Skip to Content.
Sympa Menu

permaculture - [permaculture] more re ethanol production

permaculture@lists.ibiblio.org

Subject: permaculture

List archive

Chronological Thread  
  • From: Saor Stetler <saor@ycbtal.net>
  • To: permaculture@lists.ibiblio.org
  • Subject: [permaculture] more re ethanol production
  • Date: Thu, 02 Feb 2006 12:54:57 -0800

From Plan b:2.0 by Lester Brown (earthpolicy.org)

Another perhaps more promising option for producing ethanol is to use enzymes to break down cellulosic materials, such as switchgrass, a vigorously growing perennial grass, or fast-growing trees, such as hybrid poplars. Ethanol is now being produced from cellulose in a small demonstration plant in
Canada. If switchgrass turns out to be an economic source of ethanol, as some analysts think it may, it will be a major breakthrough, since it can be grown on land that is highly erodible or otherwise not suitable for annual crops. In a competitive world market for crop-based ethanol, the future belongs to sugarcane and switchgrass.

The ethanol yield per acre for switchgrass is calculated at 1,150 gallons, higher even than for sugarcane. The net energy yield, however, is roughly 4, far above the 1.5 for corn but less than the 8 for sugarcane. Aside from the prospective use of cellulose, current and planned ethanol-producing operations use food crops such as sugarcane, sugar beets, corn, wheat, and barley. The United States, for example, in 2004 used 32 million tons of corn to produce 3.4 billion gallons of ethanol. Although this is scarcely 12 percent of the huge U.S. corn crop, it is enough to feed 100 million people at average world grain consumption levels.

In an oil-short world, what will be the economic and environmental effects of agriculture's emergence as a producer of transport fuels? Agriculture's role in the global economy clearly will be strengthened as it faces a vast, virtually unlimited market for automotive fuel. Tropical and subtropical countries that can produce sugarcane or palm oil will be able to fully exploit their year-round growing conditions, giving them a strong comparative advantage in the world market.

With biofuel production spreading, the world price for oil will, in effect, become a support price for farm products. If food and feed crop prices are weak and oil prices are high, commodities will go to fuel producers. For example, vegetable oils trading on European markets on any given day may end up in either supermarkets or service stations. The risk is that economic pressures to clear land for expanding sugarcane production in the Brazilian cerrado and Amazon basin and for palm oil plantations in countries such as Indonesia and Malaysia will pose a major new threat to plant and animal diversity. In the absence of governmental constraints, the rising price of oil could quickly become the leading threat to biodiversity, ensuring that the wave of extinctions now under way does indeed become the sixth great extinction.

With oil prices now high enough to stimulate potentially massive investments in fuel crop production, the world farm economy-- already struggling to feed 6.5 billion people--will face far greater demands. How the world manages this new incredibly complex situation will tell us a great deal about the prospect for our energy-hungry twenty-first century civilization.


hey, wait a minute
Corn Dog
The ethanol subsidy is worse than you can imagine.
By Robert Bryce
Posted Tuesday, July 19, 2005, at 8:12 AM ET

For the last generation, ethanol has been America's fuel of the future. But there has never been more hype about it than there is today. Green-energy analysts like Amory Lovins, environmental groups like the Natural Resources Defense Council, neoconservatives like James Woolsey, and farm groups like the American Coalition for Ethanol <http://www.ethanol.org/> are all touting the biofuel.

Making ethanol, they claim, will help America achieve the elusive goal of "energy security" while helping farmers, reducing oil imports, and stimulating the American economy. But the ethanol boosters are ignoring some unpleasant facts: Ethanol won't significantly reduce our oil imports; adding more ethanol to our gas tanks adds further complexity to our motor-fuel supply chain, which will lead to further price hikes at the pump; and, most important (and most astonishing), it may take more energy to produce a gallon of ethanol than it actually contains.

The greens, hawks, and farmers helped convince the Senate to add an ethanol provision to the energy bill--now awaiting action by a House-Senate conference committee--that would require refiners to more than double their use of ethanol to 8 billion gallons per year by 2012. The provision is the latest installment of the ethanol subsidy, a handout that has cost American taxpayers billions of dollars during the last three decades, with little to show for it. It also shovels yet more federal cash on the single most subsidized crop in America, corn. Between 1995 and 2003, federal corn subsidies totaled $37.3 billion <http://www.ewg.org:16080/farm/region.php?fips=00000>. That's more than twice the amount spent on wheat subsidies, three times the amount spent on soybeans, and 70 times the amount spent on tobacco.

The stickiest question about ethanol is this: Does making alcohol from grain or plant waste really create any new energy?

The answer, of course, depends upon whom you ask. The ethanol lobby claims there's a 30 percent net gain in BTUs from ethanol made from corn. Other boosters, including Woolsey, claim there are huge energy gains (as much as 700 percent) to be had by making ethanol from grass.

