一种新的颗粒炭材料的制备及其高效分离甲烷氮气性能  

Preparation of new granular carbon material and its efficient separation of methane and nitrogen

作　　者：戴琼斌 刘宏斌 夏启斌[1] 周欣[1] 李忠[1] DAI Qiongbin;LIU Hongbin;XIA Qibin;ZHOU Xin;LI Zhong(School of Chemistry and Chemical Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China)

机构地区：[1]华南理工大学化学与化工学院,广东广州510640

出　　处：《化工学报》2021年第8期4196-4203,共8页CIESC Journal

基　　金：国家自然科学基金项目(21978099)。

摘　　要：主要围绕从低品位煤层气中回收分离低浓度的CH_(4)这一重要需求,探索以生物质为碳源研制具有优良CH_(4)/N_(2)分离性能的颗粒炭吸附剂。选择大米碎粒作为碳源,通过碳化制备颗粒状炭前体,然后应用CO_(2)进行活化,制备出大米基颗粒炭材料(GRCM),研究其吸附分离CH_(4)/N_(2)的性能。所制得的颗粒炭材料具有较窄微孔分布,其中样品GRCM-900的BET比表面积为938.529 m^(2)/g。FT-IR分析结果显示大米基颗粒炭表面含有羟基及羰基等含氧官能团。其CH_(4)吸附容量和CH_(4)/N_(2)吸附选择性分别高达1.32 mmol/g和5.68(在298 K和100 kPa条件下),优于大多数已报道的粉末状炭材料和MOF材料。分子模拟揭示了甲烷和氮气在GRCM炭材料狭缝孔道中的吸附构型和差异。固定床实验证实,应用GRCM炭材料可以在常温条件下有效地分离CH_(4)/N_(2)混合物,所制得的颗粒GRCM在从低品位煤层气中回收CH_(4)方面有很好的应用前景。Focusing on the important need for the recovery and separation of low-concentration CH_(4)from low-grade coalbed methane,it mainly explores the development of granular carbon adsorbents with excellent CH_(4)/N_(2)separation performance using biomass as a carbon source.Granular rice grains were chosen as carbon source to prepare granular rice-based carbon materials(GRCM)by carbonization and then CO2 activation.The resulting granular carbon material exhibited a relatively narrow micropore distribution,and its BET specific surface area reached 938.529 m2/g.FT-IR analysis results show that the surface of rice-based granular carbon contains oxygen containing functional groups such as hydroxyl and carbonyl groups.The CH_(4)adsorption capacity and CH_(4)/N_(2)adsorption selectivity of the sample GRCM-900 are as high as 1.32 mmol/g and 5.68(298 K and 100 kPa),respectively,comparable to most of the reported powdered carbon materials and MOF.Molecular simulation revealed the different contributions of surface hydroxyl/carboxyl/aldehyde groups of GRCM to the adsorption selectivity of CH_(4)/N_(2),and the mechanism of methane and nitrogen adsorption in the slit pores of GRCM.Fixed-bed experiments confirmed that the application of GRCM carbon materials can effectively separate CH_(4)/N_(2)mixtures at normal temperature,and the prepared granular GRCM have potential application prospects in recovering CH_(4)from low-concentration CH_(4)coal mine gas.

关 键 词：多孔颗粒炭 煤层气 吸附等温线 选择性 甲烷 氮气 

分 类 号：TQ028.1[化学工程]