A stabilizer for fuel oil containing ethylene tar and a preparation process thereof

Abstract

The application discloses a stabilizer for fuel oil containing ethylene tar and a preparation process thereof and belongs to the technical field of energy chemical industry.The stabilizer is composed of a composite antioxidant (8-20%), a nanoscale dispersant (20-25%), a metal passivator (5-8%), a viscosity modifier (10-15%) and a solvent (20-50%).The composite antioxidant is prepared by compounding alkylated diphenylamine and D-tocopherol at a ratio of 3:1, the nanoscale dispersant is polyisobutylene succinimide supported on a nanoscale silicon dioxide carrier modified by a silane coupling agent, and the metal passivator is selected from six specific benzotriazole derivatives.The preparation method realizes the synergistic effect of components through surface modification of a nanoscale carrier, in-situ loading of a dispersant, compounding of an antioxidant system and high-pressure homogenization treatment and the like.The application solves the problems of storage deterioration, metal catalytic deterioration and viscosity control of ethylene tar fuel oil through innovative formula design and process optimization and has important industrial application value.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy and chemical industry, and specifically relates to a stabilizer for fuel oil containing ethylene tar and a preparation process thereof. BACKGROUND

[0002] In the field of energy today, fuel oil containing ethylene tar, as an important energy material, has been widely used in industrial production and daily life. However, the fuel oil faces many problems in storage and use, which need to be solved urgently.

[0003] Firstly, the fuel oil containing ethylene tar is prone to oxidation during storage, which leads to a decrease in its quality. Oxidation reaction generates harmful substances such as peroxide, aldehyde, and ketone, which not only reduce the calorific value of the fuel oil but also may produce carbon deposition during combustion, affecting the combustion efficiency and equipment life. Therefore, an effective antioxidant is needed to inhibit oxidation and maintain the stability of the fuel oil.

[0004] Secondly, solid particles in the fuel oil are prone to aggregation and sedimentation, affecting the flowability and uniformity of the fuel oil. This phenomenon can cause uneven injection and incomplete combustion of the fuel oil during transportation and combustion, reducing combustion efficiency and increasing pollutant emissions. In order to improve the dispersion stability of the fuel oil, a high-efficiency nanoscale dispersant is needed to uniformly disperse the solid particles in the fuel oil and prevent their re-aggregation.

[0005] In addition, metal ions contained in the fuel oil are prone to react with other components in the fuel oil, accelerating the deterioration of the fuel oil. Metal ions may also form metal oxides during combustion, causing corrosion and wear of combustion equipment. Therefore, a metal passivator is needed to passivate metal ions to prevent their negative impact on the stability of the fuel oil.

[0006] In practical application, the viscosity of the fuel oil is also a key factor. Fuel oil with too high viscosity can cause transportation difficulties and incomplete combustion, while fuel oil with too low viscosity can affect the lubrication performance and combustion stability of the fuel oil. Therefore, a viscosity modifier is needed to adjust the viscosity of the fuel oil to maintain a suitable viscosity range during storage and use.

[0007] In summary, there is a lack of a stabilizer that can simultaneously solve the problems of oxidation resistance, dispersion stability, metal passivation, and viscosity adjustment of fuel oil containing ethylene tar in the market. Based on this market demand, the present application provides a stabilizer for fuel oil containing ethylene tar and a preparation method thereof to overcome the shortcomings of the prior art, improve the comprehensive performance of the fuel oil, and meet the high-quality development needs of the energy field. SUMMARY

[0008] The present application aims to provide a stabilizer for fuel oil containing ethylene tar, which has advantages in antioxidant, dispersion stability, metal passivation and viscosity adjustment.

[0009] The present application provides a stabilizer for fuel oil containing ethylene tar, the mass ratio of the stabilizer for fuel oil containing ethylene tar is: 8-20% of composite antioxidant, 20-25% of nanoscale dispersant, 5-8% of metal passivator, 10-15% of viscosity modifier, 20-50% of solvent.

[0010] Further, the composite antioxidant comprises: alkylated diphenylamine and D-tocopherol mixed in a mass ratio of 3:1.

[0011] Further, the nanoscale dispersant is polyisobutylene succinimide and nanosilica carrier.

[0012] Further, the viscosity modifier is propylene glycol methyl ether acetate.

[0013] Further, the solvent is hydrogenated palm oil.

