Study On Catalysts And Reaction Rules Of MMA From MAL By One-Step Oxidative Esterification

Methyl methacrylate (MMA) is an important monomer, which is widely used for producing acrylic plastics (polymethyl methacrylate) or producing polymer dispersions for paints and coatings. The world production capacity has been almost doubled in past 15 years, and reached about 2.2 million tonnes per year. The demand of MMA is still expected steady growth in the future. MMA is mainly produced by the method of acetone-cyanohydrins (ACH) in the world. The synthetic route is complex, the technical line is long, and after many steps the yield is low with high cost, particularly in this method seriously poisonous substance hydrocyanic acid is used as raw material, the treatment of numerous waste acids is difficult and the environment pollution is obviously. Considering all of these, it is greatly necessary to develop a new chemical technology to synthesis MMA.Recently, in Janpanese isobutene as a raw material to produce MMA has been investigated and this method is already industrialized. Because of its green and economic good effects will be given on both economy and society if this method can be used more widely. The process of isobutene to methyl methacrylate is realized through three stages: First, isobutene is oxidized to methacrolein (MAL), then MAL is converted into methylacrylic acid (MAA) through oxidation, at last MAA is esterified to MMA with methanol. In this article the three-stage method described above was simplified to two-stage method: MMA was prepared from methacrolein (MAL) directly by one-step oxidative esterification. The original technical process was shortened and the yield increased.Firstly, a series of catalysts used to produce MMA from MAL by oxidative esterification were prepared by means of impregnation. Effects of supports , composites and preparing conditions of the catalyst were investigated. By means...