Research On Catalytic System For Carbonylation Of Butadiene To Methyl 3-Pentenoate

Comparing with the traditional method, it can effectively reduce production costs and solve environmental problems by the method of carbonylation of butadiene to methyl 3-pentenoate and preparation of adipic acid. In this paper, the first step of the preparation of adipic acid:carbonylation of butadiene to methyl 3-pentenoate is studied. Using palladium as main catalyst, the catalyst formula is screened out and the process conditions are optimized. Concrete research results are as follows:1,Using palladium as main catalyst, the catalyst formula is screened out. Under the same reaction condition, effects of the different polymerization inhibitors, alcohols, organic acids, solvents and ligands on reaction are investigated and the catalyst is screened out. p-tert-Butylcatechol is selected as polymerization inhibitors. Methanol is selected as reactant alcohol.2,4,6-Trimethylbenzoic acid is selected as organic acid additive. Diphenyl ether is selected as solvent.1,3-Bis(diphenylphosphino)propane is selected as ligand.2,On the basis of the catalyst formula, the process conditions are optimized. Inhibitor content, ratio of reactants, palladium content, solvent content, ratio of acid and palladium catalyst, ratio of ligand and palladium catalyst, temperature and pressure of reaction are studied. The optimal process conditons are listed as follows:the reaction temperature:150℃, the pressure:4.0 MPa, the mole ratio of methanol:butadiene:palladium acetate:diphenyl ether: 2,4,6-trimethylbenzoic acid:1,3-bis(diphenylphosphino)propane=400:200:3:66: 7.5:8, p-tert-butylcatechol content:1wt% of butadiene. Under that conditions, average STY of reaction is 0.51mol/L.h, stable STY is 0.54mol/L.h, conversion of butadiene is 69.7%, selectivity of methyl 3-pentenoate is 86.7%, product yield of 3-pentenoate is 60.4%.