Preparation method of alcohol-soluble demulsifying agent

Abstract

The invention discloses an alcohol-soluble demulsifier and a preparation method thereof. The demulsifier is composed of a polyether polymer, an organic dispersant, a stabilizer, an auxiliary flocculant, an alcohol solvent, a surfactant and deionized water, and has excellent oil-water separation performance and storage stability. All the components are fully mixed through stirring and ultrasonic-assisted dispersion to form a uniform transparent liquid; experiments show that the stabilizer significantly prolongs the storage period of the agent, and the auxiliary flocculant effectively shortens the oil-water separation time, reduces the effluent turbidity and improves the oil sludge sedimentation rate; when the optimal formula is applied to marine oily sludge wastewater treatment, the oil-water separation time can be shortened to about 12 minutes, the effluent turbidity is lower than 50 NTU, the separated oily sludge can be directly recycled, the water is clear and transparent, and the discharge or cyclic utilization standard is met; the preparation process is simple, environment-friendly, efficient and suitable for the field of industrial wastewater treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a preparation method of an alcohol-soluble demulsifying agent. BACKGROUND

[0002] During the operation of ships and related industrial production processes, a large amount of oily sludge wastewater is generated. This kind of wastewater not only pollutes the environment, but also contains recyclable oil sludge resources. Therefore, how to efficiently treat the ship-borne oily sludge wastewater, realize oil-water separation and oil sludge recovery has become an important technical problem in the fields of environmental protection and resource utilization.

[0003] At present, the treatment of oily wastewater mainly relies on physical sedimentation or traditional chemical demulsifying agents. The physical sedimentation method is simple to operate, but the oil-water separation speed is slow and the effluent turbidity is high, which is difficult to meet the discharge standard. Although the existing demulsifying agents can improve oil-water separation, they are mostly water-soluble or emulsified agents, which are prone to stratification or precipitation during storage and transportation, and their performance is unstable.

[0004] The existing demulsifying agents have the following problems: first, the storage stability is poor, and stratification, precipitation or gelation can occur in a short time, affecting the reliability of industrial use; second, the oil-water separation efficiency is low, the treatment time is long, the effluent turbidity is high, and the oil sludge sedimentation is not sufficient, resulting in low recovery efficiency and resource waste; third, the preparation process of some demulsifying agents is complex, and the requirements for temperature, stirring or equipment are high, which limits its industrial application and popularization.

[0005] Therefore, there is an urgent need for a new demulsifying agent and its preparation method, which can balance long-term storage stability, rapid oil-water separation and efficient oil sludge sedimentation, and at the same time, the process is simple and easy to industrialize, to meet the actual needs of ship and industrial oily sludge wastewater treatment, and improve the wastewater treatment efficiency and oil sludge resource utilization rate. SUMMARY

[0006] The present application aims to overcome the deficiencies in the prior art and provide a preparation method of an alcohol-soluble demulsifying agent.

[0007] The purpose of the present application is achieved as follows:

[0008] The main components of the alcohol-soluble demulsifying agent prepared by the present application are as follows:

[0009] Polyether polymer: as an active demulsification component;

[0010] Organic dispersant: for improving the dispersibility of oil sludge in water;

[0011] Stabilizer: for keeping the solution stable and preventing stratification;

[0012] Auxiliary flocculant: such as natural high molecular polymer (sodium alginate, xanthan gum, etc.), to enhance the flocculation and precipitation ability;

[0013] Alcohol solvent: used to dissolve polyether polymer and adjust viscosity;

[0014] Surfactant: such as non-ionic surfactant, used to improve oil-water interface demulsification efficiency;

[0015] The balance is deionized water.

