Method for converting lignocellulose into phenolic compounds, polyols and organic acids by one-pot process

Abstract

The invention discloses a method for converting lignocellulose into phenolic compounds, polyhydric alcohols and organic acids through a one-pot process. According to the method, synchronous conversion of lignin, cellulose and hemicellulose in lignocellulose is realized at a high temperature by using a strong alkali solution with a high concentration, and an oxidation system dominated by a metal oxide or a hydrogenation system dominated by a noble metal can quickly convert an intermediate product decomposed by lignocellulose, so non-selective conversion or polymerization of intermediate products (such as lignin hydrolysate and carbohydrate reverse aldol products) is effectively avoided, and the intermediate products are converted into relatively stable products (phenolic compounds, polyhydric alcohols and organic acids); and one-step efficient conversion of main components (lignin and carbohydrate) of lignocellulose into the products is realized in one pot, so a traditional multi-step reaction strategy of firstly separating the lignocellulose components and then respectively performing catalytic conversion on the components is avoided, and the efficiency and the economical efficiency of comprehensive refining of all the components of the lignocellulose are improved.

Description

technical field

[0001] The invention specifically relates to a method for converting lignocellulose into phenolic compounds, polyols and organic acids in one pot. Background technique

[0002] Currently, fossil-based phenolic compounds (such as vanillin, syringaldehyde, ethylguaiacol, and 4-ethyl-2,6-dimethoxyphenol, etc.) and polyols (such as ethylene glycol, propylene glycol, etc.) and Organic acids (such as formic acid, acetic acid, oxalic acid, lactic acid, and glycolic acid, etc.) are important chemical raw materials or solvents required by industries such as medicine, spices, pesticide chemistry, and polymers. They have become an important material basis for the development of human society.

[0003] Lignocellulose is the most abundant renewable carbon resource on Earth. Lignocellulose is mainly composed of lignin and carbohydrates (cellulose and hemicellulose). Among them, lignin is mainly polymerized by phenylpropane monomers, and carbohydrates are mainly composed o...

Examples

Embodiment 1

[0032] (1) Deoxygenation of the reaction system

[0033] Add 1 g of dry eucalyptus powder (particle size of 40-60 mesh) and 2 g of CuO into a reaction kettle containing 10 mL of 2 mol / L NaOH aqueous solution, and then the mixture is ultrasonically deoxygenated. After the treatment, the reactor was sealed, and the reactor was purged with nitrogen for 3 times, and nitrogen was continued to make the internal pressure of the reactor 0.2 MPa.

[0034] (2) One-pot conversion of lignocellulose

[0035] Heat the sealed reactor in step (1) to 210 °C, react at this temperature for 40 min, and cool down to room temperature quickly after the reaction, then filter and separate the solid-liquid mixture in the reactor to obtain alkaline solution, Cu 2 O and Cu elemental residual solids.

[0036] (3) Acidification treatment of the product

[0037] Use SO 2 Adjust the pH of the obtained alkaline solution to 2 to obtain an acidified solution containing phenolic compounds and organic acids. ...

Embodiment 2

[0039] The reaction temperature in step (1) of Example 1 was replaced by 150°C, the reaction time was replaced by 10 h, and other operations were the same as in Example 1.

Embodiment 3

[0041] Replace the reaction temperature in step (1) of Example 1 with 350°C and the reaction time with 10 s, and other operations are the same as in Example 1.

technical field

[0001] The invention specifically relates to a method for converting lignocellulose into phenolic compounds, polyols and organic acids in one pot. Background technique

[0002] Currently, fossil-based phenolic compounds (such as vanillin, syringaldehyde, ethylguaiacol, and 4-ethyl-2,6-dimethoxyphenol, etc.) and polyols (such as ethylene glycol, propylene glycol, etc.) and Organic acids (such as formic acid, acetic acid, oxalic acid, lactic acid, and glycolic acid, etc.) are important chemical raw materials or solvents required by industries such as medicine, spices, pesticide chemistry, and polymers. They have become an important material basis for the development of human society.

[0003] Lignocellulose is the most abundant renewable carbon resource on Earth. Lignocellulose is mainly composed of lignin and carbohydrates (cellulose and hemicellulose). Among them, lignin is mainly polymerized by phenylpropane monomers, and carbohydrates are mainly composed o...

Examples

Embodiment 1

[0032] (1) Deoxygenation of the reaction system

[0033] Add 1 g of dry eucalyptus powder (particle size of 40-60 mesh) and 2 g of CuO into a reaction kettle containing 10 mL of 2 mol / L NaOH aqueous solution, and then the mixture is ultrasonically deoxygenated. After the treatment, the reactor was sealed, and the reactor was purged with nitrogen for 3 times, and nitrogen was continued to make the internal pressure of the reactor 0.2 MPa.

[0034] (2) One-pot conversion of lignocellulose

[0035] Heat the sealed reactor in step (1) to 210 °C, react at this temperature for 40 min, and cool down to room temperature quickly after the reaction, then filter and separate the solid-liquid mixture in the reactor to obtain alkaline solution, Cu 2 O and Cu elemental residual solids.

[0036] (3) Acidification treatment of the product

[0037] Use SO 2 Adjust the pH of the obtained alkaline solution to 2 to obtain an acidified solution containing phenolic compounds and organic acids. ...

Embodiment 2

[0039] The reaction temperature in step (1) of Example 1 was replaced by 150°C, the reaction time was replaced by 10 h, and other operations were the same as in Example 1.

Embodiment 3

[0041] Replace the reaction temperature in step (1) of Example 1 with 350°C and the reaction time with 10 s, and other operations are the same as in Example 1.

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