Effects of Hydrothermal Dewatering on Kinetics and Mechanism of Brown Coals Pyrolysis

Abstract:

Two brown coals from China were dewatered under hydrothermal dewatering (HTD) conditions at 250–320 °C for 1 h in a 2 L autoclave. The HTD products and brown raw coals were pyrolyzed in a thermogravimetry analyzer at heat rate of 15°C/min from ambient temperature to 800°C. And the gas products were measured by Fourier Transform Infrared Spectrometer. Besides, The Coast-Redfern model was employed to analyze the effects of HTD on kinetics during coal pyrolysis process. The results showed that the initial temperatures of each pyrolysis stage of HTD products were higher than that of raw coals. The temperatures at which methane appears during pyrolysis process increased and the total absorbance intensity of CH4 was weakened as increasing HTD temperature. Moreover, the activity energy also increased as increasing HTD temperature. It meant that thermal stability of brown coals was improved during HTD process.

• Periodical: Advanced Materials Research (Volumes 614-615)
• Pages: 53-58
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.614-615.53
• Online since: December 2012
• Authors: Jian Zhong Liu, Yu Jie Yu, Fu Yan Gao, Ya Xuan Hu, Jun Hu Zhou, Ke Fa Cen
• Keywords: Brown Coal, Hydrothermal Dewatering, Kinetic, Pyrolysis

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