Method for converting fatty acid in one step by ultrasonic-assisted pressure hydrolysis of soapstock

文档序号：317575 发布日期：2021-11-30 浏览：32次中文

阅读说明：本技术 一种超声波辅助皂脚加压水解一步转化脂肪酸的方法 (Method for converting fatty acid in one step by ultrasonic-assisted pressure hydrolysis of soapstock ) 是由王佳李栋先蒋剑春于 2021-08-20 设计创作，主要内容包括：本发明公开了一种超声波辅助皂脚加压水解一步转化脂肪酸的方法,属于油脂精炼废弃物回收脂肪酸技术领域。该方法为(1)将反应物料皂脚、水和酸混合均匀；(2)将混合后的物料放入超声波反应釜中,并在不同超声作用时间、超声功率及变幅杆尺寸条件下进行加压酸化水解反应；(3)反应结束后,物料经分离得固相、油相和水相,油相经水洗、离心得产物粗脂肪酸。本发明工艺流程简便、反应条件温和、不产生含硫废水,且经过超声波的分散和乳化作用,物料间反应接触面积大大加大,皂脚可一步酸化水解成脂肪酸,减少反应时间,提高生产效率和产物酸值。(The invention discloses a method for converting fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock in one step, and belongs to the technical field of fatty acid recovery from oil refining waste. The method comprises (1) mixing reaction materials of soapstock, water and acid uniformly; (2) putting the mixed materials into an ultrasonic reaction kettle, and carrying out pressure acidification hydrolysis reaction under the conditions of different ultrasonic action time, ultrasonic power and amplitude transformer size; (3) after the reaction is finished, separating the materials to obtain a solid phase, an oil phase and a water phase, and washing and centrifuging the oil phase to obtain a crude fatty acid product. The invention has simple and convenient process flow and mild reaction condition, does not generate sulfur-containing wastewater, greatly enlarges the reaction contact area between materials through the dispersion and emulsification of ultrasonic waves, can acidify and hydrolyze the soapstock into fatty acid in one step, reduces the reaction time, and improves the production efficiency and the acid value of the product.)

1. A method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock is characterized in that 100 parts by weight of soapstock, 160 parts by weight of water and 15-25 parts by weight of acid are mixed, the pH value is adjusted to be 1.5-3.5, and then the product of crude fatty acid is obtained by one-step pressure acidification hydrolysis under the ultrasonic-assisted condition.

2. The method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock as claimed in claim 1, wherein the ultrasonic-assisted pressure acidification hydrolysis reaction is that ultrasonic waves intermittently act on the material in the form of a switch, the ultrasonic duration is 3-9s, the ultrasonic interval is 15-40s, the acting power is 450-1050W, and the size of the horn is 15-25 mm.

3. The process for the one-step conversion of fatty acids by ultrasonic assisted pressurized hydrolysis of soapstock according to claim 2, wherein the duration of the ultrasonic action is 3-6 seconds and the horn size is 20 mm.

4. The method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock as claimed in claim 1, wherein the pressure acidification hydrolysis reaction temperature is 140-200 ℃, the pressure is 0.4-2.2MPa, and the time is 45-100 min.

5. The method for converting fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock into fatty acid in one step according to claim 1, wherein the acid is any one of formic acid, oxalic acid, maleic acid, malonic acid, citric acid and pyruvic acid, wherein the concentration of formic acid is 50 wt% -80 wt%, the concentration of oxalic acid is 5 wt% -15 wt%, the concentration of maleic acid is 15 wt% -30 wt%, the concentration of malonic acid is 20 wt% -40 wt%, the concentration of citric acid is 25 wt% -45 wt%, and the concentration of pyruvic acid is 30 wt% -50 wt%.

6. The method for one-step conversion of fatty acid by ultrasonic-assisted pressurized hydrolysis of soapstock according to claim 1, comprising the steps of:

(1) uniformly mixing the reaction material nigre, water and acid;

(2) putting the mixed materials into an ultrasonic reaction kettle, and carrying out pressure acidification hydrolysis reaction under the conditions of different ultrasonic action time, ultrasonic power and amplitude transformer size;

(3) after the reaction is finished, separating the materials to obtain a solid phase, an oil phase and a water phase, and washing and centrifuging the oil phase to obtain a crude fatty acid product.

