微波辐照木质素浸渍生物炭吸附CO_(2)性能  

Adsorption performance of CO_(2) on lignin impregnated biochar activated by microwave irradiation

作　　者：张学杨[1] 徐浩亮 戴欢涛 游新秀 韦赵龙 曹苓玉 ZHANG Xue-yang;XU Hao-liang;DAI Huan-tao;YOU Xin-xiu;WEI Zhao-long;CAO Ling-yu(School of Environmental Engineering,Xuzhou University of Technology,Xuzhou 221018,China)

机构地区：[1]徐州工程学院环境工程学院,江苏徐州221018

出　　处：《中国环境科学》2023年第8期4427-4436,共10页China Environmental Science

基　　金：江苏省自然科学基金资助项目(BK20201151);徐州市科技计划项目(KC21288)。

摘　　要：以木质素钙为前驱体浸渍生物炭并进行微波辐照活化获得浸渍生物炭.利用比表面积分析仪、SEM、FTIR、Raman等对生物炭进行表征,而后考察了生物炭吸附CO_(2)的性能.结果表明,浸渍生物炭的比表面积和微孔体积均随浸渍比的降低呈现先上升后下降的趋势,浸渍比过高会导致木质素钙团聚并堵塞生物炭孔隙,而少量木质素钙浸渍后会调变生物炭孔隙改善微孔结构.浸渍生物炭对CO_(2)的吸附量可达123.11mg/g,相关性分析表明比表面积和微孔体积是影响CO_(2)吸附的主要因素.动力学拟合结果显示吸附过程符合Avrami模型,表明CO_(2)吸附过程由物理吸附和化学吸附共同作用.等温线拟合结果显示当木质素钙浸渍量较少时吸附过程符合Langmuir模型,而提高浸渍比后则更符合Freundlich模型,表明适量木质素钙浸渍可以在生物炭表面形成更均匀的微孔吸附点位.循环实验发现,浸渍生物炭经10次连续吸附-脱附后仍保持98.22%~98.98%的吸附能力,表明其具有良好的重复使用性能.综上,微波辐照木质素钙浸渍生物炭是一种具有潜力的CO_(2)吸附剂.Calcium lignosulphonate was selected as precursor to impregnate the biochar and followed by the microwave irradiation to activate the impregnated biochar.The obtained impregnated biochar was characterized by surface area analyzer,SEM,FTIR and Raman,and then its CO_(2) adsorption ability was investigated.The results showed that both specific surface area and micropore volume of impregnated biochar increased with the decrease of impregnation ratio and then decreased.That was because too much lignin impregnation would block the original pores of biochar,while appropriate small amount of lignin impregnation would modulate and improve the micropore structure of biochar by entering its large size pores.The adsorption capacity of CO_(2) on impregnated biochar could reach 123.11mg/g,and correlation analysis demonstrated that it was influenced by both specific surface area and micropore volume.Kinetic study showed that the Avrami model fitted CO_(2) adsorption on biochar more accurately,indicating this adsorption process was dominated by physical adsorption and chemical adsorption.Adsorption isotherm fitting showed that Langmuir model fitted the CO_(2) adsorption well for the biochar with less lignin impregnation,while Freundlich model fitted the biochar with more lignin impregnation better.This indicated that appropriate small amount of lignin impregnation facilitated the formation of more uniform micropore adsorption sites on biochar.Reusability experiment showed that the adsorption capacity of impregnated biochar remained 98.22%~98.98% after 10 consecutive adsorptions-desorption cycles,indicating that it had excellent reusability.In a word,lignin impregnated biochar assisted with microwave irradiation could be a potential CO_(2) adsorbent.

关 键 词：生物炭 CO_(2)吸附 微波辐照 木质素 浸渍 

分 类 号：X511[环境科学与工程—环境工程]