Research on Bipolar Membrane Electrodialysis for Ion Exchange of Molecular Sieves

In view of the problems associated with large amount of discharged wastewater and serious pollution in the existing technology for removing sodium species from molecular sieves,this research work introduces the bipolar membrane electrodialysis into the process of removing sodium species from molecular sieves,and proposes a novel method of cleanly removing sodium from molecular sieves.The results show that the technology for removing sodium ions from the molecular sieves with an indirect electrodialysis process is feasible,and can recover Na OH solution.The bipolar membrane electrodialysis is especially suitable for treating the USY,ZSM-5 and Beta molecular sieves with high acid-resistance,and the physicochemical properties and catalytic performance of the prepared molecular sieves are roughly equivalent to those of the ammonium ion-exchange method.In comparison with the ammonium ion-exchange method,the process is clean and environmentally friendly,which consumes less water,and does not discharge wastewater to exhibit a rosy prospect of industrial application.     

利用双极膜电渗析实现ZSM-5分子筛清洁化生产的研究

以双极膜电渗析为离子交换装置,对ZSM-5分子筛的脱钠过程进行研究。结果表明,双极膜电渗析工艺用于ZSM-5分子筛脱钠过程,可以达到分子筛中Na_2O质量分数低于0.1%的工业要求,同时能够回收Si、Na和部分模板剂,实现资源再利用。电渗析与铵交换制得的H-ZSM-5分子筛相比较,物化性质和催化性能基本一致,工艺过程清洁环保,水可循环利用,且无氨氮、无含盐废水排放。     

废MDEA溶液资源化回收利用研究

采用管式膜过滤技术与电渗析脱盐技术,对200 m~3的废MDEA溶液进行再生回收研究,以期解决废MDEA溶液的资源化回收利用问题。结果表明,废MDEA溶液悬浮物质量浓度由194 mg/L降至3 mg/L时,去除效率达到98.5%,热稳定盐质量分数由3.2%降至0.7%,废MDEA质量分数由18.7%提高到19.1%;该管式膜过滤与电渗析脱盐技术为废MDEA溶液的资源化回收利用提供了一种新的技术路线。     

Efficiency of Extraction of Petroleum Acids in an Extractor with Sieve Plates. Method of Calculation

TIn developing zero—waste technology for extraction of petroleum acids from light crude cuts with ammonia water [ 1], a process was created for removing unsaponifiables from an aqueous solution of petroleum acid ammonium salts ( AS PAAS) with an extracting agent. This process produces quality distilled petroleum acids. High—temperature vacuum distillation of unsaponifiables, used in treatment of fuel cuts with caustic soda, is not applicable in this case due to the thermal instability of PAAS. Moreover, this method is not economically rational . The studies showed that the naphtha cut is the most appropriate extracting agent for this purpose.     

膜分离技术在糠醛废水处理中的应用

糠醛生产中含1—2.5％乙酸的废水直接外排,浪费资源,污染环境。本文从消除糠酫废水污染、控制水质出发,介绍了新开发的电渗析-萃取-精馏法。重点阐述电渗析分离工艺过程,回收副产品工业一级乙酸,废水安全排放及回用。     

电渗析法连续脱除醇胺溶液中的热稳态盐

在阴离子交换膜和阳离子交换膜构成三室结构的电渗析装置中,对N-甲基二乙醇胺为主要组分的醇胺溶液中热稳态盐(HSS)的脱除进行了实验;采用厚1.2 mm的单层聚丙烯隔板和一级一段模式,自组装10组100 mm×300 mm的膜堆;考察了阴、阳离子交换膜的性能,膜电压和脱HSS室内醇胺溶液流速对脱除HSS的影响。实验结果表明,适宜的条件为:膜电压0.53 V、醇胺溶液流速1.32 cm/s,在此条件下,可使醇胺溶液中HSS的质量分数降至0.87%,N-甲基二乙醇胺的损耗率为0.62%;当脱除的HSS量累积达6.60 kg/m~2时,需用盐酸和Na_2CO_3溶液对膜进行再生,再生对脱除HSS基本无影响。电渗析装置脱除醇胺溶液中的HSS具有连续、清洁及经济的特点。     

电渗析技术处理LNG工厂循环冷却系统排污水研究

湖北LNG工厂循环冷却水系统每日排污量高达1 200m3,直接排放不仅造成水资源的浪费,同时对下游污水处理厂的运行产生较大冲击。为提高该部分废水的重复利用率,设计采用"多级连续式电渗析除盐系统"对其进行脱盐处理后回用于循环水系统。经计算,50m3/h的电渗析装置设计流速采用V=5.0cm/s,设计总脱盐率ε=75%~80%,产水电导率300~350μs/cm。装置建成后调试结果表明,最佳操作电压为110V,最适宜进水流量为50m3/h,产水各项指标满足预期设计要求。每年可减少新鲜水消耗和废水排放各30×104 t,产生直接经济效益约60万元。     

电解电渗析回收处理汽油碱渣的氢氧化钠

 利用电解电渗析的方法回收处理汽油碱渣中的NaOH，使剩余的废溶液容易进一步处理，降低对环境的污染。在自制的电解槽中进行电解电渗析，阳极室为汽油碱渣，阴极室为水，电压为5V。还研究了电极材料的影响。结果表明，使用电解电渗析可以将NaOH从阳极转移到阴极，当装入阳极室和阴极室的液体体积相当时，阴极室溶液中的NaOH质量分数可以达到4.4%；更换阳极室的碱渣，可以使阴极室溶液中的NaOH质量分数达到12%。以铂为阳极、镍为阴极的电解电渗析效果，镍、铅等材料不适合用作阳极材料。研究还发现，高温不利于碱渣电解电渗析的进行，适宜的电解电渗析温度为常温；电极与离子膜之间的距离越小越能提高电解渗析的效率。     

纳滤膜技术及其应用

介绍了纳滤膜技术及双极膜、两性膜2种新型纳滤膜品种,并概述了纳滤膜在石化、生化和医药、食品等工业领域以及各种工业废水处理中的应用及研究进展。     

Fractionation of multicomponent solutions by electrodialysis with bipolar membranes

The process of electrodialysis with bipolar membranes and the performance characteristics of plants that use this process are described. The first results of the laboratory tests of an electrodialysis plant with bipolar membranes are given; these results show that the salt wastes of nuclear power plants can be practically utilized with the manufacture of useful products (acids, alkalis, and boric acid) for the repeated use at the plant. The use of modified ion-exchange membranes and a two-compartment electrodialyzer design with bipolar membranes for the removal of ionic impurities from the solutions of acids and alkalis, in particular, for the production of pure boric acid, is proposed.