7. The method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock according to claim 1 or 6, wherein the ultrasonic-assisted pressure acidification hydrolysis reaction is that ultrasonic waves are intermittently applied to the material in the form of a switch, the ultrasonic duration is 3-6s, the ultrasonic interval is 15s, the application power is 450W, and the size of the horn is 20 mm.

8. The method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock according to claim 1 or 6, wherein the ultrasonic-assisted pressure acidification hydrolysis reaction is that ultrasonic waves intermittently act on the material in the form of a switch, the ultrasonic action duration is 3-6s, the ultrasonic interval is 15s, the action power is 1050W, and the size of the horn is 20 mm.

9. The method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock according to claim 1 or 6, wherein the ultrasonic-assisted pressure acidification hydrolysis reaction is that ultrasonic waves are intermittently applied to the material in a switch mode, the ultrasonic duration is 5s, the ultrasonic interval is 15s, the application power is 825W, and the size of the horn is 20 mm.

Technical Field

The invention belongs to the technical field of fatty acid recovery from oil and fat refining wastes, and particularly relates to a method for converting fatty acid in one step by ultrasonic-assisted pressure hydrolysis of soapstock.

Background

The soapstock is waste generated in the process of refining and deacidifying the grease, and comprises the main components of sodium aliphatate (the content is 30-40%), neutral oil (the content is 8-27%), water, protein, carbohydrate, pigment and the like, wherein the sodium aliphatate and the neutral oil can be converted into fatty acid through chemical treatment, and the content of the obtained fatty acid is up to 40-60%.

With the rapid development of the grease industry and the improvement of the living standard of people, the grease yield in China is greatly improved. According to statistics, the crude oil amount squeezed in 2020 of China is nearly 4000 ten thousand tons, and the soapstock yield accounts for about 10 percent of the crude oil amount, namely the soapstock yield in 2020 of China is nearly 400 ten thousand tons. If the resources are directly discarded, the environment is polluted, and the resources are greatly wasted. Therefore, the method has important significance in exploring the environment-friendly soapstock recycling process.

Fatty acids are monocarboxylic acids in which a carboxyl group is linked to a fatty hydrocarbon group, and are classified into saturated fatty acids and unsaturated fatty acids according to the difference in the structure of the hydrocarbon group. The fatty acid is used as a basic industrial raw material, can be used for preparing soap, producing biodiesel, synthesizing detergents, paints, coatings, plastics, cosmetics, edible emulsifiers, rubber auxiliaries and the like, and has wide and important application in the industrial fields of daily chemicals, foods, medicines, high polymer materials, buildings, mines and the like. Therefore, the conversion of fatty acids by using waste soapstock is becoming a research hotspot in the field of fatty acid production.