[0016] A preparation method of an alcohol-soluble demulsifying agent, comprising the following steps:

[0017] Water phase pretreatment: add 30-40% of deionized water in total mass of target formula in a reaction kettle, adjust pH to 6.5-7.5;

[0018] Organic dispersant addition: stir at room temperature, slowly add 1-2% of organic dispersant and high shear dispersion, so as to form a uniform solution;

[0019] Stabilizer and auxiliary flocculant addition: add 0.3-0.5% of stabilizer and 0.5-2% of auxiliary flocculant in turn, to prevent agglomeration and keep the system uniform;

[0020] Alcohol solubilization step: add 10-40% of alcohol solvent in stages under stirring, so as to form a medium environment suitable for polyether polymer dissolution;

[0021] Polyether polymer dissolution: add 25-45% of polyether polymer in batches, supplemented with ultrasonic dispersion, so as to completely dissolve and form a transparent or light yellow solution;

[0022] Surfactant treatment (optional): add 0.1-0.5% of non-ionic surfactant under low-speed stirring;

[0023] Standing stability: stand for 30-60 minutes at room temperature, until the bubbles escape and the solution is clear and transparent;

[0024] Packaging and storage: seal and fill the obtained solution in a polyethylene or metal container for storage.

[0025] Beneficial effects:

[0026] 1. Good long-term storage stability: by introducing polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP) as a stabilizer in the formula, the phenomenon of separation and precipitation of the agent during storage is effectively avoided. Experimental results show that the agent without stabilizer separates obviously after 3 months of storage, while the agent with stabilizer remains clear and transparent after 6 months of storage, greatly prolonging the storage period of the product and ensuring the transportation and long-term use in industrial applications.

[0027] 2. Oil-water separation efficiency is significantly improved: The introduction of natural polymers such as sodium alginate or chitosan as auxiliary flocculants in the demulsifier can accelerate the coalescence of oil droplets and the sedimentation of oil sludge. Experimental results show that after adding 1% chitosan, the oil-water separation time is shortened from 25 minutes to about 12 minutes, the turbidity of the effluent is reduced to below 50 NTU, and the sedimentation rate of the oil sludge is increased to 90%, which is significantly better than the control group without adding flocculants.

[0028] 3. Formulation optimization effect is outstanding: Through orthogonal test system optimization of polyether polymer, alcohol solvent, stabilizer and auxiliary flocculant ratio, the best formula is selected as follows: polyether polymer 35%, alcohol solvent 25%, stabilizer 0.4%, auxiliary flocculant 1%, dispersant 1.5%, and the rest is deionized water. The formula takes into account the oil-water separation efficiency, effluent clarity and storage stability, and achieves the optimal balance of overall performance.

[0029] 4. Good treatment effect: The alcohol-soluble demulsifier prepared with the best formula has rapid oil-water separation when treating marine oil-containing sludge wastewater, and the effluent after treatment is clear and transparent, meeting the recycling or direct discharge standard. The separated oil sludge can be recycled, with good economic and environmental benefits.

[0030] 5. Simple process and strong applicability: The preparation process of the invention is mild (stirring at room temperature, ultrasonic dispersion), does not require complex equipment, is simple to operate, and is easy to industrialize. At the same time, the agent can be used for the treatment of oil-containing wastewater and oil sludge of different sources, and has wide application prospects. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a flowchart of the invention.

[0032] Figure 2 is a comprehensive desirability distribution chart of the orthogonal test of the invention.

[0033] Figure 3 is a main effect curve chart of each factor (polyether polymer, alcohol solvent, stabilizer, auxiliary flocculant) on the comprehensive desirability of the invention. DETAILED DESCRIPTION

[0034] Example 1, as shown in the following table, the purpose of the invention is achieved Figures 1-3

[0035] A preparation method of an alcohol-soluble demulsifying agent, comprising the following steps:

[0036] S1: Water phase pretreatment:

[0037] Add deionized water to a clean stirring reaction kettle, and the liquid volume is 30-40% of the total mass of the target formula.

