CN110790640B

CN110790640B - Preparation method of 2-methoxy-4-vinylphenol

Info

Publication number: CN110790640B
Application number: CN201910987022.4A
Authority: CN
Inventors: 王君; 唐媛媛; 阎勇; 瞿帮齐; 杨忠寸; 孙亮
Original assignee: Anhui University of Science and Technology
Current assignee: Anhui University of Science and Technology
Priority date: 2019-10-16
Filing date: 2019-10-16
Publication date: 2023-01-24
Anticipated expiration: 2039-10-16
Also published as: CN110790640A

Abstract

The invention discloses a preparation method of 2-methoxy-4-vinylphenol. According to the method, copper oxide is used as a catalyst, furfural residues are pyrolyzed in a microwave reactor to generate 2-methoxy-4-vinylphenol, nitrogen penetrating through furfural residue materials is used for carrying out product taking, and liquid products are obtained through condensation. The preparation method of the 2-methoxy-4-vinylphenol has the advantages of low raw material cost, high yield, short reaction time and the like, and has a very good application prospect.

Description

Preparation method of 2-methoxy-4-vinylphenol

Technical Field

The invention relates to a preparation method of a chemical product, namely a preparation method of 2-methoxy-4-vinylphenol.

Background

The 2-methoxy-4-vinylphenol is an important fine chemical product and has wide application. The 2-methoxy-4-vinylphenol is mainly prepared by decarboxylation of ferulic acid through a fermentation method at present, and the fermentation method has the defects of long reaction time, low yield and high raw material cost, so the production cost is high. The furfural residue is a solid product left after the hydrolysis extraction of furfural from corncobs, and the main components of the furfural residue are cellulose and lignin, wherein structural units taking benzene rings as matrixes in macromolecules of lignin can be converted into a plurality of high-added-value chemicals, biological materials or fuel additives. At present, the furfural residue is treated as a boiler fuel, and although a large amount of furfural residue can be treated, the furfural residue is still used in an extensive way. The furfural residues generated after the long-time hydrothermal reaction for extracting furfural from the corncobs have fine granularity, the average particle size is less than 2.5mm, and the structure is loose, so that the method is an excellent industrial raw material for further deep processing and extracting high-added-value chemicals.

Disclosure of Invention

In order to avoid the problems in the prior art, the invention provides a method for preparing 2-methoxy-4-vinylphenol by using furfural residues as a raw material and utilizing microwave-assisted catalytic degradation of the furfural residues, so as to overcome the defects of high raw material cost, long reaction time and low yield in the prior art.

The technical scheme adopted by the invention for solving the technical problem is as follows:

the method comprises the steps of taking microwave as a heating source, taking potassium hydroxide as a neutralization reagent of sulfuric acid in the furfural residues, taking copper oxide as a catalyst, and degrading lignin in the furfural residues by utilizing the catalytic function of the copper oxide in the unique microwave heating field effect to obtain the 2-methoxy-4-vinylphenol.

The method of the invention is operated according to the following steps:

mixing furfural residue with water content of 10% -20% and water according to a mass ratio of 1:5, mixing, simultaneously adding copper oxide, controlling the adding amount of the copper oxide to account for 15-20% of the mass of the furfural residues, fully stirring, dropwise adding a potassium hydroxide solution with the concentration of 0.05M while stirring until the pH value of the solution reaches 7, achieving the purpose of completely neutralizing a residual sulfuric acid catalyst in the furfural residues, obtaining neutral furfural residue slurry, filtering the neutral furfural residue slurry, drying the filter residues to the water content of 30-35%, putting the filter residues into a quartz reactor, wherein the charging volume accounts for two-thirds to three-fourths of the volume of the reactor, the quartz reactor is cylindrical, the inner diameter is 10cm, the height is 10cm, the wall thickness is 2.5mm, an air inlet pipe is arranged at the bottom of the reactor, an air outlet pipe is arranged at the upper part of the reactor, the quartz reactor is placed in a microwave oven, the frequency of the microwave oven is 0Hz, and the power is adjustable within the range of 2450 kW. The gas inlet pipe of the reactor is connected with a nitrogen steel cylinder, the gas outlet pipe of the reactor is connected with a condenser, and the back of the condenser is connected with a liquid storage bottle. Putting the reactor filled with the furfural residue material into a microwave oven, starting the microwave oven, controlling the temperature of the material in the reactor to be 450-500 ℃ by adjusting the power, simultaneously starting a nitrogen bottle, controlling the flow of nitrogen to be 5-10 mL/min, reacting for 5-10 min, carrying out pyrolysis steam by using the nitrogen passing through the material, condensing, and receiving the obtained distillate rich in 2-methoxy-4-vinylphenol in a liquid storage bottle.

