Integrated process of coal pyrolysis with CO2 reforming of methane by spark discharge plasma

Abstract

An integrated process of coal pyrolysis with CO2 reforming of methane by spark discharge plasma was developed to improve the tar yield of coal pyrolysis. The effects of the reactor configuration parameters and the integrated process conditions were investigated. It was found that the conversions of CH4 and CO2 and the selectivies of H2 and CO increase with the discharge input power. The electrode with a large- diameter and long discharge gap are unbeneficial to conversion of CO2 and CH4. The reaction temperature has little effect on the conversion of reaction gases. In the integrated process, the tar and water yields increase with the pyrolysis temperature and holding time. The pyrolysis atmosphere remarkably influences the tar yield. Compared with the pyrolysis under N2 (Py-N2) or the mixture gas of CO2 and CH4 (Py-MG), the integrated process of CO2 reforming of CH4 with coal pyrolysis can produce more tar, which is ascribed to the interaction of activated CH4 by spark discharge plasma with the free radicals from coal pyrolysis. The tar yield is 1.4 times as Py-MG, and 1.5 times as Py-N2 at the pyrolysis temperature of 550°C.