Rainforest Fungus Naturally Synthesizes Diesel

A fungus that lives inside trees in the Patagonian rain forest naturally makes a mix of hydrocarbons that bears a striking resemblance to diesel. And the fungus can grow on cellulose, a major component of tree trunks, blades of grass and stalks that is the most abundant carbon-based plant material on Earth.

While genetic engineers have been trying a variety of techniques and genes to get microbes to create fuel out of sugars and starches, almost all commercial biofuel production today uses the century-old dry mill grain process. Existing ethanol plants ferment corn ears into alcohol, which is simple, but wastes the vast majority of the biomatter of the corn plant.

Using the cellulose from plants — the stalk instead of the ear, or simply wood from poplars — to make liquid fuel is a long-held dream because it would be more environmentally efficient and cheaper, but is far more difficult.

First, the cellulose must be broken down into its constituent parts — sugars bearing carbon — and then those pieces must be synthesized into more complex hydrocarbons. Both steps have proven difficult to do without applying large amounts of heat, pressure or chemicals.

What's exciting about the Gliocladium roseum fungus, however, is that it can both break down cellulose and synthesize the liquid fuel.

(Note that other technologies such as biomass gasification combined with the Fischer-Tropsch process have been developed to efficiently produce carbon based fuels using any carbon-based feedstock, such as wood waste, without the need to break down cellulose. This eliminates many of the difficulties associated specifically with "cellulosic" biofuels.)

But beyond the biofuel implications, scientists say that because the fungus can manufacture what we would normally think of as components of crude oil, it casts some doubt on the idea that crude oil is a fossil fuel. It may be the case that organisms like this produced some — maybe not all — of the world's crude oil.

Original article here.

Treethanol

Trees have been used as a source of fuel for thousands of years. According to The Economist magazine ($$), there is now a new high-tech twist on this fuel source. The idea is to make ethanol, a biofuel that usually comes from corn or sugar cane, from trees instead. Unlike oil, ethanol is renewable: to make more of it, you grow more crops. And blending ethanol into ordinary gasoline, or burning it directly in special “flex-fuel” engines, reduces greenhouse-gas emissions.

Why use trees as a feedstock for ethanol? Because “treethanol” has the potential to be much more energy efficient. The ratio of the energy yielded by a given amount of ethanol to the energy needed to produce it is called the “energy balance”. The energy balance for ethanol made from corn is about 1.3; in other words, the ethanol yields 30% more energy than was needed to produce it. For ethanol made from sugar cane in Brazil, the energy balance is 8.3.

But for ethanol made from trees, grasses and other types of biomass which contain a lot of cellulose, the energy balance can be as high as 16, at least in theory. In practice the problem is that producing such “cellulosic” ethanol is much more difficult and expensive than producing it from other crops. But the science, technology and economics of treethanol are changing fast. Researchers are racing to develop ways to chip, ferment, distill and refine wood quickly and cheaply.

Interest in cellulosic ethanol is growing as the drawbacks of making ethanol from corn and sugar become apparent. Both are important food crops, and as ethanol production is stepped up around the world, greater demand is driving up the prices of everything from animal feed to cola and biscuits. The price of a bushel of corn rose by 70% between September 2006 and January 2007 to reach its highest level in a decade. Mexico's president, Felipe Calderón, even capped the price of corn tortillas in January as America's fast-growing ethanol industry caused prices to rocket. There are clear signs of a backlash against ethanol made from food crops. Supply is struggling to keep up, and as more governments introduce schemes to promote biofuels and cut greenhouse-gas emissions, the tension between food and fuel will only intensify.

Pond Scum Power

In hopes that algae will one day serve as a replacement for natural gas used to power electric plants, researchers in Arizona over the past year have watched algae multiply in huge, bubbling test tubes beneath the hot sun in order to find just the right strand of the microscopic single-celled plant. The experiment has been so successful that it's about to expand into greenhouses on the electric plant grounds, and in time, be grown in such large quantities that it could be converted into fuel.

It works like this: Algae ingests carbon dioxide and releases oxygen in the photosynthesis process. Algae is laden with oils that can be used to produce biodiesel, starches that can be transformed into ethanol and protein that could have a market niche in cattle and fish feed.

The idea was thought of by a rocket scientist at the Massachusetts Institute of Technology, who was experimenting with growing algae on the International Space Station. The rocket scientist then founded a company called GreenFuel Technologies to market his idea. The company’s scientists now think that they may be able to produce 200 tons of algae per acre per year during mass production. Commercial production is expected to begin in 2008 in Arizona and other sites in Australia and South Africa. (See here for other articles about GreenFuel's technology).

Before fuel can be produced on a mass scale, scientists must figure out how to provide enough light to maximize algae growth and how to get the carbon dioxide in the water, where algae grows, fast enough to allow for maximum growth.