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Biofuels - Oct 26

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Many more articles are available through the Energy Bulletin homepage


Cellulosic Ethanol vs. Biomass Gasification

Robert Rapier, The Oil Drum
...I have recently seen a lot of confused claims in the media on cellulosic ethanol, so I thought I would write this essay to talk about the differences between cellulosic ethanol and biomass gasification.

Lately the media - encouraged by various ethanol advocates - has liberally applied the "cellulosic" label. It has become a buzzword.

...This brings us to some of the recent claims of a big breakthrough in "cellulosic ethanol" technology. However, one of the "breakthroughs" - biomass gasification - has been around for decades, and the technology is quite different from what is commonly denoted as cellulosic ethanol. It is not completely clear to me why some advocates are so eager to blur the distinction.

...While cellulosic ethanol has only recently gained buzzword status, the term has been around for decades. The historical definition of the term implies certain particular process steps. There is some variance from process to process, but the things that are common are that the cellulose in the plant material is broken down into simple sugars, and then the sugars are fermented into ethanol.

More money than ever before is being poured into cellulosic ethanol, but there are multiple hurdles that have proven difficult to overcome. For a good layperson's overview of the process, I recommend the recent article in the Chicago Tribune: Beyond corn: Ethanol's next generation. I think the article paints a balanced picture of the technology. In brief, there are three major hurdles that have proven challenging to resolve.
(26 Oct 2006)


Beyond corn: Ethanol's next generation

Michael Oneal, Chicago Tribune
...For a growing number of scientists, entrepreneurs and policymakers, however, the constant grumbling about corn ethanol entirely misses the point. While they don't disagree that the corn-based fuel has major limitations, they insist that obsessing over them is like disparaging first-generation personal computers for being slow and unwieldy.

Breakthroughs in genetic and industrial engineering, they insist, are changing the game. Not only is technology making corn ethanol more efficient, but researchers like Ho are making striking progress toward tapping what scientists call cellulosic biomass, the vast store of non-food plant matter that grows and renews itself daily.

If they succeed, many experts believe, cellulosic ethanol could be a plentiful, cheap and easily renewable oil alternative, with few of the negatives that plague the corn-based variety.

"It's the holy grail ... if you can make it work," said John Felmy, chief economist at the American Petroleum Institute.

The question is, can you really make it work?
(13 Oct 2006)
This is the article that Robert Rapier recommended in his recent post on The Oil Drum. At the end of the article is a summary comparing the corn and cellulosic processes. -BA


Biofuel subsidies cost U.S. billions

Philip Brasher, Des Moines Register
Washington, D.C. - America needs to rethink the cost of its appetite for biofuels, according to a European research group.

The Global Subsidies Initiative, based in Geneva, Switzerland, totaled up the cost of all the tax breaks, direct subsidies and other benefits for corn-derived ethanol, and it estimates that the assistance will cost U.S. taxpayers at least $5.1 billion this year.

The cost for subsidizing biodiesel production adds another $400 million to $500 million, according to a study the group released Wednesday. The numbers will go up as production increases.

"Subsidies to biofuels are large and growing rapidly," said Doug Koplow, the report's author.

The ethanol industry has long been criticized for its reliance on government subsidies, but there have been few attempts to calculate the costs to taxpayers. And the incentives keep growing, on the local, state and national level.

But ethanol supporters said the study overestimates the costs to taxpayers by failing to account for the biofuels' economic benefits.
(26 Oct 2006)
A surprising article to be published in the heart of the Corn Belt. -BA


When kitchen waste isn't wasted

Glen Martin, SF Chronicle
Upscale Bay Area restaurants helping feed machine that turns scraps into electricity, vehicle fuel
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...scraps from some of the region's trendiest restaurants -- Zuni Cafe, Jardiniere, Oliveto and Boulevard, among others -- are being enlisted in the quest for renewable energy. Eight tons a week of everything that comes back on plates or is rejected by the kitchen will be sent to a state-of-the-art digester at UC Davis, where it will be transformed into valuable "biogas" -- methane and hydrogen -- and fertilizer.

The digester -- an impressive amalgam of vats, piping, cables, conveyers and hoppers -- was unveiled Tuesday at a site near the campus' wastewater treatment plant. The project is a joint venture between the university and a private Davis firm, Onsite Power Systems Inc.

The system employs anaerobic bacteria -- microbes that function in the absence of oxygen -- to break down waste in large tanks, yielding copious volumes of flammable gas.

Ultimately, the plant will handle 8 tons of garbage a day, said its designer, Ruihong Zhang, a professor of biological and agricultural engineering at UC Davis. Each ton of slops will produce enough gas to supply 10 homes, but for now, enthusiasts primarily see it as a way to fuel garbage trucks and other commercial vehicles while reducing landfill volume. The digesting process converts between 60 and 90 percent of organic solids to biogas, Zhang said.

Some Bay Area cities -- including San Francisco -- already send their food waste to a composting site near Vacaville, where it is turned into soil amendment. But in a world increasingly stretched for natural resources and overflowing with garbage, that's not enough, said Zhang. Her anaerobic digester kicks things up a notch, extracting fuel as well as fertilizer from kitchen and yard waste.
(25 Oct 2006)

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