Chin.J.Chem.Eng. ›› 2018, Vol. 26 ›› Issue (5): 1171-1178.doi: 10.1016/j.cjche.2017.11.002

• Energy, Resources and Environmental Technology • Previous Articles     Next Articles

Effect of industrial microwave irradiation on the physicochemical properties and pyrolysis characteristics of lignite

Guoshun Zhou1,2, Qunxing Huang1, Ben Yu1, Hui Tong3, Yong Chi1, Jianhua Yan1   

  1. 1 State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China;
    2 Everbright Environmental Research Institute(Nanjing) Limited, Nanjing 211100, China;
    3 Kunshan Jiuhua Electronic Equipment Factory, Suzhou, 215300, China
  • Received:2017-04-21 Revised:2017-11-09 Online:2018-05-28 Published:2018-06-29
  • Contact: Qunxing Huang,E-mail
  • Supported by:

    Supported by the National Natural Science Foundation of China (51621005) and the Fundamental Research Funds for the Central Universities (2017FZA4013).

Abstract: The surface functional groups and pyrolysis characteristics of lignite irradiated by microwave were comparatively studied to evaluate the feasibility of using industrial 915 MHz for lignite drying. The drying kinetics, micro structure, chemical functional groups, re-adsorption properties, and pyrolysis characteristics of the dried coal were respectively analyzed. Results indicated that for typical Chinese lignite studied in this paper, 915 MHz microwave drying was 7.8 times faster than that of the hot air drying. After industrial microwave drying, the sample possessed much higher total specific surface area and specific pore volume than that of air dried sample. The oxygen functional groups and re-adsorption ratio of microwave irradiated coal decreased, showing weakened hydrophilicity. Moreover, during the pyrolysis of the coal dried by hot air and microwave, the yield of tar largely increased from 1.3% to 8.5% and the gas production increased correspondingly. The composition of the tar was also furtherly analyzed, results indicated that Miscellaneous hydrocarbons (HCs) were the main component of the tar, and microwave irradiation can reduce the fraction of polycyclic aromatic hydrocarbons (PAHs) from 26.4% to 22.7%.

Key words: Lignite, Industrial microwave, Physicochemical properties, Pyrolysis characteristics