【作者】 张鹏；

【导师】 余立新；

【作者基本信息】 清华大学 ， 化学工程与技术， 2009， 硕士

【摘要】 异丙苯法是生产苯酚和丙酮的主流工艺,在生产过程中,会产生一股含苯酚的循环烃,需要脱酚后才能继续循环使用。可以使用氢氧化钠溶液对烃进行洗涤,得到酚钠溶液;再用硫酸中和得到苯酚,但同时又产生大量硫酸钠,硫酸钠在精制塔中会析出,堵塞再沸器和下面的塔板,经过论证,我们决定采用使用双极性膜电渗析法连续处理酚钠溶液的新工艺来解决这一问题。?利用双极性膜可以在直流电场作用下将水解离成H+和OH‐的特性,将其与阳离子交换膜组合成双极性膜电渗析系统,可以将苯酚钠转化为相应的苯酚,本论文尝试使用该工艺来解决上面提出的问题。?本文以分别以实验室自配的酚钠、NaOH混合溶液及燕山石化所提供的工厂料液为研究体系,采用双极性膜电渗析技术酸化溶液制取苯酚。实验分为三部分:1.?实验室内使用自配料液的小试实验;2.实验室内处理工业料液的长周期小试实验;3.工厂现场处理工业料液的放大实验。?实验室内使用自配料液的小试实验的主要目的是绘制操作曲线,并分析电流效率和单位质量能耗能耗。实验结果表明,应用双极性膜电渗析技术,可以将酚钠溶液酸化转化为苯酚,且各流量下转化率均能达到90%以上。在90%转化率附近,能耗大约为2.0kWh/kg苯酚,电流效率能够保持在60%左右。NaOH浓度的降低,在达相同转化率时,能耗较少,但所需电压值较大。分别采用日本ASTOM阳离子交换膜和国产阳离子交换膜对含NaOH浓度为0.2mol/L的酚钠溶液进行转化实验,比较发现在达相同转化率的情况下,采用日本阳离子交换膜时所需电压较小,能耗较少。?实验室内处理工业料液的长周期小试实验主要目的是对操作工艺及膜的耐久性进行研究,实验结论如下:从总体而言,?由处理后料液的pH值来看,转化效果很好,酚钠转化率接近100%;碱液浓度能保持在3～6%,完全能够循环回碱洗工段使用,整个实验累计时间>1000h,未发现双极性膜破损,但阳膜性能却明显下降。? ?工厂现场处理工业料液的放大实验的主要目的是对放大效应和对膜的耐久性进行研究,通过不断调节电压,可以使得酚钠以较高的转化率转化为苯酚:,平均电流效率大于50%;碱液浓度能保持在3～6%,能够循环使用。但膜的寿命较短经过50天后,可以观在阳极液里检测到苯酚,因此基本可以认为阳膜已经穿孔。?更多还原

【Abstract】 In Yanshan chemical corporation, Ii the process of producing phenol and acetone, when the sodium phenolate is neutralized by sulfuric acid, the excess of Na2SO4 will be crystallized, which leads to the blocking of reboiler and trays near the reboiler. Aiming at solving this problem, electrodialysis of bipolar membrane is adopted.In bipolar membrane, water can be dissociated to H +and OH ?. With the characteristic of the bipolar membrane, we can establish the bipolar membrane eletrodialysis system with a cation exchange membrane and two bipolar membranes. So we can convert organic salt into the organic acid without the addition of other impurities.In the EDBM experiment , we have two research systems: 1.the solution of Phenol sodium and NaOH which is confected by ourselves. 2.the solution of Phenol sodium and NaOH with impurities offered by chemical factory. The whole experiment could be divided into three parts: 1. The treatment of confected solution in our lab. 2. The treatment of industrial solution in our lab.3.The treatment of industrial solution in chemical factory .The three parts have different emphasis, The first part is concentrated on drawing the operation curve and analyzing the current efficiency and energy cost. The main conclusions from the experiment are as following, The flow state can be thought to be plug flow in the membrane stake , the conversion ratio of sodium phenolate to phenol is over 90%, When the conversion ratio is about 90%, the energy consumption is 2.0kWh per kg phenol, and the current efficiency is about 60%. When the concentration of NaOH decreases, energy consumption is lower but the voltage increases if we want to reach the same conversion ratio. We experiment by using the ASTOM cation exchange membrane and the native cation exchange membrane when the concentration of NaOH is 0.2mol/L. And the results show that when reaching the same conversion ratio the energy consumption is lower and the voltage decreases by using the ASTOM cation exchange membrane.The second part is concentrated on the research of operating method and the duration of the membrane. The main conclusions from the experiment are as following. the conversion ratio of sodium phenolate to phenol is nearly 100%. The current efficiency is more than 50%. The concentration of NaOH obtained can maintain 3~6%, which can be circulated to the alkali washing procedure. This experiment was carried out for about two months, and the performance of the cation membrane decreased rapidly in last a few days .The third part is concentrated on the amplification effect and further research of the duration of the membrane The main conclusions from the experiment are as following, the conversion ratio of sodium phenolate is qualified . The current efficiency is more than 50%. The concentration of NaOH obtained can maintain 3~6%, which can be circulated to the alkali washing procedure. But in this experiment after 50 days, the cation membrane is outwarn更多还原