Application of phenolic antioxidant in phosphate fire-resistant oil and phosphate fire-resistant oil

Abstract

The invention discloses an application of a phenolic antioxidant in phosphate fire-resistant oil and the phosphate fire-resistant oil, and belongs to the technical field of phosphate fire-resistant oil, the adopted phenolic antioxidant is 2, 6-butylated hydroxytoluene, the additive amount is 0.03-0.1%, the main component of the phosphate fire-resistant oil is trixylyl phosphate, and the additive amount is 0.05-0.1%. After the phenol antioxidant is added into the phosphate fire-resistant oil product, the comprehensive performance of the phosphate fire-resistant oil product in the operation process can be improved, the stability of the phosphate fire-resistant oil product is enhanced, and a guarantee is provided for safe operation of a generator set.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphate fire-resistant oil, and in particular to application of a phenolic antioxidant in phosphate fire-resistant oil and the phosphate fire-resistant oil. Background Art

[0002] Phosphate ester fire-resistant oil is a fully synthetic phosphate ester flame-retardant hydraulic fluid. Due to its excellent fire retardant and lubricating properties, it is widely used in the speed control system of steam turbines and gas turbines.

[0003] The composition of phosphate ester fire-resistant oil is triaryl phosphate ester. The difference between different brands of products lies in the different substituents on the benzene ring. Since phosphate ester fire-resistant oil products are chemically synthesized products, they have poor compatibility with additives, and most additives cannot be added. Compared with mineral oils, phosphate ester fire-resistant oils deteriorate quickly. During use, the acid value of the oil often increases, the resistivity decreases quickly, and sludge is generated after a short operating time. These can lead to reduced flexibility of the turbine parts and corrosion and jamming of the servo valve of the speed control system. In severe cases, it can cause abnormal shutdown accidents of the unit, affecting the safe operation of the power plant turbine unit. At the same time, phosphate ester fire-resistant oil is expensive, and frequent oil changes will increase the economic cost of the power industry; the replaced phosphate ester fire-resistant oil is a general hazardous waste, and improper disposal will pollute water and soil. Summary of the invention

[0004] In order to overcome the problems in the prior art that phosphate ester fire-resistant oil is prone to increase in acid value, decrease in resistivity, generation of sludge, etc. during use, resulting in reduced flexibility of turbine parts and casings, corrosion and jamming of the servo valve of the speed control system, and affecting the safe operation of the steam turbine unit in the power plant, the present invention provides an application of a phenolic antioxidant in phosphate ester fire-resistant oil and a phosphate ester fire-resistant oil. The phenolic antioxidant is 2,6-di-tert-butyl-p-cresol, and the additive amount is 0.03% to 0.1%. After the phenolic antioxidant is added to the phosphate ester fire-resistant oil product, its comprehensive performance during operation can be improved, the stability of the phosphate ester fire-resistant oil product can be enhanced, and the safe operation of the generator set can be guaranteed.

[0005] To achieve the above object, the present invention provides the following technical solution: application of a phenolic antioxidant in phosphate fire-resistant oil, wherein the phenolic antioxidant is 2,6-di-tert-butyl-p-cresol.

[0006] Furthermore, the added amount of 2,6-di-tert-butyl-p-cresol is 0.03% to 0.1%.

[0007] Furthermore, the main component of the phosphate fire-resistant oil is trixylene phosphate.

[0008] The present invention also provides a phosphate fire-resistant oil, wherein 0.03% to 0.1% of 2,6-di-tert-butyl-p-cresol is added to the phosphate fire-resistant oil.

[0009] Furthermore, the main component of the phosphate fire-resistant oil is trixylene phosphate.

[0010] The present invention also provides a method for preparing a phosphate fire-resistant oil, the specific steps of which are as follows:

[0011] S1: determining the amount of 2,6-di-tert-butyl-p-cresol according to the total amount of oil products, dissolving 2,6-di-tert-butyl-p-cresol in ten times the weight of new phosphate fire-resistant oil to obtain 2,6-di-tert-butyl-p-cresol mother liquor;

[0012] In the sealed state of S2, the mother solution of 2,6-di-tert-butyl-p-cresol is added into the phosphate fire-resistant oil to be added.

[0013] Furthermore, in S1, the addition amount of the 2,6-di-tert-butyl-p-cresol is 0.03% to 0.1%, and the main component of the phosphate fire-resistant oil is trixylene phosphate.

[0014] Furthermore, in S1, 2,6-di-tert-butyl-p-cresol is dissolved in ten times the weight of the new phosphate fire-resistant oil at 60°C±5°C to obtain a 2,6-di-tert-butyl-p-cresol mother liquor.

[0015] The present invention also provides an application of the phosphate fire-resistant oil, wherein the phosphate fire-resistant oil or the phosphate fire-resistant oil prepared by the preparation method is used in a speed regulating system of a steam turbine in a power plant.

