CN114163559A

CN114163559A - Nitrogen-containing binary polymer biodiesel pour point depressant and preparation method and application thereof

Info

Publication number: CN114163559A
Application number: CN202111391348.4A
Authority: CN
Inventors: 蔺华林; 卢义麟; 袁铭霞; 李欣; 孙彬; 陈亚莉; 任飞鹤; 薛原; 韩生
Original assignee: Shanghai Institute of Technology
Current assignee: Shanghai Institute of Technology
Priority date: 2021-11-23
Filing date: 2021-11-23
Publication date: 2022-03-11
Anticipated expiration: 2041-11-23
Also published as: CN114163559B

Abstract

The invention relates to a nitrogen-containing binary polymer biodiesel pour point depressant, a preparation method and application thereof, wherein the nitrogen-containing binary polymer biodiesel pour point depressant is prepared by polymerization reaction of methacrylic acid high-carbon ester and N-vinylformamide under the heating condition, with toluene as a solvent and benzoyl peroxide as an initiator; it is added into biological diesel oil to lower the condensation point and cold filter plugging point of biological diesel oil. Compared with the prior art, the invention has the characteristics of low cost of raw materials, short time consumption in the synthesis process and small dosage, has stronger oil solubility, can effectively improve the low-temperature flow property of the biodiesel, has good effect on the reduction of condensation point and cold filter plugging point, and has excellent market value.

Description

Nitrogen-containing binary polymer biodiesel pour point depressant and preparation method and application thereof

Technical Field

The invention belongs to the technical field of diesel pour point depressants, and particularly relates to a nitrogen-containing biopolymer biodiesel pour point depressant as well as a preparation method and application thereof.

Background

Diesel oil is an indispensable fuel in industrial transportation process and agricultural production, and has the characteristics of safety, durability, safe storage and the like. However, the diesel oil has poor fluidity at low temperature, waxy crystals can be separated out at low temperature, a large filter screen of the diesel engine is blocked, and the engine can be flamed out, so that the normal work at low temperature is influenced. In order to solve the defect of poor low-temperature flow property of diesel oil, a low-temperature flow improver (namely pour point depressant) is added into the diesel oil. The addition of the diesel pour point depressant is the most economical and efficient method for solving the problem of poor low-temperature fluidity.

In recent years, pour point depressant technology has developed at a high rate in our country. The pour point depressant mainly comprises polymethacrylates, ethylene-vinyl acetate (monopropanolamine), maleic anhydride, poly alpha-olefin, nitrogen-containing and the like at present, has good pour point depression effect on diesel oil, but has certain defects, such as high addition amount, poor dispersibility, poor universality and the like.

The patent CN111592611A discloses a nitrogen-containing binary polymer diesel oil pour point depressant, a preparation method and application thereof, wherein the nitrogen-containing binary polymer diesel oil pour point depressant is prepared by polymerization reaction of methacrylic acid high-carbon ester and N-tetradecyl methacrylamide under the heating condition, toluene is used as a solvent, and benzoyl peroxide is used as an initiator; it is added into diesel oil to lower the condensation point and cold filter plugging point of diesel oil. The nitrogen-containing binary polymer diesel oil pour point depressant disclosed by patent CN111592611A is a polymer of long-chain alkane, is polymerized by adopting two long-chain monomers, has the length of a side chain consistent with that of alkane, naphthene or aromatic hydrocarbon of No. 0 diesel oil, and can generate eutectic effect with diesel oil molecules to change the crystallization behavior and the crystallization direction of the diesel oil, thereby improving the low-temperature flow property of the diesel oil, but is not suitable for biodiesel.

Disclosure of Invention

The invention aims to solve the problems, and provides a nitrogen-containing biopolymer biodiesel pour point depressant, a preparation method and application thereof, so as to overcome the technical problems that the existing pour point depressant is single in composition and poor in pour point depressing effect.

The invention is used in the biodiesel, because the low-temperature fluidity of the biodiesel mainly depends on saturated fatty acid methyl ester in the biodiesel, the higher the mass fraction of the long carbon chain of the saturated fatty acid methyl ester, the poorer the low-temperature fluidity, and the lower the content of the unsaturated fatty acid methyl ester and the saturated fatty acid methyl ester of the biodiesel which is suitable for the invention is matched with the length of the side chain of the invention, therefore, the invention can play a better role in the biodiesel.

The purpose of the invention is realized by the following technical scheme:

the nitrogen-containing binary polymer biodiesel pour point depressant is an N-vinyl formamide-methacrylic acid high-carbon ester binary polymer, and is prepared by polymerization reaction of methacrylic acid high-carbon ester and N-vinyl formamide under the heating condition and the action of an initiator in a medium solvent.

