CN105754726A - Bio lubricant base oil based on fly maggot oil and preparation method thereof - Google Patents

Abstract

The invention discloses a biological lubricating base oil based on fly maggot oil and a preparation method thereof. The preparation method comprises the steps of purifying and separating the fly maggot oil to obtain fatty acid of fly maggot oil; then esterifying with octanol, and then carrying out molecular distillation to remove unreacted octanol Alcohol and carry out alkali refining to reduce the acid value, and dry to obtain bio-lubricating base oil. The biolubricating base oil prepared by the method of the present invention has a fatty acid n-octyl/isooctyl content higher than 98%, a hydroxyl value of less than 0.3 mg KOH/g, an acid value of less than 0.3 mg KOH/g, and n-octanol/isooctyl The alcohol content is less than 1%, and the performance is extremely excellent. The method effectively overcomes the difficulty in removing unreacted octanol in the prior art, and can prepare biological lubricating base oil with lower hydroxyl value and acid value. The raw materials used in the method of the invention have wide sources, low cost, and the preparation method is simple and efficient. The method of the invention is easy to expand and can realize industrial scale production.

Description

Biolubricating base oil based on fly maggot oil and preparation method thereof

technical field

The invention relates to a novel biological lubricating base oil and a preparation method thereof, in particular to a fly maggot oil-based biological lubricating base oil and a preparation method thereof.

Background technique

The concept of bio-lubricating base oil (Biolubricant or Bio-based lubricant) originated in the United States, which refers to the use of animal and vegetable oils (fatty acids) through chemical modification (esterification) to obtain base oils, and adding other Substances (additives), such as: antioxidants, anti-extreme pressure and anti-wear agents, anti-rust agents, etc., made of a lubricating oil that can be rapidly biodegraded, does not contain toxic substances, and will not affect the environment and ecology. Bio-lubricating base oil is an environmentally friendly, green lubricant or biodegradable lubricant. It is also the development direction of the international lubricant market and has been valued by governments and enterprises in various countries.

The current process generally involves acid-catalyzed esterification of fatty acids with n-octanol/isooctanol, and then separating excess n-octanol/isooctanol by vacuum distillation. For the technology that utilizes fatty acid and n-octanol to prepare n-octyl ester, there is no report yet. For the process for preparing fatty acid isooctyl esters by esterification using fatty acids and isooctyl alcohols, CN104232323A [preparation technology of fatty acid isooctyl esters, Li Baoguo, He Lin, Tao Meixiang; Yao Weijie, etc.] relates to a process through several acidic catalysts. Or the method for combining catalysts to synthesize fatty acid isooctyl esters. Isooctyl alcohol and fatty acid catalyzed by the disclosed catalyst (especially fatty acid with sixteen-carbon or octadecyl-carbon saturated fatty acid as the main component), when the catalyst addition amount is 0.01-5wt%, and the temperature is 100-200°C, the fatty acid and iso-octanol Under the condition of octanol molar ratio of 1:1.1-1:2.0, the reaction is realized for 1.5-6 hours. After the reaction, the iso-octanol is removed by distillation (8-60 mbar, that is, 800-6000Pa), filtered, centrifuged, Settling and other methods to remove the solid catalyst. Fatty acid isooctyl esters with a hydroxyl value of less than 1 mgKOH/g, an acid value of less than 0.2 mgKOH/g and a yield of 95.9% were obtained. This method overcomes the problem that the catalyst is not easily separated and produces a large amount of waste water. However, the hydroxyl value, acid value, and yield of fatty acid isooctyl esters prepared by this method still have room for improvement, and there is no description for the purity of fatty acid isooctyl esters. At the same time, there are problems of high cost of raw materials and catalysts.

[Yin Shumei, Li Zaifeng, Yue Baotai, et al. Synthesis of isooctyl palmitate[J]. Chemical World, 2001(3):146-152] Using palmitic acid and isooctyl alcohol as raw materials, p-toluenesulfonic acid As a catalyst, the synthesis of isooctyl palmitate was studied, and the optimal process conditions were determined as follows: the molar ratio of alkyd to acid was 1.5:1, the mass fraction of catalyst was 0.15%, the reaction temperature was 140-170°C, and the time was 3.5h. The yield reached 97% under the conditions. There is also the problem of low yield and no description of the purity, and its hydroxyl value data has not been further tested and studied.

