IE20210115U1 - Polymethacrylate-vinyl acetate diesel pour point depressant and preparation and application thereof - Google Patents

Abstract

The present invention relates to a polymethacrylate-vinyl acetate diesel pour point depressant and the preparation method and application thereof, wherein the preparation method of the diesel pour point depressant comprises the following steps: 1) adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 55-65°C to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; 2) adding methacrylic acid high-carbon ester and vinyl acetate into a solvent, then adding an initiator and carrying out a polymerisation reaction to obtain a methacrylic acid high-carbon ester-vinyl acetate binary polymer, namely the polymethacrylate-vinyl acetate diesel pour point depressant. Compared with the prior art, the polymethacrylate-vinyl acetate diesel pour point depressant solves the problem of poor broad spectrum of a single methacrylic acid pour point depressant, introduces vinyl acetate to expand the composition of the pour point depressant, improves the pour point depression effect, and has simple preparation process and convenient experimental operation.

Description

Polymethacrylate-vinyl acetate diesel pour point depressant and preparation and application thereof Technical Field The invention belongs to the technical field of diesel pour point depressants, and relates to a polymethacrylate-vinyl acetate binary polymer diesel pour point depressant and the preparation method and application thereof.

Background Diesel oil is a middle distillate obtained by fractionating crude oil, and is usually prepared by blending two or more cracked or straight-run components, the distillation range is between 170 and 390 °C, and the middle distillate mainly comprises aliphatic hydrocarbons with 8-28 carbon atoms. In addition, it also contains isoparaffin, olefin and aromatic hydrocarbon and non-hydrocarbon compounds of sulfur, nitrogen, oxygen, etc., and is a multi-component complex hydrocarbon mixture. Wherein, the normal alkane in the diesel oil is closely related to the low-temperature flow property of the diesel oil, and the more the normal alkane content is, the poorer the flow property of the diesel oil under the low-temperature condition is. As the temperature of the diesel fuel system decreases, the solubility of long chain normal paraffins with a relatively large molecular mass in the diesel fuel decreases, and when the temperature of the diesel fuel is lowered to the cloud point, they will precipitate from the diesel fuel in the form of crystals. The diesel oil Pour Point Depressant (PPD), also known as a diesel oil low- temperature flow improver or a wax crystal modifier, changes the crystallization process of paraffin in diesel oil to reduce the size of wax crystals and uniformly disperse, which is also the reason for effectively reducing the condensation point and the cold filter plugging point of diesel oil, so that the diesel oil can continuously flow under the low-temperature condition. At present, the commonly used diesel pour point depressant is a single methacrylic acid pour point depressant, which has poor broad spectrum, poor sensitivity to high-wax diesel and no pour point depression effect.|n order to improve the current situation, the development of a cheap, more efficient and more universal diesel pour point depressant becomes a key point and a difficult point of the current research, and the appearance of the diesel pour point depressant has great social and economic benefits.

Summary of the Invention The present invention aims to provide a polymethacrylate-vinyl acetate diesel oil pour point depressant and preparation and application thereof, and the binary polymer diesel pour point depressant can further improve the low-temperature fluidity of diesel.

The purpose of the invention can be realized by the following technical scheme: The preparation method of the polymethacrylate-vinyl acetate diesel pour point depressant comprises the following steps: ) Adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 55-65 °C under a stirring state to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; ) Adding high-carbon methacrylate and vinyl acetate into a solvent, then adding an initiator and carrying out polymerization reaction to obtain a binary polymer of the high-carbon methacrylate and the vinyl acetate, namely the polymethacrylate-vinyl acetate diesel pour point depressant.

The reaction equation for preparing the polymethacrylate-vinyl acetate diesel pour point depressant is shown as follows: ('II., I ||:(‘=('—('—()Il o R-()|| p H (.=(._(._”_R ’ (H) Inlm-nc ' || () ('II, P-lolm-no sullhnic acid ’ lH’() (“X H —(:-R + :HI.(':('!! 7 ‘(ii 1 l“(_( 1 ’ (') Iolucuc ‘ (1. lm I I In I ;() (I) (‘=0 ( (‘:0 I (‘ll_‘ :' uv .¢_.< ,,II,,‘-( .,,n,.‘-( ,,u..

