湿度对活性炭吸附氨气的影响研究

Research on the Influence of Humidity on the Adsorption of Ammonia by Activated Carbon

活性炭是去除氨气的有效材料,不同原材料制备的活性炭吸附性能差异较大,且湿度对活性炭吸附性能有重要影响。试验研究不同湿度下3种活性炭的氨气去除效果,考察最优进气湿度下初始浓度、流量、温度对椰壳活性炭吸附氨气性能的影响,以期为活性炭工程应用提供参考。研究发现,3种活性炭吸附氨气的最佳湿度均为50%;椰壳活性炭微孔结构多,比表面积大,表面含氧官能团多,有利于对氨气的吸附;湿度较低时,水膜不足以形成,吸附效果较差;湿度较高时,孔隙结构易被堵塞,同时水分子优先在活性炭表面形成氢键,与氨气分子竞争,占据活性炭表面的活性位点,导致氨气吸附变差;活性炭更适用于处理低浓度、小流量的低温废气源。

Activated carbon is an effective material for removing ammonia,and the adsorption performance of activated carbon prepared from different raw materials varies greatly,and humidity has a significant impact on the adsorption performance of activated carbon.This experiment studies the ammonia removal efficiency of three types of activated carbon under different humidity levels,and investigates the effects of initial concentration,flow rate,and temperature under optimal intake humidity on the ammonia adsorption performance of coconut shell activated carbon,in order to provide reference for the engineering application of activated carbon.Research has found that the optimal humidity for three types of activated carbon to adsorb ammonia is 50%;coconut shell activated carbon has multiple microporous structures,a large specific surface area,and a large number of oxygen-containing functional groups on the surface,which is conducive to the adsorption of ammonia;when the humidity is low,the water film is not sufficient to form and the adsorption effect is poor;when the humidity is high,the pore structure is easily blocked,and water molecules preferentially form hydrogen bonds on the surface of activated carbon,competing with ammonia molecules to occupy the active sites on the surface of activated carbon,resulting in poor ammonia adsorption;activated carbon is more suitable for treating low-temperature waste gas sources with low concentration and small flow rate.