Scientists at the University of California in San Francisco have discovered a potentially revolutionary new way of creating gasoline without the use of food crops, and without the pesky necessity of spending millions of years buried beneath the earth.
Using a peculiar microbe discovered in a French garbage dump combined with the wonders of modern synthetic biology, a team of researchers has identified a chemical compound capable of converting carbon-based biomass into a gas that can be processed to produce gasoline.
The chemical conversion process is able to use a variety of inexpensive substrates, such as agricultural waste products like the leaves and stalks left over from corn and sugar cane harvesting.
The end product is gasoline that the researchers claim is chemically identical to that derived from fossil-fuel sources in petroleum refineries around the world.
“You could fill your car up with it right now, so there’s no difference in engine technology or anything like that,” said Chris Voigt, chief researcher for the project.
Voigt believes that the U.S. could potentially turn to this new breed of bio-fuels as a security net in the event of unstable oil prices on the world market.
“Then, if the sugar price goes high and the oil price goes down, you could flip it and the consumer would not know any difference,” he added ““ a possibility not available with ethanol.
In recent years, opponents of the ethanol movement ““ the other bio-fuel ““ have levied the double-edged criticism that production of the corn-based fuel drives up global food prices and is not environmentally friendly, despite its green reputation.
Both are criticisms that would be circumvented by the new fuel-production technology, since it utilizes essentially useless plant waste products that are typically discarded by farmers.
Voigt estimates that with advancements in the efficiency of the conversion process and use of genetically modified plants, gasoline could eventually be produced for as little as $1.65 a gallon from sugar cane bagasse.
He also believes that fuel derived from cellulosic materials such as poplar trees could be even cheaper to produce ““ at roughly $1.10 to $1.30 a gallon. The problem however lies in creating a sustainable and profitable model for growing the necessary amount of trees, which require a substantially longer growth period before they can be harvested.
For years, scientists have tried and “failed miserably” to find an enzyme that could efficiently break down cellulose ““ the main component of plants’ rigid cell walls ““ in hopes of creating cheap bio-fuels, said Voigt.
“So we started looking at organisms that can do that naturally,” he explained. “We then found this one that we realized was unique.”
Voigt’s team utilized a novel species of bacterium first discovered in a French garbage dump in the 1980’s. They then teamed the bacterium up with common yeast cells. When the two are placed together on a plant-based substrate like switchgrass, the chemistry is amazing.
The bacterium first consumes the vegetation and produces the chemical acetate as a metabolic side-product. The yeast then feeds on the acetate, which it in turn converts into methyl halides, a family of molecules traditionally used as agricultural fumigants.
The methyl halides are then released as a gas that scientists can easily collect and convert to gasoline.
According to Voigt, by simply substituting a different catalyst the methyl halides can also be converted into other useful chemicals, such as the ethylene used in plastic bags.
The group’s results are sure to reinvigorate hopes for the future of truly green bio-fuels.
Voigt estimates that the first large-scale pilot production facility for methyl halide conversion could be ready for production in as little as three years.
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