Further, in step 1), the higher alcohol includes one or more of tetradecanol, hexadecanol or octadecanol, the polymerization inhibitor is hydroquinone, and the catalyst is p- toluenesulfonic acid.

Further, in step 1) and step 2), the solvent is toluene.

Further, in the step 2), the initiator is benzoyl peroxide.

Further, in the step 1), the molar ratio of the methacrylic acid to the higher alcohol is (1.1- 1.3):1, the mass of the catalyst is 0.7-0.9% of the total mass of the methacrylic acid and the higher alcohol, and the mass of the polymerization inhibitor is 0.5-0.7% of the total mass of the methacrylic acid and the higher alcohol.

Further, in the step 1), in the catalytic reaction process, the reaction temperature is 110- 120 °C, and the reaction time is 5-6 hours.

Further, in the step 2), the mol ratio of the high-carbon methacrylate to the vinyl acetate is (3-15):1, and the mass of the initiator is 0.8-1.2% of the total mass of the high-carbon methacrylate and the vinyl acetate.

Further, in the step 2), before adding the initiator, removing air in the reaction system; in the polymerization reaction process, the reaction temperature is 90-110 °C, and the reaction time is 7-8 hours.

The polymethacrylate-vinyl acetate diesel pour point depressant is prepared by the method.

The application of polymethacrylate-vinyl acetate diesel oil pour point depressant in diesel oil.

The invention provides a binary polymer diesel oil pour point depressant which is prepared by polymerization reaction of methacrylic acid high-carbon ester and vinyl acetate, the synthesis method is simple, and the prepared polymethacrylate-vinyl acetate diesel oil pour point depressant has stronger oil solubility due to the existence of long alkyl chains in methacrylic acid high-carbon ester molecules, can also effectively improve the low- temperature flow property of diesel oil, and provides new possibility for the research and development of novel diesel oil.

Compared with the prior art, the invention has the following characteristics: ) The diesel pour point depressant can be well dissolved in diesel. The low-temperature flow property of the diesel oil can be effectively improved through the eutectic effect of the alkyl long chain provided by the methacrylic acid high-carbon ester; and secondly, the vinyl acetate can provide corresponding polar groups, and the polar groups are adsorbed on the surface of wax crystals precipitated from the diesel oil to generate repulsive force, so that the wax crystals are difficult to aggregate together, and the condensation point and the cold filter plugging point of the diesel oil are obviously reduced.

) The diesel pour point depressant has the advantages of simple preparation process, stronger system composite property, stable system performance, convenient experimental operation and obvious pour point depression effect.

Fig. 1 is a 1HNMR chart of a tetradecyl methacrylate-vinyl acetate polymer prepared in embodiment 1 (wherein m and n are integers of 1 or more); Fig. 2 is an infrared image of a tetradecyl methacrylate-vinyl acetate polymer prepared in embodiment 1.

Detailed Description of the Preferred Embodiments The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

The method for measuring the cold filter plugging point in the embodiment of the invention is carried out according to SH/T 0248-2006 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.

Embodiment 1: (1) 10.33g (0.12mol) of methacrylic acid, 21 .44g (0.1 mol) of tetradecanol, 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 °C to completely dissolve the tetradecanol in the toluene, then weighed 0.254g of catalyst p-toluenesulfonic acid is rapidly added into the three-neck flask, the temperature is raised to 110 °C and 120 °C 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; washing with distilled water to neutrality, and vacuum drying at 60 deg.C for 5 hr to obtain tetradecyl methacrylate. (2) 8.47g (0.03mol) of tetradecyl methacrylate, 0.72g (0.01mol) of vinyl acetate and 25ml of toluene solvent 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 °C, reactants are completely dissolved, the three-neck flask is pumped with nitrogen for 2-3mins, then the vacuum pumping is carried out for about 1-2mins, and the process is repeated for 3 times, so as to remove the air in the reaction system. When the reaction temperature reached 105 °C, a toluene solution (30- 45mins complete) in which 0.1g of benzoyl peroxide was dissolved was slowly added dropwise, and the mixture was refluxed for 8 hours with stirring. 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 the supernatant was separated off and the precipitate was redissolved in toluene. Repeating the steps for 3-4 times, removing benzoyl peroxide in the system, placing the precipitate in a vacuum drying oven, and carrying out vacuum drying for 5 hours at the temperature of 50 °C to obtain the tetradecyl methacrylate- vinyl acetate binary polymer. GPC determined that the molecular Mw of the bipolymer was 86301g/mol, Mn was 30917g/mol, characterization of the obtained product is shown in figure 1 , and the infrared is shown in figure 2. and Mw/Mn was 2.791. The nuclear magnetic Embodiment 2: The difference compared with embodiment 1 is that 8.47g (0.03mo|) of tetradecyl methacrylate, 0.72g (0.01 mol) of vinyl acetate, 0.1g of benzoyl peroxide, which were added in step (2), were changed to 16.94g (0.06mo|) of tetradecyl methacrylate, 0.72g (0.01mo|) of vinyl acetate and 0.1766g of benzoyl peroxide.

