阅读说明：本技术 一种脂肪酸弱碱酯化和高酸值油脂一步酯交换的方法 (Method for weak-base esterification of fatty acid and one-step ester exchange of high-acid-value oil ) 是由 周备 杜官本 陶云凤 和宇娟 李克琼 杨盈盈 谢格格 于 2020-04-07 设计创作，主要内容包括：本发明公开了一种脂肪酸弱碱酯化和高酸价油脂一步酯交换的方法,包括如下步骤：以小分子酯作为酯化介质,在弱碱的作用下,较低温度下进行酯化或者一步酯交换反应,经过滤与纯化,得到的小分子脂肪酸酯产物,具体反应式如下：<Image he="149" wi="700" file="DDA0002440345200000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>本发明专利反应条件温和、反应步骤简单、催化剂易除,避免传统脂肪酸酯化方法使用硫酸、有机酸或固体酸等强酸,高酸价油脂酯交换方法使用强酸预酯化降低酸价、强碱酯交换的两步反应,操作简单,收率良好,同时,该方法使用无溶剂的方法,并且酯化原料为绿色原料,具有污染少、环境友好等特点。(The invention discloses a method for one-step ester exchange of fatty acid weak base esterification and high acid value grease, which comprises the following steps: taking small molecular ester as an esterification medium, carrying out esterification or one-step ester exchange reaction at a lower temperature under the action of weak base, and filtering and purifying to obtain a small molecular fatty acid ester product, wherein the specific reaction formula is as follows:)

1. A method for esterification of fatty acid with weak base and one-step ester exchange of high-acid-value grease is characterized in that small molecular ester is used as an esterification medium, esterification or one-step ester exchange reaction is carried out at a lower temperature under the action of weak base, and a small molecular fatty acid ester product is obtained by filtering and purifying, wherein the specific reaction formula is as follows:

wherein the long-chain fatty group is selected from alkyl chains of C1-C25, and comprises a double-bond-containing fatty alkyl chain: long chain structure of oleic acid, linoleic acid and linolenic acid.

R¹Is H, a glyceride group;

R²is a small molecule group, comprising: methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl.

2. The method for the one-step ester exchange of the fatty acid weak base esterification and the high acid value grease according to claim 1, which is characterized by comprising the following steps:

(1) mixing the micromolecule ester and the dimethyl carbonate according to the molar ratio of 1:10-30, adding weak base with the molar mass ratio of 5-20% into a reaction kettle,

(2) stirring at a rotation speed of 500-1400 rpm, rapidly heating to a constant temperature for 30 minutes, reacting for 4-12 hours,

(3) through a suction filtration and reduced pressure distillation device,

(4) thus obtaining the product of the micromolecular fatty acid ester.

3. The method for the one-step ester interchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein the substituent is an alkyl chain containing C1-C25, and has an unsaturated group containing double bond.

4. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: r¹When the group is H, the molecular structure of the raw material is fatty acid.

5. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: r¹When the group is glyceride group, the molecular structure of the raw material is fatty glyceride structure of the grease.

6. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: the small molecular ester is selected from one or a mixture of any of the following: dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, diisopropyl carbonate, diisobutyl carbonate and di-tert-butyl carbonate.

7. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: the weak base is one or the combination of sodium bicarbonate, sodium carbonate and potassium carbonate.

8. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: the fatty acid is one or more of palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, arachidic acid, arachidonic acid, and erucic acid ester.

9. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: the natural oil is a mixture of low-acid-value oil and high-acid-value oil, and is selected from one or a mixture of any of the following: soybean oil, rapeseed oil, rubber seed oil, jatropha curcas oil, cornus wilsoniana seed oil, shinyleaf yellowhorn oil, palm oil, pistacia chinensis seed oil, Chinese tallow tree seed oil, tung oil, waste cooking oil, acidified oil and waste kitchen grease.

10. The method for the one-step ester exchange of fatty acid weak base esterification and high acid value grease as claimed in claim 1, wherein: the reaction temperature is one of 80 ℃, 100 ℃ or 120 ℃.

