The December 8, 2008 issue of Chemical & Engineering News, the weekly publication of the American Chemical Society, has a terrific piece by Stephen K. Ritter called “Genes to Gasoline”. It details recent advances in ethanol produced from non-food cellulosic sources and it should give all of us a sense of excitement about what’s possible from just this one energy source.
Although ethanol won’t solve all our energy needs, it is likely to be major component of a portfolio of sources that will replace fossil fuels in the very near future. And creating ethanol from non-food cellulosic sources is a necessary step to avoid high food costs, reduced availability of certain food sources in various parts of the world and brings to bear what I feel is the biggest strength Americans have: science-based ingenuity.
Ritter’s piece starts out with these interesting facts that put the ability of cellulosic ethanol to become an important part of our energy portfolio:
The Department of Energy estimates that about 1 billion dry tons of celluosic biomass per year in the U.S. could be converted to biofuels. This estimate is a limit of how much plant material fuel makers could use without upsetting the normal supply of food, feed, and fiber and without requiring a major change in energy infrastructure and agricultural practices.
If every scrap of that material were converted into transporation fuels and combined with biofuels that can be made from available plant starches, sugars, and oils, the total could replace about one third of U.S. petroleum consumption by 2030 and about HALF by 2050, according to several estimates.
Half in forty years. Ponder that. This is energy produced in the U.S. by U.S. manufacturers. It would significantly reduce our dependence on Middle Eastern and other petroleum while putting Americans to work. Further, as this technology develops, it can be exported around the world bringing further revenues into our country.
What are some of the ways in which this can be accomplished? There are several. Under the auspices of the Department of Energy, three different research centers are working on the science that will make this happen. The first is the BioEnergy Science Center which is headquartered at the Oak Ridge National Laboratory in Tennessee. Another is the Great Lakes Bioenergy Research Center at the University of Wisconsin in Madison in partnership with my own alma mater, Michigan State University. The third location is the Joint BioEnergy Institute located at Lawrence Berkeley National Laboratory. Each of these centers is funded with $125 million of starting capital and has five years “to see what it can accomplish in reeingineering biological processes to develop new, more efficient methods of utilizing biomass.”
One of the most promising avenues being pursued involves sequencing the genomes (DNA maps) of existing organisms so that they can be fully understood and then modified to become even more efficient. For example, a fast-growing poplar tree Populus trichocarpa grows well in cool climates and shows great promise as a non-food cellulose source.
The fungus Trichoderma reesei was found during World War II to literally eat the clothing off soldiers and reduce their canvas tents to unusable piles of fiber is being studied as a way to degrade cellulose into its constituent parts (not an easy task from an energy standpoint.)
Clostridium thermocellum is a soil bacterium that can degrade cellulose and then turn around and ferment the resulting sugars into ethanol and other products. This two-steps-for-the-price-of-one organism might be one of the keys to making energy-efficient processes for teasing ethanol out of cellulosic biomass.
The white rot fungus Phanerochaete chrysosporium can be used to degrade the lignin that holds wood together making it hard to digest.
Finally, Pichia stipitis and baker’s yeast modified with a fungus found in elephant dung are being studied due to their ability to degrade five-carbon sugars (pentoses) which would allow the use of wood-based xylose sugars for the production of ethanol.
Wow! Lotsa science garble there, eh? But that’s GOOD! It’s what we’re good at in the U.S. And we’re getting particularly good at taking what comes out of laboratories and turning them into commercial enterprises that employ Americans and help our economy. Couple this with the fact that these are renewable resources and that they reduce the net production of the greenhouse gas carbon dioxide (a major contributor to global climate change) and you have something pretty exciting. This type of research that is exactly what we should be funding in the U.S. in order to reduce our dependence on foreign petroleum. And it is the type of research that WILL be funded by the incoming Obama administration.
But there’s a final piece to this big equation that takes “Hey, that’s cool!” to “OHMYGOD, this is AWESOME!!!:
We are going to have a Secretary of Energy that is a progressive liberal AND a Nobel Prize-winning scientist. Dr. Steven Chu is long-time and outspoken supporter of cellulosic ethanol and other clean, sustainable energy sources.
The importance of this can not be over-stated.
A scientist. A Nobel laureate scientist. A clean & renewable energy-supporting Nobel laureate scientist. At the head of the Department of Energy.
Like I said: OHMYGOD, this is AWESOME!!!
I’m just sayin’…
