阅读说明：本技术 一种山嵛酸和硬脂酸的制备方法 (Preparation method of behenic acid and stearic acid ) 是由 罗金安 冯自伟 钟玉蛟 赵涛 阮国艳 石雷 于 2021-09-02 设计创作，主要内容包括：本发明公开了一种山嵛酸和硬脂酸的制备方法,包括：向高芥酸菜籽油中通入臭氧,搅拌,得高芥酸菜籽油预处理物；对高芥酸菜籽油预处理物脱硫,得到高芥酸菜籽油脱硫产物；对高芥酸菜籽油脱硫产物加氢处理,得氢化菜籽油；对氢化菜籽油进行皂化处理,得一元酸皂溶液,调整温度,析出山嵛酸皂,过滤,降温,析出硬脂酸皂；对山嵛酸皂、硬脂酸皂分别酸化处理。利用臭氧对高芥酸菜籽油中的含硫杂质进行氧化预处理,提高后续脱离效果,再通过脱硫处理,将高芥酸菜籽油中的含硫杂质脱除,避免对后续氢化过程的影响,不会出现催化剂中毒的现象,提高氢化强度、氢化催化剂的利用率、降低生产成本,并提高山嵛酸和硬脂酸的纯度,提高生产效率。(The invention discloses a preparation method of behenic acid and stearic acid, which comprises the following steps: introducing ozone into the high erucic acid rapeseed oil, and stirring to obtain a high erucic acid rapeseed oil pretreatment substance; desulfurizing the high erucic acid rapeseed oil pretreatment substance to obtain a high erucic acid rapeseed oil desulfurization product; carrying out hydrotreating on the high erucic acid rapeseed oil desulfurization product to obtain hydrogenated rapeseed oil; saponifying hydrogenated rapeseed oil to obtain monobasic acid soap solution, adjusting temperature, precipitating behenic acid soap, filtering, cooling, and precipitating stearic acid soap; respectively acidifying behenic acid soap and stearic acid soap. The method has the advantages that the sulfur-containing impurities in the high erucic acid rapeseed oil are subjected to oxidation pretreatment by using ozone, the subsequent separation effect is improved, the sulfur-containing impurities in the high erucic acid rapeseed oil are removed through desulfurization treatment, the influence on the subsequent hydrogenation process is avoided, the phenomenon of catalyst poisoning is avoided, the hydrogenation strength and the utilization rate of a hydrogenation catalyst are improved, the production cost is reduced, the purity of behenic acid and stearic acid is improved, and the production efficiency is improved.)

1. A process for the preparation of behenic acid and stearic acid, comprising:

(1) introducing ozone into the high erucic acid rapeseed oil, and stirring to obtain a high erucic acid rapeseed oil pretreatment substance;

(2) desulfurizing the high erucic acid rapeseed oil pretreatment substance to obtain a high erucic acid rapeseed oil desulfurization product;

(3) carrying out hydrotreating on the high erucic acid rapeseed oil desulfurization product to obtain hydrogenated rapeseed oil;

(4) saponifying the hydrogenated rapeseed oil to obtain a monoacid soap solution, adjusting the temperature, separating out behenic acid soap, filtering, cooling, and separating out stearic acid soap;

(5) respectively acidifying the behenic acid soap and the stearic acid soap to obtain the behenic acid and the stearic acid.

2. The method for preparing behenic acid and stearic acid according to claim 1, wherein the desulfurization process of the high erucic acid rapeseed oil pretreatment is as follows:

adding an alkali solution into the high erucic acid rapeseed oil pretreated substance, standing for liquid separation after reaction, and discharging bottom layer waste liquid to obtain a high erucic acid rapeseed oil primary treated substance;

adding hot water into the first treated matter of the high erucic acid rapeseed oil, standing and separating liquid after reaction, and discharging bottom layer waste liquid to obtain a second treated matter of the high erucic acid rapeseed oil;

and adding an adsorbent into the secondary treatment substance of the high erucic acid rapeseed oil, and circularly filtering to remove the adsorbent after reaction to obtain a high erucic acid rapeseed oil desulfurization product.

