Research And Equipment Design Of Acetylene Dimerization And Latex Devolatilization

The dimerization reaction of acetylene is the first step in the production process of industrial neoprene,and it is also the most important step.The current production process mainly uses a bubble bed reactor.Acetylene gas passes through the catalyst in the form of bubbles during the entire dimerization reaction to complete the mass and heat transfer process.This process has a long process route and a low conversion rate of acetylene,The MVA yield is not high,the process energy consumption is high,the operating pressure fluctuates greatly,the reactor is seriously clogged,and the potential safety hazards,etc.especially the problem of low conversion rate,brings trouble to the production of neoprene.At the same time,in the production process of neoprene rubber,a certain amount of unreacted monomer chloroprene and volatile solvents exist in the product neoprene latex,which makes the latex have a pungent odor,which is harmful to the operation and the user’s body.In view of the above problems,this paper studies the process of acetylene dimerization and latex devolatilization,and designs simple equipment based on the research results.In this paper,the dimerization process uses a three-stage spray reactor,that is,the catalyst is sprayed from the top of the reactor in the form of a spray,and the gaseous reaction medium enters from the bottom of the reactor.The heat and mass are transferred through countercurrent contact to complete the reaction process.The results show that the multistage reaction can improve the conversion rate of acetylene,but at the same time,the chance of side reactions increases,resulting in a decrease in the yield and selectivity of the MVA of the reaction;the addition of organic solvents increases the solubility of acetylene in the catalyst,making the catalyst solution The medium copper ion has excellent coordination ability,so that the acetylene dimerization reaction can proceed faster,the performance of the catalyst can be improved,and the conversion rate of acetylene during the dimerization reaction can be improved.Through research,it was found that when the acetylene volume fraction is 0.75,the reaction temperature is 85°C,the reaction gas flow rate is 100 ml/s,the organic solvent DMF addition amount is 10 mL,and the catalyst spray amount is 220 mL/min,the maximum conversion rate at this time is 10.95 %,MVA yield and selectivity are 46.76 and 81.6% respectively.The devolatilization experiment of neoprene latex was carried out using a self-made experimental device.The experiment showed that the devolatilization temperature was 80℃,the preheating temperature was 60℃,the neoprene latex flow rate was 1L/h,and the nitrogen flow rate was 0.1m3/h.Latex devolatilization devolatilization efficiency can reach more than 90%.Combined with the relevant experimental data of acetylene dimerization reaction and neoprene latex devolatilization process,the dimerization reaction and devolatilization process were preliminarily designed,and devolatilization equipment was applied to the production process.