Integrated Process of Coal Pyrolysis with CO₂ Reforming of Methane by Dielectric Barrier Discharge Plasma

A novel method to increase the tar yield through an integrated process of coal pyrolysis with CO 2 reforming of methane by dielectric barrier discharge plasma was put forward. The pyrolysis of Shenmu (SM) subbituminous coal was carried out under different atmospheres, including N 2, H 2, and different plasmas of H 2, CH 4, CH 4 /H 2, CO 2 /H 2, and CH 4 /CO 2 /H 2 (1/1/2, MG) to check the effect of the integrated process on improving the tar yield. Two kinds of coal samples, SM and Huolinhe (HLH) lignite were used in the integrated process to investigate the effects of gas flow rate, pyrolysis time, H 2 composition in the mixed gas (CH 4 /CO 2 /H 2 ), and discharge power on product yields. The results showed that the effect of different atmospheres on increasing the tar yield generally has the following order, especially at the temperature range 400–500 °C: MG plasma > CH 4 plasma ≈ CH 4 /H 2 plasma ≈ CO 2 /H 2 plasma > H 2 plasma > H 2 > N 2 . The tar yield of SM coal pyrolysis under MG plasma at the discharge power of 40 W for 7 min is about 2.0 and 1.8 times as that under N 2 and H 2 at 400 °C, respectively.