温度和改性浓度对改性飞灰汞吸附性能的影响

Influence of Temperature and Modified Concentration on Adsorption Property of Mercury by Modified Fly Ash

采用机械力耦合NaBr的方法对燃煤飞灰进行机械化学改性。在固定床反应装置上研究了NaBr质量浓度及吸附温度对改性飞灰脱汞性能的影响。结果表明:改性飞灰的脱汞效率受NaBr溶液质量浓度和吸附温度的影响较为明显,脱汞效率随NaBr溶液质量浓度的增加而增加,同时吸附温度越高汞吸附性能越好;在350℃的吸附温度下,机械力耦合0.5%浓度的NaBr对汞几乎完全吸附;在机械力与NaBr的协同改性过程中,随着NaBr溶液质量浓度的增加,原始飞灰中粒径占比发生改变,飞灰表面破碎程度增大,飞灰部分表面官能团发生改变,产生了活性位点与新的活性官能团,从而增强了对汞的吸附性能,促进了对汞的吸附脱除。

The mechanical coupled NaBr method was adopted to modify the coal-fired fly ash mechanically and chemically.The influence of NaBr mass concentration and adsorption temperature on the mercury removal performance by modified fly ash was explored on the fixed bed reactor.The results show that the mercury removal efficiency of modified fly ash is obviously affected by the NaBr mass concentration and adsorption temperature.The mercury removal efficiency increases with the increase of NaBr mass solution concentration,meanwhile higher adsorption temperature can promote better mercury adsorption performance.The mercury adsorption efficiency is almost 100%with mechanical coupling of 0.5%of NaBr at 350℃.In the process of collaborative modification of mechanical force and NaBr,with the increase of NaBr mass concentration,the particle size proportion of original fly ash change,the surface fragmentation degree of fly ash increases,the functional groups on partial surface of fly ash changes,the active sites and new active functional groups are produced,which can strengthen the mercury adsorption capability and promote the mercury adsorption and removal efficiency.