Opening of the world’s first commercial cellulosic ethanol plant is slated for this fall in northern Spain, even though costs of producing alcohol fuel via the emerging technology are still estimated to be about 50%-100% higher than that for plants which use grain as a feedstock.
The Ontario-based SunOpta BioProcess Group (formerly Stake Technology), a division of SunOpta Inc. (STKL), announced last week that plans for start-up of a wheat straw-to-ethanol plant near Salamanca, Spain, are proceeding on schedule.
The facility, which represents the first commercial cellulosic ethanol production plant on the planet, is being supplied to Abener Energia S.A. of Seville, Spain, a wholly-owned subsidiary of Abengoa S.A. (ABG.MC). Abengoa is the largest ethanol producer in Europe, the second largest in the world, and operator of a research and development division in St. Louis.
The Spanish facility, which is scheduled to be operational in the fall of 2006, is located adjacent to a cereal grain-to-ethanol plant operated by Abengoa, which is currently coming on-line. Manufacturing of major equipment for the cellulosic module is currently being completed and will be shipped to site in coming weeks.
Although President George W. Bush revived a 60-year-old idea of using alcohol fuel drawn from “wood chips and stalks, or switchgrass,” to replace foreign oil during his State of the Union address last week, it turns out very little of the world’s energy is actually being produced via the technology thus far.
Small research facilities focused on cellulosic ethanol have intermittently been in operation or are in development in several U.S. states – such as Louisiana, California, Idaho and Nebraska. The only other factory on earth that currently generates energy from the breakdown of plant fibers, rather than sugar, or sugar derived from grain starches, is a demonstration facility operated by the Iogen Corporation in Ottawa, Canada.
Industry experts estimate that the Iogen facility produces about 200,000 gallons of ethanol from straw annually, as opposed to the 54 million gallon capacity planned for the forthcoming Spanish plant.
Although Brazil has successfully replaced 45% of its gasoline with fuel alcohol since about 1990, experts point out that all Brazilian-produced ethanol is currently derived from the simple fermentation of sucrose, rather than cellulose from cane stalks or other fibrous materials.
Sugar cane juice is simply squeezed from cut stalks and fermented by yeast into ethanol. The waste cane stalks, known as bagasse, are burned as fuel to provide the power plant with energy for the process.
By contrast, U.S. ethanol manufacturers utilize starch from feedstock, such as corn, grain sorghum or wheat, which must be converted into sugar using enzymes, for the ultimate fermentation into ethanol by simple yeast.
Cellulosic ethanol production involves a highly technical three-step chemical process which begins by extracting the cellulose from biomass – such as corn stalks, rice straw, wheat straw, switchgrass, corn fiber, soy fiber and the like – which is basically glued together with a tough compound known as lignin.
To produce ethanol, the cellulose must first be “unglued” using a pre-treatment process, such as dilute acid hydrolysis, autohydrolysis, or ammonia fiber explosion. The cellulose is then converted to sugar using special enzymes costing 500% to 1,000% more than those commonly needed to process starch. The resultant sugar is then fermented into cellulosic ethanol utilizing a genetically modified form of yeast.
Estimates concerning the cost of producing ethanol via this process vary widely.
“Most viewers see present cost of cellulose ethanol as around $3.50 per gallon – double cost from carbohydrate,” said Harrison Cooper president of the Bountiful Applied Research Corporation in Bountiful, Utah. “There has been mention (that) cellulose enzyme/fermentation costs might be (reduced) to as low as $1.30, but this is based on hopeful conjecture.”
Murray Burke, vice president and general manager of SunOpta’s BioProcess Group, disagrees with those figures, estimating that modern grain alcohol plants being built today may have a breakeven as low as 90-95 cents per gallon, compared to a cost-of-production which likely ranges from $1.40-$1.60 per gallon for a commercial-scale cellulosic facility, such as the Spanish plant.
Nevertheless, mere mention of the technology by Bush has given further impetus to the biomass ethanol industry, which was first developed by the U.S. during World War II and was already under active development in Europe.
“Every single country in Europe is looking into this,” said Burke. “Energy security, greenhouse gas emissions and an eventual limit on corn and grain-based ethanol supply are all contributing to the push for cellulosic ethanol. We are seeing unprecedented interest in our (cellulose) pretreatment technology in the United States, Canada, Europe and Asia.”
Although no economically viable method has yet been found to directly integrate the usage of corn residue, or stover, into the U.S. ethanol-making process, Cooper points out, “a study is under planning in Nebraska on making paper mill fiber from chemically pulped stover – a process known to be practical – with the waste biomass from pulping used as power plant fuel for both ethanol and pulping operations.”
Cooper says if documented as a profitable enterprise, this approach should become attractive to corn-based grain ethanol producers as means of utilizing corn stalks – which currently have little value, apart from low-quality livestock forage – as an independently marketable product, providing a cheap fuel comparable to bagasse in Brazil.
Source: Agriculture Online Feb. 08, 2006.