阅读说明：本技术 一种用于植物油脱臭馏出物酯化反应的优化方法 (Optimization method for esterification reaction of deodorized distillate of vegetable oil ) 是由 黄辉其 孙海辉 魏国华 龚美青 熊志华 彭莉 于 2020-04-07 设计创作，主要内容包括：本发明提供了一种用于植物油脱臭馏出物酯化反应的优化方法,称量一定量的植物油脱臭馏出物,向植物油脱臭馏出物中加入甲醇；向植物油脱臭馏出物与甲醇的混合液中滴加浓硫酸,在加热条件下,进行第一轮酯化反应,完全反应后的得到反应液；将反应液静置分层,分层后进行分离得到反应后的热油,以及剩余的甲醇与浓硫酸混合液；对分离得到的热油进行水洗直至其酸价小于5mgKOH/g,并将水洗过程中产生的水收集；准备第二轮酯化反应,水洗后收集的水用于水洗第二轮酯化反应产生的热油,并将水洗后的水收集；植物油脱臭馏出物与甲醇的质量配比为1∶(0.1-0.25),植物油脱臭馏出物的酸价为100-160mgKOH/g。本发明提供的优化方法大大节约了生产成本,减少了酸性废水产生的量。(The invention provides an optimization method for esterification reaction of deodorized distillate of vegetable oil, weighing a certain amount of deodorized distillate of vegetable oil, and adding methanol into the deodorized distillate of vegetable oil; dropwise adding concentrated sulfuric acid into a mixed solution of the deodorized distillate of the vegetable oil and methanol, carrying out a first round of esterification reaction under a heating condition, and obtaining a reaction solution after complete reaction; standing and layering the reaction liquid, and separating after layering to obtain hot oil after reaction and a residual methanol and concentrated sulfuric acid mixed solution; washing the hot oil obtained by separation with water until the acid value of the hot oil is less than 5mgKOH/g, and collecting water generated in the washing process; preparing a second round of esterification reaction, washing hot oil generated by the second round of esterification reaction with water, and collecting the water after washing; the mass ratio of the deodorized distillate of the vegetable oil to the methanol is 1: 0.1-0.25, and the acid value of the deodorized distillate of the vegetable oil is 100-160 mgKOH/g. The optimization method provided by the invention greatly saves the production cost and reduces the amount of acid wastewater.)

1. An optimized method for esterification reaction of deodorized distillate of vegetable oil, which is characterized by comprising the following steps:

step 1: weighing a certain amount of plant oil deodorized distillate, and adding methanol into the plant oil deodorized distillate;

step 2: dropwise adding concentrated sulfuric acid into the mixed liquid of the deodorized distillate of the vegetable oil and the methanol, carrying out a first round of esterification reaction under a heating condition, and obtaining a reaction liquid after complete reaction;

and step 3: standing the reaction liquid until the reaction liquid is clearly layered, and separating the layered reaction liquid to obtain hot oil after reaction and the residual mixed solution of the methanol and the concentrated sulfuric acid;

and 4, step 4: washing the hot oil obtained by separation with water until the acid value of the hot oil is less than 5mgKOH/g, and collecting part of water generated in the washing process;

and 5: preparing a second round of esterification reaction, washing the hot oil generated in the second round of esterification reaction until the acid value of the hot oil is less than 5mgKOH/g, wherein the water used for washing the second round of esterification reaction is the water collected after washing in the step 4, and the water generated in the washing process is partially collected;

wherein the mass ratio of the vegetable oil deodorized distillate to the methanol in the step 1 is 1: 0.1-0.25, and the acid value of the vegetable oil deodorized distillate is 100-160 mgKOH/g.

2. The method of claim 1, wherein a part of raw materials in the second round of esterification reaction is the residual mixed solution of the methanol and the concentrated sulfuric acid in the step 3.

3. The optimized method for esterification reaction of vegetable oil deodorizer distillate according to claim 1, characterized in that the concentrated sulfuric acid newly added in the second esterification reaction accounts for 20% of the concentrated sulfuric acid in the first esterification reaction, and the methanol newly added in the second esterification reaction accounts for (20-50)% of the methanol in the first esterification reaction.

4. The method as claimed in claim 1, wherein the number of washing times of the hot oil in step 4 is 2, the acidic wastewater generated from the first washing is treated, and the acidic wastewater generated from the second washing is collected and used in the second round of esterification.

5. The optimization method for esterification reaction of vegetable oil deodorizer distillate according to claim 1, wherein the concentrated sulfuric acid is a 98% concentrated sulfuric acid solution, the mass ratio of the concentrated sulfuric acid solution to the vegetable oil deodorizer distillate is (0.03-0.04): 1, and the time for dropping the concentrated sulfuric acid in step 1 is 5-8 minutes.

