粉末活性炭孔隙结构和表面化学性质对吸附SO_2的影响

EFFECT OF PORE STRUCTURE AND SURFACE CHEMISTRY OF POWDER ACTIVATED CARBON ON SO_2 ADSORPTION

采用5种粉末活性炭,在固定床实验台上研究SO2在活性炭上的吸附过程。通过N2吸附、元素分析、Boehm滴定、热重分析、傅立叶红外光谱表征活性炭的孔隙结构和表面化学性质,研究活性炭物理化学性质对吸附SO2的影响。结果表明:由于活性炭的原料和活化方法不同,活性炭具有不同的孔隙结构和表面化学性质,呈现不同的吸附SO2的过程。关联了SO2饱和吸附量和活性炭性质之间的关系,发现SO2吸附量与活性炭的比表面积、孔隙容积之间没有明确的关系;SO2吸附量随着微孔孔径的降低而增加、随着表面碱性官能团数量的增加而增加。粉末活性炭的微孔孔径和表面化学性质共同影响着SO2的吸附。

Five kinds of powder activated carbons were used to investigate SO2 adsorption in a fixed bed reactor.The physicochemical properties were characterized by N2 adsorption isotherm,elemental analysis,Boehm titration,thermogravimetric analysis and FT- IR spectroscopy.The effects of pore structure and surface chemistry of powder activated carbon on SO2 adsorption were discussed.The results show that the activated carbons have different pore structure and surface chemical properties because of the different precursor and activation method,and present different time course of SO2 adsorption.SO2 adsorption is correlated with the properties of activated carbon.SO2 adsorption capacity is independent of specific surface area and pore volume and increases with micropore width decreasing,which is increased with the increase in the amounts of surface basic functional groups.The micropore width and surface chemistry of powder activated carbon influence SO2 adsorption.