A demulsifier special for heavy fuel oil desalting for gas turbines and a preparation method thereof

Abstract

The present application relates to the technical fields of desalting demulsifier, and discloses a heavy fuel oil desalting demulsifier for gas turbine and a preparation method thereof, wherein the esterification reaction of polyethylene glycol monomethyl ether and 4-((dimethylamino)methyl)benzoic acid is used to obtain tertiary amine group polyethylene glycol monomethyl ether, and then the quaternary ammonium reaction of bromine atoms of modified phenolic resin is used to obtain the heavy fuel oil desalting demulsifier for gas turbine. The demulsifier uses phenolic resin as a matrix, introduces cationic groups and polyether chain segments into the side chain, has strong surface activity, shows high desalination and dehydration performance, and the dehydration rate reaches 87.2-93.5% at 18h, and the salt content of heavy fuel oil after electric desalination is only 3.4-6.6mg / L after 7 days of test.

Description

Technical Field

[0001] This invention relates to the field of desalting demulsifier technology, specifically to a demulsifier for desalting heavy fuel oil used in gas turbines and its preparation method. Background Technology

[0002] Crude oil, heavy fuel oil, and other fuels contain a certain amount of water and inorganic salts, which seriously affect the quality and combustion performance of the fuel. Crude oil demulsifiers are functional additives used in oilfield development, refining units, and other fields. Crude oil demulsifiers can disrupt the emulsion state of oil and water in crude oil, promoting oil-water separation, thereby achieving desalting and dehydration treatment of crude oil and improving its quality.

[0003] Common crude oil demulsifiers mainly include nonionic and ionic demulsifiers. Among them, nonionic demulsifiers obtained by polymerizing phenolic resin with polyoxyethylene and polyoxypropylene have excellent demulsification performance and are widely used. Patent CN105885029B discloses a polyether demulsifier based on amine-modified phenolic resin and its synthesis method. Using amine-modified phenolic resin as a starting agent, the polyether macromolecular demulsifier obtained by block polymerization with propylene oxide and ethylene oxide can effectively reduce the oil-water interface strength and achieve rapid demulsification. It can be used as a demulsifier for dehydration of oilfield produced fluids and dehydration and desalting in refineries. However, this demulsifier did not show good desalting performance. Cationic demulsifiers have high surface activity, diverse preparation methods, and strong demulsification performance, and have broad application prospects in oilfield development and demulsifier applications. Summary of the Invention

[0004] The technical problem solved by this invention is to provide a method for preparing a demulsifier specifically for desalting heavy fuel oil for gas turbines, which solves the problem of poor dehydration and desalination performance of phenolic resin polyether demulsifiers.

[0005] The present invention provides a method for preparing a demulsifier specifically for desalting heavy fuel oil used in gas turbines, comprising the following steps:

[0006] (1) Phenolic resin was added to N,N-dimethylformamide, and after stirring, 4-bromobutyryl chloride and triethylamine were added. The mixture was stirred and reacted. The solution was then distilled under reduced pressure, water was added, and the mixture was allowed to stand and separate into layers. The aqueous phase was removed, and the solution was dried to obtain the modified phenolic resin. The reaction formula is as follows:

[0007]

[0008] (2) Modified phenolic resin and tertiary amine polyethylene glycol monomethyl ether are added to N,N-dimethylformamide, the mixture is stirred and reacted, the solution is distilled under reduced pressure and dried to obtain a demulsifier for desalting heavy fuel oil used in gas turbines. The reaction formula is as follows:

[0009]

[0010] Preferably, in (1), the mass of 4-bromobutyryl chloride and triethylamine are 30-80% and 18-50% of the mass of phenolic resin, respectively.

[0011] Preferably, the reaction temperature in (1) is 20-30℃ and the reaction time is 18-24h.

[0012] Preferably, (2) the mass of the tertiary amine polyethylene glycol monomethyl ether is 150-800% of the mass of the modified phenolic resin.

