生物质焦油制备多级孔碳及其二氧化碳吸附性能研究

Preparation of Hierarchically Porous Carbon from Biomass Tar for Carbon Dioxide Adsorption

以生物质焦油为前驱体,ZnCl2为活化剂,通过一步简易活化制备具有发达孔隙结构的多孔碳,并开展在CO2吸附方面的应用研究。结果表明,产物表面N含量可达5.22wt.%,其中吡啶氮占比高达71.68%,具有孔隙率可调节和比表面积高(达827.040m^2/g)等特点。当生物质焦油与ZnCl2质量比为1∶4,活化温度为800℃时,吸附剂表现出最佳CO2吸附性能,其在273K和298K的吸附量分别为2.52mmol/g和1.64mmol/g,初始等量吸附热为33.84kJ/mol,相应的CO2对氮气选择性分别为4.2和1.9。本研究为CO2分离和储存提供了一种原料来源广泛且兼具可再生特点的炭基吸附材料,同时也为生物质焦油资源化利用开辟了新思路。

Highly-developed porous carbon was prepared from biomass tar by using ZnCl2 as activator in carbonization process.The results revealed high surface nitrogen content was up to 5.22wt.%,whilst the pyridinic nitrogen accounted for nearly 71.86%.Moreover,their porosity and specific surface area can be easily tuned by controlling mass ratio of carbon source and activation agents.When applied for CO2 adsorption,a best performance was achieved with the product prepared at 800oC and tar/ZnCl2 ratio of 1:4,the CO2 adsorption capacity at 273 K and 298 K were 2.52 mmol/g and 1.64 mmol/g,respectively.Additionally,the corresponding CO2/N2 selectivity were 4.2 and 1.9,initial isosteric heat of adsorption was as high as 33.84 kJ/mol.This research enabled such hierarchically porous carbon as promising alternative absorbent for CO2 separation and storage,and opened up a new idea for the resource utilization of biomass tar.