Demulsifier based on modified polyether as well as preparation method and application of demulsifier

Abstract

The invention discloses a demulsifier based on modified polyether as well as a preparation method and application thereof, and belongs to the technical field of chemical demulsifiers. The preparation method comprises the following steps: preparation of oleic acid esterification modified polyether, synthesis of a multifunctional synergistic auxiliary agent and compounding of the demulsifier, the demulsifier is applied to demulsification of industrial quenched water, the dosage is 50-200mg / L, and the demulsifier is suitable for the range of 10-60 DEG C and pH of 3-11. In order to solve the problems that an existing demulsifier is weak in hard water resistance, poor in oil drop coalescence and insufficient in compatibility, a phosphonamide chelating group and a light cross-linked network are introduced through an auxiliary agent, modified polyether interfacial activity and chelated Ca < 2 + > / Mg < 2 + > are matched to break an ion bridge and promote oil drop coalescence, the demulsification efficiency in high-salt hard water exceeds 90%, and effluent residual oil is smaller than or equal to 10 mg / L; the natural cardanol derivative raw material is adopted, the adding amount is reduced by 20%-30%, and the method is suitable for complex working conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical demulsifier, and particularly relates to a demulsifier based on modified polyether as well as a preparation method and application thereof. BACKGROUND

[0002] Efficient treatment of oily wastewater is a common technical challenge faced by petrochemical, coal chemical and other industries, among which the quenching water generated in the production process is the most representative. This kind of wastewater usually contains a large amount of emulsified oil, dissolved acid gas, multivalent metal ions and solid suspended particles, forming an extremely stable multiphase complex system. Efficient demulsification and deep treatment are directly related to the stable operation of the device, water resource recycling and environmental protection standard discharge.

[0003] At present, the treatment of such oily wastewater in industry mainly relies on chemical demulsification method, the core of which is to use a demulsifier with specific interfacial activity. Non-ionic surfactants represented by polyether compounds, especially derivatives of polyoxyethylene polyoxypropylene ether (PEO-PPO), have become the most widely used demulsifier due to their good hydrophilic-lipophilic balance. By esterification and other chemical modifications of the terminal hydroxyl group, the interfacial properties can be further adjusted, and the demulsification efficiency for specific oil-water systems can be improved. This kind of demulsifier based on modified polyether constitutes the current mainstream solution.

[0004] However, with the increasing demand for heavy feedstocks, large-scale devices and environmental protection, the existing technical solutions have exposed significant deficiencies in practical application. First, the traditional modified polyether demulsifier has single function, mainly acting on the destruction of the oil-water interfacial film, and lacks pertinence for the increased emulsion stability caused by high concentration of calcium, magnesium and other ions commonly coexisting in quenching water (ion bridge effect), which leads to a sharp decline in efficiency under hard water conditions. Second, its limited coalescence promotion effect on the fine oil droplets released after demulsification easily leads to high residual oil content in the effluent or secondary emulsification. Third, when other functional additives are tried to be compounded to deal with problems such as system foam, corrosion or solid deposition, competition adsorption or antagonism often occurs between different molecular structure chemicals, which weakens the core demulsification efficiency, forming a dilemma of "trade-off".

[0005] Therefore, the demulsifier based on modified polyether in the prior art has the core technical bottlenecks of weak anti-ion interference ability, low oil droplet coalescence efficiency and poor compatibility with auxiliary functional components when dealing with complex industrial quenching water systems. Developing a new demulsifier system that can integrate multiple auxiliary functions such as anti-hard water and coalescence promotion without affecting or even enhancing the main demulsification performance is the key to breaking through the current technical barriers and meeting higher treatment demands. SUMMARY

[0006] The object of the present application is to solve the problems existing in the prior art, and to provide a modified polyether-based demulsifier, a preparation method and application thereof.

[0007] In order to achieve the above object, the present application adopts the following technical scheme: The preparation method of the modified polyether-based demulsifier comprises the following steps: S1, preparation of oleate-modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid and water-carrying agent are mixed in a molar ratio of 1:(1.1-1.3):(3-5), and 0.1%-0.5% of a catalyst is added to the total mass of the system, and refluxed at 110-140℃ for 6-8h, and the acid value of the reaction system is monitored in real time, and when the acid value is ≤8mg KOH / g, heating is carried out for 2h to obtain a modified polyether ester intermediate; The role of each component in the raw material: Polyoxyethylene polyoxypropylene ether (PEO-PPO): as the reaction skeleton, the terminal primary hydroxyl group is a nucleophile. The polyoxyethylene (EO) segment in its molecular structure provides hydrophilicity, and the polyoxypropylene (PO) segment provides moderate hydrophobicity and steric hindrance, which together determine the water solubility and interfacial activity of the product; Oleic acid: as an acyl donor, its long-chain alkene structure (C 17 H 33 ) will introduce a strong hydrophobic tail chain to the final product, which is the key to the demulsifier's ability to insert and destroy the oil-water interface film, and the molar ratio is set to 1:1.1-1.3, i.e. the excess of oleic acid, which aims to shift the reaction equilibrium towards the generation of esters, ensuring that the hydroxyl groups of the polyether are as completely reacted as possible, and improving the esterification rate; Water-carrying agent (such as toluene or xylene): this inert solvent can form a low-boiling azeotrope with the water generated in the reaction, and the molar ratio of (3-5) ensures sufficient azeotropic capacity, and its core role is to continuously and efficiently remove the water byproduct from the reaction system, breaking the reversible equilibrium of the esterification reaction, thereby driving the reaction to continue to the right, significantly improving the reaction rate and conversion rate; Catalyst (such as p-toluenesulfonic acid): as a Bronsted acid, its mechanism of action is to protonate the carbonyl oxygen of oleic acid, making the carbon atom more positively charged, thereby greatly increasing the electrophilicity of the carboxyl carbon, making it more susceptible to attack by the terminal hydroxyl group of the polyether (nucleophile), reducing the reaction activation energy, and the addition amount needs to be balanced between catalytic efficiency and subsequent neutralization and separation difficulty; First, the raw materials are mixed in proportion to ensure that the polyether, oleic acid, water-carrying agent and catalyst are uniformly contacted, avoiding local concentration imbalance affecting reaction uniformity; refluxing at 110-140℃ for 6-8h is to provide the thermodynamic conditions required for esterification, and the refluxing state can maintain the stability of the system temperature, ensuring uniform reaction rate; The acid value is a key indicator for monitoring the reaction progress. In the initial stage of the reaction, the acid value is high. With the generation of ester bonds and the consumption of carboxyl groups, the acid value gradually decreases. Setting "acid value ≤ 8 mg KOH / g" as the main reaction endpoint indicates that most of the carboxyl groups have reacted and the esterification is basically complete. After reaching this point, "continue heating for 2 h" is a holding and aging stage, which serves the following purposes: 1. to ensure that the reaction is complete and the conversion rate is maximized; 2. to promote the continued reaction of molecules that may react slowly due to steric hindrance; 3. to make the molecular structure of the product uniform and stable, ensuring the stability and reproducibility of the final demulsifier performance. First, the catalyst provides a proton (H + ) which combines with the carboxyl group (-COOH) of oleic acid to form a protonated carboxyl group (-C(OH)2 + ). Then, the protonated carboxyl group undergoes dehydration to form an acyl cation (-CO + ). The acyl cation, as an electrophile, attacks the oxygen atom (containing a lone pair of electrons) in the polyoxyethylene polyoxypropylene ether hydroxyl group to form a tetrahedral intermediate. Finally, the tetrahedral intermediate dehydrates, and the catalyst is regenerated, producing a modified polyether ester intermediate connected by an ester bond (-COO-) and water. The water is removed from the system by azeotropic distillation with a water-carrying agent, promoting the completion of the reaction.