[0013] Preferably, the reaction temperature in (2) is 120-140℃ and the reaction time is 48-72h.

[0014] The preferred method for preparing tertiary amine polyethylene glycol monomethyl ether is as follows: 750-2000 mg of polyethylene glycol monomethyl ether, 4-((dimethylamino)methyl)benzoic acid, and p-toluenesulfonic acid are added to toluene; the mixture is heated to 90-100°C, stirred for 6-10 hours, distilled under reduced pressure, washed with petroleum ether, and dried to obtain tertiary amine polyethylene glycol monomethyl ether. The reaction formula is as follows:

[0015]

[0016] Preferably, the molar amounts of 4-((dimethylamino)methyl)benzoic acid and p-toluenesulfonic acid are 120-180% and 7-10% of the molar amounts of polyethylene glycol monomethyl ether, respectively.

[0017] The present invention also provides a demulsifier for desalting heavy fuel oil for gas turbines prepared according to the above preparation method.

[0018] The technical advantages of this invention are as follows: Polyethylene glycol monomethyl ether is esterified with 4-((dimethylamino)methyl)benzoic acid to obtain tertiary amine polyethylene glycol monomethyl ether, which then undergoes a quaternization reaction with the bromine atoms of modified phenolic resin to obtain a demulsifier specifically for desalting heavy fuel oil used in gas turbines. This demulsifier uses phenolic resin as a matrix, introducing cationic groups and polyether segments into its side chains, exhibiting strong surface activity and high desalting and dehydration performance. The dehydration rate reaches 87.2-93.5% after 18 hours, and after 7 days of testing, the salt content of the desalted heavy fuel oil is only 3.4-6.6 mg / L. Detailed Implementation

[0019] The embodiments are described in detail below. However, various modifications can be made to the embodiments, and the scope of the present invention is not limited or restricted by the embodiments. All variations, equivalents, or substitutions of the embodiments are included within the scope of the claims.

[0020] Example 1

[0021] (1) Add 10 mmol of polyethylene glycol monomethyl ether 1500, 12 mmol of 4-((dimethylamino)methyl)benzoic acid (CAS No. 18364-71-1), and 0.8 mmol of p-toluenesulfonic acid to 30 mL of toluene, heat to 100 °C, stir and react for 8 h, distill under reduced pressure, wash with petroleum ether, and dry to obtain tertiary amine polyethylene glycol monomethyl ether.

[0022] (2) Add 3g of phenolic resin to 50mL of N,N-dimethylformamide, stir, add 1.5g of 4-bromobutyryl chloride and 0.86g of triethylamine, stir and react at 20℃ for 24h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin.

[0023] (3) Add 5g of modified phenolic resin and 7.5g of tertiary amine polyethylene glycol monomethyl ether to 300mL of N,N-dimethylformamide, heat to 120℃, stir and react for 60h, distill under reduced pressure and dry to obtain a demulsifier for desalting heavy fuel oil for gas turbines.

[0024] Example 2

[0025] (1) Add 10 mmol of polyethylene glycol monomethyl ether 1000, 12 mmol of 4-((dimethylamino)methyl)benzoic acid, and 0.7 mmol of p-toluenesulfonic acid to 40 mL of toluene, heat to 90 °C, stir and react for 10 h, distill under reduced pressure, wash with petroleum ether, and dry to obtain tertiary amine polyethylene glycol monomethyl ether.

[0026] (2) Add 3g of phenolic resin to 80mL of N,N-dimethylformamide, stir, add 2.4g of 4-bromobutyryl chloride and 1.5g of triethylamine, stir and react at 30℃ for 18h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin.

[0027] (3) Add 5g of modified phenolic resin and 18.2g of tertiary amine polyethylene glycol monomethyl ether to 400mL of N,N-dimethylformamide, heat to 140℃, stir and react for 48h, distill under reduced pressure and dry to obtain a demulsifier for desalting heavy fuel oil for gas turbines.

