Macromolecule / micromolecule composite surfactant for intensively cleaning oily sludge

Abstract

The invention belongs to the technical field of oily sludge cleaning, and particularly relates to a macromolecular / micromolecular composite surfactant for intensively cleaning oily sludge. A main monomer (such as acrylamide), a hydrophilic monomer (such as 2-acrylamido-2-methylpropanesulfonic acid) and a hydrophobic monomer (such as methacrylic acid long-chain alkyl ester) are mixed, and the macromolecular surfactant is synthesized through free radical polymerization. The specific long-chain structure of the macromolecular surfactant can form larger micelles, colloid and asphaltene can be effectively wrapped, the macromolecular surfactant is compounded with the micromolecular surfactant for use, and mixed micelles with higher solubilizing capacity can be formed, so that the colloid and asphaltene in the high-medium-concentration oily sludge can be efficiently removed, and the high-medium-concentration oily sludge can be effectively removed. Further, the removal rate of total petroleum hydrocarbon is improved. The invention provides a new technology for high-efficiency deep treatment of high-medium-concentration oily sludge.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sludge harmless treatment, and particularly relates to a macromolecule / small molecule composite surfactant for enhancing cleaning of oily sludge. BACKGROUND

[0002] Oily sludge is mainly produced in the process of oil exploitation, refining and storage, and is a complex mixture composed of crude oil, water and solid particles. The main methods for repairing high-concentration oily sludge at home and abroad are “chemical cleaning-thermal desorption” or “chemical cleaning-microbial treatment”. The role of chemical cleaning is to remove high-concentration petroleum hydrocarbons and create conditions for subsequent treatment. The key to chemical cleaning lies in the selection of cleaning agents. At present, small molecule surfactants (Mr<1000) commonly used for cleaning high-concentration oily sludge mainly include anionic surfactants (such as sodium dodecylbenzenesulfonate (SDBS), sodium dodecyl sulfate (SDS)), non-ionic surfactants (such as Triton X~100 (TX100), Tween 80) and anionic / non-ionic composite surfactants (such as SDBS+TX100) and the like. Surfactant elution mainly relies on emulsification and solubilization to clean the oil on the surface of the sludge while recovering oil resources. However, due to the limitations of the molecular structure (short hydrophobic chain, small micelle volume), small molecule surfactants have obvious limitations in cleaning high-concentration oily sludge: it is difficult to effectively penetrate the oil-solid interface film or fully wrap macromolecular colloid and asphaltene. Small molecule surfactants have good cleaning effect on light components (saturated hydrocarbons, aromatic hydrocarbons) in oily sludge, but it is difficult to achieve high cleaning effect on total petroleum hydrocarbon (TPH). The oily sludge cleaned by such small molecule surfactants is not convenient for subsequent thermal desorption and biodegradation to achieve standard repair due to the residual macromolecular petroleum hydrocarbon.

[0003] Recent studies have shown that macromolecular surfactants (MS) have significant advantages in cleaning high and medium concentration oily sludge. The research on MS at home and abroad mainly focuses on polyacrylamide derivatives and modified cellulose derivatives. The advantages of MS are as follows: it can significantly reduce the oil-water interfacial tension, making TPH more easily desorbed from the surface of soil particles; its molecular structure can form larger micelles, which can effectively wrap gum and asphaltene, and has stronger solubilizing capacity for TPH. Studies have found that although hydrophobically modified cellulose derivatives have many advantages of macromolecular surfactants, they have limited effect on the removal of heavy components such as gum and asphaltene in oily sludge. When treating oil sludge with high content of heavy components, this type of surfactant still has limitations: it is difficult to strip heavy oil from the surface of soil; limited emulsification and solubilization capacity makes oil easy to re-deposit; poor molecular penetration affects deep cleaning effect. At the same time, its preparation process is complex, and the technology and cost requirements are high. Hydrophobically modified polyacrylamide (HMPAM) grafts hydrophobic groups (such as long-chain alkyl) on the main chain of acrylamide. The hydrophobic long chain can be embedded in the hydrophobic core of gum and asphaltene through hydrophobic interaction (such as van der Waals force and hydrogen bond), strengthening its stripping from the surface of oil sludge; and the large molecular weight of HMPAM can form larger micelles to effectively wrap the stripped oil droplets, thereby achieving efficient removal of gum and asphaltene. In addition, HMPAM can be prepared by free radical polymerization, which is a simple process with low cost and can be applied on a large scale. Macromolecular surfactants, with multi-functional group structure, can enhance the removal of gum and asphaltene in oily sludge by combining the stripping of oil phase with the hydrophobic segment and improving the water phase dispersibility of the hydrophilic segment; small molecule surfactants, due to their short chain and high interfacial activity, can quickly penetrate the oil-solid interface, break the oil-soil binding force by reducing the interfacial tension, and achieve rapid stripping of the oil phase. The combination of the two can have both efficient stripping and stable dispersion of the oil phase, forming a mixed micelle structure with stronger solubilizing capacity and higher stability, which can significantly improve the cleaning efficiency of high and medium concentration oily sludge. However, there is no report on the use of macromolecular / small molecule composite surfactants for cleaning oily sludge. SUMMARY

