Oilfield wastewater treatment oil removal agent and preparation method thereof
By preparing an oil removal agent with a specific composition for oilfield wastewater treatment, the problem of unsatisfactory oil removal effect of existing oil removal agents has been solved, achieving efficient oil-water separation and oil removal. It also has demulsification, sterilization, flocculation and slow release functions, avoiding secondary pollution.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- KARAMAY XINKEAO CHEM CO LTD
- Filing Date
- 2024-03-19
- Publication Date
- 2026-06-02
Smart Images
Figure SMS_1 
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Abstract
Description
Technical Field
[0001] This invention relates to the field of oilfield treatment agent technology, specifically to an oil removal agent for oilfield wastewater treatment and its preparation method. Background Technology
[0002] Because many solids in wastewater are poorly soluble in water, when one or more of these solids are present in large quantities in oil and water, under the agitation of hydraulic or external forces, these solids and crude oil can exist in the water in an emulsified state, forming an emulsion. This emulsification is very severe, and the two phases are even difficult to separate.
[0003] Oil remover is a wastewater treatment product that can break up oil-in-water emulsions, shorten oil-water separation time, and is miscible with water. Oil remover is often also called a reverse demulsifier. For O / W emulsions, cationic reverse demulsifiers are very important. Their demulsification mechanism involves the positive charge in the reverse demulsifier combining with the negative charge in the oil droplets, thereby achieving the purpose of oil removal.
[0004] Currently, extensive research has been conducted abroad on reverse demulsifiers, and a series of reverse demulsifiers have been successively prepared and developed for the "demulsification" of O / W emulsions and the "oil removal" of oily wastewater. The principle of most reverse demulsifiers is to use cationic polymer agents for demulsification and oil removal, but existing conventional oil removal agents often have unsatisfactory oil removal effects. Summary of the Invention
[0005] This invention provides an oil removal agent for oilfield wastewater treatment and its preparation method, which overcomes the shortcomings of the prior art and can effectively solve the problem of poor oil removal effect of existing conventional oil removal agents.
[0006] One of the technical solutions of the present invention is achieved by the following measures: an oilfield wastewater treatment oil removal agent, the raw materials of which include 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea and catalyst in a molar concentration ratio of (0.2 to 1.0): (0.5 to 1.5): (0.3 to 2.0): (0.4 to 3.0): (0.1 to 0.2): (0.0002 to 0.0004).
[0007] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:
[0008] The catalyst described above consists of ammonium persulfate and sodium sulfite in a molar ratio of 1:1.
[0009] The aforementioned oil removal agent for oilfield wastewater treatment is obtained using the following method:
[0010] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere to obtain a mixed solution.
[0011] The second step involves adding the required amount of acrylamide and catalyst to the mixed solution to react and obtain the reaction product. After diluting the reaction product with water, an oil removal agent for oilfield wastewater treatment is obtained.
[0012] The amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.
[0013] The amount of water added is 60% to 70% of the total weight of the raw materials.
[0014] In the first step above, the stirring time is 30 to 40 minutes, the stirring temperature is 30°C to 40°C, and the stirring speed is 600 to 700 rpm.
[0015] In the second step above, the reaction temperature is 45℃ to 80℃, and the reaction time is 30 minutes to 40 minutes.
[0016] The mass concentration of the oil removal agent used in the above-mentioned oilfield wastewater treatment is 10% to 20%.
[0017] The second technical solution of the present invention is achieved through the following measures: a method for preparing an oil removal agent for oilfield wastewater treatment, carried out according to the following method:
[0018] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere to obtain a mixed solution.
[0019] The second step involves adding the required amount of acrylamide and catalyst to the mixed solution to react and obtain the reaction product. After diluting the reaction product with water, an oil removal agent for oilfield wastewater treatment is obtained.