[0016] The present invention also provides an application of the phosphate fire-resistant oil, wherein the phosphate fire-resistant oil or the phosphate fire-resistant oil prepared by the preparation method is used in a speed control system of a gas turbine in a power plant.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects:

[0018] The invention provides an application of a phenolic antioxidant in a phosphate fire-resistant oil. The phenolic antioxidant is specifically 2,6-di-tert-butyl-p-cresol. Currently, the phenolic antioxidant is mainly added to hydrocarbon mineral oil products, and the addition amount is generally 0.5%. The addition amount in the invention is 0.03% to 0.1%, and the phenolic antioxidant can be directly added to the phosphate fire-resistant oil. The adding method is simple. After the addition, the acid value, resistivity and stability of sludge precipitation during the use of the phosphate fire-resistant oil can be improved, the speed of the acid value increase and resistivity decrease of the phosphate fire-resistant oil product can be reduced, and the operation time before sludge is generated can be extended, thereby achieving the extension of the service life of the phosphate fire-resistant oil. The phenolic antioxidant is low in cost, the adding method is simple, and the phosphate fire-resistant oil has high economic value and social value. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0020] The present invention improves the comprehensive performance of phosphate fire-resistant oil products by adding antioxidants, and the main component of the phosphate fire-resistant oil is trixylene phosphate. The specific steps are as follows:

[0021] S1: preparing a sample: adding a certain amount of a certain additive to a phosphate ester fire-resistant oil base oil (hereinafter referred to as base oil) whose main component is trixylyl phosphate;

[0022] S1.1 Additives include phenolic additives;

[0023] The phenolic additives include 2,4-dicumylphenol, tert-butylhydroquinone, 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,6-di-tert-butyl-p-cresol, and dodecylphenol;

[0024] S1.2 The dosage of phenolic additive is 0.3% by weight of base oil;

[0025] S1.3 Preparation method of samples containing additives:

[0026] S1.3.1 Number the additives from 1 to n, take a glass bottle equipped with a sealed stopper, weigh a certain amount of base oil into the glass bottle, and number the sample bottles from 1 to n; then calculate the mass of each additive based on the mass of the base oil in the corresponding numbered sample bottle, weigh it with an analytical balance, add it to the corresponding sample bottle, and cover it with a cap to seal it.

[0027] Preferably, the volume of the sample bottle is 1000 mL, and the sealing stopper of the sample is a stopper made of polytetrafluoroethylene.

[0028] S1.3.2 Place the sealed sample bottle on a mixing device, which includes a vertically arranged triangular bracket, the bottom of which is fixed in a drying oven, and a motor is arranged on the top of the triangular bracket. The motor shaft is detachably connected to the sample bottle fixing plate. When the motor shaft is connected to the sample bottle fixing plate, the sample bottle fixing plate is driven by the motor to achieve continuous rotation in the vertical direction at a speed of 5r / min to 10r / min. A plurality of sample bottle fixing clamps are arranged along the circumference of the sample bottle fixing plate for fixing the mouths of a plurality of sample bottles toward the center of the sample bottle fixing plate.

[0029] Preferably, the sample bottle fixing clamp comprises a bottle bottom fixing clamp, a bottle body fixing clamp and a bottle top fixing clamp, wherein the bottle top fixing clamp is a movable fixing clamp, which can prevent the sample bottle from falling off during rotation after being tightened.

[0030] S1.3.3 Connect the sample bottle fixing plate with the sample bottles to the motor shaft. The temperature in the drying oven is kept constant at a fixed temperature of 60℃±5℃. Rotate the sample bottle fixing plate to rotate and mix the samples for 1 hour to ensure that the additives are dissolved in the base oil and mixed evenly.

[0031] S1.3.4 Take the sample out of the drying oven and cool it to room temperature.

[0032] S2 Preliminary screening: Test the base oil and the samples prepared in S1 for acid value, resistivity, oxidation stability, hydrolysis stability, and air release value. Compare the phosphate ester fire-resistant oil samples with the base oil after adding the additives. Samples with significantly reduced quality of the above indicators indicate that the additives are incompatible with the phosphate ester fire-resistant oil sample products, and the corresponding candidate additives are eliminated.

[0033] S3 is further screened: for the additives not eliminated in S2, phosphate ester fire-resistant oil samples are prepared according to S1, and the base oil and the prepared phosphate ester fire-resistant oil samples are subjected to closed cup aging test. During the aging test, samples are regularly sampled to test the acid value, resistivity, sludge precipitation, oxidation stability, hydrolysis stability, and air release value of the samples. The phosphate ester fire-resistant oil samples after adding each additive are compared with the base oil. If the above quality indicators deteriorate significantly faster, it indicates that the additive is incompatible with the phosphate ester fire-resistant oil product, and the corresponding candidate additive is eliminated.