3. The method for preparing behenic acid and stearic acid according to claim 1, wherein the high erucic acid rapeseed oil is rapeseed oil with an erucic acid content of 40-60%;

reacting high erucic acid rapeseed oil with ozone in an ozone reaction kettle at a stirring speed of 80-150 rpm, a reaction temperature of 25-60 ℃, a reaction time of 2-20 min, an ozone concentration of 2-30 mg/L and an ozone introduction speed of 1-100 m³/h。

4. The method for preparing behenic acid and stearic acid as claimed in claim 2, wherein the alkali solution is a mixture of one or more aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate with a mass fraction of 5-50%;

the reaction temperature of the high erucic acid rapeseed oil pretreatment substance and the alkali solution is 60-95 ℃, and the reaction time is 10-40 min;

the high erucic acid rapeseed oil preconditioning and alkali solution react in the reaction kettle of normal pressure.

5. The method for preparing behenic acid and stearic acid according to claim 2, wherein the hot water is deionized water, and the mass ratio of the hot water to the high erucic acid rapeseed oil is 0.05-0.5: 1;

the temperature of the hot water is 80-95 ℃, the reaction temperature of the first treatment substance of the high erucic acid rapeseed oil and the hot water is 80-95 ℃, and the reaction time is 5-20 min.

6. The method for preparing behenic acid and stearic acid according to claim 2, wherein the adsorbent is one or a mixture of more of activated clay, diatomite, activated carbon and a molecular sieve, and the mass ratio of the adsorbent to the high erucic acid rapeseed oil is 0.01-0.2: 1;

the reaction temperature of the secondary treatment substance of the high erucic acid rapeseed oil and the adsorbent is 60-90 ℃, the reaction time is 30 min-2 h, the secondary treatment substance reacts under the condition that the vacuum degree is-0.06-0.09 MPa, and then the adsorbent is removed by circular filtration.

7. The process of claim 1, wherein the hydrotreating process of the desulfurization product of high erucic acid rapeseed oil comprises: adding a hydrogenation catalyst into the high erucic acid rapeseed oil desulfurization product in the high-pressure reaction kettle, introducing hydrogen, wherein the reaction temperature is 150-230 ℃, the reaction pressure is 0.2-2 Mpa, and the stirring speed in the reaction process is 80-150 rpm;

the hydrogenation catalyst is one or a mixture of more of nickel, copper, molybdenum, cobalt and platinum, and the mass ratio of the hydrogenation catalyst to the high erucic acid rapeseed oil is 0.05-0.5: 100.

8. A process for the preparation of behenic acid and stearic acid as claimed in claim 1, wherein the saponification reaction is carried out by: reacting hydrogenated rapeseed oil with saponification alkali liquor to obtain monobasic acid soap solution;

the saponification reaction temperature is 60-95 ℃, and the saponified alkali liquor is one or a mixture of more of sodium hydroxide, potassium hydroxide and lithium hydroxide.

9. A process for the preparation of behenic acid and stearic acid as claimed in claim 1, wherein the acid used in the acidification treatment is a strong inorganic acid, said strong inorganic acid being one or more of sulfuric acid, hydrochloric acid, nitric acid and phosphoric acid.

Technical Field

The invention relates to the technical field of organic monobasic acid preparation, in particular to a preparation method of behenic acid and stearic acid.

Background

Behenic acid, also known as behenic acid, linoleic acid, is a white acicular crystal or waxy solid in appearance. The application and the wide range of the behenic acid and the derivatives thereof. Behenic acid is an excellent assistant and can be used as an additive of a medical bactericide, an agricultural insecticide and a cosmetic; in the textile industry, the fatty acid type finishing softener can be used as a fatty acid type finishing softener, and has better performance and effect compared with other fatty acids. As for the derivative product, the silver salt of behenic acid is a thermal development sensitive material, and has the advantages of rapid imaging, no pollution and the like when being used in the exposure field, and in addition, the silver salt of behenic acid is an excellent electrical copying material; the behenic acid amide has excellent corrosion resistance, can be used for metal corrosion prevention of ships and even warships, and can be used for placing algae to be attached to naval vessels; glyceryl behenate is also a good adjuvant for sustained release agents.