For the preparation of fatty acid isooctyl esters, the immobilized enzyme-catalyzed method has the advantages of catalyst recycling and mild reaction conditions. HeXL et al [HeXL, ChenBQ, TanTW.Enzymaticsynthesisof2-ethylhexylesteroffattyacidbyimmobilizedlipase[J].Candidaj.mol.catal.B:enzymatic,2002,18(6):333-339] initially reported the immobilized pseudo Trichotilpha lipase catalyzes the synthesis of isooctyl palmitate in the organic phase, and reacts at 40°C for 24 hours. However, the common problems of the enzymatic method are that the reaction time is domestically produced, and the esterification rate is about 90% low, which further hinders its development. industrial applications.

To sum up the current methods of synthesizing fatty acid octyl esters, most of the raw materials are selected to use fatty acids derived from traditional vegetable oils, and the cost is high; at the same time, the process has a large amount of impurities > 3% (purity is not higher than 97%), high hydroxyl value ( >1mgKOH/g), high acid value (>0.2mgKOH/g) and other issues. Impurities are generally acids and bases, and unreacted n-octanol/iso-octanol. The reasons for the high octanol content are: it may be that the removal process for unreacted octanol is not effective, and existing studies have shown [Zhang Hong, Synthesis and tribological properties of ester lubricating base oils, master thesis, 2015, Wuhan Institute of Technology], isooctyl ester is used as a lubricating oil, the longer the carbon chain, the better the lubricating performance. Its research also shows that there is a large gap between the raw material isooctyl alcohol and the lubricating performance of the product. As one of the impurities of the product, how to remove unreacted octanol is also very important. At the current stage of hydroxyl value (base value) and acid value level, when n-octyl/isooctyl fatty acid is used as lubricating oil base oil, the free acid and alkali can corrode the engine and lubricating pipelines, resulting in adverse consequences. Although the level of its acid value and base value of the preparation method at the present stage has reached a lower level, its quality still needs to be improved. Therefore, it is of great significance to find a high conversion rate, mild conditions, high efficiency and high purity fatty acid n-octyl/iso-octyl esters for the application status of fatty acid octyl esters in my country.

Compared with the transesterification reaction with a high conversion rate (>98%), water will be produced during the esterification reaction of fatty acid octyl esters, which hinders the improvement of the conversion rate. Current research shows that the esterification rate of fatty acids is about 96%. And there are problems of long reaction time, high temperature, and darker color, and the existence of unreacted fatty acids leads to the problem of high acid value of the product (corresponding to an acid value of 8 mgKOH/g), which further hinders its application prospect. If used as lubricating oil base oil, it does not meet the acid value requirements of motor vehicle fuel and lubricating oil (<0.6mgKOH/g). According to the prediction of American Chemical Society database (ACS), the boiling point of fatty acid octyl ester is about 470°C. Purification and separation of fatty acid octyl ester and fatty acid by molecular distillation.

In addition, the composition of insect oil is complex, and it is generally believed that it is difficult to handle, and the stability of the prepared bio-oil is poor. There are no reports or products of bio-lubricating oil base oil from fly larvae (fly maggots) in the existing literature.

Contents of the invention

The object of the present invention is to provide a kind of method that utilizes fly maggot oil to prepare high-quality biological lubricating base oil.

The technical scheme that the present invention takes is:

A method utilizing fly maggot oil to produce biological lubricating base oil, comprising the steps of:

1) take fly maggot oil and carry out molecular distillation, separate and obtain fly maggot oil fatty acid;

2) Carry out esterification reaction of fly maggot oil fatty acid with n-octanol or iso-octanol, the reaction temperature is 60°C-120°C, and the reaction is carried out at a pressure not higher than 5000Pa or under the protection of protective gas; after the esterification reaction is complete, The catalyst is removed to obtain the crude product of octyl ester of fatty acid of fly maggot oil;

3) carrying out molecular distillation of octyl fatty acid of fly maggot oil at 0.1-300Pa, 100-200°C, removing unreacted n-octanol or iso-octanol, and retaining the heavy phase liquid for later use;

4) Add an appropriate amount of lye to the heavy phase liquid to reduce the acid value, after heating and stirring, let it stand for stratification, and take the upper layer of oil;

5) removing the water in the upper oil ester to obtain the biolubricating base oil.

