The synergistic mechanism on microwave and MoS2 in coal pyrolysis

Microwave pyrolysis has been widely studied as a new type of coal thermal processing. In this research, we applied different amounts of MoS2 to the coal microwave pyrolysis and observed the consequent product effects to see if a higher pyrolysis efficiency and tar quality can be achieved. The catalytic action of MoS2 in solid, liquid, and gas products was further studied using both conventional and microwave pyrolysis, and a synergistic mechanism of microwave and MoS2 for coal pyrolysis was proposed. In a self-developed coal-gas microwave co-pyrolysis system, Proximate and ultimate analysis methods, X-ray diffraction, Scanning electron microscopy, Energy dispersive spectrometry, Fourier transform infrared spectroscopy, Gas chromatography-mass spectrometry and Gas analyzer were all employed to test and analyze pyrolysis products. The experimental results showed that when the amount of MoS2 was 8.3%, in microwave pyrolysis, the yield of liquid product was 28.4% with the light oil yield of 67.55%, and the yield of hydrogen was 22.19%. Compared with conventional pyrolysis, conventional pyrolysis with 8.3%MoS2 and microwave pyrolysis, a tighter structure of solid product, a higher yield of liquid product with an obvious light oil content increase could be obtained. The content of hydrogen in gas product decreased, while the valuable content of gas (CH4+CO+H2) and calorific value increased. The contrast experiments of coal pyrolysis showed that there was a synergetic effect of microwave and MoS2, and it improved the coal pyrolysis efficiency and tar quality.