Experimental investigation on methanation reaction based on coal gasification in supercritical water

• Published in: International journal of hydrogen energy 2017-02, Vol.42 (7), p.4636-4641
• Main Authors: Hui, Jin, Xiao, Zhao, Liejin, Guo, Chao, Zhu, Changqing, Cao, Zhenqun, Wu
• Format: Article
• Language: English
• Subjects: Coal; Methanation; SNG; Supercritical water gasification; Synthetic natural gas
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2016.06.216

Supercritical water gasification is a promising technology because it can convert coal into H2 and CO2 which has potential for CH4 production. In order to obtain the optimal operating parameter for methane production, experimental investigations were conducted in the typical operating parameters: reaction temperature 380–520 °C, reaction residence time 6–10 min with different type of Raney-Ni. Gas mixture with volume ratio of 4:1 of H2 and CO2 as a typical production of coal gasification in supercritical water was used as feedstock. The experiments results showed that Raney-Ni 4110 has the best performance in the methanation reaction and 400 °C reaction temperature and long residence time favored CH4 production. Based on the obtained optimal operation parameter, one-step CH4 production by Hongliulin gasification in one reactor with certain residence time at 400 °C was conducted. The results showed that one-step coal gasification was an efficient way to produce a high yield of CH4, and carbon gasification efficiency above 99% was achieved. [Display omitted] •SNG production by methanation of H2 and CO2 in SCW was investigated.•SCW was proved to be a good environment for methanation reaction.•400 °C reaction temperature and 4110 Raney-Ni favored CH4 production.•One-step methanation from coal gasification in on SCW reaction was tried.•Long residence time favored CH4 production and the yield was about 10 mol/kg.