[0008] S2. Synthesis of multifunctional synergistic additive: Add cashew phenol polyoxyethylene ether, citric acid, and methanol modified glyphosate into the reaction kettle according to a molar ratio of 1:0.8:0.05-0.25. Stir until mixed evenly, then add 0.3% p-toluenesulfonic acid and 0.2% hydroquinone based on the total mass of the system. Heat to 70-75°C, condense and reflux, react for 4 h, slowly add diethanolamine, react for 1 h, reduce pressure and distill, cool to below 30°C, and add deionized water to adjust the viscosity to 60-70 mm 2 / s. The multifunctional synergistic additive is obtained. Stir until the three core raw materials form a homogeneous system, ensuring that the functional groups are in full contact during subsequent reactions, laying the foundation for uniform cross-linking, esterification, and amination reactions. Then add an appropriate amount of catalyst. The p-toluenesulfonic acid acts as a proton acid catalyst, activating the reactivity of carboxyl and hydroxyl groups and reducing the activation energy of esterification and ester exchange reactions. Hydroquinone acts as a polymerization inhibitor, capturing free radicals that may be generated in the reaction system to prevent oxidation polymerization of the unsaturated hydrocarbon groups on the cashew phenol side chain, preventing abnormal viscosity increase or the generation of insoluble impurities in the system. The temperature is raised to 70-75°C and the reaction is condensed and refluxed for 4h. This temperature range ensures the catalytic efficiency of the catalyst and avoids degradation or excessive reaction of the raw materials at high temperature. The design of condensation and reflux can reduce the loss of volatile components in the system, maintain the concentration stability of the reaction system, and promote the full reaction of esterification and transesterification. Slowly add diethanolamine and react for 1h. Slowly adding can avoid side reactions caused by high local amine concentration (such as excessive amination or protonation), ensuring that the amination reaction is mild and controllable. The vacuum distillation step is designed to remove small molecular byproducts (such as methanol, water) and trace amounts of unreacted raw materials generated during the reaction, to improve product purity and avoid interference of byproducts with the stability and application performance of the additive. After cooling to below 30°C, deionized water is added to adjust the viscosity to 60-70mm 2 / s, in order to adapt to the flowability requirements of the additive in actual application scenarios, and water as a good solvent can further disperse the product to ensure its water solubility; The role of each component in the multifunctional synergistic additive: Cardanol polyoxyethylene ether as the core skeleton, the hydrophilic polyoxyethylene (PEO) segment in its molecule provides basic water solubility and surface activity for the product, and the hydrophobic cardanol skeleton can interact with the hydrophobic groups of the demulsifier, providing the structural basis for synergistic demulsification; Citric acid as a multifunctional crosslinking agent, the three carboxyl groups in its molecule can react with the hydroxyl groups of cardanol polyoxyethylene ether and the methyl ester groups of methanol-modified increased phosphonate at the same time, forming a light crosslinking network, and the residual carboxyl groups can enhance the hydrophilicity of the product and its interaction with the demulsifier; Methanol-modified increased phosphonate (DPGM) is a crosslinking-chelating bifunctional monomer. Its methyl ester group participates in the ester exchange reaction to form a crosslinking bond, and the imine group forms a phosphonic amine group (-PO3H-N-) after amination, giving the product the ability to chelate metal ions and improving the anti-interference stability; p-Toluene sulfonic acid as a catalyst for esterification / ester exchange reaction, by providing protonated carboxyl groups, it forms intermediates that are prone to nucleophilic attack, accelerating the reaction between carboxyl groups and hydroxyl groups or methyl ester groups; hydroquinone as a polymerization inhibitor, by itself undergoing oxidation-reduction reaction, it consumes free radicals in the system, protecting the cardanol side chain from polymerization; Diethanolamine as an amination agent, its amine group undergoes nucleophilic substitution reaction with the imine group of modified increased phosphonate, and forms amide or ammonium salt structure with the residual carboxyl groups of citric acid, introducing hydroxyl and amine groups that can enhance the water solubility of the product and its hydrogen bonding ability with the demulsifier; Deionized water as a diluent and solvent, it not only adjusts the viscosity of the product, but also provides a hydration environment for water-soluble groups, ensuring the stable dispersion of the product; Under the catalysis of p-toluenesulfonic acid, the nucleophilic addition-elimination reaction occurs between the carboxyl group (-COOH) in citric acid molecule and the hydroxyl group (-OH) in cardanol polyoxyethylene ether molecule. The carbonyl group in the carboxyl group is protonated to form a carbonium ion intermediate, and the hydroxyl group in the cardanol polyoxyethylene ether attacks the intermediate, and then loses a molecule of water to form an ester bond (-COO-). The reaction formula is as follows:

[0009] The methyl ester group (-COOCH3, -PO3(CH3)2) in the methanol-modified glyphosate molecule exchanges with the hydroxyl group of citric acid and the hydroxyl group of cardanol polyoxyethylene ether. Taking the ester exchange of the hydroxyl group of citric acid with the methyl ester group as an example, the hydroxyl group of citric acid is protonated under the action of the catalyst, attacks the ester bond in the methyl ester group of the modified glyphosate, and the methoxy group (-OCH3) is separated and generates methanol, while a new ester bond is formed. The molar amount of the hydroxyl group is relatively large, which can fully react with the modified glyphosate to realize intermolecular crosslinking. However, there is only one hydroxyl group in the cardanol polyoxyethylene ether molecule and the citric acid molecule, so the crosslinking is slight. The additive can still be well swelled and dispersed in water to form a stable hydrogel microparticle dispersion or a uniform colloidal solution. The reaction formula is as follows:

[0010] The amine group (-NH-) in the diethanolamine molecule acts as a nucleophile and attacks the carbon atom connected to the imine group in the modified glyphosate molecule, resulting in a nucleophilic substitution reaction. The dimethyl phosphonate group in the modified glyphosate is converted to a phosphonamide group, and at the same time, the remaining carboxyl group (-COOH, acidic) in the citric acid exchanges with the imino group (-NH-, basic) in the diethanolamine to form a carboxylic acid ammonium salt. These reactions collectively construct a molecular structure with slight crosslinking, chelation, and multiple hydrophilic groups, enabling the product to have high stability and synergistic effect with demulsifiers. The reaction formula is as follows:

[0011] S3, compounding of demulsifiers The multifunctional synergistic additive is dissolved in deionized water in proportion, and oleic acid esterification modified polyether is added to the compounding kettle. Stirring is carried out at room temperature and normal pressure for 0.5-1.5h. The appearance, density, kinematic viscosity, flash point, and condensation point are detected. After all the indicators are qualified, the product is packaged into the warehouse by the automatic filling system. If the indicators are unqualified, the product is returned to the process according to the unqualified product control procedure; The core role of the step of dissolving the multifunctional synergistic additive in deionized water is to use the good solvent properties of water to quickly disperse the additive to form a homogeneous mother liquor, avoiding the aggregation of the additive due to excessive local concentration, and laying a foundation for the subsequent uniform mixing with the oleic acid esterification modified polyether; After the oleate-modified polyether is added into the compounding kettle, stirring is carried out at normal temperature and pressure for 0.5-1.5 h, the purpose is to make the two core components fully contact through mechanical stirring, and to form a stable compounding system by using intermolecular forces (hydrogen bond, hydrophobic interaction, ion pair attraction), to ensure that the synergistic effect of the modifier and the polyether is fully played, and the stirring time is controlled within 0.5-1.5 h, which is a compromise between mixing efficiency and energy consumption, to avoid insufficient stirring leading to uneven system, and to prevent excessive stirring causing resource waste; Sampling and testing appearance, density, kinematic viscosity, flash point, freezing point and other indicators are to verify whether the compounded product meets the core requirements of industrial application, the uniformity of appearance ensures the dispersion stability of the product during use, the density and kinematic viscosity adapt to the conveying and filling process, and the flash point and freezing point ensure the safety and applicability of the product during storage, transportation and different temperature conditions; after all the indicators are qualified, the product is packaged into the warehouse by an automatic filling system, which is the last link to complete the production process and ensure the cleanliness and storage stability of the product, and unqualified products are processed according to the control program, which can avoid non-standard products flowing into the market and ensure the application effect and safety of the demulsifier; In the demulsifier that has been compounded and qualified, the multifunctional synergistic additive is a "synergistic strengthening component", the slightly cross-linked network in its molecular structure can enhance the structural stability of the compounding system, the phosphine amine group and the carboxyl group of citric acid can chelate metal ions such as Ca 2+ , Mg 2+ , etc. that may exist in the system, to avoid ion-induced emulsion film stabilization, and at the same time, the polyoxyethylene (PEO) segment and the carboxylic acid ammonium salt structure (-COO - NH + -) contained therein can improve the water solubility and dispersibility of the compounding system, and the hydrophobic cardanol skeleton can interact with the hydrophobic segment of the oleate-modified polyether to strengthen the adsorption capacity of the demulsifier at the oil-water interface; the oleate-modified polyether is the "core demulsification component" of the demulsifier, the hydrophobic segment (long-chain alkyl derived from oleic acid) in its molecule can be adsorbed on the oil-water interface, and the hydrophilic polyether segment can promote the separation of water after the coalescence of droplets, which is the core carrier to realize the demulsification function; deionized water as a "dispersion and adjustment medium" not only provides a uniform mixing environment for the two components, but also accurately controls the concentration and viscosity of the compounded product by adjusting the amount of water added, while avoiding the interference of impurity ions in ordinary water with the stability of the system, to ensure the performance consistency of the demulsifier.

[0012] Preferably, the multifunctional synergistic additive has the following structural characteristics: (1) using cardanol polyoxyethylene ether as the hydrophobic anchor group, wherein the number of ethylene oxide addition n is 8-20; (2) connecting the citric acid group through an ester bond to provide chelation functional sites; (3) The amide bond connects the amine compound containing hydroxyl group, and provides a coalescence promoting group.

[0013] Preferably, the polyoxyethylene chain block number of the polyoxyethylene polyoxypropylene ether is 20-50, the polyoxypropylene chain block number is 10-30, the purity is greater than or equal to 99%, and the viscosity at 25 DEG C is 80-120 mm 2 / s.

[0014] Preferably, the catalyst is selected from one of p-toluene sulfonic acid, sulfuric acid or phosphoric acid; and the water-carrying agent is selected from toluene or xylene.

[0015] Preferably, the polyoxyethylene chain block number of the cardanol polyoxyethylene ether is 12, the purity is greater than or equal to 98%, the viscosity at 25 DEG C is 50-80 mm 2 / s, and the hydroxyl value is 56-60 mg KOH / g.

[0016] Preferably, the molar ratio of the cardanol polyoxyethylene ether, citric acid, methanol modified glyphosate and diethanolamine is 1:0.8:0.15:0.9; and the preparation steps of the methanol modified glyphosate are as follows: Glyphosate and methanol are added into a reaction kettle according to a molar ratio of 1:4.2, 1% of concentrated sulfuric acid is added as a catalyst, and reflux reaction is carried out for 6 hours, and methanol modified glyphosate is obtained by vacuum distillation.

[0017] Preferably, the detection indexes of the synthesized demulsifier are as follows: Appearance: light yellow transparent liquid; Density: 0.95-1.05 g / cm 3 at 20 DEG C; Kinematic viscosity: 10-50 mm 2 / s at 40 DEG C; Flash point: greater than or equal to 60 DEG C; Freezing point: less than or equal to -5 DEG C.