[0028] Example 3

[0029] (1) Add 10 mmol of polyethylene glycol monomethyl ether 2000, 18 mmol of 4-((dimethylamino)methyl)benzoic acid, and 1 mmol of p-toluenesulfonic acid to 40 mL of toluene. Heat to 90 °C and stir for 10 h. Distill under reduced pressure, wash with petroleum ether, and dry to obtain tertiary amine polyethylene glycol monomethyl ether.

[0030] (2) Add 3g of phenolic resin to 50mL of N,N-dimethylformamide, stir, add 0.9g of 4-bromobutyryl chloride and 0.54g of triethylamine, stir and react at 20℃ for 24h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin.

[0031] (3) Add 5g of modified phenolic resin and 29.5g of tertiary amine polyethylene glycol monomethyl ether to 400mL of N,N-dimethylformamide, heat to 140℃, stir and react for 60h, distill under reduced pressure and dry to obtain a demulsifier for desalting heavy fuel oil for gas turbines.

[0032] Example 4

[0033] (1) Add 10 mmol of polyethylene glycol monomethyl ether 750, 15 mmol of 4-((dimethylamino)methyl)benzoic acid, and 1 mmol of p-toluenesulfonic acid to 30 mL of toluene. Heat to 100 °C and stir for 6 h. Distill under reduced pressure, wash with petroleum ether, and dry to obtain tertiary amine polyethylene glycol monomethyl ether.

[0034] (2) Add 3g of phenolic resin to 70mL of N,N-dimethylformamide, stir, add 1.9g of 4-bromobutyryl chloride and 1.18g of triethylamine, stir and react at 25℃ for 24h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin.

[0035] (3) Add 5g of modified phenolic resin and 40g of tertiary amine polyethylene glycol monomethyl ether to 400mL of N,N-dimethylformamide, heat to 130℃, stir and react for 72h, distill under reduced pressure and dry to obtain a demulsifier for desalting heavy fuel oil for gas turbines.

[0036] Comparative Example 1

[0037] (1) Add 3g of phenolic resin to 50mL of N,N-dimethylformamide, stir, add 1.5g of 4-bromobutyryl chloride and 0.86g of triethylamine, stir and react at 20℃ for 24h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin.

[0038] (2) Add 5g of modified phenolic resin and 7.5g of methyl 4-((dimethylamino)methyl)benzoate (CAS No. 18153-53-2) to 300mL of N,N-dimethylformamide, heat to 120℃, stir and react for 60h, distill under reduced pressure and dry to obtain demulsifier.

[0039] Comparative Example 2

[0040] (1) Add 15g polyethylene glycol monomethyl ether 1500, 1.1g succinic anhydride, 0.1g 4-dimethylaminopyridine and 1.2g triethylamine to 100mL dichloromethane. Stir and react at 25℃ for 12h. Distill under reduced pressure, wash with petroleum ether, dry, add the product to 80mL toluene, add 22g thionyl chloride, stir and react at 70℃ for 24h, distill under reduced pressure and dry to obtain acyl chloride polyethylene glycol monomethyl ether.

[0041] (2) Add 3g of phenolic resin to 80mL of N,N-dimethylformamide, stir, add 10.9g of acyl chloride polyethylene glycol monomethyl ether and 1.5g of triethylamine, stir and react at 30℃ for 18h, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain the demulsifier.

[0042] The demulsifier evaluation method was conducted in accordance with industry standards SY / T5280-2018 and SY / T 5281-2000. The sample crude oil was heavy fuel oil. The demulsifier dosage was 18 mg / L.

