Hydrogen-Rich Gas Production from Microwave Pyrolysis of Sewage Sludge at High Temperature

Abstract

Microwave pyrolysis of sewage sludge was conducted in a single-mode microwave oven. The influencing effects of experimental factors, including particle size and moisture content of sewage sludge, pyrolysis temperature, and shape of microwave adsorber, on concentration of pyrolysis gas products were studied. The results indicated that with the decrease of particle size, the H2 concentration increased from 31 vol.% to 34 vol.%, and CO concentration increased from 17 vol.% to 22 vol.%. When the moisture content of sewage sludge increased from 0 to 83 wt.%, the H2 concentration increased from 32 vol.% to 42 vol.%, and the CO concentration increased from 20 vol.% to 31 vol.%. Compared with microwave adsorber in powder phase, the microwave adsorber in fixed structure can transform more volatile compounds to uncondensable gas, and the concentrations of H2 and CO were also slightly increased.