[0018] The demulsifier prepared by the above steps is mainly applied in quenching water demulsification treatment, and the quenching water is industrial quenching water containing organic pollutants or emulsified oil; the addition amount of the demulsifier is 50-200 mg / L, the demulsification treatment temperature is 10-60 DEG C, and the applicable pH range is 3-11.

[0019] Compared with the prior art, the present application has the following beneficial effects: 1. The present application adopts the core means of "cross-linking-chelating-synergistic" integrated multifunctional synergistic agent and oil esterification modified polyether, and cooperates with the composite mechanism of "phosphonamide group chelating metal ions + slightly cross-linked network promoting oil droplet coalescence + intermolecular multi-acting force synergistic demulsification", to overcome the core bottleneck of the existing modified polyether demulsifier, such as poor hard water resistance, poor oil droplet coalescence and insufficient component compatibility. The phosphonamide group can firmly chelate Ca 2+ , Mg2+ , break "ion bridge effect", high salt hard water demulsification efficiency is still more than 90%; slightly crosslinked network promotes the coalescence of micro oil droplets, and the residual oil content of effluent is reduced to below 10mg / L; the complex system has no antagonism, and realizes the integration of "demulsification-anti-hard water-promoting coalescence".

[0020] 2, the present application adopts "oleic acid excess + water agent azeotropic dehydration" directional esterification process, cooperates with "protonation activation + azeotropic by-product" mechanism, realizes the precise regulation of modified polyether interface activity and the maximization of esterification rate. The excess of oleic acid promotes the reaction balance, and the water agent continuously removes water, and the esterification rate is increased from below 85% to above 95%; the long-chain hydrophobic tail of oleic acid is adapted to the polyoxyethylene polyoxypropylene ether block, the interface adsorption and membrane damage capacity are enhanced, the demulsification speed is increased by 30%-50%, and the different emulsification degrees of quench water are adapted.

[0021] 3, the present application adopts "methanol pre-modified glyphosate" pretreatment means, cooperates with "ester exchange crosslinking + amine decomposition bond" mechanism, solves the problem that the direct use of glyphosate cannot be crosslinked and the reaction activity is low. The methanol modified glyphosate can realize directional crosslinking and phosphonamide group grafting under mild conditions, the auxiliary agent remains stable chelating ability below 150 DEG C, pH 3-11, and adapts to the complex working conditions of quench water.

[0022] 4, the present application adopts "cardanol polyoxyethylene ether as hydrophobic skeleton" green design, cooperates with "natural raw material derivation + multifunctional integration" mechanism, realizes the environmental friendliness and multifunctional integration of demulsifier. Cardanol can replace part of petrochemical raw materials, and the hydrophilic and hydrophobic chain segments cooperatively improve the water solubility and interfacial activity; the demulsifier dosage is reduced by 20%-30%, the biodegradability is increased by more than 30%, the secondary environmental pollution is reduced, and the green chemical trend is met. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The production process flow chart of the modified polyether demulsifier is shown in the figure. DETAILED DESCRIPTION

[0024] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments.

[0025] Example 1: preparation method of modified polyether demulsifier: S1, preparation of oleic acid esterification modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid, water-carrying agent are mixed in a molar ratio of 1:1.1:4, a catalyst accounting for 0.3% of the total mass of the system is added, and reflux reaction is carried out at 125℃ for 7h, the acid value of the reaction system is monitored in real time, when the acid value is ≤8mg KOH / g, heating reaction is carried out for 2h, and a modified polyether ester intermediate is obtained; S2, synthesis of multifunctional synergistic aid: The cashew phenol polyoxyethylene ether, citric acid and methanol modified glyphosate are added into a reaction kettle in a molar ratio of 1:0.8:0.15, stirring is started until they are uniformly mixed, p-toluenesulfonic acid accounting for 0.3% of the total mass of the system and hydroquinone accounting for 0.2% of the total mass of the system are added, the temperature is increased to 70℃, and condensation reflux is carried out, 4h of reaction is carried out, diethanolamine is slowly added dropwise, 1h of reaction is carried out, vacuum distillation is carried out, the temperature is reduced to below 30℃, deionized water is added to adjust the viscosity to 65mm 2 / s, and a multifunctional synergistic aid is obtained; S3, compounding of demulsifier The multifunctional synergistic aid is dissolved in deionized water in proportion, the oil esterification modified polyether is added into a compounding kettle, stirring is carried out at room temperature and normal pressure for 1h, sampling is carried out to detect the appearance, density, kinematic viscosity, flash point, freezing point and other indexes, after the indexes are all qualified, the product is packaged into a warehouse through an automatic filling system; if the detection is unqualified, rework treatment is carried out according to the unqualified product control procedure.

[0026] Example 2: preparation method of demulsifier based on modified polyether: S1, preparation of oil esterification modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid, water-carrying agent are mixed in a molar ratio of 1:1.3:4, a catalyst accounting for 0.3% of the total mass of the system is added, and reflux reaction is carried out at 125℃ for 7h, the acid value of the reaction system is monitored in real time, when the acid value is ≤8mg KOH / g, heating reaction is carried out for 2h, and a modified polyether ester intermediate is obtained; S2, synthesis of multifunctional synergistic aid: The cashew phenol polyoxyethylene ether, citric acid and methanol modified glyphosate are added into a reaction kettle in a molar ratio of 1:0.8:0.15, stirring is started until they are uniformly mixed, p-toluenesulfonic acid accounting for 0.3% of the total mass of the system and hydroquinone accounting for 0.2% of the total mass of the system are added, the temperature is increased to 70℃, and condensation reflux is carried out, 4h of reaction is carried out, diethanolamine is slowly added dropwise, 1h of reaction is carried out, vacuum distillation is carried out, the temperature is reduced to below 30℃, deionized water is added to adjust the viscosity to 65mm 2 / s, and a multifunctional synergistic aid is obtained; S3, compounding of demulsifier The multifunctional synergistic aid is dissolved in deionized water in proportion, the oleic esterification modified polyether is added into a compounding kettle, stirred at normal temperature and pressure for 1 h, and sampling is conducted to detect indexes such as appearance, density, kinematic viscosity, flash point and freezing point, and after all indexes are qualified, the product is packaged into a warehouse through an automatic filling system; if the detection is unqualified, rework treatment is conducted according to an unqualified product control procedure.

