Hydrogen-Rich Gas Formation Characteristics under Microwave Catalytic Pyrolysis of Sewage Sludge

Abstract

Microwave catalytic pyrolysis of sewage sludge were conducted on a single mode microwave reactor. The effects of CaO and steam on hydrogen-rich gas formation characteristics were analyzed. The results indicated that the CaO can improve the formation of H2and CO. When CaO in sewage sludge increased from 0 to 0.75 g/(g dried sludge), the H2and CO concentration increased from 62 vol.% to 77 vol.%, while CH4and CO2concentrations decreased from 28 vol.% to 9 vol.%. The steam can also improve the formation of H2and CO, with 1.59 g/min of the steam flowrate, the H2and CO concentration increased to the maximum of 81 vol.%, and the CH4and CO2concentration decreased to the minimum of 16 vol.%. When the steam gasification was coupled with the CaO catalyzing, the H2concentration can reach to 61 vol.%, which was 79.3% higher than the experimental conditions absent of steam and CaO.