[0034] Preferably, a 1000 mL ground-mouth conical flask is used during the aging process, and the sample amount in the flask is 600 g;

[0035] Preferably, 3 copper wires with a purity of not less than 99.9%, a diameter of 1.00 mm to 1.02 mm, and a length of 330 mm are added to the 600 g sample;

[0036] Preferably, after removing the surface oxide layer of the copper wire with mixed acid, the acid attached to the surface is washed off with running tap water and distilled water in turn, and then the copper wire is placed in a beaker containing ethanol and acetone for 10 seconds in turn, and placed at room temperature for 5 minutes to dry the solvent;

[0037] Preferably, the mixed acid for cleaning the copper wire is a mixture of phosphoric acid and nitric acid, with a mixing ratio of 1:3;

[0038] Preferably, the water content of the samples compared in parallel during the aging process is consistent, between 200 mg / L and 300 mg / L;

[0039] Preferably, the number of time points for longitudinal comparison of a single sample is 7 to 10;

[0040] Preferably, the samples for longitudinal and transverse comparisons are prepared at the same time;

[0041] Preferably, samples for horizontal comparison are sampled at the same aging time.

[0042] S4 Additive Dosage Selection: For the additives not removed in S2, prepare samples according to S1, and conduct closed cup aging test on base oil and the prepared samples. During the aging test, samples are regularly sampled to test the acid value, resistivity, sludge precipitation, oxidation stability, and hydrolysis stability of the samples. Compare the samples with each other. Compared with the base oil, the additives and addition amounts of the samples with the slowest deterioration of the above quality indicators are suitable additives and addition amounts.

[0043] Example

[0044] The present invention provides a phosphate fire-resistant oil, and the specific steps are as follows:

[0045] S1 Sample preparation, as follows:

[0046] S1.1 Take five 1000mL sample bottles and number them 1 to 5, and weigh 1000.0g of base oil into each of the five sample bottles;

[0047] S1.2 Weigh 3.0000g + 0.0001g of 2,4-dicumylphenol, tert-butylhydroquinone, 4,4'-methylenebis(2,6-di-tert-butylphenol), 2,6-di-tert-butyl-p-cresol, and dodecylphenol respectively, and number them 1 to 5 in sequence; add the additives into sample bottles with the same numbers.

[0048] S2 preliminary screening: The base oil and the samples prepared in S1 were tested for acid value, resistivity, oxidation stability, hydrolysis stability and air release value. The test results are shown in Table 1.

[0049] Table 1 Preliminary screening test results of various additives

[0050]

[0051]

[0052] Note: The repeatability deviation of the acid value is 0.02mgKOH / g, when the resistivity is greater than 1.0×1010Ω·cm, the repeatability is no more than 25% of the relative error, and when the air release value is less than 5min, the repeatability is no more than 0.7min. Therefore, compared with the results of the base oil, when the acid value, hydrolysis stability, and oxidation stability deviations of the sample after the additive are within 0.02mgKOH / g; when the resistivity deviation is within 0.35×1011Ω·cm, and when the air release value deviation is within 0.7min, it is considered that the additive has no negative impact on the base oil under this state.

[0053] The test results in Table 1 show that after adding additives No. 1 and No. 3, compared with the base oil, one or more of the oxidation stability, hydrolysis stability, air release value, and resistivity of the sample deteriorate, so these two additives are not suitable for this phosphate ester fire-resistant oil product. Several other additives can be further screened.

[0054] S3 further screened the additives No. 2, No. 4, and No. 5 that were not removed from S2. Samples were prepared according to S1, and closed cup aging tests were performed on the base oil and the prepared samples. During the aging test, samples were regularly taken to test the acid value, resistivity, sludge precipitation, oxidation stability, and air release value of the samples. The test results are shown in Tables 2 to 6.

[0055] Table 2 Acid value test results of each sample during 115℃ closed cup aging test

[0056]

[0057]

[0058] Table 3 Resistivity test results of each sample during 115℃ closed cup aging test

[0059]

[0060] Table 4 Oxidation stability test results of each sample during 115℃ closed cup aging test

[0061]

[0062]

[0063] Table 5 Test results of air release values ​​of each sample during 115℃ closed cup aging test

[0064]

[0065] Table 6 Results of sludge precipitation during the 115℃ closed cup aging test of each sample

[0066]

[0067] The test results in Tables 2 to 6 show that after the addition of additives No. 2 and No. 5, one or more of the acid value, sludge, air release value, and resistivity of the samples deteriorated during the aging process compared with the base oil, so these two additives are not suitable for this phosphate ester fire-resistant oil product. After the addition of additive No. 4, the tendency of sludge precipitation during the aging process was improved, and there was no negative impact on other properties of the oil product. Additive No. 4 is suitable as an additive for fire-resistant oil products.

