活性炭对CO和CO2的吸附行为研究

采用重量吸附法,研究了空白活性炭A、经有机胺改性的活性炭C和经氢氧化钾与有机胺混合溶液改性得到的活性炭D在绝对温度303,313,323K下分别对单组分气体CO和CO2气体的等温吸附行为。等温吸附模型优选的结果表明:Freundlich方程是描述活性炭吸附CO气体的最佳模型方程;而Langmuir方程、D-R方程可以较好地模拟活性炭样品A在303,313,323 K下对CO2的等温吸附,Freundlich方程则能较好地模拟样品C和D在313 K下的等温吸附。CO和CO2在活性炭A上的等量吸附热均随吸附量的增加而降低。相同吸附压力下,CO2的吸附量高于CO。改性活性炭C和D上CO2的吸附量明显高于空白活性炭A;而活性炭的比表面积和微孔容积与吸附量的变化没有直接相关性。

The Adsorption of CO and CO2 on Activated Carbon

The pure component adsorption equilibrium of CO and CO_ 2 were measured on actived carbon samples A,C and D respectively by using gravimetric method.Sample A is blank actived carbon,samples C and D are actived carbons modified by ethylenediamine and the mixture of KOH and ethylenediamine respectively.The Freundlich equation is found to fit the isotherm data for the adsorption of carbon monoxide in all cases and carbon dioxide at 313K on carbon samples C and D.The Langmuir equation and D-R equation are found to fit the isotherm data for the adsorption of carbon dioxide at 303K,313K and 323K on carbon sample A.The isosteric heat of adsorption for both of CO and CO_2 decreased with surface loading increasing.At the same equilibrium pressure,the amount of CO_2 adsorbed is larger than the amount of CO.Active ingredients impregnated in carbon samples have significant influence on the adsorption for carbon dioxide and the amount of CO_2 adsorbed on modified carbon samples C and D is larger than the amount adsorbed on blank carbon sample A.However,the surface area,pore volume,micropore volume of carbon samples show less influence on the amount of adsorbed CO_2.