煤层气中CH_(4)/CO_(2)分离用椰壳活性炭的制备  

Preparation of coconut shell activated carbon used for separation of CH_(4)/CO_(2) in coal bed methane

作　　者：梁江朋 马博文 LIANG Jiangpeng;MA Bowen(Coal Chemistry Branch of China Coal Research Institute,Beijing 100013,China;Beijing Key Laboratory of Coal Based Carbon Materials,Beijing 100013,China;National Energy Technology&Equipment Laboratory of Coal Utilization and Emission Control,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,Beijing 100013,China)

机构地区：[1]煤炭科学技术研究院有限公司煤化工分院,北京100013 [2]煤基节能环保炭材料北京市重点实验室,北京100013 [3]国家能源煤炭高效利用与节能减排技术装备重点实验室,北京100013 [4]煤炭资源高效开采与洁净利用国家重点实验室,北京100013

出　　处：《洁净煤技术》2021年第3期254-261,共8页Clean Coal Technology

基　　金：国家重点研发计划资助项目(2018YFB0605604);国家科技重大专项资助项目(2016ZX05045-005)。

摘　　要：为解决煤层气中CH_(4)/CO_(2)分离用吸附剂的难题,以椰壳炭化料为原料,通过水蒸气活化工艺制备活性炭吸附剂,考察了活化温度、活化时间和改性剂添加量对变压吸附分离CH_(4)/CO_(2)性能的影响。结果表明,制备活性炭吸附剂最适宜的条件为:炭化温度600℃,活化温度800℃,活化时间30 min,改性剂添加量10%。最适宜的条件下制备的活性炭吸附剂对CH_(4)和CO_(2)的饱和吸附量分别为2.34 mmol/g和3.23 mmol/g,CO_(2)/CH_(4)平衡吸附分离系数可达到10.27,较不改性条件下平衡分离系数提高了190%,对CO_(2)/CH_(4)有良好的分离效果。随着活化温度的提高,CO_(2)/CH_(4)平衡吸附分离系数和CO_(2)和CH_(4)的吸附量均呈现先增加后降低的趋势,这是由于活化温度达到800℃后,活化温度反应速度显著增快,使微孔壁面容易烧穿形成中孔,甚至进一步形成大孔,活性炭吸附剂比表面积降低,微孔数量变少,吸附能力降低;随着活化时间的延长,CO_(2)/CH_(4)平衡分离系数和CO_(2)和CH_(4)的吸附量呈现先增加后降低的趋势,这是由于活化时间达到30 min后,更多的水蒸气和炭发生反应,使开始形成的微孔被烧穿,导致比表面积和微孔体积降低,对CO_(2)和CH_(4)的吸附能力也随之降低,对CO_(2)的吸附能力降低更明显;随改性剂添加量的增加,CO_(2)/CH_(4)平衡分离系数逐渐增加,CO_(2)和CH_(4)的饱和吸附量呈现先增加后降低的趋势,吸附剂对CO_(2)的吸附性能明显提高,对CH_(4)的吸附性能则明显降低。In order to solve the problem of adsorbents for the separation of CH_(4)/CO_(2) from coal bed methane,activated carbon adsorbent was prepared by steam activation process with coconut shell carbonized material as raw material.The effects of activation temperature,activation time and dosage of modifier on the separation performance of CH_(4)/CO_(2) by pressure swing adsorption were studied.The results show that the optimum conditions for preparation of activated carbon adsorbent are as follows:carbonization temperature is 600℃,activation temperature is 800℃,activation time is 30 min,dosage of modifier is 10%.Under the optimum conditions,the saturated adsorption capacity of the prepared activated carbon adsorbent for CH_(4) and CO_(2) is 2.34 mmol/g and 3.23 mmol/g respectively.The equilibrium adsorption separation coefficient is 10.27,which is 190%higher than that without modification.There is a good separation effect for CO_(2)/CH_(4).The CO_(2)/CH_(4) equilibrium adsorption separation coefficient and the adsorption capacity of CO_(2) and CH_(4) increase firstly and then decrease with the increase of activation temperature.This is because when the activation temperature reaches 800℃,the activation temperature reaction speed increases significantly,which makes the wall of the micropores easy to burn through to form mesopores,and even further form macropores.The specific surface area of activated carbon adsorbent decreases,the number of micropores decreases,and the adsorption capacity decreases.The CO_(2)/CH_(4) equilibrium separation coefficient and the adsorption capacity of CO_(2) and CH_(4) increase at first and then decrease with the extension of activation time.The reason is that after the activation time reaches 30 minutes,more water vapor reacts with the carbon to burn through the micropores,resulting in the decrease of the specific surface area and volume of the micropores,as well as the decrease of the adsorption capacity of adsorbent for CO_(2) and CH_(4),and the reduction of CO_(2) adsorption capac

关 键 词：煤层气 CH_(4)/CO_(2) 吸附剂 活性炭 制备 

分 类 号：TQ534[化学工程—煤化学工程]