[0068] S4 additive dosage selection: For additive No. 4, samples with additive contents of 0.03%, 0.05%, 0.08%, 0.10%, 0.20%, 0.30% and 0.50% were prepared according to S1, and closed cup aging tests were carried out on the base oil and the prepared samples. During the aging test, samples were regularly taken to test the acid value, sludge precipitation and resistivity of the samples. The test results are shown in Tables 7, 8 and 9.

[0069] Table 7 Acid value test results of each sample during 115℃ closed cup aging test

[0070]

[0071] Table 8 Detection results of sludge precipitation during the 115℃ closed cup aging test of each sample

[0072]

[0073] Table 9 Resistivity test results of each sample during 115℃ closed cup aging test

[0074]

[0075] The deterioration of triaryl phosphate fire-resistant oil is mainly due to the oxidation of aromatic ring substituents. The substituents on the aromatic ring generate free radicals under the catalysis of light or heat. The free radicals react with oxygen to generate oxidation products such as aldehydes, ketones, and acids, which in turn affect the acid value, resistivity, sludge precipitation and other indicators of the oil. After adding antioxidants, the antioxidants can react with free radicals and peroxides to form stable compounds, thereby consuming the free radicals generated in the oil and preventing the oxidation process of the oil molecules themselves. Combined with the test results in Tables 7 to 9, it is shown that when the content of No. 4 additive is high, a part of the free radicals formed by No. 4 additive may act as a nucleophilic agent to promote the hydrolysis reaction between triaryl phosphate and water, resulting in that as the aging degree deepens, the acid value of the phosphate-containing fire-resistant oil sample is higher than that of the base oil, thereby deepening the deterioration of the oil product;

[0076] When 0.03% to 0.1% of No. 4 additive 2,6-di-tert-butyl-p-cresol is added, the acid value and sludge precipitation quality indicators of the sample during the aging process can be optimally improved compared with the base oil and other additive amounts. Therefore, the additive suitable for fire-resistant oil products is No. 4 additive 2,6-di-tert-butyl-p-cresol with an additive amount of 0.03% to 0.1%, and the manufacturer is Jinan Shengda Chemical Co., Ltd.

Claims

1. A use of a phenolic antioxidant in phosphate fire-resistant oil, characterized in that: The phenolic antioxidant is 2,6-di-tert-butyl-p-cresol.

2. The use of a phenolic antioxidant in phosphate fire-resistant oil according to claim 1, characterized in that: The added amount of the 2,6-di-tert-butyl-p-cresol is 0.03% to 0.1%.

3. The use of a phenolic antioxidant in phosphate fire-resistant oil according to claim 1, characterized in that: The main component of the phosphate fire-resistant oil is trixylene phosphate.

4. A phosphate fire-resistant oil, characterized in that: 0.03% to 0.1% of 2,6-di-tert-butyl-p-cresol is added into the phosphate fire-resistant oil.

5. A phosphate fire-resistant oil according to claim 4, characterized in that: The main component of the phosphate fire-resistant oil is trixylene phosphate.

6. A method for preparing a phosphate fire-resistant oil, characterized in that: The specific steps are as follows: S1: determining the amount of 2,6-di-tert-butyl-p-cresol according to the total amount of oil products, dissolving 2,6-di-tert-butyl-p-cresol in ten times the weight of new phosphate fire-resistant oil to obtain 2,6-di-tert-butyl-p-cresol mother liquor; In the sealed state of S2, the mother solution of 2,6-di-tert-butyl-p-cresol is added into the phosphate fire-resistant oil to be added.

7. The method for preparing a phosphate fire-resistant oil according to claim 6, characterized in that: In S1, the addition amount of the 2,6-di-tert-butyl-p-cresol is 0.03% to 0.1%, and the main component of the phosphate fire-resistant oil is trixylene phosphate.

8. The method for preparing a phosphate fire-resistant oil according to claim 6, characterized in that: In S1, at 60°C±5°C, 2,6-di-tert-butyl-p-cresol is dissolved in ten times the weight of new phosphate fire-resistant oil to obtain a 2,6-di-tert-butyl-p-cresol mother liquor.

9. An application of a phosphate fire-resistant oil, characterized in that: The phosphate fire-resistant oil according to claim 4 or 5 or the phosphate fire-resistant oil prepared by the preparation method according to any one of claims 6 to 8 is used in the speed control system of the steam turbine of a power plant.

10. An application of a phosphate fire-resistant oil, characterized in that: The phosphate fire-resistant oil according to claim 4 or 5 or the phosphate fire-resistant oil prepared by the preparation method according to any one of claims 6 to 8 is used in the speed control system of the gas turbine of a power plant.

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