Composite sulfur-containing water clarifier and preparation method thereof

Abstract

The invention discloses a composite sulfur-containing water clarifier and a preparation method thereof. The water clarifier comprises the following components in percentage by mass: 40%-70% of dithiocarbamate, 0%-15% of a reverse demulsification component, 0%-8% of a surfactant, 0%-1% of a high-molecular polymer, 0%-8% of a metal chelating agent, 2%-15% of inorganic salt, 5%-20% of a solvent and the balance of water. The preparation method comprises the following steps: modifying an organic amine intermediate with carbon disulfide under an alkaline condition to obtain a DTC product, adding inorganic salt into the DTC product, stirring for dissolving, adding a metal chelating agent aqueous solution, a solvent, a reverse demulsification component, a surfactant and a high-molecular polymer aqueous solution, and uniformly stirring to obtain the product. The obtained water clarifier product has the characteristics of large floc, high floating speed of oil droplets and good water treatment effect after acting with oily sewage, and the product can effectively perform oil-water separation, reduce the oil concentration in discharged water and reduce the emission of pollutants.

Description

Technical Field

[0001] This invention relates to the field of water treatment for offshore platforms, and in particular to a composite sulfur-containing water purification agent and its preparation method. Background Technology

[0002] During the production process in offshore oil fields, produced fluids are pumped to the platform via self-flowing or pumping. After processing, qualified crude oil is exported, while oily wastewater is discharged directly into the sea after meeting standards. With continuous oilfield exploitation, the water content of the produced fluids continues to rise, reaching 97% or even higher in some offshore oilfields. The ever-increasing volume of oily wastewater places higher demands on water treatment systems.

[0003] Currently, the main water treatment equipment used on offshore platforms includes settling tanks, hydrocyclones, deaeration tanks, flotation tanks, compact flotation hydrocyclones, and filter tanks. Offshore platforms have limited space, resulting in a compact layout of equipment and facilities, and thus limited processing capacity. Oilfield produced fluids are often severely emulsified, and equipment alone is insufficient to meet discharge standards; therefore, water-cleaning agents are typically used in conjunction with the equipment. Water-cleaning agents are widely used in oilfield production.

[0004] However, existing water-cleaning agents have drawbacks in offshore oilfield applications, such as small floc size and slow oil droplet rising speed, necessitating performance improvements. Therefore, offshore oilfields require the development of a higher-performance water-cleaning agent. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a composite sulfur-containing water purification agent and its preparation method. This water purification agent is characterized by large flocs, rapid oil droplet floating, and excellent water treatment effect.

[0006] In a first aspect, the present invention provides a composite sulfur-containing water purification agent, which is achieved by the following technical solution.

[0007] A composite sulfur-containing water-removing agent comprises the following components by mass percentage: 40%–70% dithiocarbamate, 0%–15% reverse demulsifier, 0%–8% surfactant, 0%–1% polymer, 0%–8% metal chelating agent, 2%–15% inorganic salt, 5%–20% solvent, and the balance being water.

[0008] Furthermore, the method for synthesizing the dithiocarbamate (DTC) is as follows: an organic amine intermediate is mixed with NaOH solution, and modified with carbon disulfide to obtain the dithiocarbamate.

[0009] Furthermore, the molecular weight of the organic amine intermediate is 3,000 to 100,000, and the molecular structure contains primary amines and / or secondary amines, with the content of primary amines and / or secondary amines in the molecular structure being 6% to 45%.

[0010] Furthermore, the mass concentration of NaOH is 50%.

[0011] Furthermore, the molar ratio of the amine (primary amine + secondary amine), carbon disulfide, and NaOH in the organic amine intermediate is: N 伯胺+仲胺 :N 二硫化碳 :N NaOH =1:(0.8~1):(0.8~1.5).

[0012] Furthermore, the reaction temperature is 25–45℃, and the reaction time is 2–8 hours.

[0013] Furthermore, the synthesis method of the reverse demulsifying component is as follows: epichlorohydrin is added dropwise to polyetheramine. After the epichlorohydrin is completely added, the temperature is controlled at 30℃~40℃, and the polymerization reaction is carried out for 1~4 hours to obtain the reverse demulsifying component.

[0014] Furthermore, the molar ratio of polyetheramine to epichlorohydrin is: N 聚醚胺 :N 环氧氯丙烷 =1:(0.3~1).

[0015] Furthermore, the polyetheramine is T403 or D230.

[0016] Furthermore, the surfactant is selected from one or more of dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, and alkyl trimethyl ammonium bromide; The polymer used is nonionic polyacrylamide with a molecular weight of 5 million to 15 million. The metal chelating agent is selected from one or more of sodium polyphosphate, sodium pyrophosphate, sodium hexametaphosphate, thiourea, and sodium polyoxysuccinate. The inorganic salt is selected from sodium silicate, potassium silicate, and sodium aluminate. The organic solvent selected is one of ethanol, methanol, or isopropanol.