Stearic acid, also known as octadecanoic acid, is a white waxy transparent solid or yellowish waxy solid in appearance. Stearic acid has a very wide range of applications, is a very important auxiliary agent, helps to prevent 'coking' in the processing process in a plastic PVC pipe, and is an effective heat stabilizer in PVC film processing; is a vulcanizing activator widely applied to natural rubber, synthetic rubber and latex, and can also be used as a plasticizer and a softener; is also the main raw material for manufacturing almond honey and milk; in addition, as for the downstream derivatives thereof, stearic acid can be used for producing stearate, such as sodium stearate, magnesium stearate, calcium stearate, lead stearate and the like, and can be widely used for producing cosmetics, cold-resistant plasticizers for plastics, mold release agents, stabilizers, surfactants, rubber vulcanization accelerators and the like; glyceryl stearate, sorbitol stearate, sucrose stearate are widely used in the food industry as lubricants, defoamers, and the like.

For the preparation of behenic acid, the currently adopted method is to use high erucic acid rapeseed oil as raw material, and then to hydrogenate and saponify the rapeseed oil and reduce the rapeseed oil with acid to obtain behenic acid, or to directly hydrogenate erucic acid. However, when the hydrogenation is performed by the above two methods, the residual sulfur in the high erucic acid rapeseed oil and the erucic acid is present in the raw materials, so that the hydrogenation often causes catalyst poisoning, the hydrogenation degree is reduced, the product yield and the production efficiency are seriously affected, the product purity is also reduced, and the production cost is increased. For the preparation of stearic acid, CN201910708678.8 introduces a stearic acid production process, in which secondary pressure stearic acid is separated by pressure separation equipment, and then is subjected to filter pressing by filter cloth to obtain primary stearic acid. The method is the conventional stearic acid production process at present, but the stearic acid obtained by the method has low purity.

Disclosure of Invention

The technical problems to be solved by the invention are that the existing method for preparing behenic acid by high erucic acid rapeseed oil has catalyst poisoning phenomenon, reduces the product yield, production efficiency and purity, increases the production cost, and the purity of stearic acid obtained by the existing method for preparing stearic acid is lower; aims to provide a preparation method of behenic acid and stearic acid to solve the problems.

The invention is realized by the following technical scheme:

a process for the preparation of behenic acid and stearic acid comprising:

(1) introducing ozone into the high erucic acid rapeseed oil, and stirring to obtain a high erucic acid rapeseed oil pretreatment substance;

(2) desulfurizing the high erucic acid rapeseed oil pretreatment substance to obtain a high erucic acid rapeseed oil desulfurization product;

(3) carrying out hydrotreating on the high erucic acid rapeseed oil desulfurization product to obtain hydrogenated rapeseed oil;

(4) saponifying the hydrogenated rapeseed oil to obtain a monoacid soap solution, adjusting the temperature, separating out behenic acid soap, filtering, cooling, and separating out stearic acid soap;

(5) respectively acidifying the behenic acid soap and the stearic acid soap to obtain the behenic acid and the stearic acid.

Preferably, the desulfurization process for the high erucic acid rapeseed oil pretreatment substance is as follows:

adding an alkali solution into the high erucic acid rapeseed oil pretreated substance, standing for liquid separation after reaction, and discharging bottom layer waste liquid to obtain a high erucic acid rapeseed oil primary treated substance;

adding hot water into the first treated matter of the high erucic acid rapeseed oil, standing and separating liquid after reaction, and discharging bottom layer waste liquid to obtain a second treated matter of the high erucic acid rapeseed oil;

and adding an adsorbent into the secondary treatment substance of the high erucic acid rapeseed oil, and circularly filtering to remove the adsorbent after reaction to obtain a high erucic acid rapeseed oil desulfurization product.