Embodiment 3: The difference compared with embodiment 1 is that 8.47g (0.03mo|) of tetradecyl methacrylate, 0.72g (0.01 mol) of vinyl acetate, 0.1g of benzoyl peroxide, which were added in step (2), were changed to 25.41g (0.09mo|) of tetradecyl methacrylate, 0.72g (0.01mo|) of vinyl acetate and 0.2613g of benzoyl peroxide.

Embodiment 4: The difference compared with embodiment 1 is that 8.47g (0.03mo|) of tetradecyl methacrylate, 0.72g (0.01 mol) of vinyl acetate, 0.1g of benzoyl peroxide, which were added in step (2), were changed to 33.88g (0.12mo|) of tetradecyl methacrylate, 0.72g (0.01mo|) of vinyl acetate and 0.346g of benzoyl peroxide.

Embodiment 5: The difference compared with embodiment 1 is that 8.47g (0.03mo|) of tetradecyl methacrylate, 0.72g (0.01 mol) of vinyl acetate, 0.1g of benzoyl peroxide, which were added in step (2), were changed to 42.35g (0.15mo|) of tetradecyl methacrylate, 0.72g (0.01mo|) of vinyl acetate and 0.4301g of benzoyl peroxide.

The application example: The diesel pour point depressants prepared in embodiments 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 1min 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 embodiments 1 to 5 were respectively numbered 1#, 2#, 3#, 4#, and 5#, and were added to different 0# diesel fuels (purchased from different gas stations, respectively) according to different mass percentages, and condensation point tests were performed, and the pour point depressing effects are shown in tables 1 and 2: (remark: PPD is pour point depressant) Table 1 The adding amount 0 O for PPD SP ( C) ASP ( C) 0#diesel O -13 .25% -28 15 diesel adding 1# .5% -31 18 .25% -29 16 diesel adding 2# .5% -32 19 .25% -30 17 diesel adding 3# .5% -33 20 .25% -33 20 diesel adding 3# .5% -36 23 .25% -31 18 diesel adding 5# .5% -34 21 Table 2 The adding amount 0 O for PPD SP ( C) ASP ( C) 0#diesel O -7 .25% -26 19 diesel adding 1# .5% -30 23 .25% -28 21 diesel adding 2# .5% -31 24 .25% -28 21 diesel adding 3# .5% -33 26 .25% -30 23 diesel adding 4# .5% -34 27 .25% -27 20 diesel adding 5# .5% -32 25 The A SP represents the reduction of the condensation point of the diesel oil after the pour point depressant is added relative to the pure diesel oil, and as can be seen from table 1 and table 2, the pour point depressants 1#, 2#, 3#, 4#, and 5# can effectively reduce the condensation point of the diesel oil, while the pour point depressant 4# prepared in embodiment 4 has the best performance, and when the addition amount is 0.5%, the A SP is 23 °C and 27 °C.

The diesel pour point depressants prepared in embodiments 1-5 were subjected to the cold filter plugging point test, which was 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 arithmetic mean of the two results of the duplicate measurements was taken as the cold filter plugging point of the sample.