[0017] Secondly, the present invention provides a method for preparing a composite sulfur-containing water purification agent, which is achieved by the following technical solution.

[0018] A method for preparing the above-mentioned composite sulfur-containing water purification agent includes the following steps: S1. Add inorganic salt to dithiocarbamate solution and stir for 20-40 minutes until inorganic salt dissolves; S2. Dissolve the metal chelating agent in water to prepare a solution, add it to the solution obtained in step S1, and stir for 5-15 minutes. S3. Then add the solvent and stir for 5-15 minutes; S4. Add the reverse demulsifying component and stir for 5-15 minutes; S5. Then add the surfactant and stir for 5-15 minutes; S6. Dissolve the polymer in water and stir until dissolved to prepare a 0.1-0.5 wt% dilute solution. Add the solution obtained in step S5 and stir for 5-15 minutes to obtain a composite sulfur-containing water cleaner.

[0019] This application has the following beneficial effects.

[0020] The water purification agent of this invention, after reacting with oily wastewater, has the characteristics of large flocs, fast oil droplet floating speed, and good water treatment effect. The product can effectively separate oil and water, reduce the oil concentration (OIW) in the external drainage water, and reduce the discharge of pollutants. Attached Figure Description

[0021] Figure 1 These are comparison images of the water purification effect of this invention (left image is QS-301, right image is the water purification agent in use); Figure 2 These are comparison images of the water purification effect of the present invention (left image shows the water purification agent in use, right image shows QS-302); Figure 3 This is a comparison chart of the water purification effects of the present invention (the left image shows the water purification agent in use, and the right image shows QS-303). Detailed Implementation

[0022] The present patent application will be further described below with reference to the embodiments. Unless otherwise specified, the materials used in the preparation process in the following embodiments have not undergone further processing and have been commercially available.

[0023] The organic amine intermediate YF-03 used in the following embodiments of the present invention is the same as the organic amine intermediate B described in Example 1 of the invention publication CN 118955890 A, entitled "A Cleaning Agent for Offshore Oilfields and its Preparation Method". It has a molecular weight of 3500 and a primary and secondary amine content of 11%. The polyetheramine T403 used in the following embodiments of the present invention is from Shanghai Huntsman Polyurethane Co., Ltd. The polyetheramine D230 used in the following embodiments of the present invention is from Shanghai Huntsman Polyurethane Co., Ltd. The nonionic PAM (molecular weight 8 million) used in the following embodiments of the present invention is sourced from Shandong Nuoer Chemical Co., Ltd. The nonionic PAM (molecular weight 10 million) used in the following embodiments of the present invention is sourced from Shandong Nuoer Chemical Co., Ltd.

[0024] Example 1: (1) Synthesis of DTC: Add 59.9g of organic amine intermediate YF-03 to 16g of water, add 39g of NaOH (50%) solution, add 30g of carbon disulfide dropwise, control the temperature at 38℃, and react for 6 hours to obtain 122g of product DT-101.

[0025] (2) Synthesis of reverse demulsifying components: Weigh 10.88g of polyetheramine T403 into a glass reaction vessel, slowly add 1.12g of epichlorohydrin, cool in a water bath, and control the temperature at 38℃. After the epichlorohydrin is added, continue the polymerization reaction at 38℃ for 2 hours to obtain 12g of the reverse demulsifying component FX-201.

[0026] (3) Product compounding: a. Add 10g of solid sodium silicate to 122g of DT-101 solution and stir for 30 minutes until the sodium silicate is completely dissolved; b. Dissolve 6g of sodium polyphosphate in 10g of water to prepare a solution, add it to the above solution, and stir for 10 minutes; c. Add 12g of ethanol and stir for 5 minutes; d. Add 12g of reverse demulsifying component FX-201 and stir for 10 minutes; e. Add 10g of dodecyl dimethyl benzyl ammonium chloride and stir for 10 minutes; 0.04g of nonionic PAM (molecular weight 8 million) was dissolved in 17.96g of water to prepare a 0.22 wt% dilute solution, which was then added to the above solution and stirred for 10 minutes to obtain 200g of product QS-301.

[0027] The mass fractions of each component are as follows: DT-101: 61%, reverse demulsifying component FX-201: 6%, dodecyl dimethyl benzyl ammonium chloride: 5%, nonionic PAM (molecular weight 8 million): 0.02%, sodium polyphosphate: 3%, sodium silicate: 5%, ethanol: 6%, and water: 13.98%.

