Method for removing alcohol amine in organic filter membrane and method and system for removing ionic surface active agent in sulfonamide solution

Abstract

The invention provides a method for removing alcohol amine in an organic filter membrane and a method and a system for removing an ionic surfactant in a sulphone amine solution. According to the method for removing the alcohol amine in the organic filter membrane, the organic filter membrane permeated with the alcohol amine is purged by adopting BCl3. The method for removing the ionic surface active agent in the sulfonamide solution mainly comprises the following steps: adopting micellar enhanced filtration and purging an organic filter membrane permeated with alcohol amine by using BCl3 to recover the performance of the filter membrane, or firstly adopting an electrodialysis method for treatment, and then carrying out micellar enhanced filtration and filter membrane recovery. According to the method for removing the ionic surfactant in the sulfoamine solution, the anionic surfactant and the cationic surfactant in the sulfoamine solution are efficiently removed, meanwhile, the sulfoamine loss rate is low, and new impurities are not introduced.

Description

Technical Field

[0001] This invention belongs to the field of separation technology, specifically relating to a method for removing alcoholic amines from organic filter membranes and a method and system for removing ionic surfactants from sulfoneamine solutions. Background Technology

[0002] Many raw natural gas samples extracted from underground reservoirs contain impurities such as H2S and organic sulfur, and cannot be used directly. They must undergo desulfurization and purification to become usable commercial natural gas. The quality standards for commercial natural gas specify the sulfur content; GB 17820-2018 stipulates a total sulfur index of ≤200 mg / m³. 3 Significantly reduced to ≤20mg / m 3 The demand for organic sulfur removal technology and organic sulfur removal solutions is rapidly increasing in the natural gas purification field.

[0003] Sulfolane is an excellent solvent for organic sulfur, with a high removal rate. As the preferred solvent for removing organic sulfur from natural gas, sulfolane-amine desulfurization solutions, which are a mixture of sulfolane and alkanolamine, are widely used.

[0004] Desulfurization solutions are easily contaminated and deteriorated by residues from upstream mining operations during natural gas purification. Foaming due to contamination of the desulfurization solution is the most common and widespread problem in natural gas purification production, and a major factor restricting stable and increased production. Therefore, amine reactivation technology, capable of removing foaming contaminants from desulfurization solutions and restoring their performance, is a key technology for ensuring stable production in natural gas purification plants. However, existing amine reactivation technologies, when used with sulfoneamine desulfurization solutions, cannot effectively separate the foaming agents. The resulting foaming from the contaminated desulfurization solution leads to substandard natural gas quality, unstable operation of the natural gas purification unit, and even production shutdowns, severely impacting normal production. Therefore, the need for reactivation technology capable of removing foaming agents from sulfoneamine solutions is extremely urgent in the natural gas purification field.

[0005] Various surfactants in natural gas extraction residues are the cause of foaming in desulfurization solutions. For example, various surfactants are present in foam draining, demulsifying, corrosion inhibitors, drilling agents, and oil displacement agents. To solve the foaming problem in sulfoneamine desulfurization solutions, these surfactants must be removed. Because these surfactants are highly foaming, even concentrations of tens of ppm can cause foaming in sulfoneamine solutions, a removal rate of at least >90% is required. Due to the significant differences in molecular properties between anionic, cationic, and nonionic surfactants, and the varying interaction forces between them and sulfolane and alkanolamine molecules, separate removal methods need to be studied for each.

[0006] The existing reactivation technologies for sulfolane and alkanolamine solutions are mainly as follows:

[0007] (1) Ion exchange method, using anion exchange resin to reactivate deteriorated sulfolane and amine solutions, such as US5053137, CN1230545A, CN1644581A, CN1076726C, CN1125063C, CN111111306A, CN1861594A;

[0008] (2) Electrodialysis method: Under the action of an electric field, the anions and cations in the amine solution move in a directional manner and enter the concentration chamber through the anion and cation selective permeation membranes respectively. Unionized components such as sulfolane remain in the desalination chamber, thereby achieving separation. Examples include US6517700, US5162084, US5788864, CN1733355A, CN1230545A, and CN102189008A.

[0009] Ion exchange and electrodialysis can remove ionized components in water, but the anions formed by the ionization of anionic surfactants have very weak ion exchange capacity. This is because the anion exchange capacity is inversely proportional to the radius of the hydrated ion formed and directly proportional to the ion's valence state. The radius of the anions formed by the ionization of anionic surfactants is much larger than that of thermally stable salt anions such as chloride ions and OH- ions in the desulfurization solution. - Its valence state is also the lowest, so it is difficult for it to react with the OH groups on the anion exchange resin. - Exchange occurs; the cation exchange capacity of cationic surfactants is much weaker than that of alkanolamine cations in the desulfurization solution; the ions formed by the ionization of anionic and cationic surfactants have large ionic radii and low permeability on anionic and cationic selective membranes. Therefore, both ion exchange and electrodialysis methods have very low removal rates (<20%) of anionic and cationic surfactants in desulfurization solutions.

[0010] (3) Precipitation separation method, such as US4820849, which adds polybasic acid or polybasic acid anhydride to sulfolane solvent to form a solid precipitate with acidic impurities;

[0011] (4) Alkali adsorption separation method, such as Japanese Patent Application Publication No. 7-278316, CN1634917A, and CN106957297A, uses oxides, hydroxides, and carbonates of alkali metals or alkaline earth metals to adsorb acidic impurities in sulfolane. These two methods can only remove acidic impurities from sulfolane. Since neither anionic nor cationic surfactants are acidic substances, neither of these methods can effectively remove them.

[0012] (5) Activated carbon adsorption method, Japanese Patent Application Publication No. 7-101953, uses activated carbon and microfibrous natural cellulose to remove suspended particulates and impurities. Activated carbon has no selectivity for the adsorption of sulfolane and various surfactants, with a selectivity ratio <2. In sulfolane desulfurization solutions, the concentration of sulfolane is much higher than that of surfactants. Due to the concentration advantage, sulfolane will occupy the adsorption surface of activated carbon first, causing it to quickly become saturated. Moreover, the strong interaction between anionic and cationic surfactants and amine molecules makes them more difficult to separate. Therefore, the removal rate of anionic and cationic surfactants in sulfolane amine solutions by activated carbon is less than <10%.

[0013] (6) Decomposition method: CN213885678U decomposes some of the acidic substances in sulfolane by adding monoethanolamine. Anionic and cationic surfactants cannot be decomposed by monoethanolamine, so this method is not applicable.

[0014] (7) Vacuum distillation method, which uses the boiling point difference between sulfolane, alkanolamine and surfactant for separation, but because the desulfurization solution foams when it boils, the surfactants gather on the foam surface and enter the condenser along with the vapors of sulfolane and alkanolamine, so the separation degree is also very low (<30%).