A method for preparing nitrogen-containing binary polymer biodiesel pour point depressant, which comprises dissolving methacrylic acid high-carbon ester and N-vinylformamide in a solvent, repeatedly vacuumizing and filling nitrogen for multiple times, heating to raise the system temperature, adding an initiator benzoyl peroxide, and carrying out polymerization reaction to obtain the N-vinylformamide-methacrylic acid high-carbon ester binary polymer.

Further, the high-carbon methacrylate is one or more of tetradecyl methacrylate, hexadecyl methacrylate or octadecyl methacrylate.

Further, the methacrylic acid high-carbon ester is prepared by the following method: heating polymerization inhibitor, methacrylic acid and higher alcohol to 55-65 ℃ under the condition of solvent, fully dissolving, adding catalyst, and raising the temperature of a reaction system for reaction to obtain the methacrylic acid high-carbon ester.

Further, the above preparation method includes any one or more of the following conditions:

(a) the polymerization inhibitor is hydroquinone;

(b) the solvent is toluene;

(c) the higher alcohol is one or more of tetradecanol, hexadecanol and octadecanol;

(d) the catalyst is p-toluenesulfonic acid.

(a) the molar ratio of methacrylic acid to higher alcohol is 1.1-1.3:1, preferably 1.2: 1;

(b) the amount of the catalyst is 0.7 to 0.9%, preferably 0.8% of the total mass of methacrylic acid and higher alcohol;

(c) heating polymerization inhibitor, methacrylic acid and higher alcohol to 60 ℃ and fully dissolving under the condition of solvent;

(d) after adding the catalyst, raising the temperature of the reaction system to 110-120 ℃ for reaction, wherein the reaction time is 5-6 h.

Further, after the reaction is finished, carrying out reduced pressure distillation on the obtained reaction liquid, removing the solvent, and then carrying out alkali washing and water washing until the liquid is alkalescent; then distilled water is used for washing to be neutral, and methacrylic acid high carbon ester is obtained after drying.

(a) the molar ratio of the high-carbon methacrylate to the N-vinylformamide is 3-12: 1, preferably 9: 1;

(b) the temperature of the polymerization reaction is 90-110 ℃, and the polymerization reaction time is 7-8 h;

(c) the initiator is 0.8-1.2% of the total mass of the methacrylic acid high-carbon ester and the N-vinyl formamide.

The application of the nitrogen-containing binary polymer biodiesel pour point depressant is that the biodiesel pour point depressant is added into diesel oil, mixed and stirred evenly at the temperature of 30-45 ℃, and then dispersed by ultrasonic. The mass ratio of the biodiesel pour point depressant to the diesel is 1: 1000-1: 100.

In the present invention, the reaction equation of the preparation process of the binary polymer biodiesel pour point depressant is as follows:

the biodiesel pour point depressant is composed of two monomers, namely methacrylic acid high-carbon ester and N-vinyl formamide, wherein the methacrylic acid high-carbon ester has good oil solubility due to the existence of a long alkyl chain in a molecule, and the N-vinyl formamide molecule can provide certain polarity, is adsorbed on the surface of wax crystals and generates certain repulsion action to hinder wax crystal aggregation, so that a good pour point depressing effect is generated on the biodiesel.

Compared with the prior art, the invention has the beneficial effects that:

the binary polymer biodiesel pour point depressant can be well dissolved in biodiesel, wherein alkyl long chains provided by methacrylic acid high-carbon ester can effectively improve the low-temperature flow property of the biodiesel through eutectic effect, and N-vinylformamide can provide corresponding polar groups, and is adsorbed on the surface of wax crystals precipitated from the biodiesel through polarity analysis and generates repulsive force to make the wax crystals difficult to gather together, so that the condensation point and the cold filter plugging point of the biodiesel are obviously reduced.

The binary polymer biodiesel pour point depressant has the advantages of simple preparation process, stronger system compoundability, contribution to stabilizing the system performance, convenient experimental operation and obvious pour point depression effect. The binary polymer has cheap and easily obtained raw materials and simple synthesis method, not only has stronger oil solubility, but also can effectively improve the low-temperature flow property of the biodiesel, has good effect on the reduction of condensation point and cold filter plugging point, and provides new possibility for the research and development of novel biodiesel.

Drawings

FIG. 1 is a drawing of a tetradecyl methacrylate-N-vinylformamide polymer 1 HNMR;

FIG. 2 is an infrared image of a tetradecyl methacrylate-N-vinylformamide polymer.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.

Each raw material used in the following examples is a commercially available product.

The method for measuring the cold filter plugging point is carried out according to SH/T0248-2006 method for measuring the cold filter plugging point of diesel oil and civil heating oil, and the method for measuring the condensation point is carried out according to GB510-83 method for measuring the condensation point of petroleum products.

