Method for preparing Guerbet alcohol

Abstract

The invention discloses a method for preparing Guerbet alcohol, which comprises the steps of mixing aliphatic primary alcohol or secondary alcohol, KOH and nickel powder according to the ratio by parts by weight of 160: 2-5: 0.4-0.6, then adding into a reactor, carrying out condensation reaction at the temperature of 100-270 DEG C under the stirring state and the nitrogen protection of 0.2MPa-2MPa, terminating the reaction when no water is produced by detection, then cooling a reaction product to room temperature, after that, filtering and concentrating, thereby obtaining a Guerbet alcohol product. As the condensation reaction is carried out in the high-pressure reactor under the condition of nitrogen protection, the method excludes the influences of oxygen on the reaction, effectively avoids the side reactions of oxidation, the production of acid, aldehyde and other byproducts of oxidation and the consumption of the raw material alcohol, the product alcohol and a catalyst, improves the reaction yield and improves the conversion rate by more than 5%. Meanwhile, as the reaction with pressure is carried out, the boiling point of the raw material alcohol is increased, and the long-time reflux reaction is unnecessary, thereby shortening the reaction time by more than 50%, reducing the annual energy consumption which accounts for 500 tons of standard coal and having great popularization and utilization prospects.

Description

technical field [0001] The present invention relates to a kind of by C 4 ~C 20 Process for preparing Guerbet alcohols from fatty primary or secondary alcohols. Background technique [0002] Guerbet alcohols are compounds used as raw materials or intermediates in many applications such as detergents, pharmaceuticals, the cosmetics industry, and lubricants. Guerbet alcohols are prepared by condensation of primary or secondary alcohols. Most existing Guerbet alcohols are prepared in the presence of strong base catalysts and heavy metal promoters. Disclosed a kind of preparation method of Guerbet alcohol as US4518810, this method is to heat primary alcohol and react in the presence of alkaline substance and copper-nickel catalyst, wherein the weight ratio of copper and nickel is 1:9~9:1 . In the preparation method of Guerbet alcohol disclosed in US4800077, nickel or zinc oxide is used as a catalyst in the presence of KOH, and it is reported that the product yield of this me...

AI Technical Summary

Problems solved by technology

[0003] In the preparation method of the above-mentioned Guerbet alcohol, due to being limited by the boiling point of the raw material alcohol, it is not suitable for alcohols with less than 6 carbons

Secondly, because the oxygen in the air will carry out some oxidation side reactions in the presence of catalysts and under the heating reaction conditions of more than 200 degrees, a certain amount of oxidation by-products such as acids and aldehydes will inevitably be produced during the reaction process, and the production of these by-products consumes A certain amount of raw material alcohol, product alcohol and a small amount of basic catalyst lead to a decrease in the yield of Guerbet alcohol

Again, because above-mentioned preparation method is all normal pressure reaction, under normal pressure reaction, reaction temperature has surpassed raw material boiling point, therefore needs long time reflux reaction, causes reaction time very long, correspondingly increased energy consumption and manpower consumption, increased Cost of production

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