[0027] Example 3: Preparation method of the demulsifier based on modified polyether: S1, Preparation of the oleic esterification modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid and water-carrying agent are mixed in a molar ratio of 1:1.2:4, 0.3% of a catalyst is added into the system, reflux reaction is conducted at 125 DEG C for 7 h, the acid value of the reaction system is monitored in real time, when the acid value is less than or equal to 8 mg KOH / g, heating reaction is conducted for 2 h, and a modified polyether ester intermediate is obtained; S2, Synthesis of the multifunctional synergistic aid: The cardanol polyoxyethylene ether, citric acid and methanol modified glyphosate are added into a reaction kettle in a molar ratio of 1:0.8:0.15, stirring is started until they are uniformly mixed, 0.3% of p-toluenesulfonic acid and 0.2% of hydroquinone are added into the system, the temperature is increased to 70 DEG C, condensation reflux is conducted, reaction is conducted for 4 h, diethanolamine is slowly added dropwise, reaction is conducted for 1 h, vacuum distillation is conducted, the temperature is reduced to below 30 DEG C, deionized water is added to adjust the viscosity to 65 mm / s, and the multifunctional synergistic aid is obtained; 2 S3, Compounding of the demulsifier The multifunctional synergistic aid is dissolved in deionized water in proportion, the oleic esterification modified polyether is added into a compounding kettle, stirred at normal temperature and pressure for 1 h, sampling is conducted to detect indexes such as appearance, density, kinematic viscosity, flash point and freezing point, and after all indexes are qualified, the product is packaged into a warehouse through an automatic filling system; if the detection is unqualified, rework treatment is conducted according to an unqualified product control procedure.

[0028] Example 4: Preparation method of the demulsifier based on modified polyether: S1, Preparation of the oleic esterification modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid and water-carrying agent are mixed in a molar ratio of 1:1.2:4, 0.3% of a catalyst is added into the system, reflux reaction is conducted at 125 DEG C for 7 h, the acid value of the reaction system is monitored in real time, when the acid value is less than or equal to 8 mg KOH / g, heating reaction is conducted for 2 h, and a modified polyether ester intermediate is obtained; S2, Synthesis of the multifunctional synergistic aid: ​The cashew phenol polyoxyethylene ether, citric acid, methanol modified glyphosate is added to the reaction kettle according to the molar ratio of 1:0.8:0.05, and the stirring is started until the mixture is uniform. 0.3% p-toluene sulfonic acid and 0.2% hydroquinone are added to the system, and the temperature is raised to 70°C. The condenser is refluxed, and the reaction is carried out for 4h. Diethanolamine is slowly added dropwise, and the reaction is carried out for 1h. The pressure is reduced for distillation, and the temperature is lowered to below 30°C. Deionized water is added to adjust the viscosity to 65mm 2 / s, to obtain a multifunctional synergistic aid; S3, compounding of demulsifier The multifunctional synergistic aid is dissolved in deionized water in proportion, and the oleic acid esterified modified polyether is added to the compounding kettle. Stirring is carried out at room temperature and normal pressure for 1h. The appearance, density, kinematic viscosity, flash point, and freezing point are detected by sampling. After the indicators are all qualified, the product is packaged into the warehouse by the automatic filling system. If the detection is unqualified, the rework treatment is carried out according to the unqualified product control program.

[0029] Example 5: Preparation method of demulsifier based on modified polyether: S1, preparation of oleic acid esterified modified polyether: The polyoxyethylene polyoxypropylene ether, oleic acid, and water carrying agent are mixed according to the molar ratio of 1:1.2:4. The catalyst is added to the system, and the temperature is raised to 125°C. The reaction is carried out for 7h under reflux. The acid value of the reaction system is monitored in real time. When the acid value is ≤8mg KOH / g, the reaction is carried out for 2h under heating. The modified polyether ester intermediate is obtained. S2, synthesis of multifunctional synergistic aid: The cashew phenol polyoxyethylene ether, citric acid, and methanol modified glyphosate are added to the reaction kettle according to the molar ratio of 1:0.8:0.25. The stirring is started until the mixture is uniform. 0.3% p-toluene sulfonic acid and 0.2% hydroquinone are added to the system, and the temperature is raised to 70°C. The condenser is refluxed, and the reaction is carried out for 4h. Diethanolamine is slowly added dropwise, and the reaction is carried out for 1h. The pressure is reduced for distillation, and the temperature is lowered to below 30°C. Deionized water is added to adjust the viscosity to 65mm 2 / s, to obtain a multifunctional synergistic aid; S3, compounding of demulsifier The multifunctional synergistic aid is dissolved in deionized water in proportion, and the oleic acid esterified modified polyether is added to the compounding kettle. Stirring is carried out at room temperature and normal pressure for 1h. The appearance, density, kinematic viscosity, flash point, and freezing point are detected by sampling. After the indicators are all qualified, the product is packaged into the warehouse by the automatic filling system. If the detection is unqualified, the rework treatment is carried out according to the unqualified product control program.

[0030] Comparative Example 1: Compared with Example 3, the polyoxyethylene polyoxypropylene ether, oleic acid, and water carrying agent are mixed according to the molar ratio of 1:1.4:4 in Comparative Example 1.

[0031] Comparative Example 2: In comparison with Example 3, in Comparative Example 2, the molar ratio of cardanol polyoxyethylene ether, citric acid, and methanol modified glyphosate was 1:0.8:0.035.

[0032] Comparative Example 3: In comparison with Example 3, in Comparative Example 3, no citric acid was added during the preparation of the multifunctional synergistic additive.

[0033] Comparative Example 4: In comparison with Example 3, in Comparative Example 4, the multifunctional synergistic additive in Comparative Example 3 was prepared using ordinary glyphosate without modification by methanol.

[0034] Comparative Example 5: In comparison with Example 3, in Comparative Example 5, no multifunctional synergistic additive was added during the compounding of the demulsifier.

[0035] Performance Test: 1. According to the standard tests in GB / T 4472-2011 "Determination of Density, Relative Density of Chemical Products", GB / T 265-2010 "Determination Method and Dynamic Viscosity Calculation Method of Petroleum Products", GB / T 261-2021 "Determination Method of Petroleum Products Flash Point (Pensky-Martin Closed Cup Method)", GB / T 510-2018 "Determination Method of Petroleum Products Freezing Point", GB / T 16488-1996 "Determination of Water Quality Petroleum and Animal and Vegetable Oils by Infrared Spectrophotometry", GB / T 8929-2022 "Determination of Water Content in Crude Oil by Distillation Method", GB / T 6283-2008 "Determination of Moisture Content in Chemical Products by Karl Fischer Method", the basic physicochemical properties (density, kinematic viscosity, flash point, freezing point) of the invention, the water content of the oil phase after demulsification, the water content of the oil phase after demulsification, and the water content of the oil phase after demulsification were tested.

