title: [Surface characteristics of alkali modified activated carbon and the adsorption capacity of methane].
abstract: Coconut shell based activated carbon was modified by alkali with different concentrations. The surface structures of tested carbons were observed and analyzed by SEM and BET methods. Boehm's titration and SEM/EDS methods were applied to assay the functional groups and elements on the carbon surface. The adsorption of methane on tested carbons was investigated and adsorption behavior was described by the adsorption isotherms. Results showed that surface area and pore volume of modified carbon increased and surface oxygen groups decreased as the concentration of the alkali used increased, with no obvious change in pore size. When concentration of alkali was higher than 3.3 mol x L(-1), the specific surface area and pore volume of modified carbon was larger than that of original carbon. Methane adsorption capacity of alkali modified carbon increased 24%. Enlargement of surface area and pore volume, reduction of surface oxygen groups will benefit to enhance the methane adsorption ability on activated carbon. Adsorption behavior of methane followed the Langmuir isotherm and the adsorption coefficient was 163.7 m3 x mg(-1).
authors.affiliation: Department of Water Pollution Control Technology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. zhangmengzhu@yahoo.cn
authors.forename: Meng-Zhu
authors.initials: MZ
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Jun-Xin
authors.initials: JX
authors.lastname: Liu
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Sun
authors.forename: Guo-Bin
authors.initials: GB
authors.lastname: Li
mesh_terms: D000327:Adsorption; D000468:Alkalies / Q000737:chemistry; D002606:Charcoal / Q000737:chemistry*; D004785:Environmental Pollutants / Q000737:chemistry / Q000302:isolation & purification*; D008697:Methane / Q000737:chemistry / Q000302:isolation & purification*; D013499:Surface Properties
chemical_list: D000468:Alkalies; D004785:Environmental Pollutants; D002606:Charcoal; D008697:Methane