[0028] Example 2: (1) Synthesis of DTC: 31.09g of organic amine intermediate YF-03 was added to 45g of water, 14.9g of NaOH (50%) solution, and 13.7g of carbon disulfide was added dropwise. The temperature was controlled at 38℃ and the reaction time was 4h to obtain 110g of product DT-102.

[0029] (2) Synthesis of reverse demulsifying components: Weigh 9.46g of polyetheramine D230 into a glass reaction vessel, slowly add 2.58g of epichlorohydrin, cool in a water bath, and control the temperature at 38℃. After the epichlorohydrin is completely added, continue the polymerization reaction at 38℃ for 2 hours to obtain 12g of the reverse demulsifying component FX-202.

[0030] (3) Product compounding: a. Add 14g of solid potassium silicate to 110g of DT-102 solution and stir for 30 minutes until the potassium silicate is completely dissolved; b. Dissolve 8g of sodium hexametaphosphate in 12g of water to prepare a solution, then add it to the above solution and stir for 10 minutes; c. Add 12g of ethanol and stir for 5 minutes; d. Add 12g of the reverse demulsifying component FX-202 and stir for 10 minutes; e. Add 8g of dodecyl dimethyl benzyl ammonium bromide and stir for 10 minutes; 0.04g of nonionic PAM (molecular weight 8 million) was dissolved in 19.96g of water to prepare a 0.2 wt% dilute solution, which was then added to the above solution and stirred for 10 minutes to obtain 200g of product QS-302.

[0031] The mass fractions of each component are as follows: DT-102: 55%, reverse demulsifier FX-202: 8%, dodecyl dimethyl benzyl ammonium bromide: 4%, nonionic PAM (molecular weight 8 million): 0.02%, sodium hexametaphosphate: 4%, potassium silicate: 7%, ethanol: 6%, and water: 15.98%.

[0032] Example 3: (1) Synthesis of DTC: Add 58.9g of organic amine intermediate YF-03 to 14.7g of water, add 38g of NaOH (50%) solution, add 29g of carbon disulfide dropwise, control the temperature at 36℃, and react for 5h to obtain 116g of product DT-103.

[0033] (2) Synthesis of reverse demulsifying components: Weigh 10.31g of polyetheramine T403 into a glass reaction vessel, slowly add 1.69g of epichlorohydrin, cool in a water bath, and control the temperature at 36℃. After the epichlorohydrin is completely added, continue the polymerization reaction at 36℃ for 2 hours to obtain 12g of the reverse demulsifying component FX-203.

[0034] (3) Product compounding: a. Add 12g of solid sodium silicate to 116g of DT-103 solution and stir for 30 minutes until the sodium silicate is completely dissolved; b. Dissolve 8g of sodium polyphosphate in 12g of water to prepare a solution, add it to the above solution, and stir for 10 minutes; c. Add 10g of methanol and stir for 5 minutes; d. Add 16g of reverse demulsification component FX-203 and stir for 10 minutes; e. Add 6g of dodecyl dimethyl benzyl ammonium chloride and stir for 10 minutes; 0.04g of nonionic PAM (molecular weight 10 million) was dissolved in 19.96g of water to prepare a 0.20 wt% dilute solution, which was then added to the above solution and stirred for 10 minutes to obtain 200g of product QS-303.

[0035] The mass fractions of each component are as follows: DT-103: 58%, reverse demulsifier FX-203: 8%, dodecyl dimethyl benzyl ammonium chloride: 3%, nonionic PAM (molecular weight 10 million): 0.02%, sodium polyphosphate: 4%, sodium silicate: 6%, methanol: 5%, and water: 15.98%.

[0036] Performance testing The water purification performance of the compounded products QS-301, QS-302, and QS-303 from Examples 1-3 was compared with that of an existing water purification agent (the main component of which is a small molecule dithiocarbamate). The results are shown in Tables 1-3 and 3-4, respectively. Figure 1-3 .

