Thursday, November 02, 2006
Ethanol: more costly, less efficient
Costs Limit Bigger US Move to Biomass Ethanol
CHICAGO - Scientists have developed ways to make ethanol from corn stalks, switchgrass, wood chips and other plant materials, but high production costs and lack of easy access to those materials have slowed the technology's move to widespread commercial use.
In the United States, Ethanol is made primarily from corn, but industry experts have said waste materials from agriculture or forestry could be a cheaper alternative in the future.
"Some (corn-based) ethanol plants are not getting built because people are worried about corn supply. Do you think you would really want to fund a biomass plant because then you're really going to be worried about feedstock supply," said Martha Schlicher of Renewable Agricultural Energy, Inc.
"The minute we start to pay for those biomass feedstocks, the cost of those biomass feedstocks is going to go up," said Schlicher, the vice president of operations and engineering.
She was attending a conference on cellulosic ethanol that discussed issues such as the investment climate, challenges in commercialization and the crucial next steps in the sector.
The US Department of Energy has estimated the cost of producing a gallon of cellulosic ethanol is about US$2.20 per gallon, about twice the cost of producing ethanol from corn.
In his State of the Union address in January, President George W. Bush said the best way to break America's addiction to foreign oil was through the development of new technology to provide more reliable and cheaper alternative fuels.
But efficient harvest and delivery of feedstock materials such as switchgrass, wood chips, or agricultural waste is crucial for a plant's profitability, experts said.
Many investors have been reluctant to finance the new plants, which are costlier than current corn-based plants due to the extra steps needed to break down cellulose into sugars before they can be processed into ethanol.
Farmers have a narrow window to harvest corn for grain. A second harvest to cut stalks and leaves would not only take more time but could hurt future yield potential by compacting soils and removing potential nutrients, Schlicher said.
For other cellulosic feedstocks such as switchgrass or wood biomass, the machinery needed to harvest and compact those materials for shipment, then move them from fields to plants is still being developed and streamlined, the experts said.
MOVING FROM LABORATORY TO REAL WORLD
Scientists have been able to produce cellulosic ethanol from numerous feedstock sources in smaller pilot plants under nearly ideal conditions, the experts said. But making the technology work on a much larger scale, and thus making it a profitable enterprise, remains a key challenge, they said.
"Enzymes work really, really well at the pilot scale or the lab scale," said Jeff Passmore, executive vice president of Iogen Corporation, which plans to open a cellulosic ethanol plant in Idaho using barley straw as its main feedstock.
"But when you put them into the industrial scale and you're bringing in pounds and pounds of straw from farmer's fields, with all the intruders you expect to find in a bale of straw, like dirt, dead mice, whatever... they have to design a more robust enzyme," he said.
Investors are hesitant to build the high-cost cellulosic facilities until large-scale plants are proven to be profitable, although cellulosic ethanol production costs have fallen by more than half in the past five years.
Genetic engineering will most likely be utilized to produce crops that grow faster and in less ideal conditions, with more plants per acre to push the upper yield limits in the future.
"In real estate they say the three most important things are location, location, location. In a business such as this the three most important things are yield, yield, yield," said Charles Wyman, professor of Chemical and Environmental Engineering at the University of California at Riverside.
Story by Karl Plume
Story Date: 2/11/2006