[0014] Further, the metal passivator is a benzotriazole derivative;

[0015] Further, the benzotriazole derivative is selected from metal passivator-1 to metal passivator-6;

[0016] Further, the metal passivator-1 to metal passivator-6 has the structure of:

[0017]

[0018] Further, the Chinese name of metal passivator-1 to metal passivator-6 is:

[0019] The Chinese name of the metal passivator-1 is: 1-(5-(4-(6-(benzyloxy)-2-phenyl-1,2,3,4-tetrahydronaphthalene-1-yl) phenoxy) pentyl)-1H-benzo[d][1,2,3] triazole;

[0020] The Chinese name of the metal passivator-2 is: (S)-8-((5-(1H-benzo[d][1,2,3] triazole-1-yl) pentyl) oxy)-7-methoxy-10-(2-(trimethylsilyl) ethoxy) methyl)-1,11-dihydro-5H-benzo[e] pyrrolo[1,2-a][1,4] diazepine-2,5,11(3H,10H)-trione;

[0021] The Chinese name of the metal passivator-3 is: (4-(5-(1H-benzo[d][1,2,3]triazol-1-yl)pentyl)oxy)-5-methoxy-2-nitrophenyl)(2-(bis(ethylthio)methyl)pyrrolidin-1-yl)methanone;

[0022] The Chinese name of the metal passivator-4 is: 3-(4-(1H-benzo[d][1,2,3]triazol-1-yl)butyl)-4-acetyl-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyloxazolidin-2-one;

[0023] The Chinese name of the metal passivator-5 is: allyl (S)-8-(3-(1H-benzo[d][1,2,3]triazol-1-yl)propoxy)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-10(5H)-carboxylate;

[0024] The Chinese name of the metal passivator-6 is: methyl 4-((2-(5-(1H-benzo[d][1,2,3]triazol-1-yl)pentyl)oxy)phenethyl)(5-ethoxy-5-oxopentyl)amino)methyl)benzoate.

[0025] Further, the synthesis step of the benzotriazole derivative is: adding benzotriazole into a first solvent, stirring, adding raw material, adding triphenylphosphine stirring, replacing gas by nitrogen, adding target carbon, and heating to 80-90℃ for 12h.

[0026] Further, the first solvent is toluene.

[0027] Further, the structure of the raw material is:

[0028]

[0029] Further, the Chinese names of the raw materials-1 to 6 are:

[0030] The Chinese name of the raw material-1 is: 6-(benzyloxy)-1-(4-(5-bromopentyl)oxy)phenyl)-2-phenyl-1,2,3,4-tetrahydronaphthalene;

[0031] The Chinese name of the raw material-2 is: (S)-8-((5-bromopentyl)oxy)-7-methoxy-10-((2-(trimethylsilyl)ethoxy)methyl)-1,11-dihydro-5H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-2,5,11(3H,10H)-trione;

[0032] The Chinese name of the raw material-3 is: (2-(bis(ethylthio)methyl)pyrrolidine-1-yl)(4-((5-bromopentyl)oxy)-5-methoxy-2-nitrophenyl) ketone;

[0033] The Chinese name of the raw material-4 is: 4-ethylene-3-(4-propenylmethyl)-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyloxazolidine-2-one;

[0034] The Chinese name of the raw material-5 is: (S)-8-(3-bromopropoxy)-7-methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4]diazazo-10(5H)-carboxylic acid allyl ester.

[0035] The Chinese name of the raw material-6 is: methyl 4-(((2-((5-bromopentyl)oxy)phenethyl)(5-ethoxy-5-oxopentyl)amino)methyl)benzoate.

[0036] Furthermore, a method for preparing a fuel oil stabilizer containing ethylene tar includes the following steps:

[0037] S1. Disperse nano-silica (10-20nm) ultrasonically in anhydrous ethanol, add silane coupling agent KH-550, and react at 60°C for 2 hours to form the nano-silica carrier;

[0038] S2. The polyisobutylene succinimide and the nano silica carrier are mixed at a mass ratio of 1:2, dispersed in a high-speed shear machine (8000 rpm) for 1 hour, and dried under reduced pressure at 60°C to obtain a supported dispersant;

[0039] S3. The alkylated diphenylamine and the D-tocopherol are dissolved in the hydrogenated palm oil in a 3:1 ratio, and 0.5% citric acid is added as a pH stabilizer. The mixture is stirred at 50°C until transparent.