At present, the domestic methods for producing fatty acid by using soapstock mainly comprise three methods, namely a hydrolysis acidification method (firstly, neutral oil is hydrolyzed into fatty acid, and then, sodium fatty acid is converted into fatty acid), a saponification hydrolysis method (firstly, neutral oil is saponified into sodium fatty acid, and then, sodium fatty acid is converted into fatty acid), and an acidification hydrolysis method (firstly, sodium fatty acid is acidified into fatty acid, and then, neutral oil is hydrolyzed into fatty acid). The three methods can fully convert the soapstock into the fatty acid through two steps, and have the defects of complicated steps, long reaction time, low efficiency, large amount of waste water generation and the like. In addition, the prior art in China mostly uses concentrated sulfuric acid as a catalyst to carry out acidification and hydrolysis reaction of soapstock, and the process can generate a large amount of high-sulfur-content wastewater and cause extremely serious pollution to the environment and water quality. In recent years, some new hydrolysis process technologies are reported, for example, the invention CN105754724A discloses a method for directly converting fatty acid from soapstock, the process needs two times of stirring and mixing reaction and one time of static mixing reaction, the reaction steps are complicated, the time is long, and sulfur-containing wastewater is generated; the invention CN102827699A discloses a method for extracting fatty acid by hydrolyzing soapstock by a subcritical acetic acid method, the reaction needs to be carried out in a high-pressure magnetic stirring kettle at the temperature of 180 ℃ and 280 ℃ and at the pressure of 5-20MPa, and the requirement on reaction equipment is high; the invention CN103666768B discloses a hydrolysis treatment method for a high value-added gleditsia sinensis oil corner, and the process also needs to be reacted at high temperature (210-. The processes have the problems of complicated steps, harsh reaction conditions and high equipment cost, and the reaction conditions of high temperature and high pressure increase the probability of side reaction and decompose certain reaction components, thereby reducing the acid value and the yield of the fatty acid. In addition, most of the processes promote the mixing of materials by mechanical stirring or magnetic stirring, the mixing method has low efficiency, and the components of the materials are difficult to be fully mixed and reacted, so that the value of the produced fatty acid is low. In order to fully utilize the soapstock resource and protect the environment, a high-efficiency, environment-friendly, low-cost and simple soapstock fatty acid conversion process needs to be developed.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a method for converting fatty acid by one step through ultrasonic-assisted pressure hydrolysis of soapstock, which solves the problems of complicated steps, poor material mixing effect, long reaction time, low efficiency, low acid value of products, and environmental and water pollution caused by a large amount of sulfur-containing wastewater in the process for converting fatty acid from soapstock.

In order to solve the problems, the technical scheme adopted by the invention is as follows:

a method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock comprises mixing 100 parts by weight of soapstock, 160 parts by weight of water and 15-25 parts by weight of acid, adjusting pH to 1.5-3.5, and performing pressure acidification hydrolysis under ultrasonic-assisted conditions to obtain crude fatty acid.

The ultrasonic-assisted pressure hydrolysis and one-step fatty acid conversion method comprises the steps that ultrasonic-assisted pressure acidification hydrolysis reaction is carried out on materials in an intermittent mode in a switch mode, the ultrasonic duration time is 3-9s, the ultrasonic interval is 15-40s, the action power is 450-1050W, and the size of an amplitude transformer is 15-25 mm.

The ultrasonic-assisted method for converting fatty acid from nigre into fatty acid by one step through pressurized hydrolysis has the ultrasonic lasting action time of 3-6s and the size of an amplitude transformer of 20 mm.

The ultrasonic-assisted method for converting fatty acid by pressurized hydrolysis of soapstock comprises the steps of carrying out pressurized acidification hydrolysis at the temperature of 140-200 ℃, carrying out the pressure of 0.4-2.2MPa and carrying out the time of 45-100 min.

The ultrasonic-assisted method for converting fatty acid from nigre to fatty acid in one step through pressurized hydrolysis comprises the following steps of carrying out ultrasonic-assisted hydrolysis on nigre, wherein the acid is any one of formic acid, oxalic acid, maleic acid, citric acid or pyruvic acid, the concentration of the formic acid is 50-80 wt%, the concentration of the oxalic acid is 5-15 wt%, the concentration of the maleic acid is 15-30 wt%, the concentration of the malonic acid is 20-40 wt%, the concentration of the citric acid is 25-45 wt%, and the concentration of the pyruvic acid is 30-50 wt%.

The method for converting fatty acid by one step through ultrasonic-assisted pressure hydrolysis of soapstock comprises the following steps:

(1) uniformly mixing the reaction material nigre, water and acid;

(3) after the reaction is finished, separating the materials to obtain a solid phase, an oil phase and a water phase, and washing and centrifuging the oil phase to obtain a crude fatty acid product.

The ultrasonic-assisted pressure hydrolysis and one-step fatty acid conversion method comprises the steps that ultrasonic-assisted pressure acidification hydrolysis reaction is carried out, ultrasonic waves intermittently act on materials in a switch mode, the ultrasonic duration time is 3-6s, the ultrasonic interval is 15s, the acting power is 450W, and the size of an amplitude transformer is 20 mm.