[0015] Existing technologies for surfactant removal from wastewater mainly include foam separation, adsorption, biological methods, microelectrolysis, Fenton oxidation, and micellar-enhanced ultrafiltration.

[0016] (1) Foam separation is a commonly used physical method that removes various surfactants from foam by bubbling. This method has the advantages of simple operation and can achieve the purpose of separating surfactants. However, for sulfone amine desulfurization solutions with severe foaming, the entire solution foams after bubbling. After the foam is separated and removed, about 80% to 90% of the desulfurization components such as sulfolane and alkanolamine are also lost. For example, CN107935236A uses adsorbent material particles to adsorb surfactants in wastewater, and then bubbling allows the adsorbent material particles that adsorb surfactants to accumulate on the surface of the wastewater before removal. The adsorbent particles include silica, calcium carbonate, calcium sulfate, activated carbon particles, magnetite powder, hematite powder, titanium dioxide, clay minerals, fly ash or phosphate tailings powder, as well as nanoparticles of iron tetroxide, silica, titanium dioxide, and zinc oxide metal oxide synthesized through wet chemical synthesis; silica and titanium dioxide with amino or carboxyl groups modified on the surface; and polystyrene resin particles, phenolic resin particles, or melamine resin particles, including unmodified polystyrene resin particles, unmodified phenolic resin particles, or unmodified melamine resin particles. These adsorbents lack selectivity for sulfolane and surfactants, and because anionic and cationic surfactants have strong interactions with alkanolamine molecules, their adsorption rates are even lower. Therefore, the removal rate of anionic and cationic surfactants in sulfolane amine solutions is very low (<10%), and the loss of desulfurization components such as sulfolane and alkanolamines is significant (>50%).

[0017] (2) Biological methods utilize microorganisms to use surfactants as carbon sources to degrade anionic and cationic surfactants in wastewater. However, alkanolamines are also carbon sources for biodegradation and will be degraded at the same time, so they are not applicable.

[0018] (3) Micro-electrolysis is based on electrochemical principles. It involves forming electrode reactions in wastewater to cause surfactants to undergo catalytic oxidation, coagulation, adsorption, complexation, and displacement reactions, thereby rapidly removing pollutants. Fenton oxidation utilizes ferrous ions in Fenton's reagent as a catalytic initiator. Under its action, H2O2 generates a large number of free radicals, further accelerating the initiation reaction of free radical chains, thus enabling the rapid degradation and removal of various surfactants in wastewater. These two methods are often used in combination, such as CN110357357A, CN1508077A, CN104310665, and CN109626675A. These methods require adding acid to adjust the pH to 0.5-5 before introducing ferric and ferrous ions. These methods are not suitable for sulfoneamine solutions because adding acid will reduce their desulfurization performance or even completely disable them, increase their corrosiveness, and cause precipitation when ferric and ferrous ions come into contact with hydrogen sulfide, leading to blockage of the desulfurization device.

[0019] (4) Micellar-enhanced ultrafiltration increases the concentration of surfactants in the wastewater. When the concentration exceeds the critical micelle concentration, large-sized micelles (5nm-10nm in diameter) are formed. Then, ultrafiltration is performed using an ultrafiltration membrane. Water molecules, being very small, pass through the membrane, while the micelles are intercepted, thus achieving separation from water. However, when ultrafiltration membranes are used with organic solvents, they swell due to solvent permeation, causing changes in pore size and structure, leading to a decrease or complete loss of separation efficiency. Sulfolane is a highly permeable organic solvent; ultrafiltration membranes gradually swell, enlarge pores, or become clogged in sulfolane. When used for sulfoneamine solution filtration, ultrafiltration membranes gradually lose their separation capacity. Furthermore, although alkanolamines are not organic solvents, prolonged immersion in ultrafiltration membranes can also cause permeation and swelling.

[0020] In summary, existing technologies for reactivating sulfolane and alkanolamine solutions have very low removal rates (<30%) for both anionic and cationic surfactants in sulfolane amine solutions. Existing technologies for removing surfactants from wastewater result in significant losses of desulfurization components such as sulfolane and alkanolamines, or introduce new impurities into the solution, leading to decreased desulfurization performance. These technologies are unsuitable for sulfolane amine desulfurization solutions used in natural gas purification plants. Due to the lack of effective technologies for removing anionic and cationic surfactants from sulfolane amine desulfurization solutions, contaminated sulfolane-based desulfurization solutions in purification plants cannot be reused and must be replaced with new solvents. The contaminated solution removed from the unit is treated as wastewater. Since sulfolane-based desulfurization solutions contain up to 70% or more organic matter and also contain toxic components such as hydrogen sulfide, their disposal is classified as hazardous waste, making it extremely difficult and costly, placing a significant economic burden and environmental pressure on purification plants. Summary of the Invention

[0021] To address the aforementioned problems, the present invention aims to provide a method for removing alkanolamines from organic filter membranes and a method and system for removing ionic surfactants from sulfoneamine solutions. This method for removing ionic surfactants from sulfoneamine solutions achieves efficient removal of both anionic and cationic surfactants from the sulfoneamine solution while exhibiting a low sulfoneamine loss rate and does not introduce new impurities.

[0022] To achieve the above objectives, the present invention provides a method for removing alkanolamines from an organic filter membrane, which uses BCl3 to purge the organic filter membrane permeated with alkanolamines.

[0023] According to a specific embodiment of the present invention, preferably, in the above method for removing alkanolamines from an organic filter membrane, the organic filter membrane includes one or a combination of two or more of the following: sulfonated polysulfone organic filter membrane, sulfonated polyethersulfone organic filter membrane, cellulose acetate organic filter membrane, polyvinylidene fluoride organic filter membrane, polyamide organic filter membrane, polypiperazine amide organic filter membrane, and aromatic polyamide organic filter membrane.

[0024] According to a specific embodiment of the present invention, preferably, in the above method for removing alkanolamines from an organic filter membrane, the purge air velocity is ≥1hr. -1 .

[0025] According to a specific embodiment of the present invention, preferably, in the above method for removing alkanolamines from organic filter membranes, the purging time is ≥0.5hr.

[0026] This invention also provides a method for removing ionic surfactants from a sulfoneamine solution, which may be one of the following methods:

[0027] Method 1:

[0028] A macromolecular cationic surfactant and a macromolecular anionic surfactant are added to a sulfoneamine solution, mixed, and then filtered through an organic filter membrane to obtain a sulfoneamine solution free of ionic surfactants. The organic filter membrane is then treated with the method described in any one of claims 1-3.

[0029] Method 2:

[0030] (1) The sulfonamide solution was treated by electrodialysis to obtain the electrodialysis-treated sulfonamide solution, anolyte waste liquid and cathode waste liquid;

[0031] (2) Combine the anolyte waste liquid and the cathode waste liquid, add macromolecular cationic surfactant and macromolecular anionic surfactant, mix, and then filter through an organic filter membrane to obtain the filtrate;

[0032] Alternatively, a macromolecular cationic surfactant can be added to the anode waste liquid, mixed, and then filtered through an organic filter membrane to obtain the anode filtrate; a macromolecular anionic surfactant can be added to the cathode waste liquid, mixed, and then filtered through an organic filter membrane to obtain the cathode filtrate.

