INFLUENCE OF PYROLYSIS CONDITIONS AND ION-EXCHANGED CATALYSTS ON THE GASIFICATION OF COTTONWOOD CHARS BY CARBON-DIOXIDE

Wood chars of heat treatment temperature 800-1000 degree C were gasified in carbon dioxide at 800 degree C. Chars were prepared from untreated black cottonwood and from wood treated with gasification catalysts, primarily by ion exchange on cell wall carboxylic acid groups. Catalyst treatments were carried out on wood from which the indigenous mineral matter was removed by acid washing (ash-free wood) to avoid complications of interfering catalytic effects. Catalysts were selected to represent the significant inorganic constituents of wood as well as more active gasification catalysts, such as the transition metals. The results of chemical analysis and gasification rate determinations indicate that calcium is the dominant catalytic species controlling the gasification of the untreated wood.