July 26, 2006

MIT: Redesigning Life to Make Ethanol

I highly recommend reading the current issue of MIT’s Technology Review magazine. It features a well-written Special Report called “It's Not Too Late: The energy technologies that might forestall global warming already exist.”

The writers almost got the story right - but they failed to mention what some consider the most promising short-term solution to the knotty renewable-energy-global-warming-landfill-pollution-oil import-war crisis - namely syngas fermentation. Let me explain...

In one article called The Dirty Secret David Talbot writes about the promise of gasification (using high heat in a controlled near vacuum to convert the coal into a gas) for cleaning up coal burning plants of the future. It's better than combustion because you capture the greenhouse gases before they are spewed into the atmosphere. However, you still have to actually do something clean and productive with the syngas (CO, CO2, and H2) that is produced. Talbot speculates that utilities could sell the carbon dioxide to oil companies who would pump it underground to push oil to the surface while neatly sequestering the CO2 from the atmosphere.

A separate article is called Redesigning Life to Make Ethanol. Here author Jamie Shreeve writes about exciting advances being made by biotechnology companies (like the oft-cited Canadian company, Iogen) who are coming up with new strains of enzymes that can break the chemical bonds in cellulosic material to create glucose for fermentation into ethanol by a second set of micro-organisms or yeasts. There could come a time when a single, sturdy micro-organism would be developed that could perform the feedstock-to-ethanol "alchemy" all in one step. That could be decades off but partial solutions could be implemented now - albeit with crude, expensive enzyme concoctions.

What is missing is the link between gasification in the first article with fermentation in the second. Instead of creating a super enzyme to perform two very different tasks, how about using gasification to break down the chemical bonds of the feedstock and then use a micro-organism or catalyst to convert the syngas to ethanol? Using "syngas fermentation" there are several companies that have achieved very promising results (roughly 100+gallons of ethanol per ton of biomass). BRI Energy in Arkansas, BioConversion Technology (no relation) in Colorado, and Future Fuels, Inc. in Washington, DC are companies that are pioneering this technology in pilot plants right now. All are in the process of negotiating their first commercial-scale deployments.

"It's Not Too Late" to unravel the Gordian Knot. But why don't we slice it in half instead?

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