Study On Catalyst Optimization In The Process Of Dimerization Of Acetylene In Aqueous System

Chloroprene rubber (CR) is a small branch of the synthetic rubber, but itsindustrialization has opened a new era in the history of synthetic rubber. CR not onlyhas high strength, good elasticity and superior adhesion and excellent physicalproperties, but also has the advantages of oil, flame and chemical resistance and so on.Our country is a large consumption country of CR, but the production process in Chinais lagging behind in international standards, especially the serious energy consumptionand environmental pollution in the production process. Therefore, it’s of greatsignificance to carry out research on the improvement of generation process and thedevelopment of CR technology and application.Chloroprene rubber is generated by the polymerization of the monomerchloroprene. There are two methods to synthesis chloroprene, including acetylene andbutadiene. Because of the cost advantage, the acetylene method is widely used in thecurrent production of chloroprene in China.This study is about the synthesis system of adding a coordination agent and theexternal electric field to optimize the chloroprene acetylene. First, two coordinationagents, organic carboxylic acid and pyridines, are added to the water of diethyleneglycol monobutyl ether synthesis system of the acetylene dimerization. Through theanalysis of experimental results, this thesis gets conclusions as follow:1) Organiccarboxylic acids can improve the yield of the MVA and reduce the output of the DVA,as well as improve the acetylene conversion and selectivity of the catalyst. Among them,when A2is put into the system, the MVA yield and acetylene conversion rate can reach9.4%and17.6%, the MVA selectivity99.7%.2) The adding of pyridines coordinationagent to the system can improve the selectivity of the MVA and acetylene conversionrate. Respectively, the MVA yield and acetylene conversion rate can reach11.1%and21.3%. And the MVA selectively can reach96.1%, and the adding of bidentate ligandcan make the MVA selectively reach96.8%.3) According to above two points, thisthesis can get the conclusion that the two coordination agents can improve the catalyticefficiency by cuprous ion coordination, but the activities of the catalyst are different dueto the different mechanism.When the electric field is put into the acetylene dimerization of single-phase ortwo-phase catalytic system, it will affect the ionization of the acetylene and MVA, and change the catalytic properties. According to the results, the size of current, the type ofelectric field, and the type of electrode will influence the system. Using the copperelectrode, when unidirectional pulsed electric field is added into the single-phase system,the MVA yield and acetylene selectivity will reach10.3%and19.4%. Compared to thegraphite electrode, adding copper electrode into any type of electric field can increasethe MVA yield and selectivity of acetylene. However, when using the copper electrode,adding any type of electric field into the two-phase system, has little effect on the MVAyield and acetylene selectivity. In the bi-directional pulsed electric field, the MVA yieldand selectivity of the acetylene can reach9.7%and20.6%. Adding the electric field intotwo-phase system is not as efficient as that in single system. Similar to the single-phasesystem, using copper electrodes is more efficient than graphite electrodes. Adding boththe pyridines coordination agent and the electric yield into system will reduce the MVAyield, but the acetylene conversion rate is significantly improved. The MVA yield is aslow as4.4%, and the conversion rate of DVA rise to16.15%.