The pour point depressants prepared in embodiments 1 to 5 were respectively numbered as # 1, # 2, # 3, # 4 and # 5, and were added to different # 0 diesel fuels (purchased from different gas stations, respectively) according to different mass percentages, and cold filter plugging point tests were performed, and the effect of reducing cold filter plugging point is shown in tables 3 and 4: Table 3 The adding amount 0 O for PPD CFPP ( C) ACFPP ( C) 0#diesel O -2 .25% -5 3 diesel adding 1# .5% -8 6 .25% -5 3 diesel adding 2# .5% -9 7 .25% -6 4 diesel adding 3# .5% -10 8 .25% -7 5 diesel adding 4# .5% -11 9 .25% -6 4 diesel adding 5# .5% -9 7 Table 4 The adding amount 0 O for PPD CFPP ( C) ACFPP ( C) 0#diesel O -2 .25% -8 6 diesel adding 1# .5% -10 8 .25% -8 6 diesel adding 2# .5% -11 9 .25% -9 7 diesel adding 3# .5% -11 9 .25% -11 9 diesel adding 4# .5% -14 12 .25% -10 8 diesel adding 5# .5% -12 10 The A CFPP represents the reduction in cold filter plugging point ofthe diesel fuel after the pour point depressant is added, compared with the pure diesel fuel, as can be seen from tables 3 and 4, the pour point depressants 1#, 2#, 3#, 4#, and 5# all improve the cold filter plugging point of the diesel fuel to some extent, the pour point depressant prepared in example 4 shows good effect in reducing the cold filter plugging point, and when the addition amount is 0.5%, the A CFPP is 9 °C and 12 °C.

In conclusion, the polymethacrylate-vinyl acetate diesel pour point depressant solves the problem of poor broad spectrum of a single methacrylic acid pour point depressant, introduces vinyl acetate to expand the composition of the pour point depressant, and improves the pour point depression effect. The condensation point and cold filter plugging point of the diesel oil can be respectively reduced by 15-27 °C and 3-12 °C.

Embodiment 6: The preparation method of the polymethacrylate-vinyl acetate diesel pour point depressant comprises the following steps: ) Adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 55 °C to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; ) Adding methacrylic acid high-carbon ester and vinyl acetate into a solvent, then adding an initiator and carrying out polymerization reaction to obtain a methacrylic acid high-carbon ester-vinyl acetate binary polymer, namely the polymethacrylate-vinyl acetate diesel pour point depressant.

In the step 1), the higher alcohol is tetradecanol, the polymerization inhibitor is hydroquinone, the catalyst is p-toluenesulfonic acid, and the solvent is toluene. The molar ratio of methacrylic acid to higher alcohol was 1.3:1, the mass of the catalyst was 0.7% of the total mass of methacrylic acid and higher alcohol, and the mass of the polymerization inhibitor was 0.7% of the total mass of methacrylic acid and higher alcohol. In the catalytic reaction process, the reaction temperature is 110 °C, and the reaction time is 6 hours.

In the step 2), the initiator is benzoyl peroxide, and the solvent is toluene. The molar ratio of the high-carbon methacrylate to the vinyl acetate is 3:1, and the mass of the initiator is 1.2% of the total mass of the high-carbon methacrylate and the vinyl acetate. Before adding the initiator, removing air in a reaction system; in the polymerization reaction process, the reaction temperature is 90 °C and the reaction time is 8 hours.

Embodiment 7: The preparation method of the polymethacrylate-vinyl acetate diesel pour point depressant comprises the following steps: ) Adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 65 °C to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; ) Adding methacrylic acid high-carbon ester and vinyl acetate into a solvent, then adding an initiator and carrying out polymerization reaction to obtain a methacrylic acid high-carbon ester-vinyl acetate binary polymer, namely the polymethacrylate-vinyl acetate diesel pour point depressant.

In the step 1), the higher alcohol is hexadecanol, the polymerization inhibitor is hydroquinone, the catalyst is p-toluenesulfonic acid, and the solvent is toluene. The molar ratio of methacrylic acid to higher alcohol was 1.1:1, the mass of the catalyst was 0.9% of the total mass of methacrylic acid and higher alcohol, and the mass of the polymerization inhibitor was 0.5% of the total mass of methacrylic acid and higher alcohol. In the catalytic reaction process, the reaction temperature is 120 °C, and the reaction time is 5 hours.