Example 1

A preparation method of a binary polymer biodiesel pour point depressant comprises the following specific steps:

(1) 10.33g (0.12mol) of methacrylic acid, 21.44g of tetradecanol (0.1mol), 0.192g of hydroquinone and 50ml of toluene are added into a three-neck flask provided with a condenser, a water separator, a thermometer and a magnetic stirring device, the temperature is raised to 60 ℃ to completely dissolve the methacrylic acid and the tetradecanol in the toluene, then 0.254g of weighed catalyst p-toluenesulfonic acid is rapidly added into the three-neck flask, the temperature is raised to 110 ℃ and 120 ℃ for reaction for 5 hours, and when the water amount in the water separator is observed to be equal to the theoretical value, the system is in a light yellow transparent liquid state, and the reaction is stopped. After the reaction is finished, distilling the obtained reaction liquid under reduced pressure, removing the solvent, and then carrying out alkali washing and water washing, wherein the alkali washing is carried out by washing with a NaOH solution with the mass fraction of 5% to remove p-toluenesulfonic acid and unreacted methacrylic acid, and the alkali washing is generally carried out for 3-4 times until the liquid is alkalescent; then washing the mixture with distilled water to be neutral, and drying the mixture in vacuum at the temperature of 60 ℃ for 5 hours to obtain the tetradecyl methacrylate.

(2) 2.821g (0.01mol) of tetradecyl methacrylate, 0.71g (0.01mol) of N-vinylformamide and 25ml of solvent toluene are sequentially added into a three-neck flask provided with an electric stirrer, a temperature controller, a constant-pressure dropping funnel, a reflux condenser and a nitrogen inlet pipe, the temperature is raised to 50-60 ℃, reactants are completely dissolved, the three-neck flask is pumped with nitrogen for 2-3 min, then the three-neck flask is vacuumized for about 1-2 min, and the process is repeated for 3 times, so that air in a reaction system is removed. When the reaction temperature reaches 105 ℃, slowly dripping 25mL of toluene solution (added after 30-45 min) dissolved with 0.035g of benzoyl peroxide, and stirring and refluxing under the action of an initiator benzoyl peroxide to perform polymerization reaction for 8 hours. After cooling the reaction solution to room temperature, an excess of methanol was added dropwise to the reaction product to produce a white precipitate, and at this time, the supernatant was separated off, and the precipitate was redissolved in toluene. And repeating the steps for 3-4 times, removing benzoyl peroxide in the system, putting the precipitate in a vacuum drying oven, and carrying out vacuum drying for 5 hours at the temperature of 50 ℃ to obtain the tetradecyl methacrylate-N-vinyl formamide binary polymer. The nuclear magnetism characterization of the product tetradecyl methacrylate-N-vinyl formamide binary polymer is shown in figure 1 and figure 2 respectively.

Example 2

The difference from example 1 is that the addition of 2.821g (0.05mol) of tetradecyl methacrylate in step (2) was changed to the addition of 8.463g (0.03mol) of tetradecyl methacrylate and 0.71g (0.01mol) of N-vinylformamide, and the addition of 0.035g of benzoyl peroxide was changed to the addition of 0.091g of benzoyl peroxide.

Example 3

The difference from example 1 is that in step (2), 2.821g (0.05mol) of tetradecyl methacrylate was added, and 16.926g (0.06mol) of tetradecyl methacrylate and 0.71g (0.01mol) of N-vinylformamide were added, and 0.035g of benzoyl peroxide was changed to 0.176g of benzoyl peroxide.

Example 4

The difference from example 1 is that in step (2), 2.821g (0.05mol) of tetradecyl methacrylate was added, and 25.389g (0.09mol) of tetradecyl methacrylate and 0.71g (0.01mol) of N-vinylformamide were added, and 0.035g of benzoyl peroxide was changed to 0.26g of benzoyl peroxide.

Example 5

The difference from example 1 is that in step (2), 2.821g (0.05mol) of tetradecyl methacrylate was added, and 33.852g (0.12mol) of tetradecyl methacrylate and 0.71g (0.01mol) of N-vinylformamide were added, and 0.035g of benzoyl peroxide was changed to 0.34g of benzoyl peroxide.

Application examples

The biopolymer biodiesel pour point depressants prepared in examples 1-5 were tested for low temperature flow properties according to the method specified in the national Standard GB 510-83. The operation procedure is that the sample is loaded in a test tube and cooled to the expected temperature, the test tube is inclined at 45 degrees for 1 minute to observe whether the liquid level moves, and the arithmetic mean value of two results of repeated measurement is taken as the condensation point of the sample.