[0004] The purpose of the present application is to provide a macromolecular / small molecule composite surfactant for enhanced cleaning of oily sludge. In the preparation of the macromolecular surfactant, a hydrophobic monomer, long-chain alkyl methacrylate, is introduced. This structure, without benzene ring, can be embedded in the hydrophobic core of gum and asphaltene through hydrophobic interaction (such as van der Waals force and hydrogen bond), thereby enhancing the stripping ability of these components from the surface of oil sludge and improving the total petroleum hydrocarbon removal rate. The small molecule surfactant is a non-ionic surfactant.

[0005] To achieve the above object, the application adopts the following technical solutions: A macromolecule / small molecule composite surfactant for strengthening cleaning of oily sludge, wherein acrylamide is used as a main monomer, 2-acrylamido-2-methylpropanesulfonic acid is used as a hydrophilic monomer, long-chain alkyl methacrylate is used as a hydrophobic monomer, and a macromolecule surfactant is obtained through a free radical polymerization reaction; the macromolecule surfactant and a non-ionic surfactant are prepared according to a mass ratio of 1:1-10:1 to obtain the macromolecule / small molecule composite surfactant.

[0006] Further, in the preparation process of the macromolecule surfactant, the mass fraction of acrylamide in total monomers is 60%-80%, the mass fraction of 2-acrylamido-2-methylpropanesulfonic acid in total monomers is 10%-30%, and the mass fraction of long-chain alkyl methacrylate in total monomers is 5%-20%, and the total monomers are the sum of the main monomer, the hydrophilic monomer and the hydrophobic monomer, and the total mass fraction of the three monomers is 100%.

[0007] Further, the structural formula of the macromolecule surfactant is as follows:

[0008] In the formula, x=60-70%, y=15-25%, z=5-15%, x+y+z=1, and a=10-16.

[0009] Further, the long-chain alkyl methacrylate is at least one of octadecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate or hexadecyl methacrylate; and the non-ionic surfactant is at least one of triton 100, tween 60 or tween 80.

[0010] Further, the preparation process of the macromolecule surfactant is as follows: First, the main monomer acrylamide and the hydrophilic monomer 2-acrylamido-2-methylpropanesulfonic acid are weighed according to a mass ratio of 6:1-6:3, mixed in deionized water, and adjusted to weak alkalinity; Subsequently, an emulsifier is added, and after stirring until completely dissolved, the hydrophobic monomer long-chain alkyl methacrylate is added; wherein the mass ratio of the emulsifier to the main monomer acrylamide is 1:1000-10:1000, and the mass ratio of the main monomer acrylamide to the long-chain alkyl methacrylate is 6:0.5-6:2; Next, nitrogen is introduced to purge and deoxidize the system, and then the initiator ammonium persulfate is slowly added dropwise, and the mass ratio of the initiator ammonium persulfate to the main monomer acrylamide is 3:1000-9:1000; after the dropwise addition is completed, stirring is continued for 25-40 min; After the stirring is completed, the system is warmed to 60-90℃, and the reaction is carried out for 4-6 hours under stirring. After the reaction is completed, the product is collected and dried at 30-80℃ for 20-36 hours to obtain the macromolecular surfactant HMPAM.

[0011] Preparation of the macromolecular / small molecular complex surfactant: the macromolecular surfactant HMPAM prepared above and a small molecular surfactant are compounded in a certain mass ratio to obtain a macromolecular / small molecular complex surfactant for enhanced cleaning of oil-containing sludge. The small molecular surfactant is selected from non-ionic surfactants (such as Triton 100 or Tween 60 or Tween 80, etc.).

[0012] The macromolecular surfactant prepared in the application is anionic. The non-ionic small molecular surfactant has a low critical micelle concentration and good solubilizing capacity, so it is selected to be compounded with the macromolecular surfactant synthesized in the application. The two can exert a synergistic effect to enhance the cleaning effect on oil-containing sludge.

[0013] Further, the macromolecular / small molecular complex surfactant is used for cleaning oil-containing sludge.

