Spectroscopy and Spectral Analysis, Volume. 38, Issue 4, 1313(2018)

A Comparative Study on the Pyrolysis Characteristics of Direct-Coal-Liquefaction Residue Through Microwave and Conventional Methods

SONG Yong-hui*, MA Qiao-na, HE Wen-jin, TIAN Yu-hong, and LAN Xin-zhe
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    The pyrolysis of direct-coal-liquefaction residue (DCLR) was prepared using microwave and conventional pyrolysis. The composition and structure of solid coke, tar and gas were investigated and the pyrolysis products were compared after characterization by infrared spectroscopy (FTIR) and gas chromatography-mass spectrometry (GC-MS).Results showed that DCLR was rapidly heated up to 900 ℃ in 20 min with the maximum heating rate of 329 ℃·min-1 in the microwave field, while the heating rate of conventional heating was constant. Compared with conventional pyrolysis,coke yield decreased by 3% after microwave pyrolysis, whereas the tar and gas yields increased by 0.66% and 2.19%, respectively.After the pyrolysis of DCLR, the extracted compositions consisting of heavy oil(HS), as phaltene (A), and pre-asphaltene (PA) decreased significantly, while the content of tetrahydrofuran insolubles (THFIS) increased. The Soxhlet compositions of the solid coke did not evidently change compared with those after conventional pyrolysis, which indicated that the pyrolysis process of DCLR is mainly based on the conversion of HS, A and PA. After microwave pyrolysis,the intensity of the absorption peak at 3 437.6, 1 632 and 1 079.99 cm-1 on the infrared spectrum of the solid coke was significantly lower than that of conventional pyrolysis, which indicated that DCLR was more thoroughly pyrolyzed in the microwave field.Both tar and gas yields increased after pyrolysis, and the content of H2 in gas reached above 60%. The results of GC-MS showed that no obvious change in the composition for aliphatics, aromatics, alcohol and the contents of C1~5, C11~20 and C>20in tar was observed after extraction with petroleum ether. The asphaltene content of tar decreased by 7.7% after microwave pyrolysis, which indicated that microwave pyrolysis can effectively promote asphaltene decomposition in DCLR, which benefited tar conversion to light fraction.

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    SONG Yong-hui, MA Qiao-na, HE Wen-jin, TIAN Yu-hong, LAN Xin-zhe. A Comparative Study on the Pyrolysis Characteristics of Direct-Coal-Liquefaction Residue Through Microwave and Conventional Methods[J]. Spectroscopy and Spectral Analysis, 2018, 38(4): 1313

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    Paper Information

    Received: Mar. 14, 2016

    Accepted: --

    Published Online: Jun. 12, 2018

    The Author Email: Yong-hui SONG (syh1231@126.comIntroduction)

    DOI:10.3964/j.issn.1000-0593(2018)04-1313-06

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