A kind of method improving rhodium/bisphosphonite catalyst stability

Abstract

The invention discloses a method for enhancing the stability of rhodium / diphosphite catalyst, which belongs to the field of petrochemical engineering. The method disclosed by the invention enhances the stability of the rhodium / diphosphite catalyst by decreasing the separation temperature of the rhodium / diphosphite catalyst and a catalytic reaction-synthesized product, and specifically includes the following steps: the mixture of the rhodium / diphosphite catalyst and the catalytic reaction-synthesized product is first mixed with recycle gas, and the separation step is then carried out. The method disclosed by the invention improves the separation effect of the rhodium / diphosphite catalyst and the catalytic reaction-synthesized product, decreases the evaporative separation temperature of the rhodium / diphosphite catalyst and the catalytic reaction-synthesized product, and decreases the probability of the decomposition of the diphosphine ligands of the rhodium / diphosphite catalyst under high temperature in the process of separation; the recycling life of the rhodium / diphosphite catalyst ligands can be prolonged, the quantity of the supplemented catalyst ligands is reduced, and therefore economic benefit is increased.

Description

technical field [0001] The invention belongs to the petrochemical field, relates to a method for improving the stability of a rhodium / bisphosphonite catalyst, and in particular relates to a method for reducing the separation temperature by mixing the rhodium / bisphosphonite catalyst with recycle gas before separation, And then improve the method of rhodium / bisphosphonite catalyst stability. Background technique [0002] The oxo reaction of olefins can conveniently and effectively convert cheap and easy-to-obtain basic chemical raw materials such as propylene and butene into various important chemical products such as butyraldehyde and valeraldehyde. The development of this type of catalyst has undergone several updating processes. So far, four types of industrial catalysts have been developed, namely cobalt carbonyl catalyst CoH(CO) 4 , tertiary phosphine-modified cobalt carbonyl catalyst CoH(CO) 3 (RM-17), carbonyl rhodium phosphine catalyst RhH(CO)(PPh 3 ) 3 , and bisph...

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Problems solved by technology

[0004] US4567306 discloses a method for reducing the degradation of cyclic bisphosphonite ligands in the carbonylation reaction by adding tertiary amines to the reaction system, but this method cannot inhibit the degradation of non-cyclic bisphosphonite ligands At the same time, the salt generated will also cause pipeline blockage

[0005] CN1092058 proposes the use of epoxy compounds as stabilizers, but epoxy compounds are relatively expensive, and the reaction solution is controlled in a weakly alkaline environment, which will accelerate the polymerization of the product

[0006] US4599206 and US4712775 disclose a method of using ion exchange to control acidity, thereby slowing down the degradation of bisphosphonite ligands. This method requires the addition of a large additional equipment, which significantly increases the cost of investment and operation

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