Catalytic gasification of coal using eutectic salts: reaction kinetics for hydrogasification using binary and ternary eutectic catalysts

摘要

A kinetic study of the hydrogasification of Illinois #6 coal was carried out using a ternary (43.5 mol percent Li_2CO_3-31.5 mol percent Na_2CO_3-25 mol percent K_2CO_3) and a binary (29 mol percent Na_2CO_3-71 mol percent K_2CO_3) eutectic system. Hydrogasification experiments were carried out in a high-pressure, high-temperature differential fixed-bed gasifier unit to evaluate the product inhibition effect of H_2 on the overall steam gasification kinetics. The overall gasification rate was found to decrease with an increase in the H_2 partial pressure. It was also found that starting with a smaller average particle size of sample gave higher overall gasification rates. A rate expression of the Langmuir-Hinshelwood type was then used to satisfy the experimental data at different H_2 partial pressures up to carbon conversion of 85-90 percent.