[0038] ​Under stirring conditions, slowly add the buffer (sodium dihydrogen phosphate or sodium bicarbonate, 0.05-0.2% added) to maintain the pH between 6.5-7.5 by slightly adjusting the acidity and alkalinity of the system. Provide a stable aqueous environment for the subsequent dissolution of polyether polymers, and avoid precipitation or gelation caused by fluctuations in acidity and alkalinity.

[0039] S2: Addition of organic dispersant

[0040] Under normal temperature (20-30°C) conditions, start the stirring device and control the speed at 300-500 rpm.

[0041] Slowly add the organic dispersant (alkyl benzene sulfonate or alcohol ether dispersant, 1-2% added) to the aqueous phase.

[0042] To ensure that the dispersant is fully developed, use a high-shear stirrer and continue stirring for 5-10 minutes to form a uniform milky white solution. Improve the dispersibility of the oil sludge in the aqueous phase and enhance the overall efficiency of the demulsifier.

[0043] S3: Addition of stabilizer and auxiliary flocculant

[0044] Under stirring conditions, add the stabilizer and auxiliary flocculant in sequence:

[0045] The stabilizer (polyethylene glycol or PVP, 0.3-0.5% added) needs to be slowly stirred for 10 minutes after addition to prevent agglomeration;

[0046] The auxiliary flocculant (sodium alginate or chitosan, 0.5-2% added) needs to be gradually dispersed to avoid instantaneous clumping;

[0047] After addition is complete, the stirring speed can be reduced to 200-300 rpm and continue mixing for 5 minutes to form a transparent or translucent homogeneous liquid.

[0048] Enhance the stability of the reagent during storage and improve the speed of oil sludge flocculation and sedimentation when used.

[0049] S4: Alcohol solubilization step

[0050] Slowly add the alcohol solvent (such as ethanol, isopropyl alcohol or n-butanol, 10-40% added) under stirring conditions.

[0051] Use stepwise stirring when adding the alcohol solvent: first stir at low speed 100-200 rpm for 2 minutes to initially mix the alcohol solvent; then increase the speed to medium speed 300-400 rpm for 5 minutes to fully mix the aqueous phase with the alcohol phase; provide a suitable medium environment for the subsequent dissolution of polyether polymers, while adjusting the solution viscosity.

[0052] S5: Dissolution of polyether polymer

[0053] Polyether polymer is the core component of the demulsifier, accounting for 25-45% of the total formulation.

[0054] Under moderate stirring (300-400 rpm), the polyether polymer is slowly added to the system in 3-4 batches;

[0055] After each addition, stirring should be maintained for 5 minutes to prevent the accumulation of macromolecules in local areas and cause agglomeration;

[0056] To improve the solubility of the polyether polymer, ultrasonic assisted dispersion (frequency 20-40 kHz, time 5-10 minutes) is selected, which helps to break the hydrogen bonds between molecules and make the polymer uniformly distributed; after complete dissolution, the system should present a transparent or light yellow solution.

[0057] S6: Static stability

[0058] After stopping stirring, the system needs to be left at room temperature for 30-60 minutes, during which the bubbles escape naturally and the solution gradually becomes clear and transparent. The standing process helps to rearrange the molecules, making the product more stable.

[0059] S7: Packaging and storage

[0060] The final alcohol-soluble demulsifier should be a uniform transparent liquid. It is filled in polyethylene or galvanized iron barrels and stored in a sealed manner.

[0061] Experimental verification of the effect of stabilizers:

[0062] Take the same formulation of alcohol-soluble demulsifier as the base formula, and add different stabilizers to get three groups of samples:

[0063] Control group A: no stabilizer added;

[0064] Experimental group B: add 0.3% polyethylene glycol (PEG-400);

[0065] Experimental group C: add 0.5% polyvinylpyrrolidone (PVP).

