CN110790640A

CN110790640A - Preparation method of 2-methoxy-4-vinylphenol

Info

Publication number: CN110790640A
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: 2020-02-14
Anticipated expiration: 2039-10-16
Also published as: CN110790640B

Abstract

The invention discloses a preparation method of 2-methoxy-4-vinylphenol. According to the invention, copper oxide is used as a catalyst, furfural residues are pyrolyzed in a microwave reactor to generate 2-methoxy-4-vinylphenol, nitrogen penetrating through the furfural residues is used for carrying out product carrying, and liquid products are obtained by 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 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. 2-methoxy-4-vinylphenol is mainly prepared by decarboxylation of ferulic acid by 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 furfural is extracted by corncob hydrolysis, and the main components of the furfural residue are cellulose and lignin, wherein a structural unit taking a benzene ring as a parent in a lignin macromolecule can be converted into a plurality of high value-added chemicals, biological materials or fuel additives. The current mode of processing the furfural residues is used as boiler fuel, and although the mode can process a large amount of furfural residues, the mode still has extensive application. 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 the water content of 10% -20% and water according to the mass ratio of 1: 2-1: 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 to achieve the purpose of completely neutralizing the residual sulfuric acid catalyst in the furfural residues to obtain neutral furfural residue slurry, filtering the neutral furfural residue slurry, drying the filter residues to the water content of 30-35%, loading the filter residues into a quartz reactor, wherein the loading 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, the gas inlet pipe is arranged at the bottom of the reactor, the gas outlet pipe is arranged at the upper part of the reactor, the quartz reactor is arranged in a microwave oven, the frequency of the microwave oven is 2450Hz, and the power of the microwave oven is adjustable within the range of 0-3 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 in a mass ratio of 1:3, while adding copper oxide, controlling the amount of copper oxide to be 17% of the mass of 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 charging volume of two thirds of the reactor volume, the quartz reactor being cylindrical, 10cm in inner diameter, 10cm in height and 2.5mm in wall thickness, placing the quartz reactor into a microwave oven, turning on the microwave oven, adjusting the power to control the reactor material temperature to 480 ℃, simultaneously turning on a nitrogen bottle, introducing nitrogen gas from a reactor bottom gas inlet tube, controlling the flow rate of nitrogen gas to be 7mL/min, enabling the nitrogen gas to pass through the furfural residue and the catalyst bed layer, discharging the reaction product gas carried with the reaction product gas from an air outlet pipe at the upper part, enabling the reaction product gas to enter a condenser, enabling the product gas to enter a liquid storage bottle after condensation, and enabling the reaction time to be 6 minutes and the yield of the 2-methoxy-4-vinylphenol to reach 87.3%.

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 initial raw materials, microwaves as a heating source and copper oxide as a catalyst, and obtains the 2-methoxy-4-vinylphenol through a pyrolysis reaction, mixing furfural residue with water, adding copper oxide as a 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 the filter residue until the water content is 30-35%, loading the filter residue into a quartz reactor, and (3) placing the quartz reactor in a microwave oven, starting the microwave oven, heating reactants, carrying out pyrolysis steam by adopting nitrogen penetrating through the materials, and cooling to obtain a distillate rich in 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: 2-1: 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 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.