[0036] 2. Demulsification Efficiency Test Test Steps: Simulation of Industrial Quenching Water Configuration: Take 1000 mL of oil-containing wastewater (or configure according to actual working conditions, oil content 500-1000 mg / L, Ca 2 + , + Mg 2+ content 500 mg / L, NaCl content 10%) and place it in a 1000 mL separatory funnel. Adjust the temperature to 25°C (or target working temperature 10-60°C) and the pH to 7.

[0037] Demulsifier Addition: Accurately add the demulsifier of the invention at a dosage of 50-200 mg / L. Stir with a magnetic stirrer at 300 r / min for 5 min to ensure uniform mixing.

[0038] Static separation: the separatory funnel was vertically static for 30 min, the oil phase, water phase delamination interface was recorded, and the lower water phase sample was taken.

[0039] Residual oil content determination: the residual oil content of the water phase (denoted as C1) was determined according to GB / T16488-1996; at the same time, a blank test (without adding a demulsifier, and the rest of the steps were the same) was performed, and the blank residual oil content (denoted as C0) was measured.

[0040] Calculation formula: Demulsification efficiency (η) = (C0-C1) / C0 x 100%, wherein: η is the demulsification efficiency (%); C0 is the residual oil content of the blank test (mg / L); C1 is the residual oil content of the water phase after demulsification (mg / L).

[0041] 2. Metal ion chelating ability test Test steps: Preparation of metal ion solution: 500 mL of an aqueous solution containing Ca 2+ (or Mg 2+ ) with a concentration of 100 mg / L was accurately prepared in a 1000 mL beaker.

[0042] Demulsifier addition: according to the molar ratio of demulsifier to metal ion of 1:1, the demulsifier of the application was added, and the magnetic stirrer was stirred at 200 r / min for 30 min (temperature 25℃).

[0043] Centrifugal separation: 50 mL of the above solution was centrifuged at 8000 r / min for 10 min, and the supernatant was taken.

[0044] Free metal ion concentration determination: the free Ca 2+ (or Mg 2+ ) concentration (denoted as C2) in the supernatant was determined by EDTA complexometric titration method; at the same time, a blank test (without adding a demulsifier) was performed, and the initial metal ion concentration (denoted as C0) was measured.

[0045] Calculation formula: Chelating rate (θ) = (C0-C2) / C0 x 100%, wherein: θ is the metal ion chelating rate (%); C0 is the initial metal ion concentration (mg / L); C2 is the free metal ion concentration (mg / L).

[0046] Table 1 Basic physicochemical parameters of demulsifiers prepared in examples and comparative examples Group Density (20°C, g / cm 3 )]]> Kinematic viscosity (40°C, mm 2 / s) Flash point (closed, °C) Freezing point (°C) Self moisture (%) Example 1 0.98 28 76 -9 0.35 Example 2 1 32 72 -8 0.38 Example 3 0.99 30 75 -10 0.32 Example 4 0.99 29 75 -10 0.34 Example 5 1.01 35 74 -9 0.36 Comparative Example 1 1.02 38 70 -7 0.4 Comparative Example 2 0.99 28 75 -10 0.33 Comparative Example 3 0.97 42 73 -8 0.39 Comparative Example 4 0.98 40 74 -9 0.37 Comparative Example 5 0.96 25 78 -12 0.3 Table 2 Core performance data of demulsifiers prepared in examples and comparative examples Group Residual oil after demulsification (mg / L) Water content in oil phase after demulsification (%) Demulsification efficiency (%) Ca 2+ % chelation Viscosity deviation rate (%) Demulsification efficiency retention rate (%) Example 1 15 0.6 97 88 4.2 96.2 Example 2 12 0.5 97.6 89 5.8 95.5 Example 3 10 0.4 98 92 3.1 97.8 Example 4 28 0.8 94.4 65 6.5 93.1 Example 5 13 0.5 97.4 96 7.2 94.8 Comparative Example 1 18 0.7 96.4 90 9.8 92.7 Comparative Example 2 35 0.9 93 52 12.3 88.6 Comparative Example 3 42 1.2 91.6 45 18.5 82.3 Comparative Example 4 48 1.5 90.4 38 22.1 79.5 Comparative Example 5 85 2 65 5 8.6 85.2 Data analysis: Figure 1The production process flow chart of the modified polyether demulsifier produced by the present application is as follows: polyoxyethylene polyoxypropylene ether and oleic acid are respectively stored in corresponding storage tanks, pumped, and then sent to a reaction kettle after precise control of the feed amount by cooperating with a flow meter (FIO) and a control valve; at the same time, a mixed solution of multifunctional synergistic additives and water is also sent to the reaction kettle after being pumped and instrumentally regulated. The reaction kettle is equipped with monitoring instruments such as temperature (TIC) and liquid level (LIC), and the temperature, flow rate and equipment start-stop are automatically controlled by a distributed control system (DCS). The reaction process can be sampled and detected, and after completion, the material is sent to a packaging or storage tank through the discharge port, and the whole process is guaranteed by automatic instruments to ensure precise feeding and controllable reaction.

[0047] Tables 1 and 2 show the basic physicochemical and core performance data of the demulsifiers prepared in the examples and comparative examples. It is found from the data in the tables that: The performance indicators of Example 3 are all optimal, the basic physicochemical indicators such as density, kinematic viscosity, flash point and freezing point are all in the ideal range of the target range, the water content is low and the storage stability is excellent; in terms of core demulsification performance, the demulsification efficiency is the highest, the residual oil content in the water after demulsification and the water content in the oil phase are the lowest, and the metal ion chelation rate also reaches the peak. From the mechanism, in this example, the molar ratio of polyoxyethylene polyoxypropylene ether to oleic acid in S1 step is 1:1.2, under this ratio, the oleic acid ensures the full esterification of the polyether terminal hydroxyl group, and avoids the problem of excess or insufficient oleic acid, the introduced hydrophobic long chain and the polyether PEO-PPO block form a precise balance of hydrophilic and hydrophobic, maximizing the interfacial activity; the ratio of cashew phenol polyoxyethylene ether, citric acid and methanol modified DPGM in S2 step is reasonable, the crosslinking effect of citric acid and the grafting efficiency of DPGM chelating groups are the highest, the formed light crosslinking network can promote oil droplet coalescence without affecting water solubility, the chelation function of phosphonamide groups is fully played, and the ability to break ion bridge effect is the strongest; the intermolecular forces (hydrogen bond, hydrophobic interaction) between the additives and the modified polyether in the compounding process are synergistically best, and finally a stable and balanced demulsification system is formed.

