活性炭吸附二氧化碳性能的研究

Properties of activated carbon for carbon dioxide adsorption

采用常压流动吸附法研究了活性炭吸附剂在二氧化碳／氮气体系中对二氧化碳的动态吸附性能，比较了其吸附量、吸附穿透曲线和吸附性能的差异，研究了活性炭的比表面积、孔径分布及表面官能团对其二氧化碳吸附性能的影响。结果表明。原料煤的性质影响活性炭对二氧化碳的吸附性能；二氧化碳的吸附量与吸附剂的比表面积、孔径分布有关。但孔径分布是主要的因素。吸附剂的孔径分布在0．5～1．7nm范围内时，有利于对二氧化碳的吸附；经多次循环吸脱附后。吸附剂对二氧化碳的吸附量略有减小并达到恒定值，孔容小和孔径分布窄的吸附剂的吸附量衰减较快。

A study of the dynamic adsorption characteristics of carbon dioxide in CO2/N2 gas mixtures on activated carbon at atmospheric pressure is reported. Correlations of breakthrough curves, and carbon dioxide saturated adsorption quantities with the physical properties and surface chemical properties of the adsorbent have been studied. It was found that the adsorption of carbon dioxide depends on the properties of the raw coal from which the adsorbents were derived. Specific surface area, pore size and identity of surface groups were all found to influence the carbon dioxide adsorption. A pore size distribution in the range of 0.5 - 1.7 nm leads to enhanced adsorption of carbon dioxide. The carbon dioxide saturated adsorption quantities decrease gradually with cycle number when the support is reused, and eventually attain a constant value. Adsorbents with small pore size show a more rapid decrease in adsorption ability with cycle number. The results reported here offer a method for improving the efficacy of activated carbon adsorbents for use in pressure swing adsorptive processes for removal of carbon dioxide.