6. The optimized method for esterification reaction of vegetable oil deodorizer distillate according to claim 1, characterized in that the time for the first round of esterification reaction in step 2 is 1-2 hours.

7. The optimized method for esterification reaction of vegetable oil deodorizer distillate according to claim 1, characterized in that the heating temperature of the heating condition in step 2 is 70-80 ℃.

8. The optimized method for esterification reaction of vegetable oil deodorizer distillate according to claim 1, characterized in that the time for the reaction solution to stand until complete stratification in step 3 is 0.5-1 hour.

9. The method of claim 1, wherein the mass of the vegetable oil deodorizer distillate in step 1 is 100g, and the amount of methanol is 10-25 g.

Technical Field

The invention relates to the technical field of biochemical engineering, in particular to an optimization method for esterification reaction of deodorized distillate of vegetable oil.

Background

Esterification is a type of organic chemical reaction, which is the reaction of alcohol with carboxylic acid or oxygen-containing inorganic acid to produce ester and water. The method is divided into three types of reactions, namely a reaction of carboxylic acid and alcohol, a reaction of inorganic oxyacid and alcohol and a reaction of inorganic strong acid and alcohol. The esterification of carboxylic acids with alcohols is reversible and generally very slow, so concentrated sulfuric acid is often used as a catalyst. The reaction of a polycarboxylic acid with an alcohol produces a variety of esters. The reaction of strong inorganic acids with alcohols is generally rapid. A typical esterification reaction is a reaction of ethanol and acetic acid to produce ethyl acetate having an aromatic odor, which is a raw material for producing dyes and medicines. The esterification reaction is widely applied to the fields of organic synthesis and the like.

In the process of recycling the deodorized distillate of vegetable oil, esterification reaction is often used, usually, the deodorized distillate of vegetable oil and methanol are proportioned according to a certain proportion, then a catalyst is used for esterification reaction under a certain condition, the product oil obtained after the reaction needs to meet the product standard requirement, in the process, the mixed solution after the esterification reaction needs to be repeatedly washed to generate a large amount of acidic wastewater, and the washed mixed solution of acid, alcohol and water needs to be subjected to preliminary distillation and rectification to recover the methanol solvent, so that the operation process is complicated, and the production cost is high.

Disclosure of Invention

In view of the above situation, the present invention provides an optimized method for esterification of deodorized distillate of vegetable oil, so as to solve the problems of generation of a large amount of wastewater and high production cost in the prior art.

The technical scheme of the invention is as follows:

step 1: weighing a certain amount of plant oil deodorized distillate, and adding methanol into the plant oil deodorized distillate;

step 2: dropwise adding concentrated sulfuric acid into the mixed liquid of the deodorized distillate of the vegetable oil and the methanol, carrying out a first round of esterification reaction under a heating condition, and obtaining a reaction liquid after complete reaction;

and step 3: standing the reaction liquid until the reaction liquid is clearly layered, and separating the layered reaction liquid to obtain hot oil after reaction and the residual mixed solution of the methanol and the concentrated sulfuric acid;

and 4, step 4: washing the hot oil obtained by separation with water until the acid value of the hot oil is less than 5mgKOH/g, and collecting part of water generated in the washing process;

and 5: preparing a second round of esterification reaction, washing the hot oil generated in the second round of esterification reaction until the acid value of the hot oil is less than 5mgKOH/g, wherein the water used for washing the second round of esterification reaction is the water collected after washing in the step 4, and the water generated in the washing process is partially collected;

wherein the mass ratio of the vegetable oil deodorized distillate to the methanol in the step 1 is 1: 0.1-0.25, and the acid value of the vegetable oil deodorized distillate is 100-160 mgKOH/g.

According to the method provided by the invention, esterification reaction is carried out on methanol and fatty acid in the deodorized distillate of vegetable oil under the condition of concentrated sulfuric acid as a catalyst, lipid substances such as fatty acid methyl ester and the like are obtained after reaction, the mass ratio of the deodorized distillate of vegetable oil to the methanol is 1 to (0.1-0.25) at the initial taking amount, a small amount of methanol is remained after the reaction under the condition that the density of an obtained hot oil layer (mainly comprising methyl ester, VE, sterol, residue oil and the like) is smaller than that of water generated by the reaction, the small amount of methanol is fused with water in a lower layer to be gathered to the lowest layer, the density of a concentrated sulfuric acid solution is maximum and is deposited to the lowest layer, so that obvious layering phenomenon can occur, the lower layer is a mixed liquid layer of the residual methanol and the concentrated sulfuric acid, the upper layer is a hot oil layer formed by methyl ester and oil residue, the hot oil layer in the upper layer is washed after separation, and the concentrated sulfuric acid and the, at the moment, the hot oil after reaction can reach the standard that the acid value is less than 5mgKOH/g after being washed for 2 times, and part of water after washing is collected and used in the washing process of the second round of esterification reaction, so the washing times are reduced, the operation process is simpler and more convenient, the generated acid wastewater is reduced, and the production cost is greatly saved. The water after the first round of water washing is used for the second round of esterification reaction again, so that the production cost can be further saved, and the generation of acid wastewater can be reduced.

