Chin.J.Chem.Eng. ›› 2016, Vol. 24 ›› Issue (6): 803-810.doi: 10.1016/j.cjche.2016.04.012

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Evolvement behavior of microstructure and H2O adsorption of lignite pyrolysis

Yingyue Teng, Shijun Lian, Quansheng Liu, Yuzhe Liu, Yinmin Song, Runxia He, Keduan Zhi   

  1. College of Chemical Engineering, Inner Mongolia University of Technology, Inner Mongolia Key Laboratory of Industrial Catalysis, Hohhot 010051, China
  • Received:2015-11-18 Revised:2016-03-06 Online:2016-06-28 Published:2016-07-12
  • Contact: Quansheng Liu
  • Supported by:

    Supported by the National Science Foundation of China (Nos. 21566029, 21566028 and 21266017).

Abstract: The effect of pyrolysis on the microstructure and moisture adsorption of lignite was investigated with low field nuclear magnetic resonance spectroscopy. Changes in oxygen-containing groups were analyzed by Fourier transform infrared spectroscopy (FTIR), and H2O adsorption mechanism on the surface of lignite pyrolysis was inferred. Two major changes in the pore structure of lignite char were observed as temperature increased in 105-200℃ and 500-700℃. Pyrolysis temperature is a significant factor in removing carboxyl and phenolic hydroxyl from lignite. Variation of ether bond content can be divided into three stages; the content initially increased, then decreased, and finally increased. The equilibrium adsorption ratio, content of oxygen-containing groups, and variation of pore volume below 700° were closely correlated with each other. The amount of adsorbed water on char pyrolyzed at 700℃ increased. Moreover, the adsorption capacity of the lignite decreased, and the adsorption state changed.

Key words: Lignite, Pore structure, Moisture adsorption, Oxygen-containing Groups