Monday, November 8, 2010

Beyond Corn Ethanol: Bioproducts from 'Garbage'

Though algae has great promise to secrete oils or be biomass itself,  algae always seems to about “five years away,” according to Dr. William J. Orts of USDA’s agriculture research service  in Albany, CA who spoke at UC Davis Energy Institute this past week.

Seemingly to prove his point, one of the large oil companies has been running a TV advertisement, featurng a middle-aged researcher:

“It is was 1975 and my professor at Berkeley asked if I wanted to change the world.   I said sure.  And he said, ‘Let's grow some algae’.”

Dr Orts talk, “Agriculturally Derived Biofuels and Bioproducts: Going Beyond Corn Ethanol” began with corn ethanol summary: Though it is in production now, enjoys a $0.51 per gallon subsidy  and “we know how to do it,”   it suffers from several drawbacks, including a bad carbon footprint when all the fertilizer use and transportation is factored in.  Ethanol is also corrosive, so can not be put into pipelines, and there is not enough of it to make a real dent in US demand for transportation fuels.

Much research is now focused on second generation biofuels.  Energy crops are “very hot now”, he said, for example switchgrass.    Dr. Orts outlined the basic line of attack on cellulosic biomass (think: harder to degrade corn or rice stalks, not the corn) by pointing out that  we should learn from anything that ‘eats wood’, from fungus to cows.  

Like algae, it is not so easy.   Whereas corn starch breaks down with just 2-3 enzymes, heavy cellulosic materials can need 16.  The goal for many researchers is finding the right “3-in-1” kind of sauce with the right genetic-modified material and optimized enzymes to seek out and attack the chemical and biological weaknesses of cellulose.

But Dr. Ortis then turned to one of his favorite approaches which can work now:  garbage.  Garbage, or municipal solid waste ( MSW), is about 40% cellulosic.    MSW - the waste,  plastic bottles and all - can be sorted,  ‘cooked’ in the right environment  (temperature, enzymes, etc) to yield biofuel (ethanol) or biogas (ex: natural gas) or even paper for paper plates.  (There are hopes of this new bioproducts industry will even replace petroleum  in the manufacture of man-made  fibers, polymers or even the medicines that we have become so used to. )

The city of Salinas is planning   a project with uses pre-treatment and sorting MSW.   The equipment then “cooks” it and  creates ethanol.   It avoids the landfills completely.  And, it can be done now.


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