In the step 2), the initiator is benzoyl peroxide, and the solvent is toluene. The molar ratio of the high-carbon methacrylate to the vinyl acetate is 15:1, and the mass of the initiator is 0.8 percent of the total mass of the high-carbon methacrylate and the vinyl acetate. Before adding the initiator, removing air in a reaction system; in the polymerization reaction process, the reaction temperature is 110 °C, and the reaction time is 7 hours.

Embodiment 8: The preparation method of the polymethacrylate-vinyl acetate diesel pour point depressant comprises the following steps: ) Adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 60 °C to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; ) Adding methacrylic acid high-carbon ester and vinyl acetate into a solvent, then adding an initiator and carrying out polymerization reaction to obtain a methacrylic acid high-carbon ester-vinyl acetate binary polymer, namely the polymethacrylate-vinyl acetate diesel pour point depressant.

In the step 1), the higher alcohol is octadecanol, the polymerization inhibitor is hydroquinone, the catalyst is p-toluenesulfonic acid, and the solvent is toluene. The molar ratio of methacrylic acid to higher alcohol was 1.2:1, the mass of the catalyst was 0.8% of the total mass of methacrylic acid and higher alcohol, and the mass of the polymerization inhibitor was 0.6% of the total mass of methacrylic acid and higher alcohol. In the catalytic reaction process, the reaction temperature is 110-1205°C, and the reaction time is 5.5 hours.

In the step 2), the initiator is benzoyl peroxide, and the solvent is toluene. The molar ratio of the high-carbon methacrylate to the vinyl acetate is 7:1, and the mass of the initiator is 1% of the total mass of the high-carbon methacrylate and the vinyl acetate. Before adding the initiator, removing air in a reaction system; in the polymerization reaction process, the reaction temperature is 100 °C, and the reaction time is 7.5 hours.

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 (5)

CLAIMS:

1. The preparation method of the polymethacrylate-vinyl acetate diesel pour point depressant is characterized by comprising the following steps: 1) adding methacrylic acid, higher alcohol and a polymerization inhibitor into a solvent, heating to 55-65 °C to fully dissolve, then adding a catalyst and carrying out catalytic reaction to obtain methacrylic acid high-carbon ester; 2) adding high-carbon methacrylate and vinyl acetate into a solvent, then adding an initiator and carrying out polymerization reaction to obtain a binary polymer of the high-carbon methacrylate and the vinyl acetate, namely the polymethacrylate-vinyl acetate diesel pour point depressant.

2. The preparation method for the polymethacrylate-vinylacetate diesel oil pour point depressant according to claim 1, characterized in that in the step 1), the higher alcohol comprises one or more of tetradecanol, hexadecanol or octadecanol, the polymerization inhibitor is hydroquinone, and the catalyst is p-toluenesulfonic acid; in the step 1) and the step 2), the solvent is toluene; in the step 2), the initiator is benzoyl peroxide; in the step 1), the molar ratio of the methacrylic acid to the higher alcohol is (1 .1-1 .3):1, the mass of the catalyst is 0.7-0.9% of the total mass of the methacrylic acid and the higher alcohol, and the mass of the polymerization inhibitor is 0.5-0.7% of the total mass of the methacrylic acid and the higher alcohol.

3. The preparation method for preparing the polymethacrylate-vinyl acetate diesel pour point depressant according to claim 1, characterized in that in the step 1), the reaction temperature is 110-120 °C and the reaction time is 5-6 hours in the catalytic reaction process; in the step 2), the molar ratio of the high-carbon methacrylate to the vinyl acetate is (3-15):1, and the mass of the initiator is 0.8-1 .2% of the total mass of the high-carbon methacrylate and the vinyl acetate; in the step 2), before adding the initiator, air in a reaction system is removed, then in the polymerization reaction process, the reaction temperature is 90-110 °C, and the reaction time is 7-8 hours.

4. Polymethacrylate-vinylacetate diesel pour point depressant, characterized in that it is prepared by the process according to any one of claims 1 to 3.

5. The application of a polymethacrylate-vinyl acetate diesel pour point depressant according to claim 4 in diesel.