Preferably, the acid value of the fly maggot oil used in the above method is not lower than 15mgKOH/g.

Preferably, in the above method, the reaction conditions for the molecular distillation of the fly maggot oil are as follows: the degree of vacuum is 0.1-10 Pa, and the distillation temperature is 100-200°C.

Preferably, in the above method, the molar ratio of the carboxyl group of the fly maggot oil fatty acid to the hydroxyl group of n-octanol or iso-octanol is 1: (1-4).

Preferably, in the above method, the pressure of the esterification reaction is between 500Pa and 5000Pa.

Preferably, in the above method, the protective gas is nitrogen.

Preferably, in the above method, the esterification product is washed with water at 60-90° C. to remove the catalyst or filtered to remove the solid catalyst.

Preferably, in the above method, the esterification catalyst used in the esterification reaction is an acidic esterification catalyst.

Preferably, in the above method, the concentration of the lye is 25-40wt%.

Preferably, in the above method, the water in the upper layer of oil and ester is removed using a water remover, and the water remover is selected from molecular sieves, anhydrous calcium carbonate, and anhydrous sodium sulfate.

The beneficial effects of the present invention are:

The biological lubricating base oil prepared by the method of the present invention has a fatty acid n-octyl/isooctyl content higher than 98%, a hydroxyl value less than 0.3 mgKOH/g, an acid value less than 0.3 mgKOH/g, and a n-octanol/isooctanol content Less than 1%, the performance is extremely excellent. The method effectively overcomes the difficulty in removing unreacted octanol in the prior art, and can prepare biological lubricating base oil with lower hydroxyl value and acid value.

The raw materials used in the method of the invention have wide sources, low cost, and the preparation method is simple and efficient.

The method of the invention is easy to expand and can realize industrial scale production.

detailed description

A method utilizing fly maggot oil to produce biological lubricating base oil, comprising the steps of:

1) take fly maggot oil and carry out molecular distillation, separate and obtain fly maggot oil fatty acid;

2) Carry out esterification reaction of fly maggot oil fatty acid with n-octanol or iso-octanol, the reaction temperature is 60°C-120°C, and the reaction is carried out at a pressure not higher than 5000Pa or under the protection of protective gas; after the esterification reaction is complete, The catalyst is removed to obtain the crude product of octyl ester of fatty acid of fly maggot oil;

3) carrying out molecular distillation of octyl fatty acid of fly maggot oil at 0.1-300Pa, 100-200°C, removing unreacted n-octanol or iso-octanol, and retaining the heavy phase liquid for later use;

4) Add an appropriate amount of lye to the heavy phase liquid to reduce the acid value, after heating and stirring, let it stand for stratification, and take the upper layer of oil;

5) removing the water in the upper oil ester to obtain the biolubricating base oil.

The time of the esterification reaction can be determined according to existing methods, and the general reaction time is 0.5h-3h.

Preferably, the acid value of the fly maggot oil used in the above method is not lower than 15mgKOH/g. The fly maggot oil with high acid value is easier to separate to obtain the fly maggot oil fatty acid.

Preferably, in the above method, the reaction conditions for the molecular distillation of the fly maggot oil are as follows: the degree of vacuum is 0.1-10 Pa, and the distillation temperature is 100-200°C.

Preferably, in the above method, the molar ratio of the carboxyl group of the fly maggot oil fatty acid to the hydroxyl group of n-octanol or iso-octanol is 1: (1-4).

Preferably, in the above method, the pressure of the esterification reaction is between 500Pa and 5000Pa.

Preferably, in the above method, the protective gas is nitrogen.

Preferably, in the above method, the esterification product is washed with water at 60-90° C. to remove the liquid catalyst or filtered to remove the solid catalyst.

Preferably, in the above method, the esterification catalyst used in the esterification reaction is an acidic esterification catalyst.