[0048] Compared with the standard example, the oleic acid ratio in S1 of Example 1 is lower, the demulsification efficiency and chelation rate are slightly lower, the residual oil is slightly higher, and the physicochemical indicators are close to each other except that the viscosity is slightly lower. At the mechanism level, the lack of oleic acid leads to a lack of acyl donors, the esterification rate of polyether hydroxyl group is slightly low, the amount of introduced hydrophobic long chain is reduced, and the interfacial adsorption and membrane damage efficiency are decreased; although it does not significantly affect the physicochemical indicators, the unreacted hydroxyl group slightly interferes with the hydrophobic interaction of the additives, the interfacial coordination of the chelating groups is slightly limited, and finally the core performance is slightly attenuated.

[0049] The oleic acid ratio in Example 2 is higher than the standard example, the flash point is slightly reduced, the viscosity is slightly increased, the demulsification chelation is close to the standard example but slightly inferior, and the oil phase water content is slightly higher. Mechanically, although the excess of oleic acid ensures complete esterification of hydroxyl groups, the free residual unreacted oleic acid reduces the system flash point and increases the molecular entanglement, resulting in an increase in viscosity; more importantly, the excess of hydrophobic chains breaks the hydrophilic-hydrophobic balance, and the regularity of the interfacial adsorption layer decreases, although it is not seriously destabilized, but the core performance is still slightly inferior to the standard example.

[0050] Comparative Example 1 has only S1 oleic acid ratio far exceeding the standard example, viscosity increases sharply, flash point decreases greatly, demulsification chelation deteriorates significantly, residual oil and oil phase water content increases dramatically, and storage stability deteriorates. Mechanically, a large amount of free oleic acid becomes an impurity, and the strong hydrophobicity makes the system have too high a hydrophobicity ratio, the molecular force increases dramatically, resulting in a sharp increase in viscosity; the low flash point of free oleic acid lowers the overall index, and the interfacial adsorption layer is chaotic, which not only destroys the original emulsion film but also forms a new unstable structure, interfering with chelation and coalescence, and the uneven composition also exacerbates the storage viscosity fluctuations.

[0051] The core difference between Example 4 and the standard example is that the amount of methanol modified glyphosate is reduced, and the data shows that the metal ion chelation rate is significantly reduced, the demulsification efficiency is significantly reduced, the residual oil content in the effluent after demulsification is significantly increased, and only the kinematic viscosity is slightly lower than the standard example, and the rest of the indicators fluctuate slightly. Mechanically, the insufficient amount of methanol modified glyphosate results in a sharp decrease in the number of graftable phosphonamide chelating groups it provides, significantly weakening its ability to chelate metal ions and break ion bridges; at the same time, the light crosslinking network formed by the methanol modified glyphosate is incomplete due to insufficient monomers, and the promotion of coalescence of micro-fine oil droplets after demulsification is weakened, although it does not seriously affect the basic physical and chemical properties, but the core demulsification and hard water resistance function is significantly attenuated.

[0052] Example 5 has a higher amount of methanol modified glyphosate than the standard example, and the data shows that the metal ion chelation rate is further improved, but the kinematic viscosity is slightly higher than the standard example, the demulsification efficiency is close to the standard example but slightly lower, and the oil phase water content after demulsification is slightly higher. Mechanically, the increase in the amount of methanol modified glyphosate increases the number of phosphonamide chelating groups, and the chelation capacity is enhanced; but the excess of methanol modified glyphosate will cause the degree of ester exchange crosslinking reaction between molecules to be slightly higher, the density of the crosslinking network formed is slightly increased, although it is still in the light crosslinking category and does not affect water solubility, but the increased molecular entanglement increases the viscosity, and the slightly dense network has a slight impact on the flexibility of the interfacial adsorption, resulting in a slightly inferior demulsification efficiency to the standard example.

[0053] Compared with the standard example, the amount of methanol-modified glyphate in Comparative Example 2 is extremely small, and the data shows significant degradation: the metal ion chelation rate drops significantly, the demulsification efficiency drops sharply, the residual oil in the water after demulsification and the water content in the oil phase increase sharply, the viscosity deviation rate during storage increases significantly, and only the density and the condensation point in the basic physical and chemical indicators are close to those of the standard example. Mechanically, when the amount of methanol-modified glyphate is too low, it is almost impossible to form effective phosphoramide chelating groups, and the ionic bridge effect cannot be broken; at the same time, there is not enough methanol-modified glyphate to participate in crosslinking, and a light crosslinking network that promotes oil droplet coalescence cannot be built, the synergistic effect of the additive and the modified polyether is almost ineffective, and the compatibility between components decreases, which leads to an increase in viscosity fluctuation during storage, and the core performance is completely degraded.

[0054] Compared with the standard example, Comparative Example 3 does not add citric acid in step S2, and the data shows that the demulsification efficiency drops significantly, the residual oil in the water after demulsification and the water content in the oil phase increase significantly, the kinematic viscosity increases significantly and the storage stability is extremely poor, the metal ion chelation rate also drops significantly, and only the basic density and condensation point fluctuate slightly. Mechanically, citric acid is a key crosslinking agent in the system, and after its absence, it cannot form ester exchange crosslinking with the hydroxyl group of cashew phenol polyether and the methyl ester group of methanol-modified glyphate, and a light crosslinking network cannot be built; without a crosslinking network, it cannot provide a "flexible skeleton" for oil droplet coalescence, and the molecular structure of the additive is loose, the synergistic adsorption effect with the modified polyether is weakened, and at the same time, the residual group lacks carboxyl auxiliary coordination, the phosphoramide chelation function is also affected, and finally the core performance is completely degraded.

[0055] Comparative Example 4 uses unmodified glyphate instead of methanol-modified glyphate in the standard example, and the data shows that the metal ion chelation rate drops sharply to an extremely low level, the demulsification efficiency decays significantly, the residual oil and the water content in the oil phase after demulsification increase sharply, the viscosity deviation rate during storage increases significantly, and the kinematic viscosity is high among the basic physical and chemical indicators. Mechanically, ordinary glyphate has no methyl ester group, and cannot react with citric acid and cashew phenol polyether through ester exchange reaction, neither can it form a crosslinking network nor graft phosphoramide chelating groups through amine decomposition reaction; the additive is only a simple mixture of cashew phenol polyether and amine, without chelation and crosslinking functions, and has no effective synergy with the modified polyether, the ionic bridge effect in hard water environment is not broken, and the demulsification effect drops sharply.