[0033] (3) Combine the filtrate obtained in step (2) with the sulfonamine solution obtained in step (1) after electrodialysis treatment to obtain a sulfonamine solution free of ionic surfactants;

[0034] Alternatively, the anolyte and catholyte obtained in step (2) can be combined with the sulfonamide solution obtained in step (1) after electrodialysis treatment to obtain a sulfonamide solution free of ionic surfactants.

[0035] (4) The organic filter membrane is treated using the above-described method for removing alkanolamines from the organic filter membrane.

[0036] According to a specific embodiment of the present invention, preferably, in the above method for removing ionic surfactants from sulfonamide solution, in step (1), before treating the sulfonamide solution by electrodialysis, the molar amount n1 of the anionic surfactant and the molar amount n2 of the cationic surfactant in the sulfonamide solution are determined, and sodium chloride is added to the sulfonamide solution.

[0037] According to a specific embodiment of the present invention, preferably, in the above-described method for removing ionic surfactants from sulfoneamine solution, the molar amount of sodium chloride is ≥(n1+n2), more preferably 3×(n1+n2) to 4×(n1+n2).

[0038] According to a specific embodiment of the present invention, preferably, the above-mentioned method for removing ionic surfactants from sulfonamide solution further includes the operation of: washing the organic filter membrane with a washing solution; more preferably, water is used as the washing solution, because if an organic solvent is used as the washing solution, the filter membrane will swell after a long period of use, and the separation efficiency will decrease; more preferably, the organic filter membrane is washed by backwashing, because the solubility of large molecular surfactant micelles in water is small and their adhesion to the filter membrane is strong, and pressure is required to remove them from the filter membrane.

[0039] According to a specific embodiment of the present invention, preferably, in the above method for removing ionic surfactants from sulfonamide solution, in step (4), when the cumulative usage time of the organic filter membrane is ≤120h, the organic filter membrane is treated by the above method for removing ionic surfactants from sulfonamide solution.

[0040] According to a specific embodiment of the present invention, preferably, in the above-described method for removing ionic surfactants from sulfonamide solution, the molar ratio of the macromolecular cationic surfactant to the molar ratio of the anionic surfactant in the sulfonamide solution is 1:1.

[0041] According to a specific embodiment of the present invention, preferably, in the above-described method for removing ionic surfactants from sulfonamide solution, the molar ratio of the macromolecular anionic surfactant to the molar ratio of the cationic surfactant in the sulfonamide solution is 1:1.

[0042] According to a specific embodiment of the present invention, preferably, the above-described method for removing ionic surfactants from a sulfonamide solution satisfies one or more of the following conditions:

[0043] (1) The direct current density of the electrodialysis method is ≥30A / m 2 ;

[0044] (2) The macromolecular cationic surfactant includes one or more of the following: octadecylamine, octadecylpyridine chloride, 1-polyoxyvinyl-2-perfluorooctane iodide imidazoline, trimethyloctadecyl ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and bis(octadecyl)dimethylammonium chloride, more preferably dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride;

[0045] (3) The macromolecular anionic surfactant includes one or more of oleate, sodium salt of 1-tetrate phosphate, hexadecyl sulfate, octadecyl phosphate, and octadecyl sulfate, more preferably octadecyl sulfate; such macromolecular anionic surfactant has a large molecular weight and good water solubility. The larger the molecular weight, the more conducive it is to forming a difference between the macromolecular size and the size of sulfolane, alkanolamine, and water molecules.

[0046] (4) The organic filter membrane includes one or more of the following: sulfonated polysulfone organic filter membrane, sulfonated polyethersulfone organic filter membrane, cellulose acetate organic filter membrane, polyvinylidene fluoride organic filter membrane, polyamide organic filter membrane, piperazine amide organic filter membrane, and aromatic polyamide organic filter membrane; more preferably, it is a polyamide organic filter membrane and / or a piperazine amide organic filter membrane; polyvinylidene fluoride organic filter membrane, sulfonated polysulfone organic filter membrane, sulfonated polyethersulfone organic filter membrane, and aromatic polyamide organic filter membrane have a high adsorption capacity for sulfolane, which easily leads to a relatively high sulfolane loss rate;

[0047] (5) The pore size of the organic filter membrane is 1-3 nm; more preferably 1-2 nm; the filter membrane with a pore size > 3 nm has a low molecular rejection rate for anionic and cationic surfactants, and the filter membrane with a pore size < 1 nm has a combined loss rate of sulfolane and alkanolamines of up to 80% or more; when the pore size is 2-3 nm, the rejection rate for anionic and cationic surfactants is > 65% but < 75%; when the pore size is 1-2 nm, the rejection rate for anionic and cationic surfactants is > 90%, and the loss rate of sulfolane and alkanolamines is < 1%;

[0048] (6) The pressure of organic filter membrane filtration should be ≥0.4 MPa, preferably 0.8-3 MPa; the online regeneration of the desulfurization solution should balance the requirements of quickly eliminating production problems and ensuring that the amount of desulfurization solution extracted from the purification unit for purification does not affect the operation of the purification unit. The minimum requirement for the desulfurization solution purification flow rate is 2 m³ / s. 3 / h, optimal flow range 4-15m 3 / h. When the filtration pressure is <0.4MPa, the permeation rate of sulfolane and alkanolamine through the filtration membrane is <2m. 3 / h, with no practical production application value; at filtration pressures of 0.8-3MPa, the velocity of sulfolane, alkanolamine, and water permeable membranes is 4-15m / h. 3 / h can well meet production needs, and the higher the pressure, the greater the energy consumption. Therefore, the preferred range for filtration pressure is 0.8-3MPa.

[0049] According to a specific embodiment of the present invention, the method for removing ionic surfactants from a sulfoneamine solution includes the following specific steps:

[0050] (1) Determine the molar amount n1 of the anionic surfactant and the molar amount n2 of the cationic surfactant in the sulfoneamine solution;

[0051] (2) Add sodium chloride to the sulfonamide solution and mix well;

[0052] (3) Place the solution obtained in step (2) between two anion and cation exchange membranes and pass a direct current through it. The solution between the anion and cation exchange membranes is called solution 1. Solution 1 contains sulfolane, water and unionized alcohol amine.

[0053] (4) Collect the solution outside the ion exchange membrane and mix it evenly. The solution outside the ion exchange membrane is part of the alcohol amine and surfactant that have passed through the ion exchange membrane.