Preferably, in the above method, the concentration of the lye is 25-40wt%.

Preferably, in the above method, the water in the upper layer of oil and ester is removed using a water remover, and the water remover is selected from molecular sieves, anhydrous calcium carbonate, and anhydrous sodium sulfate.

The technical solutions of the present invention will be further described below in conjunction with the embodiments.

In the following examples, unless otherwise specified, the molar ratio refers to the ratio of carboxyl to hydroxyl. Percentages refer to mass percentages unless otherwise specified.

Example 1:

1) Take high acid value fly maggot oil with an acid value of 80mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 140°C, vacuum degree 5Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid with n-octanol in a molar ratio of 1:3, heat and reflux at 120°C under nitrogen protection, and add esterification catalyst p-toluenesulfonic acid with 3% weight of fly maggot oil, stir, After reacting for 0.5 hours, washing with water, standing for stratification, and separating the crude product of n-octyl fatty acid of the upper layer of fly maggot oil;

3) The crude product of octyl fatty acid of fly maggot oil is molecularly distilled, the conditions of molecular distillation are: 100° C., 0.1 Pa, n-octanol is removed, and the heavy phase is n-octyl fatty acid of fly maggot oil with low acid value;

4) Add 5% by weight of 40% sodium hydroxide solution to the low acid value fly maggot oil fatty acid octyl ester, heat to 90°C and stir for 20 minutes;

5) Standing for stratification, taking out the upper layer liquid, adding molecular sieves to dry, filtering after standing, and obtaining the product of n-octyl fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid n-octyl ester product has a hydroxyl value of 0.03 mg/KOH, an acid value of 0.03 mg/KOH, and a purity of 99.2% of the fly maggot oil fatty acid n-octyl ester product.

Example 2:

1) Take high acid value fly maggot oil with an acid value of 15mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 130°C, vacuum degree 5Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol at a molar ratio of 1:3, heat and reflux at 120°C under nitrogen protection, add p-toluenesulfonic acid with 3% weight of fly maggot oil, stir, and react for 1 hour Finally, wash with water, let stand for stratification, and separate the crude product of fatty acid isooctyl ester of fly maggot oil in the upper layer;

3) Molecular distillation is carried out on the crude octyl ester of fatty acid of fly maggot oil, the conditions of molecular distillation are: 100°C, pressure 0.1Pa, to remove isooctyl alcohol, wherein the heavy phase is isooctyl fatty acid of fly maggot oil with low acid value;

4) Add 5% by weight of 40% sodium hydroxide solution to the low acid value fly maggot oil fatty acid octyl ester, heat to 90°C and stir for 20 minutes;

5) Standing for stratification, taking out the upper layer liquid, adding molecular sieves to dry, filtering after standing, and obtaining the product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid isooctyl ester has a hydroxyl value of 0.03 mg/KOH, an acid value of 0.03 mg/KOH, and the fly maggot oil fatty acid isooctyl ester has a purity of 99.5%.

Example 3:

1) Take high acid value fly maggot oil with an acid value of 120mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 105°C, vacuum degree 4Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol in a molar ratio of 1:2, heat to reflux at 4000Pa, 60°C, add concentrated sulfuric acid with 0.5% weight of fly maggot oil, stir, react for 3 hours, and wash with water , standing for stratification, and separating the crude product of octyl fatty acid ester of fly maggot oil in the upper layer;

3) The crude octyl fatty acid of fly maggot oil is subjected to molecular distillation, the molecular distillation conditions are: 90° C., pressure 400 Pa, and isooctyl alcohol is removed, wherein the heavy phase is isooctyl fatty acid fly maggot oil with low acid value;

4) Add 30% sodium hydroxide solution with a weight of 3% to the low-acid value fly maggot oil fatty acid octyl ester, heat to 60° C., and stir for 15 minutes;

5) Standing for stratification, taking out the upper layer liquid, adding molecular sieves to dry, filtering after standing, and obtaining the product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid isooctyl ester has a hydroxyl value of 0.1 mg/KOH, an acid value of 0.2 mg/KOH, and the fly maggot oil fatty acid isooctyl ester has a purity of 98.0%.