[0040] S4. Add the dispersant from S2 and the metal passivating agent to hydrogenated palm oil and premix at 60°C for 30 minutes;

[0041] S5. Add the antioxidant complex system, heat to 70℃ and stir continuously for 1 hour;

[0042] S6. Finally, add glycol methyl ether acetic acid and process it three times using a high-pressure homogenizer (50 MPa) to obtain a fuel oil stabilizer containing ethylene tar.

[0043] Compared with the prior art, the advantages of the present invention are:

[0044] 1. Breakthrough the activity bottleneck of single antioxidant by 3:1 compounding of alkylated diphenylamine and D-tocopherol, the oxidation induction period is increased to 420 hours, which is 110% longer than the traditional BHT system, and the oxidation gum generation of ethylene tar fuel oil is significantly inhibited.

[0045] 2. Nanodispersant structure innovation: using silane coupling agent modified nanosilica as carrier, in-situ loading of polyisobutylene succinimide, forming a double stabilizing mechanism of steric hindrance and electrostatic repulsion, making the particle D50≤200nm in fuel oil, no precipitation after 30 days standing, overcoming the particle aggregation problem caused by the lack of carrier in conventional dispersants.

[0046] 3. Outstanding target metal passivation performance: based on the chelate barrier formed by the passivator of benzotriazole derivative and metal ions, the copper sheet corrosion grade is optimized to 1a grade, the passivation efficiency is ≥98.5%, and the corrosion risk is reduced by 80% compared with nitrite passivator.

[0047] 4. Low temperature viscosity regulation and optimization: through the complex solvent system of hydrogenated vegetable oil and propylene glycol methyl ether acetate, synergistic viscosity modifier, the viscosity of fuel oil at-20℃ is kept at 150cP, the flowability is better than 180cP of mineral oil based solvent, and the problem of viscous storage and transportation in high cold environment is solved. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 The structure of the metal passivator described in the present application. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be described below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of protection of the present application.

[0050] Example 1-1

[0051] Synthesis of metal passivator-1.

[0052] Benzotriazole 1eq was added to toluene, stirred, and raw material-1 (6-(benzyloxy)-1-(4-(5-bromopentyl)oxy)phenyl)-2-phenyl-1,2,3,4-tetrahydronaphthalene) 1eq was added, triphenylphosphine was added and stirred 1.5eq, nitrogen was introduced to replace the gas, target carbon 0.01eq was added, the temperature was raised to 85℃, and the reaction was carried out for 12h. The solvent was rotary evaporated, and the metal passivator-1 was purified by silica gel purification column.

[0053] MS (MS+1) shows: 594.

[0054] Example 1-2

[0055] Synthesis of Metal Passivator-2, refer to the synthesis procedure of Metal Passivator-1 in Example 1-1, replace the starting material with Starting Material-2 ((S)-8-((5-bromopentyl)oxy)-7-methoxy-10-((2- (trimethylsilyl)ethoxy)methyl)-1,11-dihydro-5H-benzo[e]pyrrolo[1,2-a][1,4]diazepine-2,5,11(3H,10H)-trione), and follow the same procedure as in Example 1-1.

[0056] MS (MS+1) shows: 594.

[0057] Example 1-3

[0058] Synthesis of Metal Passivator-3, refer to the synthesis procedure of Metal Passivator-1 in Example 1-1, replace the starting material with Starting Material-3 ((2-(bis(ethylthio)methyl)pyrrolidin-1-yl)(4-((5-bromopentyl)oxy)-5-methoxy-2-nitrophenyl)methanone), and follow the same procedure as in Example 1-1;

[0059] MS (MS+1) shows: 588.

[0060] Example 1-4

[0061] Synthesis of Metal Passivator-4, refer to the synthesis procedure of Metal Passivator-1 in Example 1-1, replace the starting material with Starting Material-4 (4-ethylen-3-(4- ethyl)-5-((R)-1-((tert-butyldiphenylsilyl)oxy)propyl)-5-methyloxazolidin-2-one), and follow the same procedure as in Example 1-1;

[0062] MS (MS+1) shows: 612.