[0066] The three groups of samples are stored in a sealed manner at room temperature, and the appearance and stability are observed at 1 month, 3 months and 6 months of storage, respectively. The results are as follows:

[0067] Sample 1 month 3 months 6 months Group A Slightly turbid, beginning to have a small amount of sediment Obvious stratification Stratification is serious, the bottom sediment is obvious Group B Clear and transparent Clear and transparent Clear and transparent, no sediment Group C Clear and transparent Clear and transparent Slightly turbid, but no sediment and stratification

[0068] The results show that after adding stabilizers, the demulsifier remains clear and transparent within 6 months of storage, while the demulsifier without stabilizers separates and precipitates after 3 months, indicating that the stabilizer significantly improves the stability of the demulsifier during storage.

[0069] Experimental verification of the auxiliary flocculant effect:

[0070] The same batch of marine oily sludge wastewater was added with different formulations of demulsifiers, and the operating conditions were stirring at room temperature and the dosage was 200 mg / L:

[0071] Control group D: base formulation (polyether polymer + dispersant + stabilizer);

[0072] Experimental group E: additional 1% sodium alginate was added to the D group formulation;

[0073] Experimental group F: additional 1% chitosan was added to the D group formulation.

[0074] Each group of samples was subjected to oil-water separation experiment, and the oil-water separation time, water turbidity and oil sludge sedimentation rate were recorded. The results are as follows:

[0075] Sample Oil-water separation time (min) Water turbidity (NTU) Oil sludge sedimentation rate (%) Group D (without flocculants) 25 120 68 Group E (+1% sodium alginate) 15 65 85 Group F (+1% chitosan) 12 50 90

[0076] The results show that after adding auxiliary flocculants, the oil-water separation time is significantly shortened, the water turbidity is reduced by more than 50%, and the oil sludge sedimentation rate is increased to 85-90%, which is significantly better than the control group.

[0077] Experimental verification of the best formulation:

[0078] 1. Orthogonal test design

[0079] In order to systematically evaluate the influence of each formulation factor on the performance of alcohol-soluble demulsifiers, four main factors were selected for orthogonal design test:

[0080] Factor A: mass fraction of polyether polymer (25%, 35%, 45%);

[0081] Factor B: mass fraction of alcohol solvent (15%, 25%, 35%);

[0082] Factor C: mass fraction of stabilizer (0%, 0.3%, 0.5%);

[0083] Factor D: mass fraction of auxiliary flocculant (0%, 1%, 2%).

[0084] L9 (3 4 ) orthogonal table was used, a total of 9 groups of tests were conducted, each group of formulation was added to marine oily sludge wastewater at 200 mg / L at room temperature, and the following indicators were measured:

[0085] Oil-water separation time (min, the lower the better);

[0086] Water turbidity (NTU, the lower the better);

[0087] Oil sludge sedimentation rate (%) (the higher the better);

[0088] 2. Index normalization and comprehensive desirability D

[0089] In order to compare the overall performance of different formulations, the expected function method was used to normalize each index:

[0090] Set the target value: oil-water separation time ≤ 15 min, effluent turbidity ≤ 60 NTU, and oil sludge sedimentation rate ≥ 85%;

[0091] Convert each test index to a desirability value between 0 and 1;

[0092] Calculate the comprehensive desirability using the geometric mean:

[0093]

[0094] where are the normalized values of the three indices, respectively.

[0095] 3. Results and analysis

[0096] Figure 2 shows the distribution of comprehensive desirability for the 9 groups of orthogonal tests;

[0097] Figure 3 gives the main effect curve of each factor (polyether polymer, alcohol solvent, stabilizer, auxiliary flocculant) on comprehensive desirability;

[0098] Orthogonal test results table:

[0099] When the polyether polymer is 35%, the D value is the highest;

[0100] When the alcohol solvent is 25%, the comprehensive effect is the best;

[0101] Stabilizer 0.3%~0.5% significantly improves the storage stability of the agent and the separation effect;

[0102] Auxiliary flocculant 1% has the highest D value, and 2% has a slight excess effect.