Preferably, the high erucic acid rapeseed oil is rapeseed oil with an erucic acid content of 40-60%;

reacting high erucic acid rapeseed oil with ozone in an ozone reaction kettle at a stirring speed of 80-150 rpm, a reaction temperature of 25-60 ℃, a reaction time of 2-20 min, an ozone concentration of 2-30 mg/L and an ozone introduction speed of 1-100 m³/h。

Preferably, the alkali solution is a mixture of one or more aqueous solutions of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate with the mass fraction of 5-50%;

the reaction temperature of the high erucic acid rapeseed oil pretreatment substance and the alkali solution is 60-95 ℃, and the reaction time is 10-40 min;

the high erucic acid rapeseed oil preconditioning and alkali solution react in the reaction kettle of normal pressure.

Preferably, the hot water is deionized water, and the mass ratio of the hot water to the high erucic acid rapeseed oil is 0.05-0.5: 1;

the temperature of the hot water is 80-95 ℃, the reaction temperature of the first treatment substance of the high erucic acid rapeseed oil and the hot water is 80-95 ℃, and the reaction time is 5-20 min.

Preferably, the adsorbent is one or a mixture of more of activated clay, diatomite, activated carbon and a molecular sieve, and the mass ratio of the adsorbent to the high erucic acid rapeseed oil is 0.01-0.2: 1;

the reaction temperature of the secondary treatment substance of the high erucic acid rapeseed oil and the adsorbent is 60-90 ℃, the reaction time is 30 min-2 h, the secondary treatment substance reacts under the condition that the vacuum degree is-0.06-0.09 MPa, and then the adsorbent is removed by circular filtration.

Preferably, the hydrotreating process of the high erucic acid rapeseed oil desulfurization product is as follows: adding a hydrogenation catalyst into the high erucic acid rapeseed oil desulfurization product in the high-pressure reaction kettle, introducing hydrogen, wherein the reaction temperature is 150-230 ℃, the reaction pressure is 0.2-2 Mpa, and the stirring speed in the reaction process is 80-150 rpm;

the hydrogenation catalyst is one or a mixture of more of nickel, copper, molybdenum, cobalt and platinum, and the mass ratio of the hydrogenation catalyst to the high erucic acid rapeseed oil is 0.05-0.5: 100.

Preferably, the saponification reaction is carried out by: reacting hydrogenated rapeseed oil with saponification alkali liquor to obtain monobasic acid soap solution;

the saponification reaction temperature is 60-95 ℃, and the saponified alkali liquor is one or a mixture of more of sodium hydroxide, potassium hydroxide and lithium hydroxide.

Preferably, the acid used in the acidification treatment is a strong inorganic acid, which is a mixture of one or more of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid.

The invention relates to a preparation method of behenic acid and stearic acid, which comprises the steps of firstly, reacting high erucic acid rapeseed oil with ozone to oxidize sulfur-containing impurities in the high erucic acid rapeseed oil by the ozone to obtain a pretreatment substance, wherein the oxidized sulfur-containing impurities are easy to react with an alkali solution in subsequent reactions to generate hydrophilic impurities, so that the hydrophilic impurities are easy to separate from the rapeseed oil; then the high erucic acid rapeseed oil preconditioning thing is sequentially treated with alkali solution, deionized water, further process the impurity containing sulfur, discharge the lower floor sulfur-containing waste liquid, get the high erucic acid rapeseed oil second grade treatment thing; then, removing the residual sulfur-containing impurities in the secondary treatment substance of the high erucic acid rapeseed oil by using an adsorbent; then hydrogenation, saponification and acidification are carried out to obtain the behenic acid and the stearic acid.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the preparation method of the behenic acid and the stearic acid, provided by the embodiment of the invention, firstly, the sulfur-containing impurities in the high erucic acid rapeseed oil are subjected to oxidation pretreatment, so that the oxidized sulfur-containing impurities generate hydrophilic impurities when reacting with an alkali solution, the hydrophilic impurities are easy to separate from the rapeseed oil, and the removal effect of the sulfur-containing impurities is improved; then, sulfur-containing impurities in the high erucic acid rapeseed oil are removed through desulfurization treatment, the influence on the subsequent hydrogenation process is avoided, the phenomenon of catalyst poisoning does not occur, the hydrogenation strength is improved, the utilization rate of a hydrogenation catalyst is improved (the mass ratio of the hydrogenation catalyst to the high erucic acid rapeseed oil can reach 0.05:100 at the lowest), the production cost is reduced, the purity of the behenic acid and the purity of the stearic acid are both improved to reach more than 90%, and the production efficiency is improved.