But the ethanol critics have shown that the industry calculations are bogus. David Pimentel, a professor of ecology at Cornell University who has been studying grain alcohol for 20 years, and Tad Patzek, an engineering professor at the University of California, Berkeley, co-wrote a recent report that estimates that making ethanol from corn requires 29 percent more fossil energy than the ethanol fuel itself actually contains.

The two scientists calculated all the fuel inputs for ethanol production--from the diesel fuel for the tractor planting the corn, to the fertilizer put in the field, to the energy needed at the processing plant--and found that ethanol is a net energy-loser. According to their calculations, ethanol contains about 76,000 BTUs per gallon, but producing that ethanol from corn takes about 98,000 BTUs. For comparison, a gallon of gasoline contains about 116,000 BTUs per gallon. But making that gallon of gas--from drilling the well, to transportation, through refining--requires around 22,000 BTUs.

In addition to their findings on corn, they determined that making ethanol from switch grass requires 50 percent more fossil energy than the ethanol yields, wood biomass 57 percent more, and sunflowers 118 percent more. The best yield comes from soybeans, but they, too, are a net loser, requiring 27 percent more fossil energy than the biodiesel fuel produced. In other words, more ethanol production will increase America's total energy consumption, not decrease it. (Pimentel has not taken money from the oil or refining industries. Patzek <http://petroleum.berkeley.edu/papers/patzek/CRPS416-Patzek-Web.pdf> runs the UC Oil Consortium <http://petroleum.berkeley.edu/UCOil/structure.htm>, which does research on oil and is funded by oil companies. His ethanol research is not funded by the oil or refining industries* <http://www.slate.com/toolbar.aspx?action=print&id=2122961#correct>.)

Ethanol poses other serious difficulties for our energy economy. First, 8 billion gallons of ethanol will do almost nothing to reduce our oil imports. Eight billion gallons may sound like a lot, until you realize that America burned more than 134 billion gallons of gasoline last year. By 2012, those 8 billion gallons might reduce America's overall oil consumption by 0.5 percent. Way back in 1997, the General Accounting Office concluded that "ethanol's potential for substituting for petroleum is so small that it is unlikely to significantly affect overall energy security." That's still true today.

Adding more ethanol will also increase the complexity of America's refining infrastructure, which is already straining to meet demand, thus raising pump prices. Ethanol must be blended with gasoline. But ethanol absorbs water. Gasoline doesn't. Therefore, ethanol cannot be shipped by regular petroleum pipelines. Instead, it must be segregated from other motor fuels and shipped by truck, rail car, or barge. Those shipping methods are far more expensive than pipelines.

There's another problem: Ethanol, when mixed with gasoline, causes the mixture to evaporate very quickly. That forces refiners to dramatically alter their gasoline to compensate for the ethanol. (Throughout the year, refiners adjust the vapor pressure of their fuel to compensate for the change in air temperature. In summer, you want gasoline to evaporate slowly. In winter, you want it to evaporate quickly.) In a report released last month, the GAO underscored the evaporative problems posed by ethanol, saying that compensating for ethanol forces refiners to remove certain liquids from their gasoline: "Removing these components and reprocessing them or diverting them to other products increases the cost of making ethanol-blended gasoline."

In addition to the transportation and volatility issues, ethanol will add yet more blends of gasoline to the retail market. Last year, American refiners produced 45 different types of gasoline. Each type of gasoline needs specific tanks and pipes. Adding ethanol to the 45 blends we already have means we will be "making more blends for more markets. That complexity means more costs," says David Pursell, a partner at Pickering Energy Partners, <http://www.pickeringenergy.com/> a Houston brokerage.

There's a final point to be raised about ethanol: It contains only about two-thirds as much energy as gasoline. Thus, when it gets blended with regular gasoline, it lowers the heat content of the fuel. So, while a gallon of ethanol-blended gas may cost the same as regular gasoline, it won't take you as far.

What frustrates critics is that there are sensible ways to reduce our motor-fuel use and bolster renewable energy--they just don't help the corn lobby. Patzek points out that if we channeled the billions spent on ethanol into fuel-efficient cars and solar cells, "That would give us so much more bang for the buck that it's a no-brainer."

Correction, July 20, 2005: The article originally stated that ethanol critics David Pimentel and Tad Patzek received no oil-industry funding. Pimentel receives no such funding, but Patzek runs the UC Oil Consortium <http://petroleum.berkeley.edu/UCOil/structure.htm>, which does research on oil and is funded by oil companies. His ethanol research is not funded by the oil industry. Return <http://www.slate.com/toolbar.aspx?action=print&id=2122961#in> to the corrected sentence.

Robert Bryce <mailto:robert@robertbryce.com>, managing editor of World Energy Monthly Review, is the author of Cronies: Oil, the Bushes, and the Rise of Texas, America's Superstate <http://www.amazon.com/exec/obidos/tg/detail/-/1586483374/ref=lpr_g_1/103-3866961-2195062?v=glance&s=books&n=507846>, which was just released in paperback.

Article URL: http://www.slate.com/id/2122961/




Archive powered by MHonArc 2.6.24.

Top of Page