[0054] (5) Add n1 moles of macromolecular cationic surfactant and n2 moles of macromolecular anionic surfactant to the solution in step (4) and stir evenly to obtain solution 2; introduce macromolecular anionic surfactant or cationic surfactant to form larger macromolecules with the original cationic surfactant or anionic surfactant molecules in the solution, significantly increase the difference in size with the alcohol amine molecules, so as to achieve separation.

[0055] (6) Solution 2 is filtered using an organic filter membrane to obtain solution 3; by selecting a filter membrane that allows small molecules to pass through while retaining large molecules, the separation of alkanolamines from anionic and cationic surfactants can be achieved. Solution 3 is the alkanolamine from which the surfactant has been removed by filtration;

[0056] (7) Collect solution 1 and solution 3 and mix them evenly to obtain a sulfoneamine solution from which anionic and cationic surfactants have been removed;

[0057] (8) When the cumulative usage time of the organic filter membrane is ≤120 hours, purge the organic filter membrane with BCl3;

[0058] (9) When the pressure difference of the organic filter membrane increases and the liquid flow rate decreases significantly, the filter membrane is regenerated with washing solution until the pressure is restored to the initial value. The retained anionic and cationic surfactants accumulate on the filter membrane, leading to an increase in pressure difference and a decrease in separation efficiency. The separation efficiency can be restored by washing off the surfactants on the filter membrane with washing solution.

[0059] The present invention also provides a system for removing ionic surfactants from sulfoneamine solutions, comprising an electrodialysis system, an organic membrane filtration system, and a BCl3 purging system; wherein the waste liquid outside the ion exchange membrane in the electrodialysis system is filtered by the organic membrane filtration system; and the BCl3 purging system purges the organic membrane in the organic membrane filtration system.

[0060] According to a specific embodiment of the present invention, preferably, the organic membrane filtration system is provided with a macromolecular surfactant feeding system.

[0061] The method for removing ionic surfactants from sulfonamide solutions of the present invention first involves adding sodium chloride to the sulfonamide solution to enhance the ionization of anionic and cationic surfactants. Then, the solution is placed between two anion and cation exchange membranes. Under the action of direct current, the anionic and cationic surfactants in the solution ionize and aggregate onto the surfaces of the anion and cation exchange membranes, respectively. Surfactants pass through the ion exchange membranes, and some alcoholic amines also ionize and pass through the membranes. Sulfolane and water do not ionize and remain in place. The solution between the anion and cation exchange membranes, i.e., sulfolane, water, and unionized alcoholic amines, is removed, achieving separation from the surfactants. The solution outside the anion and cation exchange membranes is collected... After collection and mixing, a large-molecule anionic or cationic surfactant is introduced to form even larger molecules with the existing cationic or anionic surfactant molecules in the solution, significantly increasing the size difference with the alkanolamine molecules. Then, a filter membrane with a specific pore size and material is used for filtration under specific pressure. This selectively traps the large molecules formed by the anionic and cationic surfactants while allowing the alkanolamine to pass through the membrane, thus achieving the separation of the alkanolamine from the anionic and cationic surfactant micelles. These alkanolamines are then mixed with unionized alkanolamines, sulfolane, and water to obtain a sulfoneamine solution free of anionic and cationic surfactants. The swelling effect of the alkanolamine on the filter membrane is periodically eliminated by BCl3 purging. This invention has the following beneficial effects:

[0062] (1) The method of the present invention has a high removal rate of anionic and cationic surfactants in sulfonamide solution, which is much higher than the removal rate of anionic and cationic surfactants in sulfonamide solution in the prior art (<30%).

[0063] (2) The method of the present invention has a very small loss rate of sulfolane and amines, and does not introduce new impurities into the sulfolane solution.

[0064] (3) The method of the present invention can efficiently remove anionic and cationic surfactants from sulfonamide desulfurization solution, solving the problems of unqualified natural gas quality, unstable equipment operation and shutdown caused by foaming of sulfonamide desulfurization solution due to anionic and cationic surfactant contamination in natural gas purification plants. It can restore the performance of deteriorated sulfolane desulfurization solution that could only be used as waste liquid in the past and continue to be used. It not only ensures normal production, but also solves the problems of solvent consumption and waste liquid disposal, significantly reducing the production cost and environmental pressure of purification plants, and has excellent economic and social benefits. Attached Figure Description

[0065] Figure 1 This is a graph showing the relationship between filtration pressure and solution outflow rate. Detailed Implementation

[0066] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0067] Preparation of sulfoneamine desulfurization solution:

[0068] 1 # Sulfonium amine desulfurization solution: Samples of foamed sulfonium amine desulfurization solutions from different natural gas purification units were analyzed to determine their anionic surfactant composition. Then, these anionic surfactants (i.e., the molar ratio of sodium dodecyl sulfate: sodium dodecyl sulfate: sodium butyl sulfonate: sodium isooctanoate: sodium butyl sulfonate: sodium isooctanoate: sodium butyl sulfonate: sodium dodecylbenzene sulfonate: sodium diisooctyl succinate: sodium perfluorononenoxybenzene sulfonate = 1:1:1:1:1:1:1:1) were added in an equal proportion to obtain 1 # Sulfonamide desulfurization solution, 1 # The total concentration of anionic surfactant in the sulfoneamine desulfurization solution was 15.3 mol / m³. 3 .

[0069] 2 # Sulfonium amine desulfurization solution: Samples of foamed sulfonium amine desulfurization solutions from different natural gas purification units were analyzed to determine their cationic surfactant composition. These cationic surfactants (i.e., a molar ratio of dodecylammonium chloride: dodecyltrimethylammonium chloride: tetradecyltrimethylammonium bromide: dodecylpyridine chloride: dodecylpyridine bromide = 1:1:1:1:1) were then added to the fresh sulfonium amine solution to obtain 2 # Sulfonamide desulfurization solution, 2 # The total concentration of cationic surfactant in the sulfoneamine desulfurization solution was 15.2 mol / m³. 3 .

[0070] 3 # Sulfonamide desulfurization solution: 1 # Sulfonamide desulfurization solution and 2 # Sulfonamide desulfurization solution was mixed at a volume ratio of 1:1 to obtain 3 # Sulfonamide desulfurization solution, 3 # The total concentration of anionic surfactants in the sulfoneamine desulfurization solution was 7.65 mol / m³. 3 The total concentration of the cationic surfactant was 7.6 mol / m³. 3 .

[0071] Example 1

[0072] This embodiment investigated the removal efficiency of different types of organic filter membranes and different types of macromolecular ionic surfactants on ionic surfactants in sulfoneamine desulfurization solutions. The steps are as follows:

[0073] (1) In 1 # Sulfonamide desulfurization solution at 15.3 mol / m 3 Add a cationic surfactant and stir until homogeneous to obtain solution 1 # -Solution 6 # :

[0074] Solution 1 # -Solution 6 # The added cationic surfactants are octadecylamine, octadecylpyridine chloride, 1-polyoxyvinyl-2-perfluorooctane iodide imidazoline, trimethyloctadecyl ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and dioctadecyl dimethyl ammonium chloride.