[0014] Further, the process for cleaning oil-containing sludge by using the macromolecular / small molecular complex surfactant is as follows: oil-containing sludge with an oil content of 15%wt-20%wt is placed in a reactor, and the macromolecular / small molecular complex surfactant and water are added for cleaning. The mass ratio of the complex surfactant to the oil-containing sludge is 1:100-10:100, the cleaning temperature is 50-90℃, the rotation speed is 100-150 rpm, and the cleaning time is 0.5-2 hours. Alternatively, the macromolecular / small molecular complex surfactant is first mixed with water to obtain a complex surfactant solution with a concentration of 1-5 g / L, and then the complex surfactant solution is added to oil-containing sludge with an oil content of 15%wt-20%wt for cleaning. The cleaning conditions are as follows: the cleaning temperature is 50-90℃, the rotation speed is 100-150 rpm, and the cleaning time is 0.5-2 hours.

[0015] Further, an auxiliary agent is added during the cleaning process. The auxiliary agent is at least one of sodium carbonate, sodium bicarbonate or sodium silicate, and the addition amount of the auxiliary agent is 1-5 g / L.

[0016] Further, after the oil-containing sludge is cleaned, the total petroleum hydrocarbon removal rate in the oil-containing sludge is calculated by using the gravimetric method, and the colloid removal rate and the asphaltene removal rate are measured by using the stepwise solvent extraction-chromatographic column method. The total petroleum hydrocarbon removal rate is stably controlled at 65% or more, and the removal rate of heavy components including colloid and asphaltene is controlled at 70% or more.

[0017] The macromolecule / small molecule composite surfactant of the present application enhances the removal of heavy components including colloid and asphaltene in oily sludge, and through the synergistic effect of the macromolecule / small molecule composite surfactant, the removal of total petroleum hydrocarbon, especially the removal of colloid and asphaltene in the oily sludge is enhanced, so that the high-concentration oily sludge can be cleaned efficiently.

[0018] Compared with the prior art, the present application has the following advantages: 1) The macromolecule surfactant in the macromolecule / small molecule composite surfactant for cleaning oily sludge in the present application uses long-chain alkyl methacrylate as a hydrophobic monomer, which can be embedded in the hydrophobic core of colloid and asphaltene through hydrophobic interaction (such as van der Waals force and hydrogen bond), so that the colloid and asphaltene can be more easily detached from the oily sludge, and the HMPAM with high molecular weight can form larger micelles to effectively wrap the detached oil droplets, thereby achieving efficient removal of colloid and asphaltene in the oily sludge.

[0019] 2) The macromolecule / small molecule composite surfactant is obtained by compounding the synthetic macromolecule surfactant HMPAM and the small molecule surfactant (non-ionic surfactant TX100), and under the conditions of a composite surfactant solution concentration of 3 g / L, a temperature of 75℃, a cleaning time of 1 h, and a rotation speed of 120 rpm, the oily sludge is cleaned. Compared with the effect of cleaning the oily sludge under the same conditions by using the traditional small molecule composite surfactant (SDBS+TX100), the total petroleum hydrocarbon TPH removal rate is increased by 38.6%, the colloid removal rate is increased by 80.7%, and the asphaltene removal rate is increased by 61.2%. The specific experimental data are shown in Table 1.

[0020] Table 1. Comparison of the effects of macromolecule / small molecule composite surfactant and traditional small molecule composite surfactant

[0021] 3) The process of the present application is simple, low in cost, and good in cleaning effect, and can be applied to large-scale efficient cleaning of high-concentration oily sludge. DETAILED DESCRIPTION

[0022] The present application will be further described below in conjunction with examples, but this is not intended to limit the protection scope of the present application.

[0023] The present application takes acrylamide as the main monomer, 2-acrylamido-2-methylpropanesulfonic acid as the hydrophilic monomer, and long-chain alkyl methacrylate as the hydrophobic monomer, and a new type of hydrophobically modified polyacrylamide macromolecular surfactant is obtained through a free radical polymerization reaction. The long-chain alkyl methacrylate in the macromolecular surfactant can be combined with heavy components such as colloid and asphaltene in the oily sludge through hydrophobic interaction, and inserted into the interior of the aggregates, thereby destroying the intermolecular force and promoting the desorption of oil from the surface of soil particles. At the same time, the steric hindrance effect generated by the macromolecular skeleton can further inhibit the collision and aggregation of oil droplets, enhance the removal effect of heavy components, and finally significantly improve the removal efficiency of total petroleum hydrocarbon.

[0024] The above macromolecule / small molecule composite surfactant is used for cleaning oily sludge: a certain mass of oily sludge with an oil content of 15% wt ~20% wt is placed in a reactor, a corresponding mass of macromolecule / small molecule composite surfactant (the mass ratio of composite surfactant to oily sludge is 1:100~10:100) is added, and an appropriate amount of water is added, and the cleaning is carried out at a cleaning temperature of 50~90℃ and a rotation speed of 100~150 rpm for 0.5~2 h. After the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, the TPH content of the oily sludge is determined by the weight method, and then the TPH removal rate is calculated, and the four components of crude oil are determined by the stepwise solvent extraction-chromatographic column method.

