Catalyst for olefin ammoxidation producing unsaturated nitriles

Abstract

The invention is a catalyst used in the producing of unsaturated nitriles by the ammonoxidation of olefin, in particular to a catalyst adaptable for the producing of acrylonitrile and methacrylonitrile by the ammonoxidation of propylene and butylenes. A general formula of the active component of the catalyst is a complex of catalytic oxidation of BiaFebNicMgdLaeC1gAlhAiBjCkMo12Ox, wherein the A isone element or a compound of more than two elements of lithium, potassium, rubidium and caesium, the B is one element or a compound of more than two elements of cerium, gadolinium and samarium, and the C is one element or a compound of more than two elements of zinc, manganese, cobalt, calcium, copper, wolfram and phosphorus. The catalyst is capable of producing unsaturated nitriles of which theyield rate reaches to 84% or higher under the condition of high catalyst load, high reaction pressure, low reaction temperature, low ratio of air and olefin and low ratio of ammonia and olefin, and with the adoption of the catalyst, the catalyst is capable of long-term operation under the condition of low reaction temperature, and the catalyst has long service life. Further, reaction products havea small amount of impurity substances, and the catalyst is environment friendly.

Description

technical field [0001] The invention relates to a catalyst suitable for the ammoxidation of olefins to produce unsaturated nitriles, especially a catalyst suitable for the ammoxidation of propylene and isobutene to produce acrylonitrile and methacrylonitrile. Background technique [0002] Many patents have been introduced to produce unsaturated nitriles with molybdenum-bismuth-iron catalysts. The most typical in the industry is the production of acrylonitrile or methacrylonitrile by ammoxidation of propylene or isobutene. Most of the catalysts used are supported catalysts. Molybdenum-bismuth-iron catalysts are widely used, which mostly use silicon dioxide as a carrier to support active substances containing various metal oxides such as molybdenum, bismuth, and iron. For example, Chinese patents CN1053197A, CN94191775.4, and CN1194180A, these catalysts all contain multiple metal oxides such as molybdenum, bismuth, iron, etc., and have relatively high alkene nitrile yield and ...

AI Technical Summary

Problems solved by technology

Patent CN1061166A, CN1171693A and other literatures not only contain molybdenum, bismuth, iron and other metal oxides, but also introduce halogen elements. The main function of halogen elements is to reduce the generation of side reaction products carbon monoxide and carbon dioxide, and then achieve the purpose of improving the yield of the target product , although the catalysts mentioned in these documents have good unsaturated nitrile yields, the catalyst load is low, and it is difficult to adapt to the catalyst load required by the current large-scale reactor

Images