Fluid bed catalyst in use for oxidizing reaction of olefin ammonia

Abstract

A fluidized-bed catalyst for the ammoxidation reaction of olefin is composed of the carrier consisting of nano-SiO2 and silica sol, and the active component Mo(12-g)BiaFebNicXdZfOgOx, where X is chosen from Mg, Co, Ca, Be, Cu, Zn, Pb, Sb, Mn and Cr, Y is chosen from La, Ce and Sm, Z is chosen from Li, K, Rb, Na and Cs, Q is chosen from B, W, P and V, a=0.1-6, b=0.01-10, c=0.01-10, d=0.01-10, e=0.01-10, g=0-2 and f is more than (0-0.5).

Description

technical field [0001] The invention relates to an ammoxidation catalyst for preparing unsaturated nitrile from olefin, and its active component contains multiple metal oxides such as molybdenum, bismuth and iron. Background technique [0002] α or β unsaturated nitriles can be prepared from olefins through ammoxidation, and the most typical industrial acrylonitrile or methacrylonitrile is prepared from propylene or isobutylene through ammoxidation. This type of ammoxidation reaction is usually carried out in a fluidized bed reactor, and the catalysts used are mostly supported catalysts, the most mature and widely used of which are molybdenum-bismuth-iron catalysts, which use silica as a carrier and support The active component contains molybdenum, bismuth, iron and other metal oxides, as introduced in Chinese patents ZL91100078.X and ZL97106771.6. Since the birth of this type of catalyst, people have paid more attention to the improvement of the active components. Through ...

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Problems solved by technology

However, for supported catalysts, although the carrier itself has no catalytic activity, the physical properties of the carrier have a great influence on the catalytic performance of the catalyst. Especially for supported fluidized bed catalysts, the wear resistance of the carrier directly affects the catalytic performance of the catalyst. service life

In the prior art, it is proposed that adding sodium to the catalyst can improve the wear resistance of the catalyst, but it is generally believed that the introduction of sodium will cause the catalyst to be poisoned in the later stage of use, resulting in a rapid decrease in the late activity of the catalyst

Another conventional method is to improve the wear resistance of the catalyst by increasing the content of the carrier in the catalyst. However, this method is generally considered to be a negative method, because the increase of the carrier content means that the content of the active component of the catalyst is reduced. Reduction, that is, the reduction of the active site of the unit catalyst, which must reduce the olefin load of the catalyst, which means a reduction in the production capacity of the reactor in production

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