[0063] Example 1-5

[0064] Synthesis of Metal Passivator-5, refer to the synthesis procedure of Metal Passivator-1 in Example 1-1, replace the starting material with Starting Material-5 ((S)-8-(3-bromopropoxy)-7- methoxy-2-(4-methoxyphenyl)-5-oxo-11,11a-dihydro-1H-benzo[e]pyrrolo[1,2-a][1,4] diazepine-10(5H)-carboxylate), and follow the same procedure as in Example 1-1;

[0065] MS (MS+1) shows: 596.

[0066] Example 1-6

[0067] Synthesis of Metal Deactivator-6, refer to the synthesis procedure of Metal Deactivator-1 in Reference Example 1-1, replace raw material-1 with raw material-6 (methyl 4-(((2-((5-bromopentyl)oxy)phenethyl)(5-ethoxy-5- oxopentyl)amino)methyl)benzoate), and follow the same procedure as Example 1-1.

[0068] MS (MS+1) shows: 601.

[0069] Example 1: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0070] Preparation of nano-silica carrier: 10 g of nano-silica (15 nm) was dispersed in 200 mL of anhydrous ethanol, ultrasonically treated for 30 minutes, 2 g of silane coupling agent KH-550 was added, and stirred at 60°C for 2 hours. The modified carrier was obtained by centrifugal drying.

[0071] Preparation of supported dispersant: 5 g of polyisobutylene succinimide was mixed with 10 g of modified carrier, dispersed in a high-speed shear machine at 8000 rpm for 1 hour, and dried at 60°C under reduced pressure.

[0072] Preparation of antioxidant system: 9 g of alkylated diphenylamine and 3 g of D-tocopherol were dissolved in 30 g of hydrogenated palm oil, 0.15 g of citric acid was added, and stirred at 50°C until transparent.

[0073] Pre-mixing of dispersing system: the dispersant of step 2 and 6 g of metal deactivator-1 (prepared in Example 1-1) were added to 20 g of hydrogenated palm oil, and pre-mixed at 60°C for 30 minutes.

[0074] Final mixing treatment: the antioxidant system was added to the pre-mixed system, heated to 70°C and stirred for 1 hour. Finally, 12 g of propylene glycol methyl ether acetate was added, and homogenized 3 times at 50 MPa high pressure to obtain stabilizer A.

[0075] Formulation composition: composite antioxidant 12%, nano-dispersant 20% (including carrier), metal deactivator 6%, viscosity modifier 12%, solvent 45%.

[0076] Example 2: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0077] According to the preparation method of Example 1, the formulation ratio was adjusted as follows: composite antioxidant 10%, nano-dispersant 25% (including carrier), metal deactivator 7%, viscosity modifier 15%, solvent 40%, and the rest was the same as Example 1.

[0078] Example 3: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0079] Referring to the preparation method of Example 1, replace the metal deactivator-1 with metal deactivator-4 (prepared in Example 1-4), and the rest is the same as Example 1.

[0080] Example 4: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0081] Referring to the preparation method of Example 1, adjust the formula ratio to: increase the viscosity modifier to 18%, and the rest is the same as Example 1.

[0082] Example 5: Preparation of a stabilizer for fuel oil containing ethylene tar.

[0083] Referring to the preparation method of Example 1, adjust the formula ratio to: increase the viscosity modifier to 18%, and the rest is the same as Example 1.

[0084] Comparative Example 1: No nano-dispersant system

[0085] Referring to the preparation method of Example 1, omit the nano-silica carrier and directly use polyisobutylene succinimide, and the rest is the same as Example 1.

[0086] Comparative Example 2: Traditional antioxidant replacement

[0087] Referring to the preparation method of Example 1, replace the composite antioxidant with BHT (dibutyl hydroxytoluene), and the rest is the same as Example 1.

[0088] Comparative Example 3: Non-benzotriazole deactivator

[0089] Referring to the preparation method of Example 1, replace the metal deactivator with sodium nitrite, and the rest is the same as Example 1.

[0090] Comparative Example 4: Solvent replaced with mineral oil

[0091] Referring to the preparation method of Example 1, replace the hydrogenated palm oil with an equal amount of mineral oil, and the rest is the same as Example 1.

[0092] Comparative Example 5: No metal deactivator

[0093] Referring to the preparation method of Example 1, omit the metal deactivator, and the rest is the same as Example 1.

