King Midas of agricultural wastes
Whether it’s cornstalks, switchgrass, or hybrid poplar, Robert Brown, Professor of ME and ChemE, and Director of the Center for Coal and the Environment (CfCE), turns plant wastes into proverbial gold
He has developed a gasifier that uses solid agricultural wastes to produce a gaseous fuel for use in internal combustion engines, gas turbines, and fuel cells. Moreover, the gasifier is a learning lab for students and is technology that can be transferred to industries in this country and overseas. 
To turn plant wastes to fuel, Brown uses a fluidized bed filled with sand and agitated by a stream of air. Although the actual reactor vessel is small—8 inches in diameter—400 pounds of biomass can be processed through the huge material handling system in an hour.
In addition, the gasifier can be run intermittently. After plant material is injected and gasified, the gasifier can be shut down. The whole bed slumps and becomes a huge insulator with heat stored in the center, like a giant Thermos™ bottle.
Graduate and undergraduate students learn the ropes on a large unit like they would find in industry. “We think the opportunity to work with large equipment gives them a better perspective on the kinds of systems they will work with after graduating,” says Brown. In the United States, the impetus for using a gasifier is to get rid of waste products; e.g., Pioneer Seed Company is exploring the use of such a gasifier to transmute piles of cornhusks and cobs to energy, a potentially advantageous byproduct.
Internationally there’s a different perspective. The Henan Province in China, for example, is rich in biomass materials but lacks gaseous fuels for cooking. A delegation came to Iowa State to discover if Brown’s gasifier would meet their needs, and an agreement has been signed.
For Brown, the gasifier project has allowed him to fulfill his center’s three goals: to help internationalize the university, transfer technology, and promote sustainable development. In the process, he is collaborating with other departments in the engineering and agricultural colleges and with the U.S. Department of Energy.
Brown’s research will soon move from the ISU campus to the Biomass Energy Conversion (BECON) facility being built in Nevada, Iowa, by the Iowa Energy Center. This new facility will showcase a variety of biomass energy conversion systems, including the biomass gasifier developed by Brown. |