[0075] (2) In 2 # Sulfonamide desulfurization solution at 15.2 mol / m 3 Add anionic surfactant and stir until homogeneous to obtain solution 7 # -Solution 11 # :

[0076] Solution 7 # -Solution 11 # The added anionic surfactants are sodium oleate, sodium 1-tridecyl phosphate, sodium hexadecyl sulfate, octadecyl phosphate, and sodium octadecyl sulfate.

[0077] (3) Solution 1 was filtered using an organic filter membrane. # -Solution 11 # The filtration pressure was 0.5 MPa. Each solution was filtered using sulfonated polysulfone membranes, sulfonated polyethersulfone membranes, cellulose acetate membranes, polyvinylidene fluoride membranes, polyamide membranes, piperazine amide membranes, and aromatic polyamide membranes with pore sizes of 1-2 nm, respectively, to obtain sample 1-1. # To sample 11-7 # (Numbering description: Solution 1) # Samples 1-1 were obtained after treatment with these seven different membranes. # To samples 1-7 # Solution 2 # Samples 2-1 were obtained after treatment with these seven different membranes. # To sample 2-7 # ...a total of 77 samples).

[0078] (4) Determination of sample 1-1 # To sample 11-7 # Calculate the surfactant removal rate, alkanolamine loss rate, and sulfolane loss rate based on the surfactant concentration, alkanolamine concentration, and sulfolane concentration. Surfactant removal rate = ((1) # or 2# (Concentration of surfactant in sulfoneamine desulfurization solution - concentration of surfactant in sample) × 100) / (1 # or 2 # Surfactant concentration in sulfoneamine desulfurization solution). Alkylamine loss rate = ((1 # or 2 # (Concentration of sulfone amine in desulfurization solution - concentration of sulfone amine in sample) × 100) / (1 # or 2 # Concentration of sulfoneamine in desulfurization solution). Loss rate of sulfolane = ((1 # or 2 # (sulfolane concentration in sulfoneamine desulfurization solution - sulfolane concentration in sample) × 100) / (1 # or 2 # (Concentration of sulfolane in sulfoneamine desulfurization solution).

[0079] Experimental results: The cellulose acetate membrane exhibited swelling and dissolution during the experiment. Samples 1-3 filtered using the cellulose acetate membrane... # To sample 11-3 # The turbidity indicates that the cellulose acetate membrane is not suitable for sulfonamide solutions. Samples filtered through other membranes were clear and transparent. The concentrations of surfactant, alkanolamine, and sulfolane in these clear and transparent samples were measured, and the surfactant removal rate, alkanolamine loss rate, and sulfolane loss rate were calculated. The results are shown in Tables 1 to 6.

[0080] Table 1. Results of surfactant removal rate, alcohol amine and sulfolane loss rate (1), unit: %

[0081]

[0082] Table 2. Results of surfactant removal rate, amine and sulfolane loss rate (2), unit: %

[0083]

[0084]

[0085] Table 3. Results of surfactant removal rate, amine and sulfolane loss rate (3), unit: %

[0086]

[0087] Table 4. Test results of surfactant removal rate, alkanolamine and sulfolane loss rate (4), unit: %

[0088]

[0089] Table 5. Results of surfactant removal rate, amine and sulfolane loss rate (5), unit: %

[0090]

[0091] Table 6. Results of surfactant removal rate, amine and sulfolane loss rate (6), unit: %

[0092]

[0093] Tables 1-3 show that when removing anionic surfactants from sulfonamide solutions, amines, pyridines, imidazolines, and quaternary ammonium cationic surfactants with similar molecular weights were used. Among them, quaternary ammonium cationic surfactants showed the highest removal rate. Larger molecular weight cationic surfactants were beneficial for improving the removal rate, but excessively large molecular weights could lead to decreased removal rates due to reduced solubility in sulfonamide solutions. (Sample 5-1) # ~5-7 # The quaternary ammonium cationic surfactant used, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, has an ideal molecular weight and solubility in sulfoneamine solution, so the removal rate can reach more than 95%.

[0094] Tables 4-6 show that the removal rate of cationic surfactants from sulfonamide solution is related to the molecular weight of the added anionic surfactant and its solubility in the sulfonamide solution. (Sample 11-1) # ~11-7 # The sodium octadecyl sulfate used has an ideal molecular weight and solubility in sulfoneamine solution, so the removal rate can reach more than 90%.

[0095] Tables 1-6 show the loss rates of alkanolamines and sulfolane, indicating that sulfonated polysulfone membranes, sulfonated polyethersulfone membranes, polyvinylidene fluoride membranes, and aromatic polyamide membranes have a greater adsorption effect on sulfolane and a larger loss rate of sulfolane; while polyamide membranes and polypiperazine amide membranes have a very small adsorption effect on alkanolamines and sulfolane, and the loss rates of alkanolamines and sulfolane are very small (<1%).

[0096] Example 2

[0097] This embodiment investigated the removal effect of different membrane pore sizes on ionic surfactants in sulfoneamine desulfurization solutions. The steps are as follows:

[0098] Solution 5 in Example 1 was filtered using a polyamide membrane. # Solution 11 # Solution 5 # 11 # The solutions were filtered through polyamide membranes with pore sizes of 3-4 nm, 2-3 nm (filtration pressure 0.5 MPa), 1-2 nm (filtration pressure 0.5 MPa), and <1 nm (the filtration pressure was increased to 1.3 MPa before the solution flowed out due to the small pore size), respectively, yielding samples 5-8. #~5-11 # and 11-8 # ~11-11 # The concentrations of surfactant, alkanolamine, and sulfolane in the samples were determined, and the surfactant removal rate, alkanolamine loss rate, and sulfolane loss rate were calculated. The results are shown in Table 7.

[0099] Table 7 Results of surfactant removal rate, alkanolamine and sulfolane loss rate (7), unit: %

[0100]

[0101] The experimental results shown in Table 7 indicate that filter membranes with pore sizes >3 nm have a removal rate of <50% for anionic and cationic surfactants, which does not meet production requirements; filter membranes with pore sizes <1 nm have a loss rate of >80% for sulfolane and alkanolamines, which also does not meet production requirements; filter membranes with pore sizes of 2-3 nm have a removal rate of >65% but <75% for anionic and cationic surfactants, which are usable but not ideal; filter membranes with pore sizes of 1-2 nm have a removal rate of >90% for anionic and cationic surfactants, and a loss rate of <1% for sulfolane and alkanolamines, which both meet production requirements well in terms of surfactant removal rate and effective component loss rate.

