Charring Peanut Shells for Hydrogen Fuel

By Don Comis
August 25, 2004

Donald C. Reicosky, an Agricultural Research Service soil scientist at the North Central Soil Conservation Research Laboratory in Morris, Minn., has teamed up with an inventor of a patent-pending process to turn agricultural biomass—wastes like peanut shells—into hydrogen fuel and charcoal fertilizer. The inventor, Danny Day, president of Eprida, Inc., a technology and development company in Athens, Ga., has also joined forces with U.S. Department of Energy scientists who hold a patent on a related technology.

Volatiles and steam released by charring biomass produce hydrogen. The charring turns the biomass into charcoal pieces. This charcoal becomes a nitrogen-enriched fertilizer with the addition of ammonia formed by combining a third of the hydrogen with nitrogen. The remaining hydrogen can be sold as fuel, both for a hydrogen-based, clean diesel and to run fuel cells.

This morning, at the American Chemical Society's 228th national meeting, in Philadelphia, Pa., Day made a presentation [view abstract] on the fuel production. Tomorrow, he will discuss the charcoal's fertilizer value [view abstract]. The porous charcoal potentially gives soil microbes an improved environment for nutrient cycling. If the charcoal were used as a scrubber in the smokestack of a coal-burning power plant to remove carbon dioxide, it could then become more valuable as an ammonium bicarbonate nitrogen fertilizer.

Reicosky has devoted the past decade to measuring tillage-induced carbon loss and improving soil carbon storage. His interest in Eprida's technology lies in the fact that this is a biomass technique that returns a large portion of harvested carbon to the soil, since plants are not completely burned.

Reicosky used his knowledge of soil carbon and agriculture to help Day with the original concept and continues to help in many ways, including measuring yields of corn fertilized with the charcoal. The charring process has been tested successfully in both the laboratory and in a pilot plant, and will soon be tested on a larger scale—generating a renewable fuel for University of Georgia buses.

ARS is the U.S. Department of Agriculture's chief scientific research agency.