(574b) Pyrolysis and Gasification Reactivity of Coal and Petcoke Under High Pressure Conditions

Nearly all gasification systems targeted for use in IGCC or chemical/fuel production systems operate at high pressures, sometimes exceeding 1000 psi. In order to better understand the processes by which gasification feedstocks are converted in high pressure systems, three fuels--a lignite coal, an eastern bituminous coal and petroleum coke--were subjected to a series of laboratory experiments. The objective of the study was to evaluate pyrolysis behavior and reactivity under high pressure conditions relevant for entrained-flow gasification applications. Pyrolysis tests were conducted in nitrogen using a high pressure wire mesh heater, which allowed fast heating rates (in excess of 1000 K/s) and pressures to 900 psi. Reactivity of the fuels was studied by thermogravimetric analysis under gasification conditions. This paper compares devolatilization behavior (e.g., volatiles and char yields) of the fuels under a variety of pressures and final temperatures. Gasification rates of chars formed from the fuels are also presented.