[0102] Example 3

[0103] This embodiment investigated the removal effect of different filtration pressures on ionic surfactants in sulfoneamine desulfurization solutions. The steps are as follows:

[0104] Solution 5 in Example 1 was filtered using a polyamide membrane. # Solution 11 # Solution 5 # Solution 11 # All samples were filtered using polyamide membranes with pore sizes of 1-2 nm. The filtration pressure was gradually increased from 0.1 MPa, and the outflow rate of the solution was measured at different filtration pressures. The results are as follows: Figure 1 As shown.

[0105] Figure 1 The experimental results show that, regardless of whether anionic or cationic surfactants are removed from the sulfoneamine solution, when the filtration pressure is <0.4 MPa, the permeation rate of sulfolane and alkanolamine through the filtration membrane is <2 m / s. 3 / h, which cannot meet the minimum flow rate requirement (2m³ / h) for desulfurization solution purification in natural gas purification plants. 3 / h); when the filtration pressure is 0.8-3MPa, the velocity of sulfolane, alkanolamine, and water permeation through the filtration membrane is 4-15m. 3 The flow rate is within the optimal range for desulfurization solution purification in a natural gas purification plant, effectively meeting production requirements. Therefore, the minimum filtration pressure is 0.4 MPa, and the optimal range is 0.8-3 MPa.

[0106] Example 4

[0107] This embodiment examines the regeneration effects of different filter membrane regeneration methods. The steps are as follows:

[0108] Solution 5 in Example 1 was filtered using a polyamide membrane. # Solution 11 # : The solution was continuously filtered using polyamide membranes with pore sizes of 1-2 nm. # Solution 11 # The filtration pressure is 2 MPa, and the solution outflow velocity is 10.5 m / s. 3 / h decreased to 8.5m 3 Stop feeding the solution at / h and regenerate the filter membrane using distilled water by soaking and backwashing.

[0109] Soak the filter membrane in distilled water at twice its volume for 0.5, 1, 2, and 3 hours, then reintroduce the solution. The outflow rates of the solution are 8.5, 8.5, 8.6, and 8.8 m / s, respectively. 3 / h; Backwash the filter membrane with distilled water. When the amount of distilled water is 5.8 times the filter membrane volume, the outflow velocity of the solution recovers to 10.5m. 3 / h.

[0110] The above experimental results indicate that when the washing solution for regenerating the filter membrane is water, a reverse rinsing regeneration method is required.

[0111] Comparative Example 1

[0112] Use 3 # The removal efficiency of the present invention's method and existing sulfolane and alkanolamine solution reactivation techniques for anionic and cationic surfactants in sulfoneamine solutions was investigated using the following steps:

[0113] (1) Ion exchange method: 150 mL of 3 # Sulfonamide desulfurization solution was discharged at a space velocity of 4 h⁻¹ -1 The solution flowing out of the column is the reactivated sulfonamide desulfurization solution, which is obtained by passing through a 100mL D201 strong basic anion exchange resin column from top to bottom. The concentrations of anionic and cationic surfactants in this solution are then measured.

[0114] (2) Electrodialysis: The anion and cation exchange membranes, concentrated and dilute water separators, positive and negative electrodes, electrode frames, and water-conducting plates are clamped together using a clamping device to form an electrodialysis device; 500g of 3 # The sulfonamide desulfurization solution was poured into the electrodialysis device, and a direct current (50A / m) was passed through it. 2 The solution remaining in the fresh water is the reactivated sulfonamide desulfurization solution. The concentrations of anionic and cationic surfactants in this solution are measured.

[0115] (3) Vacuum distillation: Add 200g of 3 to the distillation flask # The sulfonium amine desulfurization solution was evacuated to a pressure of 90.3 kPa in the distillation system, heated to 150°C, and distilled for 20 minutes. The solution in the receiving bottle is the reactivated sulfonium amine desulfurization solution. The concentrations of anionic and cationic surfactants in this solution were then measured.

[0116] (4) Precipitation separation method: 20 g of sodium carbonate, 30 g of magnesium oxide powder, and 50 g of 4A molecular sieve powder are thoroughly mixed, and appropriate amounts of water and binder are added. The mixture is then extruded into strips using a twin-screw extruder and dried to obtain a solid alkali adsorbent. 8 g of the solid alkali adsorbent is loaded into an adsorption bed 15 cm high, and then 3... # The sulfone amine desulfurization solution was passed from bottom to top through the adsorption bed at an average flow rate of 0.2 m / h at room temperature. The outflowing solution was the reactivated sulfone amine desulfurization solution. The concentrations of anionic and cationic surfactants in this solution were measured.

[0117] (5) Activated carbon adsorption method: 150 mL of 3 # Sulfonamide desulfurization solution was discharged at a space velocity of 4 h⁻¹ -1 The solution flowing out of the 100mL activated carbon column from top to bottom is the reactivated sulfonamide desulfurization solution. The concentrations of anionic and cationic surfactants in this solution are then measured.

[0118] (6) Decomposition method: In 200mL of 3 # 0.1 mol of monoethanolamine was added to a sulfoneamine desulfurization solution and stirred for 30 min. The concentrations of anionic and cationic surfactants in the solution were then measured.

[0119] (7) The method of the present invention for removing ionic surfactants from sulfoneamine solution: to 1m 3 3 # 7.65 mol of dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 7.6 mol of sodium octadecyl sulfate were added to the sulfonium amine desulfurization solution. After stirring evenly, the solution was filtered through a polyamide membrane with a pore size of 1-2 nm at a filtration pressure of 2 MPa. The filtered solution was the reactivated sulfonium amine desulfurization solution. The concentrations of anionic and cationic surfactants in this solution were measured.

[0120] Calculate the removal rates of anionic and cationic surfactants using various methods = ((3) # (Sum of anionic and cationic surfactant concentrations in the sulfonamide desulfurization solution - Sum of anionic and cationic surfactant concentrations in the reactivated sulfonamide desulfurization solution) × 100) / (3 # The sum of the concentrations of anionic and cationic surfactants in the sulfoneamine desulfurization solution); (sulfolane + alcoholamine) loss rate = ((3 #(Sum of sulfolane and alkanolamine concentrations in the sulfoneamine desulfurization solution - Sum of sulfolane and alkanolamine concentrations in the reactivated sulfoneamine desulfurization solution) × 100) / (3 # (The sum of the concentrations of sulfolane and alkanolamine in the sulfoneamine desulfurization solution). The results are shown in Table 8.

[0121] Table 8. Results of surfactant removal rate, alcohol amine and sulfolane loss rate by method (8), unit: %

[0122]

[0123]

[0124] The test results shown in Table 8 demonstrate that the method of the present invention significantly increases the removal rate of anionic and cationic surfactants in sulfoneamine solution from <30% in the prior art to 96.1%, while the loss rate of sulfolane and alkanolamine is <1%.

