Method for preparing fatty aldehyde by means of a hydroformylation reaction

Abstract

The invention discloses a method for preparing fatty aldehyde by means of a hydroformylation reaction. A catalyst system consisting of a water-soluble rhodium phosphine complex and a diphosphine ligand is used in water / organic two phases for catalyzing 1-butene, 2-butene and a mixture of the 1-butene to be subjected to the hydroformylation reaction so as to prepare n-valeraldehyde; due to the combination of the water-soluble bisphosphine ligand BISBIS and organic additives, the hydroformylation reaction of the butene is accelerated, and the molar ratio of the produced n-valeraldehyde / isovaleraldehyde is greater than 93 to 7. A catalyst aqueous solution is simple and convenient to separate from the product; furthermore, the catalytic performance is stable, the reaction conditions are mild,the service life of a catalyst is long, and the production cost of the n-valeraldehyde is remarkably lowered.

Description

technical field [0001] The invention relates to the technical field of fatty aldehyde preparation, in particular to the preparation of fatty aldehyde by hydroformylation reaction. Background technique [0002] The hydroformylation of butene to valeraldehyde is an important way for the comprehensive utilization of C4 olefin resources. A series of intermediates and fine chemicals needed for organic synthesis can be prepared from valeraldehyde: pentanol can be produced by hydrogenation of valeraldehyde, and isodecyl alcohol can be prepared by bimolecular condensation and hydrogenation of valeraldehyde, which is very popular at home and abroad in recent years. Focus on and actively develop the best way to produce isodecyl alcohol required for excellent advanced plasticizers. [0003] There have been many reports at home and abroad that 1-butene is used as raw material to generate n-valeraldehyde-based products through hydroformylation reaction, but because the price of pure 1-b...

AI Technical Summary

Problems solved by technology

Since the butene hydroformylation described in the above-mentioned patent is a homogeneous catalytic process, in the reaction system after the completion of the reaction, the catalyst and the product valeraldehyde are in the same organic phase, and the rhodium catalyst and the product are to be separated and recycled. After the product is distilled out by the distillation method, the catalyst solution is recycled back to the reactor, and the boiling point of the valeraldehyde generated by the hydroformylation of butene is higher than that of the butyraldehyde generated by the hydroformylation of propylene. Higher temperature will result in high separation energy consumption, increased generation of valeraldehyde condensation products, and after the catalyst is separated, it needs to be regenerated and activated to be recycled, which will cause rhodium complexes and phosphine ligands in the process of separation and regeneration. loss, which increases the consumption of catalysts and phosphine ligands, and at the same time complicates the production process and increases production costs

In addition, the preparation process of bisphosphite and bisphosphonamidite is complicated, expensive, and the stability is poor during use, easy to be oxidized and hydrolyzed, and the alkyl hydroxyphosphonic acid generated by its degradation is easy to gel, which is easy to cause catalyst circulation. The process pipeline is blocked, so appropriate measures must be taken during the reaction, and trace oxygen and water must be strictly removed to ensure the stability of the catalyst performance, which also greatly increases the complexity of the entire process

In addition, in order to accelerate the reaction rate of 2-butene hydroformylation in the process of homogeneous catalysis, H in the synthesis gas used 2 The molar ratio of / CO is as high as 2:1 to 25:1, which will cause a large amount of butane to be hydrogenated from butene, resulting in underutilization of butene resources

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