Study On The Application Of A Clustered Countercurrent-flow Micri-channel Reaction In Liquid-liquid Extraction

Process intensification is very important for modern chemical industry.As an important equipment for process intensification,micro-reactor has received increasing attention in recent years.There are many reactors currently designed,but they are rarely used in industrial production because of problems such as channel blockage and scaling-up.Because of that,countercurrent-flow micro-channel reactors(CFMCR)were designed in our research group.In previous studies,it was confirmed that CFMCR has good micro-mixing performance,and the structure is simple,easy to clean and magnify.This experiment studied the application of convective microchannel reactors in liquid-liquid extraction and further demonstrated its value in industrial applications.The main research content of this thesis is as follows:(1)Both the single countercurrent-flow micro-channel reactor(S-CFMCR)and the clustered countercurrent-flow micro-channel reactor(C-CFMCR)were applied to the extraction of Cr(VI)at a low extractant concentration,and the results showed that the extraction effect could be improved by increasing the concentration of hydrogen ions.Cyclohexane,kerosene,and carbon tetrachloride were used as diluents,respectively,and it was that cyclohexane as the diluent had the best extraction effect.When carbon tetrachloride was used as the diluent,the extraction effect was the worst.The extraction rate was enhanced first and then decreased as the Reynolds number increases and the best results were obtained when the two phases were fed at the same volumetric flow rate.The optimal structural parameters are:the channel diameter of 0.8 mm and opening hole of 1.3 mm in diameter.Under the optimal operating conditions,the subsequent stirring for 10 min,the extraction rate can reach about 55%.Almost no difference in extraction effect was found between S-CFMCR and C-CFMCR under the same operating conditions,indicating that the reactor has no noticeable scaling-up effect.For the recovering of TBP,the optimal process conditions were explored as well.(2)The ultrasonic treatment combined with microwave was used to extract rutin from black buckwheat,and the process conditions were optimized by orthogonal experiments.The results showed that the optimum conditions were as follows:ethanol concentration is 70%;extraction time is 60 min;microwave temperature is 80 ? and ultrasonic power is 200 W.Under the optimal operating conditions,the extraction rate can reach about 1.85.Then the solution of rutin was extracted by CFMCR.The results showed that the best feed volume ratio between solution of rutin and n-butanol was 1:1.The extraction rate increased first and then decreased with the increase of Reynolds number.The optimal structural parameters are:the channel diameter of 0.8 mm and the opening hole of 0.8 mm in diameter.Under the optimal operating conditions,the subsequent stirring for 5 min,the extraction rate can reach about 90%.Number-up experiments showed that the reactor has no scaling-up effect.This study further confirmed that CFMCR has a significant intensifying on liquid-liquid extraction.In addition,the reactor is easy to scaling-up and has no negative effect.Therefore,CFMCR will be a promising process intensification technology in industrial applications.