Compared with the existing preparation method of 2-methoxy-4-vinylphenol, the invention has the beneficial effects that: the reaction time is short, the reaction can be completed in less than 10 minutes, the yield is high, the yield of the 2-methoxy-4-vinylphenol reaches 80-90 percent by taking the average benzene ring matrix mole number of lignin in the furfural residue as a reference, the raw material cost is low, and the furfural residue is a waste for producing furfural, and has large amount and low price.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The invention is further described below with reference to specific examples:

example 1 according to the procedure of the present invention, 250g of furfural residue having a water content of 18% and deionized water were mixed according to a mass ratio of 1 to 3, while adding copper oxide, controlling the amount of copper oxide added to be 17% of the mass of the furfural residue, stirring thoroughly, adding dropwise a potassium hydroxide solution having a concentration of 0.05M while stirring until the pH of the solution reached 7 to obtain a neutral furfural residue slurry, filtering the neutral furfural residue slurry, drying the residue to a water content of 32%, charging the residue into a quartz reactor having a cylindrical shape with an inner diameter of 10cm and a height of 10cm and a wall thickness of 2.5mm, placing the quartz reactor into a microwave oven, turning on the microwave oven, adjusting the power to control the temperature of the reactor material to be 480 ℃, simultaneously turning on a nitrogen bottle, introducing nitrogen from an inlet pipe at the bottom of the reactor, controlling the flow of nitrogen to be 7mL/min, passing through the furfural residue and catalyst bed, carrying reaction product gas discharged from an outlet pipe at the upper portion, entering a condenser, condensing the product gas, entering a liquid storage bottle, and achieving a yield of 2-4.3% of vinyl phenol.

Example 2 in the same way as example 1, the yield of the 2-methoxy-4-vinylphenol reaches 88.6 percent by controlling the adding amount of the copper oxide to be 15 percent of the mass of the furfural residue, adjusting the power to control the material temperature of the reactor to be 460 ℃ and the reaction time to be 8 minutes, and keeping other conditions unchanged.

Example 3 in the same way as example 1, the yield of the 2-methoxy-4-vinylphenol reaches 86.9 percent by controlling the adding amount of the copper oxide to be 20 percent of the mass of the furfural residue, adjusting the power to control the material temperature of the reactor to be 490 ℃ and the reaction time to be 5 minutes, and keeping other conditions unchanged.

It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application.

Claims

1. A preparation method of 2-methoxy-4-vinylphenol adopts furfural residues as a starting raw material, adopts microwaves as a heating source, adopts copper oxide as a catalyst, and obtains the 2-methoxy-4-vinylphenol through a pyrolysis reaction, which is characterized by comprising the following process operations of mixing the furfural residues with water, simultaneously adding the copper oxide as the catalyst, fully stirring the mixed materials, dropwise adding a potassium hydroxide solution with the concentration of 0.05M while stirring until the pH value of the solution reaches 7, filtering the neutral furfural residue slurry, drying filter residues until the water content is 30-35%, loading the filter residues into a quartz reactor, placing the quartz reactor into a microwave oven, starting the microwave oven, heating reactants, carrying out pyrolysis steam by adopting nitrogen passing through the materials, and cooling to obtain a distillate rich in the 2-methoxy-4-vinylphenol.

2. The method for preparing 2-methoxy-4-vinylphenol according to claim 1, wherein the mass ratio of furfural residue to water is 1:2 to 1:5, mixing, wherein the addition amount of the catalyst copper oxide accounts for 15-20% of the mass of the furfural residue.

3. The process of claim 1, wherein the temperature of the materials in the reactor is 450-500 ℃, the microwave frequency is 2450Hz, and the microwave oven power is 0-3 kW.

4. The process according to claim 1, wherein the nitrogen flow rate through the reaction mixture is 5-10 mL/min, and the reaction time is 5-10 min.