[0056] Comparative Example 5 does not add a multifunctional synergistic additive, and it has the worst performance among all the comparisons: the metal ion chelation rate is almost ineffective, the demulsification efficiency drops sharply to about 60% of the standard example, the residual oil in the water after demulsification and the water content in the oil phase soar to the peak value, the water content in the oil phase also increases significantly, and only the basic flash point is slightly higher due to the absence of water-containing additives, and the remaining physical and chemical indicators have no advantage. Mechanically, the absence of the additive means that there is no phosphoramide chelating group at all (the Ca 2+ / Mg 2+The ion bridge and the slightly cross-linked network are only modified by the oleate modification of the polyether single action; the emulsion film in the hard water system is abnormally stable due to the ion bridge, the modified polyether can only destroy part of the film structure, and cannot solve the problems of fine oil droplet coalescence and secondary emulsification, and the demulsification efficiency is completely collapsed.

[0057] The above examples and comparative examples show that the performance of the demulsifier of the present application depends on the precise matching of key parameters and components: the optimal molar ratio of oleic acid to polyether, the appropriate amount of methanol modified glyphosate, the cross-linking effect of citric acid and the compounding of multifunctional synergistic additives are the core of guaranteeing the demulsification efficiency, the hard water resistance and the stability. Deviating from the optimal ratio or missing the key components will lead to chelation failure, insufficient cross-linking or destruction of the balance between hydrophilic and hydrophobic, which will significantly deteriorate the core performance. In summary, the present application can realize efficient demulsification in complex systems through the design of "directional modification + multifunctional integration", and the reasonable regulation of parameters and components is the key to performance standard.

[0058] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A demulsifier based on modified polyether, characterized in that, The components include the following parts by weight: Oleate-modified polyether: 25-45 parts; Multifunctional synergist: 1-8 parts, cashew phenol polyether-citric acid-ethanolamine derivative; The remainder is deionized water.

2. The demulsifier based on modified polyether according to claim 1, characterized in that, The multifunctional synergist has the following structural features: (1) Cashew phenol polyoxyethylene ether is used as a hydrophobic anchoring group, wherein the number of ethylene oxide addition n is 8-20; (2) Citric acid groups are linked by ester bonds, providing chelation functional sites; (3) A hydroxyl-containing amine compounds are linked through amide bonds to provide polymerization-promoting groups.

3. A method for preparing a demulsifier based on modified polyether as described in any one of claims 1-2, characterized in that, Includes the following steps: S1. Preparation of oleate-modified polyether: Polyoxyethylene polyoxypropylene ether, oleic acid, and dehydrating agent are mixed in a molar ratio of 1:(1.1-1.3):(3-5). A catalyst accounting for 0.1%-0.5% of the total mass of the system is added, and the mixture is refluxed at 110-140℃ for 6-8 hours. The acid value of the reaction system is monitored in real time. When the acid value is ≤8mg KOH / g, the reaction is heated for 2 hours to obtain the modified polyether ester intermediate. S2. Synthesis of multifunctional synergistic agents: Cashew phenol polyoxyethylene ether, citric acid, and methanol-modified glyphosate were added to a reactor in a molar ratio of 1:0.8:0.05-0.

25. Stirring was started until the mixture was homogeneous. Then, 0.3% p-toluenesulfonic acid and 0.2% hydroquinone (by mass of the total system) were added. The mixture was heated to 70-75°C, refluxed, and reacted for 4 hours. Diethanolamine was slowly added dropwise, and the reaction was continued for 1 hour. The mixture was then distilled under reduced pressure, cooled to below 30°C, and deionized water was added to adjust the viscosity to 60-70 mm. 2 / s, to obtain a multifunctional synergistic agent; S3, Demulsifier Compound The multifunctional synergistic agent is dissolved in deionized water in a certain proportion, and then added to the compounding kettle oleate esterified modified polyether. The mixture is stirred at room temperature and pressure for 0.5-1.5 hours. Samples are taken to test the appearance, density, kinematic viscosity, flash point, pour point and other indicators. After all indicators are qualified, the product is packaged and stored in the warehouse through the automatic filling system. If the test results are unqualified, the product is reworked in accordance with the non-conforming product control procedure.

4. The method for preparing a demulsifier based on modified polyether according to claim 3, characterized in that, The polyoxyethylene polyoxypropylene ether in S1 has 20-50 polyoxyethylene chain blocks and 10-30 polyoxypropylene chain blocks, with a purity ≥99% and a viscosity of 80-120 mmHg at 25°C. 2 / s.

5. The method for preparing a demulsifier based on modified polyether according to claim 3, characterized in that, The catalyst in S1 is selected from p-toluenesulfonic acid, sulfuric acid, or phosphoric acid; the dehydrating agent is selected from toluene or xylene.

6. The method for preparing a demulsifier based on modified polyether according to claim 3, characterized in that, The cardamom polyoxyethylene ether in S2 has 12 polyoxyethylene chain blocks, a purity ≥98%, and a viscosity of 50-80 mmHg at 25°C. 2 / s, hydroxyl value 56-60mg KOH / g.

7. The method for preparing a demulsifier based on modified polyether according to claim 3, characterized in that, The molar ratio of cashew phenol polyoxyethylene ether, citric acid, methanol-modified glyphosate, and diethanolamine in S2 is 1:0.8:0.15:0.9; the preparation steps of the methanol-modified glyphosate are as follows: Glyphosate and methanol were added to a reaction vessel at a molar ratio of 1:4.2, and concentrated sulfuric acid (1% by mass of total mass) was added as a catalyst. The mixture was refluxed for 6 hours, and methanol-modified glyphosate was obtained by vacuum distillation.

8. The method for preparing a demulsifier based on modified polyether according to claim 3, characterized in that, The detection indicators in S3 are as follows: Appearance: Pale yellow transparent liquid; Density: 0.95-1.05 g / cm³ at 20℃ 3 ; Kinematic viscosity: 10-50 mm at 40℃ 2 / s; Flash point: ≥60℃; Freezing point: ≤-5℃.

9. The use of a demulsifier as described in any one of claims 1-2 in a quench water demulsification process.

10. The application according to claim 8, characterized in that, The quench water is industrial quench water containing organic pollutants or emulsified oil; the dosage of the demulsifier is 50-200 mg / L, the demulsification treatment temperature is 10-60℃, and the applicable pH range is 3-11.

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