(2) According to the preparation method of behenic acid and stearic acid provided by the embodiment of the invention, in the desulfurization process, firstly, the polarity of sulfur-containing impurities is enhanced by using an alkali solution, then, water washing is carried out, and then, the sulfur-containing impurities are adsorbed again by using an adsorbent.

Drawings

In order to more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the drawings that are required to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and that for those skilled in the art, other related drawings can be obtained from these drawings without inventive effort. In the drawings:

fig. 1 is a schematic diagram of a preparation method of behenic acid and stearic acid provided in the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to examples, and the exemplary embodiments and descriptions thereof are only used for explaining the present invention and are not used as limitations of the present invention.

Example 1

A preparation method of behenic acid and stearic acid comprises the following steps:

(1) putting 500Kg high erucic acid rapeseed oil (mass fraction of erucic acid is 48%) into an ozone reaction kettle, stirring at 80rpm, introducing ozonized gas with 20mg/L ozone content into the ozone reaction kettle through a gas distributor at a gas introduction speed of 60m³Controlling the temperature of the reaction system at 25 ℃ to react for 10min to obtain a high erucic acid rapeseed oil pretreatment substance;

(2) transferring the high erucic acid rapeseed oil pretreatment substance to a normal pressure reaction kettle, heating to 80 ℃, adding a 10% sodium hydroxide aqueous solution with stirring, stirring and reacting for 20min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil primary treatment substance;

(3) raising the temperature to 90 ℃, adding 100Kg of 90 ℃ deionized water into a normal pressure reaction kettle, stirring, reacting for 5min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil secondary treatment substance;

testing the sulfur content in the high erucic acid rapeseed oil secondary treatment substance, and if the sulfur content is higher than a set value of 15ppm, sequentially repeating the steps (2) and (3) until the sulfur content is lower than 15 ppm;

(4) adding a mixture of 25Kg of argil and 5Kg of diatomite into the secondary treatment substance of the high erucic acid rapeseed oil, controlling the temperature of a reaction system to be 80 ℃ and the vacuum degree to be-0.09 MPa, reacting for 1 hour, and circularly filtering the argil and the diatomite to obtain a desulfurization product of the high erucic acid rapeseed oil;

and (3) testing the sulfur content of the high erucic acid rapeseed oil desulfurization product, and if the sulfur content is higher than a set value by 10ppm, repeating the adsorption reaction of the argil and the diatomite until the sulfur content is less than 10 ppm.

(5) Transferring the high erucic acid rapeseed oil desulfurization product to a high-pressure reaction kettle, adding 1Kg of nickel, controlling the reaction temperature at 170 ℃, the stirring speed at 80rpm and the reaction pressure at 1.0MPa for reaction until the iodine value of the product<5I₂100g to obtain hydrogenated rapeseed oil;

(6) the method comprises the steps of carrying out saponification reaction on hydrogenated rapeseed oil and 900L of 10% sodium hydroxide solution at 95 ℃, after the reaction is finished, reducing the temperature of the materials to 35 ℃ for crystallization, separating out sodium behenate, filtering to obtain 190Kg of sodium behenate and filtrate, further reducing the filtrate to 15 ℃ for crystallization, and separating out 173Kg of sodium stearate.

(7) Dissolving 190Kg of sodium behenate in 1000L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, cooling to 20 ℃, and filtering the separated solid to obtain 170Kg of behenic acid; through gas chromatography analysis, the content of C22:0 in the behenic acid is as follows: 90.3 percent;

dissolving 173Kg of sodium stearate in 600L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, reducing the temperature to 5 ℃, and filtering the separated solid to obtain 155Kg of stearic acid; according to gas chromatographic analysis, the content of C18:0 is as follows: 94.1 percent.

