Comparative Study on Microwave Co-pyrolysis Products of Low-Rank Coal under CH_4 and N_2 Atmosphere

摘要

Microwave pyrolysis is a new research method for deeply processing of low-rank coal. This paper conducted comparative study on microwave co-pyrolysis products of low-rank coal under CH_4 and N_2 atmosphere, respectively. The composition and content of tar and bluecoke were analyzed by gas chromatography-mass spectrometry and fourier transform infrared spectrometer. The results indicated that compared with N_2 atmosphere, the yield of liquid products (tar and pyrolysis water) obtained under CH_4 atmosphere increased by 5.4 wt.%, whereas the bluecoke yield decreased by 3.0 wt.%; The content of S element in the bluecoke obtained under CH_4 atmosphere was less than 0.30 wt.% to meet Bluecoke Standard S-1 Grade, and the ash content was just 6.72 wt.% to meet Bluecoke Standard A-3 Grade. Furthermore, the content of -OH、C=C and -C=O functional groups in the bluecoke were higher; The alkanes and olefins compound content in tar obtained under CH_4 atmosphere were 9.1 wt.% and 7.9 wt.% higher than that under N_2 atmosphere, meanwhile, the aromatic hydrocarbons compound content was 35.5 wt.% lower than that under N_2 atmosphere.