Example 4:

1) Take high acid value fly maggot oil with an acid value of 20mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 0.5Pa, and the distillate is purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol at a molar ratio of 1:3, heat and reflux at 100°C under nitrogen protection, add solid acid with 3% weight of fly maggot oil, stir, react for 1 hour and filter Remove solid acid to obtain fly maggot oil fatty acid octyl ester crude product;

3) The crude product of octyl fatty acid of fly maggot oil is molecularly distilled, the molecular distillation conditions are: 110° C., pressure 10 Pa, and isooctyl alcohol is removed, wherein the heavy phase is isooctyl fatty acid of fly maggot oil with low acid value;

4) Add 20% sodium hydroxide solution with a weight of 2.5% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 15 minutes, and let stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid isooctyl ester has a hydroxyl value of 0.2 mg/KOH, an acid value of 0.3 mg/KOH, and the fly maggot oil fatty acid isooctyl ester has a purity of 99.0%.

Example 5:

1) Take high acid value fly maggot oil with an acid value of 20mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 9Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and n-octanol in a molar ratio of 1:2, heat and reflux at 110°C under nitrogen protection, add benzenesulfonic acid with 3% weight of fly maggot oil, stir, and react for 100 minutes Washing with water, standing for stratification, and separating the crude product of fatty acid octyl ester of fly maggot oil in the upper layer;

3) The crude product of octyl fatty acid of fly maggot oil is subjected to molecular distillation, molecular distillation conditions: 110°C, pressure 10Pa, n-octanol is removed, wherein the heavy phase is n-octyl fatty acid fly maggot oil with low acid value;

4) Add 40% sodium hydroxide solution with a weight of 3.5% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 15 minutes, and let stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of n-octyl fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid n-octyl ester has a hydroxyl value of 0.08 mg/KOH, an acid value of 0.05 mg/KOH, and a purity of 99.2% of the fly maggot oil fatty acid n-octyl ester.

Embodiment 6:

1) Take high acid value fly maggot oil with an acid value of 100mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 9Pa, and the distillate is purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and n-octanol in a molar ratio of 1:2, heat and reflux at 110°C under nitrogen protection, add benzenesulfonic acid with 3% weight of fly maggot oil, stir, and react for 100 minutes Washing with water, standing for stratification, and separating the crude product of fatty acid octyl ester of fly maggot oil in the upper layer;

3) The crude product of octyl fatty acid of fly maggot oil is subjected to molecular distillation, molecular distillation conditions: 110°C, pressure 50Pa, n-octanol is removed, wherein the heavy phase is n-octyl fatty acid fly maggot oil with low acid value;

4) Add 5% of its 40% sodium hydroxide solution by weight to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let it stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of n-octyl fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid n-octyl ester has a hydroxyl value of 0.05 mg/KOH, an acid value of 0.03 mg/KOH, and a purity of 98.8% of the fly maggot fatty acid n-octyl ester.

Embodiment 7:

1) Take high acid value fly maggot oil with an acid value of 50mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 9Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol at a molar ratio of 1:3, heat and reflux at 110°C under nitrogen protection, add benzenesulfonic acid with 3% weight of fly maggot oil, stir, and react for 100 minutes Obtain the crude product of octyl fatty acid ester of fly maggot oil;

3) Molecular distillation of the crude octyl ester of fatty acid of fly maggot oil, molecular distillation conditions: 110°C, pressure 50Pa, removal of isooctyl alcohol, wherein the heavy phase is isooctyl fatty acid of fly maggot oil with low acid value;

4) Add 5% of its 40% sodium hydroxide solution by weight to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let it stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the hydroxyl value of the obtained fly maggot oil fatty acid isooctyl ester is 0.3 mg/KOH, the acid value is 0.08 mg/KOH, and the purity of the fly maggot fatty acid isooctyl ester is 98.0%.

