Packed Bed Electrochemical Reactor And Its Application In Preparation Of Succinic Acid

Succinic acid can be used widely as intermidate and raw material in many industry areas,such as medicines,foods,pesticides,dyes and plastics.In the recent years,poly butylene succinate?PBS?as biodegradable plastic has been developed successfully.Thus,the demands of succinic acid will be increased sharply in the future.Electrolytic synthesis is the most competitive industrial process for succinic acid.In the existing production process of succinic acid,there are many disadvantages,such as high equipment investment,low space-time yield and small effective volume of electrolysis.Therefore,a new electrochemical reactor with high space-time yield and current efficiency is demanded to substitute for the traditional tank type electrochemical reactor.In this paper,a Packed Bed Electrochemical Reactor?PBER?used in electrolytic synthesis of succinic acid was proposed and fabricated.Based on this PBER,two sets of packed bed electrochemical reaction device were assembled.One device was used to optimize the electrolytic process of succinic acid and evaluate the electrolytic performance,while another was used to explore the method of decreasing the content of fumaric acid as the byproduct of electrolysis.The results of this study were as follows:?1?the suitable operation conditions were maleic anhydride weight percent of 9.8%and sulphuric acid weight percent of 5%,electrolysis temperature of 50?,the anodic current density of 1000A·m^-2,ratio of current density of 1:4,quantity of electric charge of 100%,and under above suitable conditions,the reduction yield can reach 72.6%and the working voltage can reach 2.6-3.1V;?2?under above suitable conditions,when technique of filtrate recycle was adopted,the average reduction yield and the working voltage reached 93.7%and 2.6-3.0V respectively;?3?under the same suitable conditions,electrolytic performances of PBER were better than those of tank type electrochemical reactor,the reduction yield and current efficiency can increase about 4%,and space-time yield was about 1.6 times of the latter one;?4?when the pratical quantity of electric charge was 1.2 times of the theoretical one,the content of fumaric acid as the byproduct of electrolysis can be controlled less than 0.1%with two-segmented electrolysis of PBER;?5?when the pratical quantity of electric charge was 1.1 times of the theoretical one,the content of fumaric acid as the byproduct of electrolysis can be controlled less than 0.1%with multi-segmented electrolysis of PBER.