[0125] Example 5

[0126] This embodiment investigated the removal stability of different filter membranes, and the steps are as follows:

[0127] In 3 # Add 7.65 mol / m to sulfoneamine solution 3 The cationic surfactant is dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride and 7.6 mol / m 3 After mixing with sodium octadecyl sulfate, an anionic surfactant, the solution was continuously circulated through sulfonated polysulfone membranes, sulfonated polyethersulfone membranes, polyvinylidene fluoride membranes, polyamide membranes, piperazine amide membranes, and aromatic polyamide membranes with pore sizes of 1-2 nm. The removal rate of these membranes was then tested every other day. The experimental results are shown in Table 9.

[0128] Table 9. Stability test results, in %

[0129]

[0130] Experimental results show that sulfonated polysulfone membranes, sulfonated polyethersulfone membranes, polyvinylidene fluoride membranes, and aromatic polyamide membranes lost their separation ability after one day of contact with sulfonamide solution; polyamide and polypiperazine amide membranes lost their separation ability after two days of contact with sulfonamide solution.

[0131] Example 6

[0132] This embodiment provides a method for removing ionic surfactants from a sulfonamide solution, the steps of which are as follows:

[0133] In 3 # Sulfonamide desulfurization solution added: 45.8 mol / m 3Sodium chloride, after being mixed thoroughly, is placed between two anion and cation exchange membranes, and a direct current with a current density of 50 A / m is passed through it. 2 The solution between the anion and cation exchange membranes was removed to obtain solution 1; the solution outside the ion exchange membrane was collected and mixed thoroughly, and then the macromolecular cationic surfactant dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride was added at a concentration of 7.65 mol / m³. 3 ×3 processed # The volume of the sulfoneamine desulfurization solution and the amount of the macromolecular anionic surfactant sodium octadecyl sulfate added were 7.6 mol / m³. 3 ×3 processed # The volume of the sulfonylamine desulfurization solution was measured and stirred to obtain solution 2. Solution 2 was continuously circulated using a pump and passed through sulfonated polysulfone membranes, sulfonated polyethersulfone membranes, polyvinylidene fluoride membranes, polyamide membranes, piperazine amide membranes, and aromatic polyamide membranes with pore sizes of 1-2 nm to obtain solution 3. The removal rate of these membranes was then tested every other day. Solutions 1 and 3 were collected, mixed thoroughly, and the loss rates of sulfolane and alkanolamine were measured. The experimental results are shown in Table 10.

[0134] Table 10 Stability test results, in %

[0135]

[0136] The experimental results shown in Table 10 indicate that the method of removing sulfolane to allow each organic membrane to contact only the alkanolamine significantly improves the stability of the surfactant treatment in the sulfoneamine solution. However, after the 5th day, the removal rate of the organic filter membranes decreased significantly due to the permeation of alkanolamine molecules.

[0137] On day 7, the above organic membranes were soaked in various extractants, reactants, or distilled water heated to 75±1℃ for 24 hours, and then purged with BCl3 (space velocity 1hr). -1 After 24 hours, the above experiment was repeated, and the results are shown in Table 11.

[0138] Table 11 Test results of the organic filter membrane recovery method, in %

[0139]

[0140] The experimental results shown in Table 11 indicate that soaking in hot water and purging with BCl3 can eliminate the effect of alkanolamines on the removal rate of organic filter membranes.

[0141] The effects of reducing the soaking time in hot distilled water and the purging time with BCl3 on the recovery of organic filter membrane performance were investigated. The experimental results are shown in Tables 12 and 13.

[0142] Table 12 Relationship between hot distilled water soaking time and recovery effect of organic filter membrane (%)

[0143]

[0144] Table 13 Relationship between BCl3 purging time and organic filter membrane recovery effect (%)

[0145]

[0146] The results showed that the BCl3 purging method led to a faster recovery of the organic filter membrane's performance.

[0147] The removal of ionic surfactants from sulfonamide solution was investigated by continuously applying the method of this embodiment in the field, using hot water immersion (75±1℃, 24 hours) and BCl3 purging (0.5h, space velocity 1hr). -1 The long-term stability of these two methods, corresponding to the number of days in Table 14, was assessed by restoring the organic filter membrane using hot water immersion and BCl3 purging methods, respectively. The results are shown in Table 14.

[0148] Table 14. Results of long-term stability studies for the two recovery methods (in %)

[0149]

[0150]

[0151] Experimental results show that only the BCl3 purging method can meet the practical application requirements of ≥12 months of performance stability of organic filter membranes in production.

[0152] When an organic filter membrane is in prolonged contact with an alkanolamine, alkanolamine molecules gradually permeate the membrane, causing it to swell. When the contact time between the organic filter membrane and the alkanolamine is less than 120 hours, the swelling effect is very slight and its impact on separation efficiency is not yet apparent. However, after 120 hours, the swelling effect becomes noticeable. Therefore, it is necessary to remove the alkanolamine molecules that have permeated into the organic filter membrane to restore its original structure. There are two common approaches: one is to use an alkanolamine to extract the solvent, and the other is to use a reagent that can react with alkanolamines. In this embodiment, various alkanolamine extractants and reactants were tested. It was found that organic extraction solvents for alkanolamines further swell and damage the microstructure of the organic filter membrane. Hot water can "extract" alkanolamine molecules that have permeated the filter membrane, but the efficiency is low, requiring at least 24 hours of soaking each time. Moreover, the heat effect gradually affects the microporous structure of the organic membrane, and the recovery effect of the filter membrane performance gradually deteriorates with the increase of hot water soaking (the removal rate will not reach 90% after 85 days; the production requirement is best ≥95%, and the minimum should not be lower than 90%), which cannot meet the production requirement of stable performance of organic filter membranes for one year or more. Using components that react with alkanolamines, such as hydrochloric acid and other acids, the heat generated by the reaction accumulates in the micropores, which also changes the microporous structure. After in-depth research on the electronic configuration of alkanolamine molecules, this invention uses BCl3 to purge the organic membrane and achieves excellent results. It can not only quickly (<1 hour) remove alkanolamine molecules that have permeated the organic filter membrane, but also maintain the stable performance of the organic filter membrane for 1 year and 9 months or more.

[0153] Example 7

[0154] This embodiment investigated the removal effect of different dosages of sodium chloride on ionic surfactants in sulfoneamine desulfurization solution. The steps are as follows:

[0155] In 3 # Sodium chloride was added to the sulfoneamine desulfurization solution at a concentration of 7.6 mol / m³. 3 15.3 mol / m 3 30.5 mol / m 3 45.8 mol / m 3 61.0 mol / m 3 76.3 mol / m 3 After mixing, place the mixture between two anion and cation exchange membranes, and pass a direct current with a current density of 50 A / m. 2 The solution between the anion and cation exchange membranes was removed to obtain solution 1; the solution outside the ion exchange membrane was collected and mixed thoroughly, and then the macromolecular cationic surfactant dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride was added at a concentration of 7.65 mol / m³. 3 ×3 processed #The volume of the sulfoneamine desulfurization solution and the amount of the macromolecular anionic surfactant sodium octadecyl sulfate added were 7.6 mol / m³. 3 ×3 processed # The volume of the sulfonamide desulfurization solution was measured and stirred to obtain solution 2. Solution 2 was filtered through a polyamide membrane with a pore size of 1-2 nm to obtain solution 3. Solution 1 and solution 3 were collected and mixed evenly, and the surfactant removal rate was measured. The experimental results are shown in Table 15.