Embodiment 8:

1) Take high acid value fly maggot oil with an acid value of 60mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 120°C, vacuum degree 5Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and n-octanol at a molar ratio of 1:1, heat to reflux at 5000Pa, 80°C, add solid acid with 3% weight of fly maggot oil, stir, react for 100 minutes, and then filter to obtain Crude n-octyl ester of fly maggot fatty acid;

3) The crude product of octyl fatty acid of fly maggot oil is molecularly distilled, the conditions of molecular distillation are: 130° C., pressure 300 Pa, n-octanol is removed, and the heavy phase is n-octyl fatty acid fly maggot oil with low acid value;

4) Add 30% sodium hydroxide solution with a weight of 5% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let stand for stratification;

5) Take out the upper layer liquid, add molecular sieve, filter after standing, and obtain the upper layer which is the pure n-octyl ester of fly maggot oil fatty acid.

After testing, the obtained fly maggot oil fatty acid n-octyl ester has a hydroxyl value of 0.05 mg/KOH, an acid value of 0.05 mg/KOH, and a purity of 98.1% of the fly maggot fatty acid n-octyl ester.

Embodiment 9:

1) Take high acid value fly maggot oil with an acid value of 75mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 9Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol at a molar ratio of 1:3, heat and reflux at 110°C under nitrogen protection, add benzenesulfonic acid with 3% weight of fly maggot oil, stir, and react for 100 minutes Washing with water, standing for stratification, and separating the crude product of fatty acid octyl ester of fly maggot oil in the upper layer;

3) The crude product of octyl fatty acid of fly maggot oil is subjected to molecular distillation, the molecular distillation conditions are: 110°C, pressure 50Pa, and isooctyl alcohol is removed, wherein the heavy phase is isooctyl fatty acid of fly maggot oil with low acid value;

4) Add 5% of its 40% sodium hydroxide solution by weight to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let it stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the hydroxyl value of the obtained fly maggot oil fatty acid isooctyl ester is 0.05 mg/KOH, the acid value is 0.03 mg/KOH, and the purity of the fly maggot fatty acid isooctyl ester is 98.8%.

Example 10:

1) The high acid value fly maggot oil with an acid value of 110mgKOH/g is purified by molecular distillation, the molecular distillation conditions are: oil wall temperature 130°C, vacuum degree 10Pa, the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and n-octanol at a molar ratio of 1:4, heat and reflux at 115°C under nitrogen protection, add concentrated sulfuric acid with 1% weight of fly maggot oil, stir, react for 80 minutes, and then water Washing, standing for stratification, and separating the crude product of n-octyl fatty acid in the upper layer of fly maggots;

3) The crude product of octyl fatty acid of fly maggot oil is subjected to molecular distillation, the conditions of molecular distillation are: 150° C., pressure 300 Pa, n-octanol is removed, and the heavy phase is n-octyl fatty acid of fly maggot oil with low acid value;

4) Add 25% sodium hydroxide solution with a weight of 3% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let stand for stratification;

5) Take out the upper layer liquid and add anhydrous sodium sulfate, filter after standing, and obtain the upper layer which is the pure product of n-octyl fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid n-octyl ester has a hydroxyl value of 0.08 mg/KOH, an acid value of 0.1 mg/KOH, and a purity of 98.3% of the fly maggot fatty acid n-octyl ester.

Example 11:

1) Take high acid value fly maggot oil with an acid value of 25mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 140°C, vacuum degree 8Pa, and the distillate is purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid with n-octanol at a molar ratio of 1:2, heat and reflux at 115°C under nitrogen protection, add concentrated sulfuric acid with 3% weight of fly maggot oil, stir, react for 80 minutes, and then water Washing, standing for stratification, and separating the crude product of n-octyl fatty acid in the upper layer of fly maggots;

3) The crude octyl fatty acid of fly maggot oil is subjected to molecular distillation, molecular distillation conditions: 150° C., pressure 300 Pa, n-octanol is removed, wherein the heavy phase is n-octyl fatty acid fly maggot oil with low acid value;

4) Add 25% sodium hydroxide solution with a weight of 3% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 20 minutes, and let stand for stratification;

5) Take out the upper layer liquid and add anhydrous calcium chloride, filter after standing, and obtain the upper layer which is the pure product of n-octyl fatty acid of fly maggot oil.