[0094] Performance test:

[0095] 1. Oxidation induction time (OIT) test:

[0096] Operation steps:

[0097] (a) Take 10.0 ± 0.2 mg of the fuel oil sample to be tested and place it in an open aluminum crucible;

[0098] (b) Temperature raised to 120°C at 10°C / min under nitrogen atmosphere (flow rate 50 mL / min), and kept for 5 min;

[0099] (c) Switched to oxygen atmosphere (flow rate 50 mL / min), and recorded the onset time of exothermic peak of oxidation, defined as oxidation induction period.

[0100] Data recording: Each group of samples was tested in triplicate, and the arithmetic mean value was taken with standard deviation ≤3%.

[0101] 2. Suspension stability evaluation

[0102] Test condition: Constant temperature at 25°C, lightless standing, and observation period of 30 days;

[0103] Quantitative method:

[0104] (a) 50 mL sample was injected into a transparent glass container (inner diameter 30 mm), and sealed after vertical standing;

[0105] (b) Laser scattering method was used to determine the particle size distribution before and after standing;

[0106] (c) The volume ratio of precipitate was calculated: Precipitation rate (%) = (lower layer precipitation height / total liquid surface height) x 100%.

[0107] Judgment standard:

[0108] Good: Precipitation rate ≤1%;

[0109] Qualified: 1% < Precipitation rate ≤5%;

[0110] Poor: Precipitation rate >5%.

[0111] 3. Metal corrosivity test

[0112] Operation steps:

[0113] (a) Copper sheet (purity ≥99.9%, size 10 mm x 20 mm x 1 mm) was polished with 400 mesh sandpaper, washed with acetone and dried in sequence;

[0114] (b) The copper sheet was completely immersed in 50 mL of the fuel oil to be tested, and heated in an oil bath at 100°C for 3 h;

[0115] (c) The copper sheet was taken out, washed with isooctane, and compared with ASTM standard color card to record the corrosion grade.

[0116] Grade definition:

[0117] 1a grade: Light yellow, no corrosivity;

[0118] 2c grade: Purple or dark brown, slight corrosion;

[0119] 3b: black or green, severe corrosion.

[0120] 4. Low temperature fluidity test.

[0121] Test condition: -20℃±0.5℃, shear rate 100s-1.

[0122] Operation steps:

[0123] (a) Put the sample into the low temperature thermostat and pre-cool to -20℃, keep constant temperature for 30min;

[0124] (b) Start the viscometer, record the viscosity value (unit: cP) after the torque is stable;

[0125] (c) Repeat the test for 3 times, take the average value after eliminating abnormal values.

[0126] 5. Metal passivation efficiency calculation

[0127] Steps:

[0128] (a) Add 50ppm Fe 3+ / Cu 2+ mixed ions (molar ratio 1:1) into the fuel oil;

[0129] (b) Put the experimental group containing the passivator and the blank control group (without passivator) into the 120℃ oxygen flow (flow rate 20mL / min) at the same time;

[0130] (c) Sample every 2h, determine the acid value according to ASTM D664, calculate the oxidation rate (ΔAV / ΔT);

[0131] (d) Passivation efficiency (%) = [(oxidation rate of blank group-oxidation rate of experimental group) / oxidation rate of blank group]x100%.

[0132] Performance comparison data table.

[0133]

[0134]

[0135] The present application significantly improves the oxidation stability, dispersion uniformity and metal passivation effect of fuel oil through the synergistic effect of the composite antioxidant system, nano loading dispersion technology and specific benzotriazole derivatives, and the comprehensive performance is significantly better than that of the traditional scheme.

[0136] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A stabilizer for fuel oil containing ethylene tar, characterized by comprising: The mass ratio of the stabilizer for the fuel oil containing ethylene tar is: 8-20% of the composite antioxidant, 20-25% of the nanoscale dispersant, 5-8% of the metal deactivator, 10-15% of the viscosity modifier, and 20-50% of the solvent, and the total mass ratio is 100%; The metal deactivator is a benzotriazole derivative; The benzotriazole derivative is selected from metal deactivator-1 to metal deactivator-6; The metal deactivator-1 to metal deactivator-6 are structured as shown in the description; ； The composite antioxidant comprises alkylated diphenylamine and D-tocopherol mixed at a mass ratio of 3:1; The nanoscale dispersant is nanoscale silicon dioxide modified by a silane coupling agent as a carrier, and in-situ loaded with polyisobutylene succinimide; The solvent is hydrogenated palm oil.

2. A stabilizer for fuel oil containing ethylene tar according to claim 1, characterized by The viscosity modifier is propylene glycol methyl ether acetate.

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