[0020] The raw materials of this invention are readily available, and the process is simple. The oil removal agent for oilfield wastewater treatment obtained by the preparation method of this invention has strong oil removal ability and high oil removal rate, making it suitable for oil-water separation in oilfield wastewater, and requiring only a small dosage. This oil removal agent for oilfield wastewater treatment is effective over a wide pH range, does not contain metal ions to avoid secondary pollution, and also has the effects of demulsification, sterilization, flocculation, and slow release, effectively solving the problem of poor oil removal effect of existing oil removal agents. Detailed Implementation
[0021] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solution of this invention and actual conditions. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art; unless otherwise specified, all percentages in this invention are mass percentages.
[0022] The present invention will be further described below with reference to embodiments:
[0023] Example 1: The oil removal agent for oilfield wastewater treatment comprises 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst in a molar concentration ratio of (0.2 to 1.0): (0.5 to 1.5): (0.3 to 2.0): (0.4 to 3.0): (0.1 to 0.2): (0.0002 to 0.0004).
[0024] Example 2: As an optimization of the above example, the catalyst is composed of ammonium persulfate and sodium sulfite in a molar ratio of 1:1.
[0025] Example 3: As an optimization of the above examples, the oil removal agent for oilfield wastewater treatment is obtained by the following method:
[0026] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere to obtain a mixed solution.
[0027] The second step involves adding the required amount of acrylamide and catalyst to the mixed solution to react and obtain the reaction product. After diluting the reaction product with water, an oil removal agent for oilfield wastewater treatment is obtained.
[0028] Example 4: As an optimization of the above example, the amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.
[0029] Example 5: As an optimization of the above example, the amount of water added is 60% to 70% of the total weight of the raw materials.
[0030] Example 6: As an optimization of the above example, in the first step, the stirring time is 30 to 40 minutes, the stirring temperature is 30°C to 40°C, and the stirring speed is 600 to 700 rpm.
[0031] Example 7: As an optimization of the above example, in the second step, the reaction temperature is 45°C to 80°C and the reaction time is 30 minutes to 40 minutes.
[0032] Example 8: As an optimization of the above examples, the mass concentration of the oil removal agent for oilfield wastewater treatment is 10% to 20%.
[0033] Example 9:
[0034] The oil removal agent for oilfield wastewater treatment comprises 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1:1) in a molar ratio of 0.2:0.5:0.3:0.4:0.1:0.0002, obtained by the following method:
[0035] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 600 rpm and a stirring temperature of 30°C for 30 minutes to obtain a mixed solution. The amount of anhydrous ethanol added is 10% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst).
[0036] The second step involves adding the required amount of acrylamide and catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1:1) to the mixed solution. After reacting at 45°C for 30 minutes, the reaction product is obtained. The reaction product is then diluted with water to obtain an oil removal agent with a mass concentration of 10% for oilfield wastewater treatment.
[0037] The chemical structural formula of the oil removal agent for oilfield wastewater treatment prepared in Example 9 of this invention is as follows:
[0038]
[0039] Among them, R1 and R2 are alkyl groups, and the alkyl groups are methyl or ethyl, etc.;
[0040] a = 5 to 180, b = 20 to 450, c = 10 to 300, d = 10 to 350.
[0041] Example 10:
[0042] The oil removal agent for oilfield wastewater treatment comprises 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1.0:1.5:2.0:3.0:0.2:0.0004) in a molar ratio of 1.0:1.5:2.0:0.2:0.0004, obtained by the following method:
[0043] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 700 rpm and a stirring temperature of 40°C for 40 minutes to obtain a mixed solution. The amount of anhydrous ethanol added is 20% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 70% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst).
[0044] The second step involves adding the required amount of acrylamide and catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1:1) to the mixed solution. After reacting at 80°C for 40 minutes, the reaction product is obtained. The reaction product is then diluted with water to obtain an oil removal agent for oilfield wastewater treatment with a mass concentration of 20%.
