不同极性吸附质交替吸附对吸附性能的影响

摘要

研究四种吸附剂(两种市售活性炭和两种自制硅胶)对甲醇、正己烷和水蒸气的交替吸附性能以及动态吸附过程中吸附剂温度的的变化.结果表明:吸附顺序的不同对吸附剂最后总的吸附量没有较大的影响,相比先吸附正己烷对吸附剂的影响大于先吸附甲醇对吸附剂的影响;活性炭吸附少量的甲醇对水的吸附率影响较大,AC-1吸水率降低71.7%,AC-2降低98.4%;硅胶吸附少量的甲醇后再吸附水时吸附率为负,而先吸附少量的水后因为甲醇和水的互溶,所以硅胶吸附甲醇的效果会得到一定的提高,SG-1提高69.5%,SG-2提高了81.1%,因此在需要紧急处理时可以先短暂的吸附水之后再去吸附甲醇;甲醇的解吸率高于正己烷的解吸率,硅胶的解吸比活性炭的解吸的更彻底,解吸之后活性炭的吸附率明显降低,因此连续性长期使用可以选择硅胶作为吸附剂;AC、SG最大温差分别为23.3 ℃、13.5 ℃、18.2 ℃和21.4 ℃,AC-2对甲醇具有较大的吸附量,温度变化较小,为以后应用于醇类的吸附回收技术提供实验支撑.%The alternate adsorption capacities of four commercially available adsorbents (two activated carbon and two silica gel) to the vapors of methanol and n-hexane and water as well as the change of adsorbent temperature in the dynamic adsorption process were studied.Results show that the different adsorption order has little influence on the final total adsorption amount, the effect of the adsorption of n-hexane on the adsorbent is greater than (that of methanol) the adsorption of methanol on the adsorbent.Adsorption of a small amount of methanol with activated carbon has greater impact on adsorption rate of water, the water absorption rate of AC-1 decreases by 71.7%, AC-2 decreases by 98.4%.The adsorption rate is negative when first adsorption of a small amount of methanol and then adsorption of water with silica gel, the effect of silica gel adsorption of methanol will be improved when first adsorption of a small amount of water because of the solubility of water and methanol, SG-1 increases by 69.5%, SG-2 increases by 81.1%, so you can first adsorption of water after a short time to go to adsorption of methanol when emergency treatment is needed.The desorption rate of methanol is higher than that of n-hexane, the desorption of silica gel is more through than that of activated carbon, the adsorption rate of activated carbon is reduced significantly after desorption, therefore, silica gel can be used as adsorbent for continuous use.The maximum temperature difference between AC and SG is 23.3 ℃、13.5 ℃、18.2 ℃ and 21.4 ℃ respectively, AC-2 has a large adsorption capacity for methanol, and the temperature change is smaller, which can provide experimental support for the adsorption recovery technology of alcohols.