Method for preparing phenol or alkylphenol from methoxyphenol compounds

Abstract

The invention mainly aims to provide a method for preparing phenol or alkylphenol from methoxyphenol compounds. The method comprises the following step of: performing a reaction on a methoxyphenol compound in a water phase at the temperature of between 120 and 220 DEG C under the condition of a Raney nickel catalyst to obtain phenol or alkylphenol. The technical problem to be solved is to providea water-phase reaction system which does not need to additionally introduce hydrogen and is used for a medium-low-temperature normal-pressure reaction. The defect that phenol or alkylphenol can only react in a high-boiling-point organic solvent phase in a high-temperature and high-pressure hydrogen atmosphere through a supported metal catalyst when the phenol or alkylphenol is prepared from methoxyphenol compounds in the prior art is overcome; according to the technical scheme, the method is mild in reaction condition, low in catalyst cost, convenient to separate and purify, high in reaction conversion rate and good in alkylphenol selectivity, and is more practical.

Description

technical field [0001] The invention relates to the technical field of high-value utilization of biomass, in particular to a method for preparing phenol or alkylphenol from methoxyphenol compounds. Background technique [0002] With the rapid consumption of non-renewable energy such as petroleum and coal, and the growing demand for energy and chemical products due to the rapid development of the global economy, it is urgent to find alternative products that use renewable energy as raw materials. [0003] Lignin is an amorphous aromatic polymer widely present in plants. As the second most abundant natural polymer on land, it is an extremely abundant renewable energy source. However, lignin has long been a by-product of industries such as papermaking and biorefining, lacking high-value applications. Current research has found that lignin can be selectively degraded under high temperature and the action of a catalyst to obtain a mixture rich in methoxyphenol compounds. The c...

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Problems solved by technology

[0005] According to the reports so far, the above-mentioned reactions have the following common problems: first, the reaction temperature is relatively high, and the reactions all occur above 240°C, sometimes even as high as 450°C; 2 It can only take place under atmospheric conditions, and the pressure during the reaction is relatively high, and sometimes the reaction pressure can even be as high as 65bar to react; the third is that the reaction almost all uses high-boiling alkanes as the reaction solvent, which makes it difficult to separate and purify the product; The catalyst system for this reaction all uses supported metal catalysts, such as MoN-A, Mo / C, NiMo / Al 2 o 3 , α-MoC 1-x / AC, MoWBO x / AC, MoN / SBA15, MoC x / C, Re / ZrO 2 , WP / SiO 2 , Au / TiO 2 、Ce 0.6 Zr 0.4 o 2 , CoFe@NC, etc., the reaction conditions of the catalytic system used are harsh, the catalyst is expensive and the preparation is complicated, and the yield of the prepared product is low, and the product is difficult to separate and purify.

In addition, while this reaction produces alkylphenol, it also generates some by-products of methanol, but there are few studies on the separation and utilization of by-product methanol in the prior art.

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