NONCOMBUSTIVE GASIFICATION OF KOH-IMPREGNATED FUEL SOOT OR ACTIVE-CARBON GRANULE

Selective conversion to useful syngas or methane of fuel soots impregnated with KOH was investigated in respect of air pollution or lowering engine efficiency. Reactant soot was prepared from propane gas and light oil fuel by flame incomplete combustion, and gasification of these soots was performed using flow type reactor (U tube) under atmospheric pressure. Water gas reaction or shift reaction of the KOH-impregnated soots exhibited much higher as well as more stable gas evolution rate on steam-helium mixture stream than that of active carbon granule as reference carbon (550-700-degrees-C). Gasificated products from these soot/KOH by steam were largely H-2, CO, CO2 and small amount of CH4 (under 1%). It was found that the light oil-soot interacted strongly with KOH gave higher carbon consumption rate (138 g.l-1.h-1 at 650-degrees-C) as compared with that of gasoline fuel-soot (70 g.l-1.h-1 at 650-degrees-C). Impregnation with KOH caused soot to promote increase in the surface area at elevated temperature and to catalyze water gas reaction. The results presented on the products distribution and the gasification rate suggest that reduction-oxidation cycle of potassium was caused by the contact of carbon with water molecules at the elevated temperature. From the results of water gas reaction on K2CO3-impregnated soot and XRD it was infered that the gradual deactivation of KOH in the gasification of soot was due to the formation of K2CO3.