Methane Sorption on Brown and Sapropelite Coals

摘要

Based on the results of IR-spectroscopic and gas-chromatographic analysis, the release and absorption of methane on the modification of Kizelovsk brown coal, Barzas sapromixite, and Balkhash alg-inite was considered. The dispersion of strong bulk aggregates of brown coal to particles of size 0.1-1.2 mm resulted in the release of methane; the process was enhanced as the temperature was increased from-35 to 200℃. Brown coal particles became incapable of generating CH_4 and intensely chemisorbed it as the coal matter became alkylated and esterified by methanol vapor at 67℃. This transition occurred under mild conditions in a laboratory experiment without the use of special catalysts at comparatively small CH_3OH additives to brown coal (no more than 1.5 ml/g). Brittle particles of flag barzassite and rubberlike balkhashite did not generate methane; however, they changed from initially slow physical adsorption of CH_4 in native particles to intense chemisorption upon interaction with methanol at 67℃ (to 0.3 ml of CH_3OH per gram of balkhashite and to 1.2 ml per gram of barzassite).