Investigation on the reforming reactions of coke-oven-gas to H2 and CO in oxygen-permeable membrane reactor

Abstract

The reaction mechanisms for the reforming of coke oven gas (COG) and partial oxidation of methane (POM) to H2 and CO in Ba1.0Co0.7Fe0.2Nb0.1O3−δ (BCFNO) membrane reactor packed with NiO/MgO catalyst were investigated through designing experiments and test of oxygen permeation. The results indicated the direct partial oxidation mechanism was the dominant mechanism of POM process in BCFNO membrane reactor. The H2 in COG was proven to have an important effect on the oxygen permeation. The packing amount of catalysts in catalyst bed has little effect on oxygen permeation, while it has obvious effects on CO and H2 selectivity. Then the reaction mechanism was proposed. The H2 in COG adsorbs and reacts with the permeated oxygen to form H2O. Simultaneously the CH4 dissociates over Ni0 sites to form hydrogen and surface active carbon. The formed hydrogen reacts with oxygen to give H2O again. The remained CH4 was converted to H2 and CO by reforming with produced H2O in catalyst bed. Based on the reaction mechanism, the author had given a permeation-reforming tubular membrane reactor configuration for the COG conversion to hydrogen. The permeation-reforming reactor shows promise for scale-up of the reforming of COG.