[0045] Example 11:
[0046] The oil removal agent for oilfield wastewater treatment comprises 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1:1) in a ratio of 0.6:1.0:1.0:1.5:0.15:0.0003, obtained by the following method:
[0047] The first step involves mixing the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water under a nitrogen atmosphere at a stirring speed of 650 rpm and a stirring temperature of 35°C for 35 minutes to obtain a mixed solution. The amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 65% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst).
[0048] The second step involves adding the required amount of acrylamide and catalyst (ammonium persulfate and sodium sulfite in a molar ratio of 1:1) to the mixed solution. After reacting at 60°C for 35 minutes, the reaction product is obtained. The reaction product is then diluted with water to obtain an oil removal agent for oilfield wastewater treatment with a mass concentration of 15%.
[0049] Example 12:
[0050] The oil removal agent for treating oilfield wastewater is obtained using the following method:
[0051] First, nitrogen gas was introduced into a reactor equipped with a stirrer, thermometer and reflux condenser. Then, 0.2 mol / L of 1-ethyl-4-vinylbenzene, 0.8 mol / L of methacrylate, 1.2 mol / L of long-chain alkyl dimethyl allyl ammonium chloride and 0.1 mol / L of urea were added sequentially. Anhydrous ethanol and water were then added to the reactor. The reactor was heated to 35°C and stirred at 650 rpm for 30 min to obtain a mixed solution.
[0052] The second step involves adding 1.5 mol / L acrylamide, 0.15 mmol / L ammonium persulfate, and 0.15 mmol / L sodium sulfite to a reactor containing the mixed solution. The temperature is then slowly raised to 45°C, and the reaction is allowed to proceed for 30 minutes (the reaction is exothermic; when the temperature reaches approximately 95°C), a reaction product is obtained. After diluting the reaction product with water, an oil removal agent with a mass concentration of 15% for oilfield wastewater treatment is obtained. The amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst).
[0053] Example 13:
[0054] The oil removal agent for treating oilfield wastewater is obtained using the following method:
[0055] First, nitrogen gas is introduced into a reactor equipped with a stirrer, thermometer, and reflux condenser. Then, 0.5 mol / L of 1-ethyl-4-vinylbenzene, 1.2 mol / L of methacrylate, 1.5 mol / L of long-chain alkyl dimethyl allyl ammonium chloride, and 0.1 mol / L of urea are added sequentially. Next, anhydrous ethanol and water are added to the reactor. The reactor is heated to 30°C to 40°C and stirred at 600 to 700 rpm for 30 minutes to obtain a mixed solution.
[0056] The second step involves adding 2.0 mol / L acrylamide, 0.15 mmol / L ammonium persulfate, and 0.15 mmol / L sodium sulfite to a reactor containing the mixed solution. The temperature is then slowly raised to 45°C, and the reaction is allowed to proceed for 30 minutes (the reaction is exothermic; when the temperature reaches approximately 95°C), a reaction product is obtained. After diluting the reaction product with water, an oil removal agent with a mass concentration of 15% for oilfield wastewater treatment is obtained. The amount of anhydrous ethanol added is 15% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst), and the amount of water added is 60% of the total weight of the raw materials (1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and catalyst).
[0057] Comparative Example 1: Compared with Example 12, the raw material 1-ethyl-4-vinylbenzene was omitted, and the remaining steps were the same as those in Example 12.
[0058] Comparative Example 2: Compared with Example 13, the raw material long-chain alkyl dimethyl allyl ammonium chloride was omitted, and the remaining steps were the same as the preparation method of Example 12.
[0059] Example 14: The wastewater in the wastewater tank was heavy oil wastewater with an oil content of 650 mg / L. The oil removal agent for oilfield wastewater treatment prepared in Examples 11 and 12 of this invention was added to the wastewater tank at a dosage of 5 mg / L. Meanwhile, Comparative Examples 1 and 2 and existing oil removal agent models including SP169, CW-01 and BY01B were used as controls. The method specified in Q / SY XJ0354-2022 "Technical Specification for Oil Removal Agent for Water Injection Treatment" was followed.