After testing, the obtained fly maggot oil fatty acid n-octyl ester has a hydroxyl value of 0.3 mg/KOH, an acid value of 0.08 mg/KOH, and a purity of 98.5% of the fly maggot fatty acid n-octyl ester.

Example 12:

1) Take high acid value fly maggot oil with an acid value of 85mgKOH/g and purify it by molecular distillation. The molecular distillation conditions are: oil wall temperature 110°C, vacuum degree 9Pa, and the distillate is the purified fly maggot oil fatty acid;

2) Mix the obtained fly maggot oil fatty acid and isooctyl alcohol at a molar ratio of 1:1.5, heat and reflux at 120°C under nitrogen protection, add concentrated sulfuric acid with 1% weight of fly maggot oil, stir, and react with water for 80 minutes Washing, standing for stratification, and separating the crude product of isooctyl fatty acid in the upper layer of fly maggots;

3) The crude octyl fatty acid of fly maggot oil is subjected to molecular distillation, the molecular distillation conditions are: 130° C., pressure 300 Pa, and isooctyl alcohol is removed, wherein the heavy phase is isooctyl fatty acid fly maggot oil with low acid value;

4) Add 35% sodium hydroxide solution with a weight of 3% to the low-acid value fly maggot oil fatty acid octyl ester, stir for 15 minutes, and let stand for stratification;

5) Take out the upper layer liquid and add molecular sieve, filter after standing, and obtain the upper layer which is the pure product of isooctyl ester of fatty acid of fly maggot oil.

After testing, the hydroxyl value of the obtained fly maggot oil fatty acid isooctyl ester is 0.3 mg/KOH, the acid value is 0.06 mg/KOH, and the purity of the fly maggot fatty acid isooctyl ester is 98.5%.

The method of the present invention breaks through the limitation of the current technology, and effectively realizes the purification and separation of fatty acid octyl ester and fatty acid by purifying raw materials, optimizing the reaction process and molecular distillation purification process, and obtaining high-quality biological lubricating base oil.

Claims (10)

1. a method utilizing fly maggot oil to produce bio-lubricating base oil, comprising the steps: 1) take fly maggot oil and carry out molecular distillation, separate and obtain fly maggot oil fatty acid; 2) Carry out esterification reaction of fly maggot oil fatty acid with n-octanol or iso-octanol, the reaction temperature is 60°C-120°C, and the reaction is carried out at a pressure not higher than 5000Pa or under the protection of protective gas; after the esterification reaction is complete, The catalyst is removed to obtain the crude product of octyl ester of fatty acid of fly maggot oil; 3) carrying out molecular distillation of octyl fatty acid of fly maggot oil at 0.1-300Pa, 100-200°C, removing unreacted n-octanol or iso-octanol, and retaining the heavy phase liquid for later use; 4) Add an appropriate amount of lye to the heavy phase liquid to reduce the acid value, after heating and stirring, let it stand for stratification, and take the upper layer of oil; The water in the upper oil ester is removed to obtain the biolubricating base oil. 2. The method according to claim 1, characterized in that: the acid value of the fly maggot oil is not less than 15mgKOH/g. 3. The method according to claim 1, characterized in that: the reaction conditions for the molecular distillation of the fly maggot oil are: a vacuum degree of 0.1 to 10 Pa, and a distillation temperature of 100 to 200° C. 4. The method according to claim 1, characterized in that the molar ratio of the carboxyl group of the fly maggot oil fatty acid to the hydroxyl group of n-octanol or iso-octanol is 1: (1-4). 5. The method according to claim 1, characterized in that: the pressure of the esterification reaction is between 500Pa and 5000Pa. 6. The method according to claim 1, characterized in that: the protective gas is nitrogen. 7. The method according to claim 1, characterized in that: washing the esterification product with water at 60-90° C. to remove the catalyst or filtering to remove the solid catalyst. 8. The method according to claim 1, characterized in that: the esterification catalyst used in the esterification reaction is an acidic esterification catalyst. 9. The method according to claim 1, characterized in that: the concentration of the lye is 25-40wt%. 10. The method according to claim 1, characterized in that: use a water remover to remove the water in the upper layer of oil, and the water remover is selected from molecular sieves, anhydrous calcium carbonate, and anhydrous sodium sulfate.