Example 2

A preparation method of behenic acid and stearic acid comprises the following steps:

(1) putting 500Kg high erucic acid rapeseed oil (the mass fraction of erucic acid is 52%) into an ozone reaction kettle, stirring at 100rpm, introducing ozonized gas with the ozone content of 30mg/L into the ozone reaction kettle through a gas distributor at the gas introduction speed of 50m³Controlling the temperature of the reaction system at 30 ℃ to react for 5min to obtain a high erucic acid rapeseed oil pretreatment substance;

(2) transferring the high erucic acid rapeseed oil pretreatment substance to a normal pressure reaction kettle, heating to 85 ℃, adding a 10% sodium hydroxide aqueous solution with stirring, stirring and reacting for 15min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil primary treatment substance;

(3) raising the temperature to 90 ℃, adding 75Kg of 90 ℃ deionized water into a normal pressure reaction kettle, stirring, reacting for 5min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil secondary treatment substance;

testing the sulfur content in the high erucic acid rapeseed oil secondary treatment substance, and if the sulfur content is higher than 20ppm, sequentially repeating the steps (2) and (3) until the sulfur content is lower than 20 ppm;

(4) adding a mixture of 25Kg of argil and 5Kg of activated carbon into the secondary treated matter of the high erucic acid rapeseed oil, controlling the temperature of a reaction system to be 85 ℃ and the vacuum degree to be-0.085 MPa, reacting for 1 hour, and circularly filtering the argil and the activated carbon to obtain a high erucic acid rapeseed oil desulfurization product;

testing the sulfur content of the high erucic acid rapeseed oil desulfurization product, if the sulfur content is higher than a set value by 10ppm, repeating the adsorption reaction of the argil and the diatomite until the sulfur content is less than 10 ppm;

(5) transferring the high erucic acid rapeseed oil desulfurization product to a high-pressure reaction kettle, adding 0.8Kg of nickel, controlling the reaction temperature to be 190 ℃, the stirring speed to be 100rpm and the reaction pressure to be 1.0MPa, and reacting until the iodine value of the product is reached<10I₂100g to obtain hydrogenated rapeseed oil;

(6) carrying out saponification reaction on hydrogenated rapeseed oil and 900L of 10% sodium hydroxide solution at 95 ℃, after the reaction is finished, reducing the temperature of the materials to 35 ℃ for crystallization to separate out sodium behenate, filtering to obtain 188Kg of sodium behenate and filtrate, further reducing the filtrate to 15 ℃ for crystallization to separate out 145Kg of sodium stearate;

(7) dissolving 188Kg of sodium behenate in 1000L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, cooling to 20 ℃, and filtering the separated solid to obtain 170Kg of behenic acid; according to gas chromatographic analysis, the content of C22:0 is as follows: 90.01 percent;

dissolving 145Kg of sodium stearate salt in 600L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, reducing the temperature to 5 ℃, and filtering the precipitated solid to obtain 130Kg of stearic acid, wherein the content of C18:0 is determined by gas chromatography: 93.2 percent.

Example 3

A preparation method of behenic acid and stearic acid comprises the following steps:

(1) putting 500Kg of high erucic acid rapeseed oil (the mass fraction of erucic acid is 52%) into an ozone reaction kettle, stirring at 150rpm, introducing ozonized gas with the ozone content of 25mg/L into the ozone reaction kettle through a gas distributor at the gas introduction speed of 60m3/h, and controlling the temperature of a reaction system at 30 ℃ to react for 6min to obtain a high erucic acid rapeseed oil pretreatment substance;

(2) transferring the high erucic acid rapeseed oil pretreatment substance to a normal pressure reaction kettle, heating to 85 ℃, adding a 10% sodium hydroxide aqueous solution with stirring, stirring and reacting for 15min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil primary treatment substance;

