a variety of chemicals–diesel fuel among them. The final products are excreted by the bacteria and then float to the top of the fermentation vat before being siphoned off [Technology Review].
When algae is discussed as an alternative source of biofuel, it’s often in tones of breathless excitement; many green tech boosters believe that the slimy goo can be turned into fuel superior to that made from corn, canola, or switch grass.
You don’t need vast tracts of land to cultivate algae for biofuel, the thinking goes, all you need is the right strain of algae, water, sunlight, and carbon dioxide. Even Exxon and Dow Chemical recently joined the biofuel brigade, and are now investing millions in algae operations.
But a new study suggests that while algae might produce good fuel, the environmental costs involved in the production would be heavy. A life-cycle assessment published in the journal Environmental Science and Technology argues that algae production consumes more water and energy than other biofuel sources like corn, canola, and switch grass, and also has higher greenhouse gas emissions. While the study’s results are sobering, they’re also being met with harsh criticism from alage-based biofuel companies and their trade group, the Algal Biomass Association.
Companies and governments all over the world are racing to find cleaner, greener fuels to end our society’s addiction to oil and cut down on the greenhouse gas emissions that cause global warming. But in the rush and tumult of new developments and optimistic predictions, it’s hard to separate the hype from real hope. So a recent series of articles from Nature News feels like a public service, as the articles investigate the scientific and economic state of affairs for four different kinds of biofuels.
The first article focused on the weedy plant jatropha, which was initially hailed as a biofuel wonder plant because it can survive in poor soil and harsh conditions, and because of its extremely oily seeds. But recently, investments in jatropha projects have fallen off dramatically. Environmental scientist Robert Bailis says that “over the past three years, the investment got way ahead of the plant science.” … Early investors are now realizing the plant’s limitations. Jatropha can live in very dry conditions, but doesn’t necessarily yield a lot of seeds. The plant takes three years or more to reach maturity, requiring care along the way. And jatropha seedlings are often not well-suited to the climate in which they are planted [Nature News].
Now, companies are regrouping and going back to basic science; they’re crossbreeding plants to create strains that mature faster or have higher oil yields, and are seeking out the habitats most suited for jatropha plantations. The plant may well have a role to play in the future energy mix, but it’s no botanical cure-all.
Watermelons could do more than grace the tables at picnics across the land: They could also serve as a source of biofuel. Researchers fermented watermelon juice to produce ethanol, according to a study published in Biotechnology for Biofuels, and while the melons aren’t likely to become a primary biofuel crop, the process could help out farmers.
Nearly one-fifth of the watermelon crop grown in the United States is left in the fields after harvest because of defects on the melons’ rinds. “It’s not that there’s anything wrong with the melon on the inside, but our only method of judgment is the outside,” said [lead author] Wayne Fish [Greenwire]. Although farmers often till the abandoned melons into the soil, the value of the nutrients provided by this practice is much less than the overall cost to farmers of losing so much of their crop.