Method for selectively preparing acraldehyde and hydroxy-acetone

Abstract

The invention discloses a catalyst for selectively preparing acraldehyde and hydroxy-acetone from biological glycerol in a controllable manner and a preparation method of the catalyst. The catalyst is prepared by adopting a novel impregnation in-situ reduction method; the Cu / HZSM-5 catalyst, which is prepared from pure glycerol by using the method, has a glycerol catalytic conversion rate of 92.1% in a reaction kettle under gentle condition and has controllable selectivity of 87.3wt% and 12.4wt% to acraldehyde and hydroxy-acetone, respectively; and 98.2wt% conversion rate for glycerol and 86.2wt% selectivity for hydroxy-acetone can be obtained by similar glycerol catalytic dehydration reaction in a reaction distillation device. The dispersed and stable catalyst, which is obtained by adopting a catalyst preparation method, is simple and easy to operate and favorable for large-scale production. Moreover, the catalytic glycerol is gentle in solvent-free dehydration reaction, high in catalytic activity, strong in controllable selectivity, and therefore, the method is a green process with advantages of environment friendliness and low cost.

Description

technical field [0001] The invention belongs to the technical field of biomass catalysis in fine chemical industry, and specifically relates to a method for selectively preparing acrolein and hydroxyacetone from biomass glycerol catalytic dehydration and a new preparation method for a supported catalyst used in the method. Background technique [0002] As the world pays attention to the environment and sustainable development, the cheap biomass resource glycerol has a large surplus with the rapid development of biodiesel, which is basically measured in millions of tons and is growing at a rate of nearly 50% every year. Glycerol is a versatile molecular cut-off that can be converted into a variety of important products or intermediates to replace non-renewable and increasingly depleted petrochemical raw materials. [0003] Acrolein and hydroxyacetone are two important chemical raw materials. Acrolein is mainly used in the production of various resins, pesticide imidacloprid,...

AI Technical Summary

Problems solved by technology

[0005] For the glycerol dehydration reaction, considering the recovery of the catalyst and the ease of separation of the product, heterogeneous catalysis is often used, and in order to avoid the loss of the catalyst, the gas phase dehydration is the main method, but the problem is that the catalyst is unstable at high temperature, mainly in the catalyst. It is easy to coke and deactivate. At the same time, the gas phase reaction of glycerol is carried out at high temperature, which is unfavorable from the perspective of energy consumption, and its stability is worrying for catalysts that are not resistant to temperature, such as heteropolyacids.

From the various catalysts currently developed, regardless of the form (liquid phase, gas phase, and supercritical) of glycerol catalytic dehydration, or different reactors, although catalytic species with higher activity have been found, there is more or less selectivity. And the lack of stability, especially after repeated use, it is prone to coking and serious inactivation

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