(3) raising the temperature to 90 ℃, adding 100Kg of 90 ℃ deionized water into a normal pressure reaction kettle, stirring, reacting for 5min, stopping stirring and heating, standing for liquid separation, and discharging bottom waste liquid to obtain a high erucic acid rapeseed oil secondary treatment substance;

testing the sulfur content in the high erucic acid rapeseed oil secondary treatment substance, and if the sulfur content is higher than 10ppm, sequentially repeating the steps (2) and (3) until the sulfur content is lower than 10 ppm;

(4) adding a mixture of 25Kg of argil and 5Kg of activated carbon into the secondary treated matter of the high erucic acid rapeseed oil, controlling the temperature of a reaction system to be 85 ℃ and the vacuum degree to be-0.085 MPa, reacting for 1 hour, and circularly filtering the argil and the activated carbon to obtain a high erucic acid rapeseed oil desulfurization product;

testing the sulfur content in the high erucic acid rapeseed oil desulfurization product, if the sulfur content is higher than 5ppm, repeating the adsorption reaction of the argil and the diatomite until the sulfur content is less than 5 ppm;

(5) transferring the high erucic acid rapeseed oil desulfurization product to a high-pressure reaction kettle, adding 1.25Kg of nickel, controlling the reaction temperature at 180 ℃, the stirring speed at 150rpm and the reaction pressure at 1.0MPa for reaction until the iodine value of the product<5I₂100g to obtain hydrogenated rapeseed oil;

(6) carrying out saponification reaction on hydrogenated rapeseed oil and 900L of 10% sodium hydroxide solution at 95 ℃, after the reaction is finished, reducing the temperature of the materials to 35 ℃ for crystallization, separating out sodium behenate, filtering to obtain 215Kg of sodium behenate and filtrate, further reducing the filtrate to 15 ℃ for crystallization, and separating out 168Kg of sodium stearate;

(7) dissolving 215Kg of sodium behenate in 1000L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, cooling to 20 ℃, and filtering the separated solid to obtain 193Kg of behenic acid; according to gas chromatographic analysis, the content of C22:0 is as follows: 91.9 percent;

dissolving 168Kg of sodium stearate salt in 600L of water at 95 ℃, adjusting the pH of the solution to 2.8 by using concentrated sulfuric acid, reducing the temperature to 5 ℃, and filtering the separated solid to obtain 150Kg of stearic acid; according to gas chromatographic analysis, the content of C18:0 is as follows: 95.8 percent.

According to the preparation method of behenic acid and stearic acid provided by the above embodiments, firstly, high erucic acid rapeseed oil is reacted with ozone, so that the ozone oxidizes sulfur-containing impurities in the high erucic acid rapeseed oil to obtain a pretreatment substance, and the oxidized sulfur-containing impurities are more likely to react with an alkali solution in subsequent reactions to generate hydrophilic impurities, so that the impurities are easy to separate from the rapeseed oil, and a good basis is provided for subsequent desulfurization; then the high erucic acid rapeseed oil preconditioning thing is processed sequentially through alkali solution, deionized water, the impurity containing sulfur can strengthen the polarity under the influence of alkali solution, strengthen the dissolubility in deionized water, offer the good foundation for subsequent water washing, further process the impurity containing sulfur, discharge the waste liquid containing sulfur of the lower floor, get the high erucic acid rapeseed oil second grade treatment thing; then, removing the residual sulfur-containing impurities in the secondary treatment substance of the high erucic acid rapeseed oil by using an adsorbent to ensure that the sulfur-containing impurities are basically removed; then hydrogenation, saponification and acidification are carried out to obtain the behenic acid and the stearic acid.

The preparation method of the behenic acid and the stearic acid provided by the embodiment of the invention can reduce the production cost and improve the production efficiency under the condition of simultaneously considering the high purity of the behenic acid and the stearic acid. The purity of the obtained behenic acid and the stearic acid is more than 90 percent, which is obviously higher than that of the behenic acid and the stearic acid obtained by the existing preparation process of the behenic acid and the stearic acid.

The above embodiments are provided to further explain the objects, technical solutions and advantages of the present invention in detail, it should be understood that the above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.