[0060] The oil removal effect of the oil removal agent of the present invention is shown in Table 1. As can be seen from Table 1, when the oil removal agent for oilfield wastewater treatment prepared in Examples 12 and 13 of the present invention is used to treat the wastewater in the wastewater pond, the oil content of the wastewater after dosing is reduced to between 15 mg / L and 18 mg / L, and the oil removal rate reaches 97.7%. When the oil removal agent prepared in Comparative Examples 1 and 2 is used to treat the wastewater in the wastewater pond, the oil content of the wastewater after dosing is reduced to between 76 mg / L and 85 mg / L, and the oil removal rate is only between 86% and 88%. When the existing oil removal agent is used to treat the wastewater, the oil content of the wastewater after dosing is reduced to about 98 mg / L (approximately 125 mg / L), and the oil removal rate is only between 60% and 84%.
[0061] In summary, the raw materials of this invention are readily available, and the process is simple. The oil removal agent for oilfield wastewater treatment obtained by the preparation method of this invention has strong oil removal ability and high oil removal rate, and is suitable for oil-water separation of oilfield wastewater. Generally, for oilfield wastewater with an oil content of less than 2000 mg / L, the dosage is small, approximately 2 mg / L to 5 mg / L. The oil removal agent for oilfield wastewater treatment of this invention is effective over a wide pH range, does not contain metal ions, avoids secondary pollution, and also has the effects of demulsification, sterilization, flocculation, and slow release, effectively solving the problem of poor oil removal effect of existing oil removal agents.
[0062] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.
[0063]
Claims
1. An oil removal agent for oilfield wastewater treatment, characterized in that... The raw materials include 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, acrylamide, urea, and a catalyst in a molar concentration ratio of 0.2 to 1.0: 0.5 to 1.5: 0.3 to 2.0: 0.4 to 3.0: 0.1 to 0.2: 0.0002 to 0.0004, and are obtained by the following method: First, under a nitrogen atmosphere, the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water are stirred and mixed to obtain a mixed solution; Second, the required amounts of acrylamide and catalyst are added to the mixed solution and reacted to obtain a reaction product. The reaction product is diluted with water to obtain an oil removal agent for oilfield wastewater treatment, wherein the catalyst is composed of ammonium persulfate and sodium sulfite in a molar concentration ratio of 1:
1.
2. The oil removal agent for oilfield wastewater treatment according to claim 1, characterized in that... The amount of anhydrous ethanol added is 10% to 20% of the total weight of the raw materials.
3. The oil removal agent for oilfield wastewater treatment according to claim 1 or 2, characterized in that... In the first step, the amount of water added is 60% to 70% of the total weight of the raw materials.
4. The oil removal agent for oilfield wastewater treatment according to claim 3, characterized in that... In the first step, the stirring time is 30 to 40 minutes, the stirring temperature is 30°C to 40°C, and the stirring speed is 600 to 700 rpm.
5. The oil removal agent for oilfield wastewater treatment according to claim 1, 2, or 4, characterized in that... In the second step, the reaction temperature is 45℃ to 80℃, and the reaction time is 30 minutes to 40 minutes.
6. A method for preparing an oil removal agent for oilfield wastewater treatment according to any one of claims 1 to 5, characterized in that... The process is as follows: First, under a nitrogen atmosphere, the required amounts of 1-ethyl-4-vinylbenzene, methacrylate, long-chain alkyl dimethyl allyl ammonium chloride, urea, anhydrous ethanol, and water are stirred and mixed to obtain a mixed solution; Second, the required amounts of acrylamide and catalyst are added to the mixed solution to react and obtain the reaction product. The reaction product is then diluted with water to obtain an oil removal agent for oilfield wastewater treatment.