[0156] Table 15 Stability Test Results

[0157]

[0158] Experimental results show that adding sodium chloride can significantly improve the removal rate of surfactant in sulfoneamine solution. The removal rate is highest when the number of moles of sodium chloride added is 3-4 times the number of moles of surfactant in sulfoneamine solution.

[0159] Example 8

[0160] This embodiment investigated the effect of different DC current densities on the removal of ionic surfactants in sulfoneamine desulfurization solution. The steps are as follows:

[0161] In 3 # Sodium chloride was added to the sulfoneamine desulfurization solution at a concentration of 45.8 mol / m³. 3 After mixing, the mixture is placed between two anion and cation exchange membranes, and a direct current with a current density of 10 A / m is passed through it. 2 20A / m 2 30A / m 2 40A / m 2 50A / m 2 The solution between the anion and cation exchange membranes was removed to obtain solution 1; the solution outside the ion exchange membrane was collected and mixed thoroughly, and then the macromolecular cationic surfactant dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride was added at a concentration of 7.65 mol / m³. 3 ×3 processed # The volume of the sulfoneamine desulfurization solution and the amount of the macromolecular anionic surfactant sodium octadecyl sulfate added were 7.6 mol / m³. 3 ×3 processed # The volume of the sulfonamide desulfurization solution was measured and stirred to obtain solution 2. Solution 2 was filtered through a polyamide membrane with a pore size of 1-2 nm to obtain solution 3. Solution 1 and solution 3 were collected and mixed evenly, and the surfactant removal rate was measured. The experimental results are shown in Table 16.

[0162] Table 16 Stability Test Results

[0163]

[0164]

[0165] Experimental results show that the applied DC current density is ≥30A / m 2 Only then can a removal rate of >90% be obtained.

Claims

1. A method for removing alkanolamines from an organic filter membrane, wherein the organic filter membrane permeated with alkanolamines is purged with BCl3.

2. The method according to claim 1, wherein, The organic filter membrane includes one or more of the following: sulfonated polysulfone organic filter membrane, sulfonated polyethersulfone organic filter membrane, cellulose acetate organic filter membrane, polyvinylidene fluoride organic filter membrane, polyamide organic filter membrane, polypiperazine amide organic filter membrane, and aromatic polyamide organic filter membrane.

3. The method according to claim 1, wherein, The purge air velocity is ≥1hr -1 ; And / or, the purging time is ≥0.5hr.

4. A method for removing ionic surfactants from a sulfoneamine solution, wherein one of the following methods may be used: Method 1: A macromolecular cationic surfactant and a macromolecular anionic surfactant are added to a sulfoneamine solution, mixed, and then filtered through an organic filter membrane to obtain a sulfoneamine solution free of ionic surfactants. The organic filter membrane is then treated with the method described in any one of claims 1-3. Method 2: (1) The sulfonamide solution was treated by electrodialysis to obtain the electrodialysis-treated sulfonamide solution, anolyte waste liquid and cathode waste liquid; (2) Combine the anolyte waste liquid and the cathode waste liquid, add macromolecular cationic surfactant and macromolecular anionic surfactant, mix, and then filter through an organic filter membrane to obtain the filtrate; Alternatively, a macromolecular cationic surfactant can be added to the anode waste liquid, mixed, and then filtered through an organic filter membrane to obtain the anode filtrate; a macromolecular anionic surfactant can be added to the cathode waste liquid, mixed, and then filtered through an organic filter membrane to obtain the cathode filtrate. (3) Combine the filtrate obtained in step (2) with the sulfonamine solution obtained in step (1) after electrodialysis treatment to obtain a sulfonamine solution free of ionic surfactants; Alternatively, the anolyte and catholyte obtained in step (2) can be combined with the sulfonamide solution obtained in step (1) after electrodialysis treatment to obtain a sulfonamide solution free of ionic surfactants. (4) The organic filter membrane is treated with the method described in any one of claims 1-3.

5. The method according to claim 4, wherein, In step (1), before treating the sulfonamide solution by electrodialysis, the molar amount n1 of the anionic surfactant and the molar amount n2 of the cationic surfactant in the sulfonamide solution are determined, and sodium chloride is added to the sulfonamide solution.

6. The method according to claim 5, wherein, The molar amount of sodium chloride is ≥ (n1 + n2).

7. The method according to claim 4, wherein, The method further includes the operation of washing the organic filter membrane with a washing solution.

8. The method according to claim 4, wherein, In step (4), when the cumulative usage time of the organic filter membrane is ≤120h, the organic filter membrane is treated by the method described in any one of claims 1-3.

9. The method according to claim 4, wherein, The molar ratio of the macromolecular cationic surfactant to the molar ratio of the anionic surfactant in the sulfoneamine solution is 1:

1. And / or, the molar ratio of the macromolecular anionic surfactant to the molar ratio of the cationic surfactant in the sulfoneamine solution is 1:

1.

10. The method according to any one of claims 4-9, wherein, The method satisfies one or more of the following conditions: (1) The direct current density of the electrodialysis method is ≥30A / m 2 ; (2) The macromolecular cationic surfactant includes one or more of the following: octadecylamine, octadecylpyridine chloride, 1-polyoxyvinyl-2-perfluorooctane iodide imidazoline, trimethyloctadecyl ammonium chloride, dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride, and dioctadecyl dimethyl ammonium chloride; (3) The macromolecular anionic surfactant includes one or more of oleate, sodium 1-tetrate phosphate, hexadecyl sulfate, octadecyl phosphate, and octadecyl sulfate; (4) The organic filter membrane includes one or more of the following: sulfonated polysulfone organic filter membrane, sulfonated polyethersulfone organic filter membrane, cellulose acetate organic filter membrane, polyvinylidene fluoride organic filter membrane, polyamide organic filter membrane, polypiperazine amide organic filter membrane, and aromatic polyamide organic filter membrane; (5) The pore size of the organic filter membrane is 1-3 nm; (6) The pressure of organic filter membrane filtration is ≥0.4Mpa.

11. A system for removing ionic surfactants from a sulfoneamine solution, comprising an electrodialysis system, an organic membrane filtration system, and a BCl3 purging system; In the electrodialysis system, the waste liquid outside the ion exchange membrane is filtered through an organic membrane filtration system; the BCl3 purging system purges the organic membrane in the organic membrane filtration system.

12. The system according to claim 11, wherein, The organic membrane filtration system is equipped with a macromolecular surfactant feeding system.

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