炭活化一步法制备豆渣基极微孔活性炭  

Preparation of N-doped ultramicropore-containing active carbons from waste soybean dreg by one-step carbonization/activation

作　　者：李大伟[1] 田原宇[1] 郝俊辉 田斌[1] 李俊花[1] 车远军 

机构地区：[1]中国石油大学(华东)重质油国家重点实验室,青岛266580

出　　处：《农业工程学报》2015年第19期309-314,共6页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金(51206099);中央高校基本科研业务费专项资金资助(15CX02024A);浙江省林业工程重中之重一级学科开放基金(2014lygcz019)

摘　　要：鉴于以含氮生物质为原料,采用炭化碱活化两步法制备掺氮活性炭的工艺较长,该研究以大豆渣为原料,K2CO3为活化剂,尝试采用炭活化一步法制备含极微孔的掺氮活性炭,并考察活化温度对活性炭化学组成、孔结构及低压CO2吸附性能的影响。研究表明,该方法可用于制备富含极微孔的掺氮活性炭。当活化温度从560℃升高到650℃时,1）活性炭的氮元素皆均匀分布在体相及表面,其质量分数（4.1%~4.4%）变化不大,而其化学状态发生变化;2）比表面积、总孔容、微孔孔容均呈单调递增,但极微孔孔容先增大后减小。活化温度为600℃的样品,极微孔孔容较大（0.13 m L/g）,极微孔主要集中在0.42~0.70 nm,微孔孔容、总孔容、比表面积分别为0.40 m L/g、0.43 m L/g、948 m2/g。该样品在10 k Pa、0℃下的CO2吸附量达1.94 mmol/g,CO2/N2表观选择性为41.6,说明它对低压CO2能同时展现出较高的吸附量及表观选择性。该研究为含氮活性炭的便捷制备提供了参考。So far, some studies have been conducted on preparation of nitrogen-doped（N-doped） active carbon from N-containing biomasses using alkalis as activators. In these studies, the commonly used preparation method was activation with alkali after biomass carbonization. Compared with this method, the one-step carbonization/activation method was simple and apt to reduce energy consumption, but its application in the preparation of N-doped active carbon was not investigated. In this research, N-doped active carbon with ultramicropores was prepared from waste soybean dreg using K2CO3 as activator via one-step carbonization/activation technology. The effects of activation temperature on chemical composition, pore structure, and low-pressure CO2 adsorption performances of the active carbon were investigated. To prepare active carbon, waste soybean dreg with particle size of 0.15-0.90 mm was impregnated with K2CO3 aqueous solution at K2CO3/dreg dry-basis weight ratio of 2：1, and after mixing uniformly, the mixture was sealed and kept for 4 h. Then, it was dried in an oven at 110℃ till constant weight was achieved. Subsequently, the dried mixture was heated to 500-650 ℃ at an average heating rate of 6℃/min and then kept for 75 min. Afterwards, the heated mixture was washed with distilled water until the pH value reached about neutral, and then dried at 110℃ for 12 h to produce active carbon. The obtained samples were subsequently characterized; pore structure and CO2 adsorption performance were measured with volumetric adsorption analyzers, elemental composition was measured with an elemental analyzer, surface chemistry was measured with an X-ray photoelectron spectroscopy, and surface morphology was measured with a scanning electron microscope（SEM） and a transmission electron microscope（TEM）. To gain an insight into the mechanism of pore formation, the soybean dreg and K2CO3-impregnated soybean dreg were pyrolyzed and analyzed using a thermogravimetric analyzer coupled with an infra-red spectrometer. Th

关 键 词：活性炭 废弃物 工艺 吸附 氮掺杂 二氧化碳捕集 极微孔 

分 类 号：TQ424.1[化学工程]