[0037] Table 1. Water Color Evaluation Data for Water Cleaning Agents Oil-water sample: Manifold oil-water mixture; Test temperature: 82℃; Water content of oil sample: approximately 95%. Volume: 500 mL oil-water sample dilution concentration: stock solution mixing method: shake 50 times Note: Oil droplet rising speed (fast: A+, A, A-; average: B+, B, B-; slow: C+, C, C-). Oil droplet size (large: A+, A, A-; medium: B+, B, B-; small: C+, C, C-); Water color (Clear: A+, A, A-; Average: B+, B, B-; Poor: C+, C, C-); Table 2 Water Color Evaluation Data Table for Water Cleaning Agents Oil-water sample: Manifold oil-water mixture; Test temperature: 82℃; Water content of oil sample: approximately 95%. Volume: 500 mL oil-water sample dilution concentration: stock solution mixing method: shake 50 times Note: Oil droplet rising speed (fast: A+, A, A-; average: B+, B, B-; slow: C+, C, C-). Oil droplet size (large: A+, A, A-; medium: B+, B, B-; small: C+, C, C-); Water color (Clear: A+, A, A-; Average: B+, B, B-; Poor: C+, C, C-); Table 3. Water Color Evaluation Data for Water Cleaning Agents Oil-water sample: Manifold oil-water mixture; Test temperature: 82℃; Water content of oil sample: approximately 95%. Volume: 500 mL oil-water sample dilution concentration: stock solution mixing method: shake 50 times Note: Oil droplet rising speed (fast: A+, A, A-; average: B+, B, B-; slow: C+, C, C-). Oil droplet size (large: A+, A, A-; medium: B+, B, B-; small: C+, C, C-); Water color (Clear: A+, A, A-; Average: B+, B, B-; Poor: C+, C, C-); The three samples obtained in Examples 1-3, after reacting with oily wastewater, formed large oil droplets that floated quickly, and the water color after reacting with the three samples was better than that of the water purification agent used, which can effectively improve the treatment effect of oily wastewater on the platform.

[0038] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A composite sulfur-containing water purification agent, characterized in that: It includes the following components by mass percentage: 40%–70% dithiocarbamate, 0%–15% reverse demulsifier, 0%–8% surfactant, 0%–1% polymer, 0%–8% metal chelating agent, 2%–15% inorganic salt, 5%–20% solvent, and the balance being water.

2. The composite sulfur-containing water purification agent according to claim 1, characterized in that: The method for synthesizing the dithiocarbamate is as follows: an organic amine intermediate is mixed with NaOH solution, and then modified with carbon disulfide to obtain the dithiocarbamate.

3. The composite sulfur-containing water purification agent according to claim 2, characterized in that: The molecular weight of organic amine intermediates ranges from 3,000 to 100,000, and their molecular structure contains primary and / or secondary amines, with the content of primary and / or secondary amines in the molecular structure ranging from 6% to 45%.

4. The composite sulfur-containing water purification agent according to claim 2, characterized in that: The molar ratio of amine, carbon disulfide, and NaOH in the organic amine intermediate is: N 伯胺+仲胺 :N 二硫化碳 :N NaOH =1:(0.8~1):(0.8~1.5).

5. The composite sulfur-containing water purification agent according to claim 2, characterized in that: The reaction temperature is 25–45℃, and the reaction time is 2–8 hours.

6. The composite sulfur-containing water purification agent according to claim 1, characterized in that: The synthesis method of the reverse demulsifying component is as follows: epichlorohydrin is added dropwise to polyetheramine. After the epichlorohydrin is completely added, the temperature is controlled at 30℃~40℃, and the polymerization reaction is carried out for 1~4 hours to obtain the reverse demulsifying component.

7. A composite sulfur-containing water purification agent according to claim 6, characterized in that: The molar ratio of polyetheramine to epichlorohydrin is: N 聚醚胺 :N 环氧氯丙烷 =1:(0.3~1).

8. A composite sulfur-containing water purification agent according to claim 6, characterized in that: The polyetheramine is T403 or D230.

9. A composite sulfur-containing water purification agent according to claim 1, characterized in that: The surfactant is selected from one or more of dodecyl dimethyl benzyl ammonium chloride, dodecyl dimethyl benzyl ammonium bromide, and alkyl trimethyl ammonium bromide; The polymer used is nonionic polyacrylamide with a molecular weight of 5 million to 15 million. The metal chelating agent is selected from one or more of sodium polyphosphate, sodium pyrophosphate, sodium hexametaphosphate, thiourea, and sodium polyoxysuccinate. The inorganic salt is selected from sodium silicate, potassium silicate, and sodium aluminate. The organic solvent selected is one of ethanol, methanol, or isopropanol.

10. A method for preparing the composite sulfur-containing water-repellent agent according to any one of claims 1-9, characterized in that: Includes the following steps: S1. Add inorganic salt to dithiocarbamate solution and stir for 20-40 minutes until inorganic salt dissolves; S2. Dissolve the metal chelating agent in water to prepare a solution, add it to the solution obtained in step S1, and stir for 5-15 minutes. S3. Then add the solvent and stir for 5-10 minutes; S4. Add the reverse demulsifying component and stir for 5-15 minutes; S5. Then add the surfactant and stir for 5-15 minutes; S6. Dissolve the polymer in water and stir until dissolved to prepare a 0.1-0.5 wt% dilute solution. Add the solution obtained in step S5 and stir for 5-15 minutes to obtain a composite sulfur-containing water cleaner.

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