Technical Field

The invention belongs to the field of esterification reaction, and particularly relates to a method for one-step ester exchange of fatty acid weak base esterification and high acid value grease.

Background

The fatty acid ester synthesized by taking the grease and the derivatives thereof as raw materials is taken as a novel renewable resource and widely applied to the fields of medicines, cosmetics, high polymer materials, energy sources and the like, and the research and development of the preparation technology have important academic value and far-reaching social benefits.

Disclosure of Invention

Aiming at the defects of the prior art, the method for esterifying the fatty acid and high-acid-value oil mixture under the mild condition has the advantages of low raw material cost, mild condition, simple operation and good yield.

In order to achieve the above purpose, the invention provides the following technical scheme: a method for weak-base esterification of fatty acid and one-step ester exchange of high-acid-value grease comprises the following steps: taking small molecular ester as an esterification medium, carrying out esterification or ester exchange reaction at a lower temperature under the action of weak base, and filtering and purifying to obtain a small molecular fatty acid ester product, wherein the specific reaction formula is as follows:

wherein the long-chain aliphatic group is selected from an alkyl chain of C1-C25, and comprises an aliphatic alkyl chain containing double bonds: long chain structure of oleic acid, linoleic acid and linolenic acid.

R¹Is H, a glyceride group;

R²is a small molecule group, comprising: methyl, ethyl, propyl, butyl, isopropyl, isobutyl, tert-butyl.

The invention provides a method for one-step ester exchange of fatty acid weak base esterification and high acid value grease, which comprises the following steps:

(1) small molecules are addedEstersMixing with dimethyl carbonate according to the molar ratio of 1:10-30, adding weak base with the molar mass ratio of 5-20% into a reaction kettle,

(2) stirring at a rotation speed of 500-1400 rpm, rapidly heating to a constant temperature for 30 minutes, reacting for 4-12 hours,

(3) through a suction filtration and reduced pressure distillation device,

(4) thus obtaining the product of the micromolecular fatty acid ester.

Preferably, the substituent is an alkyl chain containing C1-C25, and has an unsaturated group containing a double bond.

Preferably, R¹When the group is H, the molecular structure of the raw material is fatty acid.

Preferably, R¹When the group is glyceride group, the molecular structure of the raw material is fatty acid glyceride of grease.

Preferably, the small molecule ester is selected from one or a mixture of any of the following: dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, diisopropyl carbonate, diisobutyl carbonate and di-tert-butyl carbonate.

Preferably, the weak base is a combination of one or more of sodium bicarbonate, sodium carbonate and potassium carbonate.

Preferably, the fatty acid is one or more of palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, eleostearic acid, arachidic acid, arachidonic acid, and erucic acid.

Preferably, the natural oil is a mixture of low-acid-value oil and high-acid-value oil, and is selected from one or a mixture of any of the following: soybean oil, rapeseed oil, rubber seed oil, jatropha curcas oil, cornus wilsoniana seed oil, shinyleaf yellowhorn oil, palm oil, pistacia chinensis seed oil, Chinese tallow tree seed oil, tung oil, waste cooking oil, acidified oil and waste kitchen grease.

Preferably, the reaction temperature is one of 80 ℃, 100 ℃ or 120 ℃.

The invention has the beneficial effects that: the fatty acid and grease mixture from natural sources is used as raw materials, and the raw materials are wide.

(2) The weak base catalysis condition replaces the fatty acid strong acid catalysis esterification condition, and the one-step weak base catalysis replaces the two-step strong acid esterification-ester exchange high acid value grease ester exchange condition; meanwhile, the method is also suitable for common low-acid-value grease, and has wide applicability.

(3) Triglyceride is converted into small molecular ester by an ester exchange method, and the molecular weight of the grease is reduced; the method has mild reaction conditions, avoids the use of strong acids such as concentrated sulfuric acid and the like and strong bases such as sodium hydroxide, potassium hydroxide and the like in the traditional method, and has simple operation and good yield.

Detailed Description