[0043] Table 1 Dehydration rate test of demulsifier

[0044]

[0045] Table 2. Salt content test of electro-desalted heavy fuel oil

[0046]

[0047] After testing, the demulsifier for desalting heavy fuel oil for gas turbines in Examples 1-4, with phenolic resin as the matrix and cationic groups and polyether segments introduced into its side chain, has strong surface activity and exhibits high desalting and dehydration performance. The dehydration rate reaches 87.2-93.5% after 18 hours, and after 7 days of testing, the salt content of heavy fuel oil after electro-desalting is only 3.4-6.6 mg / L.

[0048] Comparative Example 1 utilizes a quaternization reaction between modified phenolic resin and the tertiary amine group of methyl 4-((dimethylamino)methyl)benzoate. The resulting phenolic resin-based demulsifier does not contain polyether segments in its side chain, exhibits poor surface activity, and has poor desalting and dehydration performance. At 18 hours, the dehydration rate is only 24.9%. After 7 days of testing, the salt content of heavy fuel oil after electro-desalting reaches 63.4 mg / L.

[0049] Comparative Example 2 utilizes the hydroxyl groups of phenolic resin to react with the acyl chloride groups of acyl chloride polyethylene glycol monomethyl ether. The resulting phenolic resin-based demulsifier has polyether segments in its side chains but no cationic groups, resulting in poor surface activity and mediocre desalting and dehydration performance. The dehydration rate is only 66.9% after 18 hours. After 7 days of testing, the salt content of heavy fuel oil after electro-desalting reaches 19.3 mg / L.

[0050] In summary, the embodiments have been described through limited examples, and those skilled in the art can make various modifications and variations to the above description. For example, the described techniques may be performed in a different order than the described methods, and / or the described constituent elements may be combined or integrated in a different form than the described methods, or the same effect may be obtained by replacing or substituting other constituent elements or equivalents.

Claims

1. A method for preparing a demulsifier specifically for desalting heavy fuel oil used in gas turbines, characterized in that, The preparation method includes the following steps: (1) Add phenolic resin to N,N-dimethylformamide, stir, add 4-bromobutyryl chloride and triethylamine, stir to react, distill the solution under reduced pressure, add water, let stand to separate the layers, remove the aqueous phase, dry, and obtain modified phenolic resin. (2) Add modified phenolic resin and tertiary amine polyethylene glycol monomethyl ether to N,N-dimethylformamide, stir and react, distill the solution under reduced pressure and dry to obtain a demulsifier for desalting heavy fuel oil for gas turbines. The preparation method of the tertiary amine polyethylene glycol monomethyl ether includes: adding polyethylene glycol monomethyl ether, 4-((dimethylamino)methyl)benzoic acid and p-toluenesulfonic acid to toluene, stirring and reacting, followed by vacuum distillation, washing, and drying to obtain tertiary amine polyethylene glycol monomethyl ether.

2. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, In (1), the mass of 4-bromobutyryl chloride and triethylamine are 30-80% and 18-50% of the mass of phenolic resin, respectively.

3. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, The temperature of the stirring reaction in (1) is 20-30℃ and the reaction time is 18-24h.

4. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, The mass of the tertiary amine polyethylene glycol monomethyl ether in (2) is 150-800% of the mass of the modified phenolic resin.

5. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, The temperature of the stirring reaction in (2) is 120-140℃ and the reaction time is 48-72h.

6. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, The molar amounts of 4-((dimethylamino)methyl)benzoic acid and p-toluenesulfonic acid are 120-180% and 7-10% of the molar amount of polyethylene glycol monomethyl ether, respectively.

7. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, The molecular weight of the polyethylene glycol monomethyl ether is 750-2000.

8. The preparation method of the demulsifier for desalting heavy fuel oil for gas turbines according to claim 1, characterized in that, In the preparation method of the tertiary amine-based polyethylene glycol monomethyl ether, the stirring reaction is carried out at 90-100℃ for 6-10 hours.

9. A demulsifier for desalting heavy fuel oil for gas turbines, prepared by the method according to any one of claims 1-8.

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