[0103] Main effect analysis: through the mean value calculation of each factor level, the best combination is obtained:

[0104] That is: polyether polymer 35%, alcohol solvent 25%, stabilizer 0.4%, auxiliary flocculant 1%;

[0105] Variance analysis shows that:

[0106] Auxiliary flocculant and polyether polymer have the most significant contribution to the comprehensive effect (p < 0.05);

[0107] The stabilizer has a significant effect on the improvement of long-term storage stability (p < 0.05);

[0108] The alcohol solvent is at the best balance point when the content is 25%, but the statistical difference is slightly lower than the first two.

[0109] 4. Conclusion

[0110] Through orthogonal test and statistical analysis, the superiority of the optimal formula of the present application is verified: the oil and water are quickly separated, the water is clear, and the oil sludge is efficiently settled while ensuring green environmental protection and simple process; the introduction of the stabilizer ensures the long-term storage stability of the medicament; and the optimization of the auxiliary flocculant significantly shortens the separation time and improves the water clarity.

[0111] Therefore, the optimal formula is selected: polyether polymer 35%, dispersant 1.5%, stabilizer 0.4%, auxiliary flocculant (chitosan) 1%, alcohol solvent 25%, and the balance is deionized water. The alcohol-soluble demulsifier prepared has a clear and transparent appearance after being stored for 6 months. When treating ship oil sludge wastewater, the oil and water separation time is shortened to about 12 minutes after adding the medicament, the effluent turbidity is less than 50 NTU, the separated oil sludge can be directly recycled, the treated water is clear and transparent, and the discharge or recycling standard is reached.

[0112] That is, the addition of the stabilizer effectively prolongs the storage period of the product, ensuring transportation and long-term use in industrial applications; and the auxiliary flocculant significantly improves the flocculation and sedimentation speed of the oil sludge and the water clarity, improving the overall treatment effect of the demulsifier.

[0113] In Example 2, a surfactant treatment is added after step 5; according to the properties of the oil sludge, a non-ionic surfactant (such as Tween-80, Span-60, with an addition amount of 0.1-0.5%) can be selectively added to the system. Mixing for 5 minutes under low-speed stirring can be carried out; this step mainly enhances the action of the demulsifier on the oil-water interface and improves the coalescence efficiency of oil droplets in the oil sludge.

[0114] In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0115] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A process for the preparation of an alcohol soluble demulsifying agent, characterized in that, The method comprises the following steps: S1, water phase pretreatment: adding deionized water in a stirring reaction kettle, and adding a buffer to adjust the pH to 6.5-7.5; S2, adding an organic dispersant: adding the organic dispersant into the water phase at room temperature and stirring to make the system uniformly dispersed; S3, adding a stabilizer and an auxiliary flocculant: sequentially adding the stabilizer and the auxiliary flocculant, and mixing to form a homogeneous liquid; S4, alcohol solubilization step: slowly adding an alcohol solvent and stirring to fully mix the water phase and the alcohol phase; S5, adding and dissolving a polyether polymer: adding the polyether polymer into the system and stirring until completely dissolved to obtain a transparent or light yellow liquid; S6, standing and stabilizing and packaging: stopping stirring, standing, and then filling and storing after the liquid is clear and transparent.

2. The production method according to claim 1, characterized by, The stabilizer is polyethylene glycol or polyvinylpyrrolidone, and the addition amount is 0.3-0.5%.

3. The preparation method according to claim 1, characterized in that, The auxiliary flocculant is sodium alginate or chitosan, and the addition amount is 0.5-2%.

4. The method of claim 1, wherein, The polyether polymer accounts for 25-45% of the total formula mass, is added in batches, and is dispersed by using ultrasonic waves.

5. The preparation method according to claim 1, characterized in that, The alcohol solvent is ethanol, isopropyl alcohol or n-butanol, and the addition amount is 10-40%, and the stirring is stepwise.

6. The method of claim 1, wherein, A non-ionic surfactant is added after step 5 to improve the demulsification efficiency.

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