液化残渣基CO_(2)吸附剂的制备与性能优化

Preparation and performance optimization of liquefied residue-based CO_(2) adsorbents

以煤液化残渣(CLR)为原料制备CO_(2)吸附剂,在实现碳减排的同时,可有效提高煤直接液化工艺的经济性和环保价值。本文采用神华煤直接液化残渣为碳源,通过预氧化、炭化活化等工艺,制备出了吸附性能较优的CO_(2)吸附剂。利用热重分析仪(TGA)、低温氮吸附仪(BET)、扫描电镜(SEM)以及透射电子显微镜(TEM)等分析手段对吸附材料的微观形貌、孔径结构以及吸附性能进行了表征测试。结果显示,低灰分液化残渣所制备的吸附材料具有更高的比表面积和更多的微孔结构,更有利于CO_(2)的吸附。以低灰分液化残渣为原料,在较优活化条件下(活化剂/原料质量比为1∶1、升温速率5℃/min、活化时间1h)制备的CO_(2)吸附剂表现出良好的吸附性能,在40℃、15%(体积分数)CO_(2)模拟烟气条件下的CO_(2)吸附容量为4.47%(质量分数),在0℃、1bar(1bar=105Pa)条件下的CO_(2)吸附容量可高达27.70%(质量分数),低温吸附性能优异,吸附速率快且具有良好的循环稳定性。

Using coal liquefaction residue(CLR)as the raw material to prepare CO_(2)adsorbents can effectively improve the economic and environmental value of direct coal liquefaction process while achieving carbon emission reduction,which is of great significance.The direct liquefaction residue of Shenhua coal was used as carbon source,and the CO_(2)adsorbents with better adsorption performance were prepared through the process of pre-oxidation and carbonization activation.The microstructure,pore size structure and adsorption properties of the adsorbents were characterized and tested by thermogravimetric analyzer(TGA),low temperature nitrogen adsorption instrument(BET),scanning electron microscope(SEM)and transmission electron microscope(TEM).The results showed that the adsorbents prepared from low ash liquefied residue had higher specific surface area and more microporous structure,which were more conducive to the adsorption of CO_(2).The CO_(2)adsorbent prepared from low ash liquefied residue under optimal activation conditions(mass ratio of activator/raw material was 1∶1,heating rate was 5℃/min,activation time was 1h)showed good adsorption performance.The CO_(2) adsorption capacity at 40℃and 15%CO_(2) simulated flue gas was 4.47%.At 0℃and 1bar,the CO_(2)adsorption capacity could be up to 27.70%,the low temperature adsorption performance was excellent,the adsorption rate was fast,and it had good cycle stability.