Construction begins on large-scale biofuels plant
COLLEGE STATION, Texas - More affordable gasoline prices could potentially be on the way now that construction has begun on a demonstration-scale facility that will further validate a Texas A&M process that transforms biomass into liquid fuels. By September, the facility is expected to be operational in Bryan, Texas. It will test the "MixAlco" technology developed by Professor Mark T. Holtzapple and Research Engineer Cesar B. Granda, both in the Artie McFerrin Department of Chemical Engineering at Texas A&M. "This demonstration plant is a major step towards relieving our nation's dependence on expensive imported oil," Holtzapple said. The MixAlco technology can commercially make cellulosic ethanol and renewable gasoline, said a representative from Terrabon, LLC, the company that holds the license to the technology. It accomplishes that by transforming biomass - trees, grass, manure, sewage sludge, garbage, agricultural residues and non-food energy crops - into mixed alcohols that can be blended into gasoline. Using additional steps, the alcohols can be converted into gasoline that is nearly identical to that which is derived from crude oil, Holtzapple explained. For three years, testing has been underway at a smaller pilot plant in College Station. The pilot plant can process up to 100 pounds per day of biomass feedstocks, such as paper wastes and even chicken manure. The tests, Holtzapple said, have been so successful that the process is now ready to be validated at a larger scale. And that's exactly what the new, larger demonstration plant will do, moving the entire process a step closer to commercial feasibility. The demonstration plant will have a loading capacity of 400 tons of biomass, which equates to a digestion rate of five tons per day, stated a Terrabon representative. Sorghum will be the primary feedstock utilized. Current plans call for the process to run in 80-day cycles. "With construction of this facility, we are one step closer to bringing cost effective, renewable energy products to consumers," said Gary W. Luce, Terrabon¿s Chief Executive Officer. "Using municipal solid waste as a feedstock at a price of $10 per ton, we believe this technology can produce fuel-grade ethanol for $1.00 per gallon and renewable gasoline for $1.65 per gallon for a facility processing around 300 tons per day of municipal solid waste." In the process, which has been developed during the last 17 years by Holtzapple and Granda, biomass feedstock is treated with lime and then fermented to form organic salts. Water is removed and the mixture is then heated to form ketones - which are commonly used solvents, such as nail polish remover. At an oil refinery, hydrogen is added to the ketones to form mixed alcohols, which are then combined with existing gasoline before being transported. Unlike ethanol, which cannot be transported through pipelines because of its tendency to absorb water, mixed alcohol can be transported via pipelines to gas stations throughout the country. A key aspect of the MixAlco process that differentiates it from more costly alternatives is its ability to rely on naturally occurring soil organisms to digest the biomass, Holtzapple said. This means that the MixAlco process doesn't require the often costly sterile environments needed by other methods that utilize genetically engineered organisms, he explained. In addition, the alcohol-based fuels produced from the crops used by the MixAlco process are more productive in terms of net energy per acre than the well-publicized method that involves utilizing corn to produce ethanol, Holtzapple said. In lay terms, this means less land is required to grow feedstocks. Per acre, farmers can grow two to 10 times more energy crops than if they were growing corn, he said. What's more, Holtzapple says his process is environmentally friendly. The combustion of biofuels doesn't contribute to global warming because no net carbon dioxide is released into the atmosphere, he explained. Any carbon dioxide that is released is recycled through photosynthesis, unlike what occurs during combustion of fossil fuels. And there is less potential to damage ground water because less waste is being stored in landfills. In addition, the energy crops that the process uses require less fertilizer, pesticides, and herbicides than do traditional crops such as corn, Holtzapple added. Terrabon, LLC was organized in 1995 to commercialize three technologies that share the same suite of patented intellectual property developed at Texas A&M University. Terrabon plans to deliver this cutting-edge technology via licensing the three processes.