Further, part of the raw materials in the second round of esterification reaction is the residual mixed solution of the methanol and the concentrated sulfuric acid in the step 3.

Further, the concentrated sulfuric acid newly added in the second round of esterification reaction accounts for 20% of the concentrated sulfuric acid in the first round of esterification reaction, and the methanol newly added in the second round of esterification reaction accounts for (20-50)% of the methanol in the first round of esterification reaction.

Furthermore, the number of times of washing the hot oil in the step 4 is 2, the acidic wastewater generated by the first washing enters the treatment process, and the acidic wastewater generated by the second washing is collected and used in the washing process of the second round of esterification reaction.

Further, the concentrated sulfuric acid is a concentrated sulfuric acid solution with the concentration of 98%, the mass ratio of the concentrated sulfuric acid solution to the deodorized distillate of the vegetable oil is (0.03-0.04) to 1, and the time for dripping the concentrated sulfuric acid in the step 1 is 5-8 minutes.

Further, the time for the first round of esterification reaction in the step 2 to complete the reaction is 1-2 hours.

Further, the heating temperature of the heating condition in the step 2 is 70-80 ℃.

Further, the time for the reaction solution to stand until complete separation in step 3 is 0.5 to 1 hour.

Further, the mass of the vegetable oil deodorized distillate in the step 1 is 100g, and the using amount of the methanol is 10-25 g.

Detailed Description

The present invention will now be described more fully hereinafter with reference to various embodiments for the purpose of facilitating an understanding of the invention, but the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

The embodiment of the invention provides an optimization method for esterification reaction of deodorized distillate of vegetable oil, which comprises the following steps:

step 1: weighing a certain amount of plant oil deodorized distillate, and adding methanol into the plant oil deodorized distillate;

step 2: dropwise adding concentrated sulfuric acid into the mixed liquid of the deodorized distillate of the vegetable oil and the methanol, carrying out a first round of esterification reaction under a heating condition, and obtaining a reaction liquid after complete reaction;

and step 3: standing the reaction liquid until the reaction liquid is clearly layered, and separating the layered reaction liquid to obtain hot oil after reaction and the residual mixed solution of the methanol and the concentrated sulfuric acid;

and 4, step 4: washing the hot oil obtained by separation with water until the acid value of the hot oil is less than 5mgKOH/g, and collecting water generated in the washing process;

and 5: preparing a second round of esterification reaction, washing the hot oil generated in the second round of esterification reaction until the acid value of the hot oil is less than 5mgKOH/g, wherein the water used for washing the second round of esterification reaction is the water collected after washing in the step 4, and the water generated in the washing process is partially collected;

wherein the mass ratio of the vegetable oil deodorized distillate to the methanol in the step 1 is 1: 0.1-0.25, and the acid value of the vegetable oil deodorized distillate is 100-160 mgKOH/g.

Further, part of the raw materials in the second round of esterification reaction is the residual mixed solution of the methanol and the concentrated sulfuric acid in the step 3.

Further, the concentrated sulfuric acid newly added in the second round of esterification reaction accounts for 20% of the concentrated sulfuric acid in the first round of esterification reaction, and the methanol newly added in the second round of esterification reaction accounts for (20-50)% of the methanol in the first round of esterification reaction.

Furthermore, the number of times of washing the hot oil in the step 4 is 2, the acidic wastewater generated by the first washing enters the treatment process, and the acidic wastewater generated by the second washing is collected and used in the washing process of the second round of esterification reaction.

Further, the concentrated sulfuric acid is a concentrated sulfuric acid solution with the concentration of 98%, the mass ratio of the concentrated sulfuric acid solution to the deodorized distillate of the vegetable oil is (0.03-0.04) to 1, and the time for dripping the concentrated sulfuric acid in the step 1 is 5-8 minutes.

Further, the time for the first round of esterification reaction in the step 2 to complete the reaction is 1-2 hours.

Further, the heating temperature of the heating condition in the step 2 is 70-80 ℃.

Further, the time for the reaction solution to stand until complete separation in step 3 is 0.5 to 1 hour.

Further, the mass of the vegetable oil deodorized distillate in the step 1 is 100g, and the using amount of the methanol is 10-25 g.

The following examples are intended to illustrate the invention in more detail. The embodiments of the present invention are not limited to the following specific examples. The present invention can be modified and implemented as appropriate within the scope of the main claim.