氨碱法制碱中基于直接接触膜蒸馏原理的膜吸收氨回用技术  

Membrane absorption technology to recover and reuse ammonia based on the principle of direct contact membrane distillation in ammonia soda process

作　　者：孙伟[1] 高启君[1] 吕晓龙[1] 陈华艳[1] 武春瑞[1] 王暄[1] 贾悦[1] 

机构地区：[1]天津工业大学生物化工研究所,省部共建分离膜与膜过程国家重点实验室,天津300387

出　　处：《膜科学与技术》2016年第3期118-123,共6页Membrane Science and Technology

摘　　要：氨碱法制碱中,为回收氨,氨冷却塔产生的冷凝氨液需经二次蒸氨工序,因此过程能耗高;循环回用的高含水率氨,降低了氨化工序中精盐水的浓度,最终限制了钠利用率的提高.本文采用精盐水作为吸收液,研究基于直接接触膜蒸馏原理的膜吸收氨回用技术.将模拟冷凝氨液中的氨转移到精盐水中而被吸收,同时抑制与氨传质同向的水传质过程,从而降低回用氨的含水率,节省水的汽化相变热.实验研究了膜吸收组件用聚偏氟乙烯(PVDF)中空纤维疏水膜丝内径ri和组件装填密度δ、吸收液与原料液进入膜组件时的温度差ΔT对膜吸收氨回用过程性能的影响.当ri为0.80mm,δ为16.8%,ΔT为9℃时,氨通量为1.17kg/(m^2·h),水通量仅为0.04kg/(m^2·h),表明该技术具有可行性.In the process of ammonia soda,the condensate produced by ammonia cooling tower is usually distilled into the ammonia distillation tower again in order to recover ammonia,which increases the energy consumption.Ammonia with high water content is reused in ammoniating process,which decreases the concentration of refined brine,thus preventing sodium utilization rate from enhancing.In the paper,refined brine is used as absorbent.Membrane absorption（MA）technology to recover and reuse ammonia based on the principle of direct contact membrane distillation（DCMD）was studied.Ammonia in simulated condensed ammonia solution was transferred to refined brine,at the same time,mass transfer of water vapor whose direction of mass transfer was the same as ammonia is inhibited.So the rate of water content of ammonia recovered and reused was reduced and heat of phase transition produced by vaporization of water was saved.The influence of internal diameter（ri）of PVDF hollow fiber hydrophobic membrane used in the MA module,packing density（δ）of module and the temperature difference（ΔT）of absorbent and feed between inlet of shell and that of tube on the performance of MA to recover and reuse ammonia was studied experimentally.When riis 0.80 mm,δis 16.8%,andΔTis 9℃,the flux of ammonia is 1.17kg/（m2·h）and the flux of water is only 0.04kg/（m2·h）,indicating that the technology is feasible.

关 键 词：膜吸收 直接接触膜蒸馏 氨回用 含水率 氨碱法制碱 

分 类 号：TQ114[化学工程—无机化工] TQ028.8