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Method for preparing catechol from lignin

A catechol, lignin technology, applied in chemical instruments and methods, preparation of organic compounds, organic chemistry, etc., can solve problems such as low selectivity and non-renewable

Active Publication Date: 2012-09-05
TIANJIN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art, overcome the problem of low selectivity of the prior art, solve the problem that the raw material phenol is derived from non-renewable fossil fuels, and provide a renewable biomass-based The o-methoxyphenol obtained from the lignin degradation of waste is used as a reactant to prepare catechol, which is a renewable and green process with a yield of 90%.

Method used

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  • Method for preparing catechol from lignin
  • Method for preparing catechol from lignin
  • Method for preparing catechol from lignin

Examples

Experimental program
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Effect test

Embodiment 1

[0027] First, mix 0.5g of alkali lignin with 70mL of deionized water, put it into the autoclave, protect it with nitrogen, make the initial pressure in the autoclave 0 MPa, raise the temperature to 250°C, and stir for 5 hours. After the reaction, pump filtered, extracted with dichloromethane, and then rotary evaporated to obtain o-methoxyphenol;

[0028] Add 0.5g of o-methoxyphenol and 70mL of aqueous hydrochloric acid solution with pH=1.8 into the reaction kettle, when the reaction atmosphere is H 2 , the initial pressure is 1MPa, the temperature is raised to 280°C, the reaction time is 3h, the conversion rate of o-methoxyphenol is 100%, and the yield of catechol is 90%.

Embodiment 2

[0030]First, mix 0.5g of alkali lignin with 70mL of deionized water, put it into the autoclave, protect it with nitrogen, make the initial pressure in the autoclave 0MPa, raise the temperature to 350°C, stir and react for 3h, after the reaction, pump filtered, extracted with dichloromethane, and then rotary evaporated to obtain o-methoxyphenol;

[0031] Add 0.5g of o-methoxyphenol and 70mL of aqueous hydrochloric acid solution with pH=1.5 into the reaction kettle, when the reaction atmosphere is H 2 , the initial pressure is 0.5MPa, the temperature is raised to 280°C, the reaction time is 3h, the conversion rate of o-methoxyphenol is 93%, and the yield of catechol is 84%.

Embodiment 3

[0033] First, mix 0.5g of alkali lignin with 70mL of deionized water, put it into the autoclave, protect it with nitrogen, make the initial pressure in the autoclave 0 MPa, raise the temperature to 300°C, and stir for 4 hours. After the reaction, pump filtered, extracted with dichloromethane, and then rotary evaporated to obtain o-methoxyphenol;

[0034] Add 0.5g of o-methoxyphenol and 70mL of aqueous hydrochloric acid solution with pH=1.8 into the reaction kettle, when the reaction atmosphere is H 2 , the initial pressure is 0 MPa, the temperature is raised to 300° C., the reaction time is 1 h, the conversion rate of o-methoxyphenol is 83%, and the yield of catechol is 76%.

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Abstract

The invention discloses a method for preparing catechol from lignin, which comprises the following steps: after mixing alkali lignin and a solution, adding the mixture into a high-pressure reaction kettle, and reacting in an inert gas atmosphere to generate guaiacol; and hydrolyzing the guaiacol to obtain the catechol. The invention overcomes the defect of low selectivity in the prior art, solves the problem that the raw material phenol is derived from non-renewable fossil fuels, and provides a method for preparing catechol from the reactant guaiacol prepared by degrading lignin, which is often used as waste in renewable biomass.

Description

technical field [0001] The invention relates to a method for preparing catechol, more specifically, a method for preparing catechol by using lignin as a raw material. Background technique [0002] Catechol is an important chemical in the chemical industry. 50% of catechol is used to produce pesticides, and the rest is used to make spices or medicines, and can also be used as a developer. The ethoxylated phenol obtained by the ethylation of catechol can be used to produce vanillin, which is an important ingredient in the production of chocolate. Piperonal is also produced from catechol, and piperonal is usually used as a flavoring agent. At present, the industrialized production method of catechol is phenol hydroxylation method, and the process is that phenol is oxidized by oxides (peroxyacid, hydrogen peroxide, etc.) to obtain o-catechol and hydroquinone, which can be separated to obtain catechol. The disadvantage of this method is that the selectivity is poor and the by-...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C39/08C07C37/055
Inventor 李永丹杨乐
Owner TIANJIN UNIV
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