Study For The Catalyst Of The Isobutene Selection Oxidation For Methacrolein

Methyl methacrylate (MMA) is an important monomer in the preparation of acrylic resins. At present, MMA is mainly produced by the method of acetone-cyanohydrins(ACH). The raw material are acetone and hydrocyanic acid which is seriously poisonous substance, in the reaction process, high corrosive sulphuric acid is also used, and the by-product of the ammonium hydrogen sulfate is difficult to deal with. The atom utilization of the route is only 47%. The selective oxidation of isobutylene to methacrolein (MAL) is a critical step for clean production of methyl methacrylate (MMA) from isobutylene instead of highly toxic hydrocyanic acid.The main contents and results of this work were as follows:(1) The catalysts were prepared by the method of the co-precipitation. The influence of the preparation conditions such as:,,addition sequence of solutions,the rate of whipped, calcination temperature, component and the ratio of the elements in catalysts on catalytic performance for selective oxidation of isobutylene to methacrolein were studied. The physico-chemical properties of the catalysts were characterized by XRD,SEM,IR and so on. The optimum preparation conditions for catalysts with the component of Mo12Bi1.6Fe1Co8Ce0.4Cs0.4K0.2Sb0.48Ni0.12Ox were that: solution B was added into solution A , the rate of whipped is 80 rev/min, calcination temperature=500℃.(2) Some important reaction parameters for selective oxidation of isobutylene to MAL, such as concentration of isobutylene, reaction temperature, space velocity and the vapor were systematically investigated. The based kinetics equation was obtained. Reaction optimized conditions were optimized. At 380℃, 4500h-1 and volume concentration of isobutylene 6%, conversion of isobutylene was 97.31%,and selectivity to MAL was 92.34%.