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Surface Modification of Bituminous Coal and Its Effects on Methane Adsorption
Author(s) -
Feng Yanyan,
Yang Wen,
Liu Daijun,
Chu Wei
Publication year - 2013
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201300215
Subject(s) - chemistry , adsorption , x ray photoelectron spectroscopy , methane , titration , coal , nitrogen , langmuir equation , inorganic chemistry , langmuir adsorption model , volume (thermodynamics) , langmuir , oxygen , chemical engineering , organic chemistry , thermodynamics , physics , engineering
This paper studied the role of O ‐containing groups over the coal surface in methane adsorption. The coal was modified with H 2 SO 4 , (NH 4 ) 2 S 2 O 8 or H 2 SO 4 /(NH 4 ) 2 S 2 O 8 ), respectively, to introduce O ‐containing functional groups, and characterized by proximate analysis, ultimate analysis, Boehm titration, X‐ray photoelectron spectroscopy (XPS) and nitrogen adsorption. The results of ultimate analysis, Boehm titration and XPS indicate that there were increases in terms of both the content of oxygen and the quantities of O ‐containing groups over the modified coals surface, especially for the carboxyl. Nitrogen adsorption shows that the modified coals possessed higher surface area and pore volume than that of 0‐XQ. The methane adsorption data were measured at 298 K at pressures up to 4.0 MPa by the volumetric method and fitted well by Langmuir model. Experimental results implied that O ‐containing groups and pore structure affected methane adsorption. The adsorption capacities decreased as increasing quantities of O ‐containing groups.