Adsorption separation of CH4/N2 on modified coal-based carbon molecular sieve

• Published in: Separation and purification technology Vol. 218; no. C; pp. 130 - 137
• Main Authors: Yang, Zhiyuan, Wang, Dechao, Meng, Zhuoyue, Li, Yinyan
• Format: Journal Article
• Language: English
• Published: United Kingdom Elsevier B.V 01.07.2019; Elsevier
• Subjects: Adsorption separation; Breakthrough curve; Carbon molecular sieve; Coal-bed methane; Modification; Modification; Coal-bed methane; Adsorption separation; DBD; CMS; Carbon molecular sieve; Breakthrough curve; CBM
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2019.02.048

Simple description: The CMS samples were modified by two types of modification methods. One is impregnation modification with three different organic reagents and the other is low temperature plasma modification with different gas atmosphere as depicted in the graphical abstract. [Display omitted] •The carbon molecular sieves (CMS) were modified by two types of modification methods. One is impregnation modification with organic reagents and the other is low temperature plasma modification with different gas atmosphere.•The separation coefficient (3.3) of CH4/N2 was obtained for the CMS modified by low temperature plasma modification under nitrogen atmosphere. This value is higher than that of previous other reports.•The low temperature plasma modification for the CMS may supply a promising approach towards adsorption separation of CH4/N2. Coal-based carbon molecular sieves (CMS) were modified by organic reagents with affinities for hydrocarbons including tetracosane (C24), lauryl sodium sulfate (SDS), and polyethylene imine (PEI), and low temperature plasma treatment in a CH4 and N2 atmosphere, respectively. The modified CMS samples were characterized by FT-IR analysis, low-temperature N2 adsorption tests and SEM. In addition, the adsorption capacities of pure CH4 and N2 were measured by the static volume method and the CH4/N2 separation coefficients of the modified samples were also compared. The saturated adsorption capacities qm after modification and separation coefficients were investigated. CH4 was more strongly adsorbed on all the modified samples. The sample of CMS-P-N has the best modification effect and its saturated adsorption capacities qm were 6.76 mmol/g for CH4 and 5.56 mmol/g for N2, respectively. The separation coefficient of CH4/N2 of CMS-P-N was 3.32. Besides, CH4 breakthrough tests were performed using a fixed bed apparatus. The breakthrough curves confirmed that low temperature plasma treatment of CMS in an N2 atmosphere was beneficial for the adsorption separation of CH4/N2.