The ultrasonic-assisted pressure hydrolysis and one-step fatty acid conversion method comprises the steps that ultrasonic-assisted pressure acidification hydrolysis reaction is carried out, ultrasonic waves intermittently act on materials in a switch mode, the ultrasonic duration time is 3-6s, the ultrasonic interval is 15s, the acting power is 1050W, and the size of an amplitude transformer is 20 mm.

The ultrasonic-assisted pressure hydrolysis and one-step fatty acid conversion method comprises the steps that ultrasonic waves are intermittently acted on materials in a switch mode in an ultrasonic-assisted pressure acidification hydrolysis reaction, the ultrasonic duration is 5s, the ultrasonic interval is 15s, the action power is 825W, and the size of an amplitude transformer is 20 mm.

Has the advantages that: compared with the prior art, the invention has the advantages that:

(1) the method has simple and convenient process steps, integrates the acidification and the hydrolysis of the soapstock into one step, and has short reaction time and high reaction efficiency; the reaction condition is mild, the reaction can be carried out at lower temperature and pressure, the energy consumption can be reduced, and the cost is low.

(2) The ultrasonic-assisted pressure acidification hydrolysis reaction can improve the efficiency of converting soapstock into fatty acid and increase the acid value of the fatty acid; the ultrasonic wave can perform the functions of crushing, stirring, dispersing and emulsifying the material components and can also accelerate the mass transfer process among the components; under the assistance of ultrasonic wave, the soapstock can be fully dispersed and mixed in an acid solution, sodium fatty acid can fully react with acid to generate fatty acid, neutral oil can also form micro-sized acid oil-in-water droplets due to the emulsification of the ultrasonic wave, and the neutral oil can fully generate hydrolysis reaction to generate the fatty acid under the catalysis of the acid.

(3) The invention does not use sulfuric acid as a catalyst in the process of pressure acidification hydrolysis, does not generate sulfur-containing wastewater, and is environment-friendly.

Drawings

FIG. 1 is a process flow diagram of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with examples are described in detail below. The reaction apparatus used in examples 1 to 11 is an ultrasonic reaction kettle of model S250, manufactured by shanghai leibei scientific instruments ltd, but is not limited to this reaction apparatus, as long as the reaction apparatus can satisfy the reaction conditions of the process of converting fatty acid into fatty acid by ultrasonic-assisted pressure acidification hydrolysis of soapstock.

The fatty acid yield is calculated by the formula:

wherein, alpha is the yield, m₁M is the mass of the crude fatty acid₀Is the mass of the reactant soapstock.

Comparative example 1

A method for preparing fatty acid by soapstock acidification comprises the following steps:

(1) mixing 100 parts by weight of soapstock and 160 parts by weight of water in a reaction lining, and dropwise adding 15 parts by weight of 50 wt% formic acid until the pH value of the mixed solution is 3.3;

(2) carrying out acidification hydrolysis reaction on the mixture obtained in the step (1) for 45min at the temperature of 140 ℃ and under the pressure of 0.4 MPa;

(3) after the reaction is finished, separating the materials to obtain a solid phase, an oil phase and a water phase, washing the oil phase with water, centrifuging to obtain a crude fatty acid product, and measuring the acid value of the crude fatty acid to be 177mg KOH/g, wherein the yield is 42%.

Example 1

A method for one-step conversion of fatty acid by ultrasonic-assisted pressure hydrolysis of soapstock is shown in figure 1, and specifically comprises the following steps:

(2) putting the lining filled with the mixed solution into an ultrasonic reaction kettle, and performing pressure acidification hydrolysis reaction under the conditions of ultrasonic continuous action time of 5s, ultrasonic interval of 15s, action power of 825W and amplitude transformer size of 20mm, wherein the reaction temperature is 140 ℃, the pressure is 0.4MPa, and the time is 45 min;

(3) after the reaction is finished, separating an oil phase at the uppermost layer of the material, a small amount of solid phase in the middle and a water phase at the lowest layer of the material to obtain a solid phase, an oil phase and a water phase; washing the oil phase to neutrality by water, removing reactant acid, and removing a small amount of water in the lower layer by centrifugal demulsification; finally, crude fatty acid is obtained, the acid value of the crude fatty acid is 185mg KOH/g, and the yield is 54 percent.

Example 2