Pour point depressants prepared in examples 1-5 were numbered as # 1, # 2, # 3, # 4, and # 5, respectively, and added to the soybean oil biodiesel according to different addition amounts for condensation point testing, and the pour point depressing effect is specifically shown in table 1:

TABLE 1

ASP shows the reduction value of the condensation point of the biodiesel after the pour point depressant is added relative to the pure biodiesel, and as can be seen from Table 1, the pour point depressants 1#, 2#, 3#, 4#, and 5# can effectively reduce the condensation point of the biodiesel, while the pour point depressant 3# prepared in example 5 has the best performance, and when the addition amount is 0.5%, the ASP is 19 ℃.

The nitrogen-containing binary copolymer biodiesel pour point depressants prepared in examples 1-5 were subjected to a cold filter plugging point test on soybean oil biodiesel, the test being performed according to the method specified in national standard SH/T0248-2006. The cold filter plugging point is the highest temperature at which the volume of liquid passing through the filter screen of the sample in a specified time does not exceed 20 ml. The pour point depressants prepared in examples 1 to 5 were respectively numbered 1#, 2#, 3#, 4#, and 5#, and were added to 0# biodiesel in different amounts, respectively, and subjected to a cold filter plugging point test, and the effect of reducing the cold filter plugging point is shown in Table 2.

TABLE 2

ACFPP shows the reduction value of the cold filter plugging point of the biodiesel after the pour point depressant is added relative to the pure biodiesel, and as can be seen from Table 1, the pour point depressants 1#, 2#, 3#, 4#, and 5# can improve the cold filter plugging point of the biodiesel to a certain extent, the pour point depressant 3# prepared in example 5 has a good effect on the reduction of the cold filter plugging point, and when the addition amount is 0.5%, the delta CFPP is 12 ℃.

In conclusion, the preparation method of the nitrogen-containing binary polymer biodiesel pour point depressant solves the problem that the single methacrylic acid pour point depressant is poor in broad spectrum, introduces the novel monomer N-vinyl formamide to expand the composition of the pour point depressant, improves the pour point depression effect, and can respectively reduce the condensation point and the cold filter plugging point of the biodiesel by 7-19 ℃ and 6-12 ℃.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. The nitrogen-containing binary polymer biodiesel pour point depressant is characterized in that the nitrogen-containing binary polymer biodiesel pour point depressant is an N-vinyl formamide-methacrylic acid high-carbon ester binary polymer and is prepared by carrying out polymerization reaction on the methacrylic acid high-carbon ester and the N-vinyl formamide under the heating condition and the action of a medium solvent and an initiator.

2. The method for preparing the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 1, wherein the N-vinylformamide and the N-vinylformamide are dissolved in the solvent, the vacuum pumping and the nitrogen charging are repeated for a plurality of times, the system temperature is heated and increased, the initiator benzoyl peroxide is added, and the polymerization reaction is carried out to obtain the N-vinylformamide-methacrylic acid high-carbon biopolymer.

3. The method for preparing the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 2, wherein the high-carbon methacrylate is one or more of tetradecyl methacrylate, hexadecyl methacrylate or octadecyl methacrylate.

4. The preparation method of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 3, wherein the high-carbon methacrylate is prepared by the following method: heating polymerization inhibitor, methacrylic acid and higher alcohol to 55-65 ℃ under the condition of solvent, fully dissolving, adding catalyst, and raising the temperature of a reaction system for reaction to obtain the methacrylic acid high-carbon ester.

5. The preparation method of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 4, wherein any one or more of the following conditions are included:

(a) the polymerization inhibitor is hydroquinone;

(b) the solvent is toluene;

(d) the catalyst is p-toluenesulfonic acid.

6. The preparation method of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 4, wherein any one or more of the following conditions are included:

(a) the molar ratio of the methacrylic acid to the higher alcohol is 1.1-1.3: 1;

(b) the amount of the catalyst is 0.7-0.9% of the total mass of the methacrylic acid and the higher alcohol;

7. The method for preparing the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 6, wherein after the reaction is completed, the obtained reaction solution is subjected to reduced pressure distillation, and after the solvent is removed, alkali washing and water washing are carried out until the solution is weakly alkaline; then distilled water is used for washing to be neutral, and methacrylic acid high carbon ester is obtained after drying.

8. The preparation method of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 2, wherein any one or more of the following conditions are included:

(a) the molar ratio of the high-carbon methacrylate to the N-vinylformamide is 3-12: 1;

9. The application of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 1, wherein the biodiesel pour point depressant is added into diesel, mixed and stirred uniformly at the temperature of 30-45 ℃, and then ultrasonically dispersed.

10. The application of the nitrogen-containing biopolymer biodiesel pour point depressant according to claim 9 is characterized in that the mass ratio of the biodiesel pour point depressant to diesel is 1: 1000-1: 100.