不同原料制备的生物炭形貌结构及表面特性研究  

Microscopic Morphology and Surface Features of Biochars Derived from Different Raw Materials

作　　者：王彤彤[1] 王晓琳[1] 任志胜[1] 郑纪勇[1,2] 

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所黄土高原土壤侵蚀与旱地农业国家重点实验室,陕西杨凌712100

出　　处：《环境科学与技术》2017年第1期42-48,共7页Environmental Science & Technology

基　　金：国家自然科学基金项目(41571225);教育部基本科研业务费(QN2013077;2452015250)

摘　　要：选取槐树皮、锯末、苹果枝、玉米秸秆、杂木五种原料采用干蒸裂解工艺制备生物炭通过扫描电子显微镜(SEM)观察生物炭的形貌结构利用氮气吸附BET容量法,测定生物炭的比表面积和孔体积,获得吸附脱附等温线,根据吸附等温线计算BJH孔径分布并将5种生物炭的形貌结构和表面特性对比分析,以期为生物炭深入研究提供科学依据。结果表明;5种生物炭均表现为多孔结构,孔结构大小和形状各异;不同原料对生物炭的比表面积有影响,杂木生物炭的比表面积最大(17.807 m^2/g),苹果枝生物炭最小(1.674 m^2/g)。随着玉米秸秆、锯末、槐树皮、杂木生物炭的孔体积和孔径的减小,其比表面积依次增大;槐树皮、锯末、玉米秸秆生物炭的氮气吸附脱附等温线为Ⅲ型,属于结块形成,苹果枝、杂木生物炭为Ⅳ型;5种生物炭均在2~65 nm范围内孔径分布较宽,呈中孔和大孔。Five raw materials：Sophora japonica skin,sawdust,apple branch,corn stalk,and miscellaneous wood were selected for producing biochars through pyrolysis without oxygen supply.The microscopic morphology of biochar were characterized by SEM,the specific surface area and pore size distribution was measured using the method of BET with nitrogen adsorption,and the pore size distribution of BJH equation was investigated based on adsorption-desorption isotherms.The microscopic morphology and surface features of above-mentioned five kinds of biochar were comparatively analyzed in order to provide scientific basis for further study.Findings of the study revealed that five different kinds of biochar had their own porous structures in terms of size and shape,as well as specific surface area due to the different raw materials;the biochar derived from miscellaneous wood had the largest specific surface area（17.807 m2/g）,while the biochar derived from apple branch had the minimum（1.674 m2/g）;and with decreases of the pore volume and pore diameter of the biochars,the specific surface areas of them increased.In addition,the adsorption-desorption isotherms of three biochars（Sophora japonica skin,sawdust,corn stalk） was type Ⅲ belonging to agglomerate formation,on the other hand the biochars of apple branch and miscellaneous wood was type Ⅳ.The pore diameters of the five biochars ranged widely（2 to 65 nm）,featuring the size from mesopore to macropore.

关 键 词：生物炭 形貌结构 BET比表面积 孔径分析 不同原料 

分 类 号：X132[环境科学与工程—环境科学]