[0025] In the following examples, the mass ratio of emulsifier to main monomer is 3:1000, and the mass ratio of initiator ammonium persulfate to main monomer is 5:1000. The “%” not explicitly stated in the present application refers to mass percentage.

[0026] Example 1: Preparation of macromolecular surfactant: the main monomer acrylamide and the hydrophilic monomer 2-acrylamido-2-methylpropanesulfonic acid are mixed in deionized water according to a mass ratio of 6:3, the pH of the solution is adjusted to 8.0, the emulsifier sodium dodecyl sulfate is added, and after stirring until completely dissolved, the hydrophobic monomer hexadecyl methacrylate is added, and the mass ratio of the main monomer acrylamide to hexadecyl methacrylate is 6:1; nitrogen is introduced to purge and deoxidize the system, and then the initiator ammonium persulfate is slowly added dropwise, and after the dropwise addition is completed, stirring is continued for 30 min; after the stirring is completed, the system is controlled to be heated to a reaction temperature of 80℃, and stirring is carried out for 6 h; after the reaction is completed, the product is collected, and the product is dried at 50℃ for 25 h to obtain the macromolecular surfactant HMPAM. The yield of HMPAM is more than 92%.

[0027] Preparation of macromolecule / small molecule composite surfactant: HMPAM and TX100 are compounded according to a mass ratio of 2:1 to obtain the macromolecule / small molecule composite surfactant.

[0028] Cleaning oily sludge: Take 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt, and place it in a reaction container. Add 600 g of the above-prepared macromolecular / small molecular complex surfactant, 600 g of sodium silicate, and 200 L of water. Then clean at 75°C and 120 rpm for 1 h. After the reaction is complete, collect the soil solids by centrifugal separation and air dry naturally. The TPH removal rate in the oily sludge is 84.5% by weight method, and the removal rates of gum and asphaltene are 89.5% and 91.2%, respectively, by stepwise solvent extraction-chromatographic column method.

[0029] Example 2: Preparation of macromolecular surfactant: First, weigh the main monomer acrylamide and the hydrophilic monomer 2-acrylamido-2-methylpropanesulfonic acid in a mass ratio of 6:2, add deionized water for mixing, and adjust to weak alkaline pH=7.0; Then, add the emulsifier, stir until completely dissolved, and then add the hydrophobic monomer dodecyl methacrylate; wherein the mass ratio of emulsifier to main monomer is 3:1000; the mass ratio of main monomer acrylamide to dodecyl methacrylate is 6:0.5; Next, purge the system with nitrogen to remove oxygen, then slowly add the initiator ammonium persulfate, and the mass ratio of initiator ammonium persulfate to main monomer is 5:1000. After the addition is complete, continue stirring for 30 min; After the stirring is completed, the system is warmed to 80°C, and the reaction is carried out under stirring for 6 h. After the reaction is complete, the product is collected and dried at 50°C for 25 h to obtain the macromolecular surfactant HMPAM.

[0030] Preparation of macromolecular / small molecular complex surfactant: Compound HMPAM and TX100 in a mass ratio of 2:1 to obtain the macromolecular / small molecular complex surfactant.

[0031] Cleaning of oily sludge: Take 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt, and place it in a reaction container. Add 600 g of the above-prepared macromolecular / small molecular complex surfactant, 600 g of sodium silicate, and 200 L of water. Then clean at 75°C and 120 rpm for 1 h. After the reaction is complete, collect the soil solids by centrifugal separation and air dry naturally. The TPH removal rate in the oily sludge is 84.5% by weight method, and the removal rates of gum and asphaltene are 89.5% and 91.2%, respectively, by stepwise solvent extraction-chromatographic column method.

[0032] Example 3: The process of preparing the macromolecular surfactant of the present example is the same as that of Example 2, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and methacrylic acid tetradecyl ester is 6:1:1.

[0033] Preparation of macromolecule / small molecule complex surfactant: HMPAM and TX100 are compounded according to a mass ratio of 2:1 to obtain a macromolecule / small molecule complex surfactant.

[0034] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt is placed in a reaction container, 600 g of the prepared macromolecule / small molecule complex surfactant is added, 600 g of sodium silicate is added, and 200 L of water is added. Subsequently, cleaning is performed at 75°C and 120 rpm for 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 72.5%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 78.3% and 80.7% respectively.

[0035] Example 4: The process of preparing the macromolecular surfactant of the present example is the same as that of Example 2, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and methacrylic acid tetradecyl ester is 6:1:1.

[0036] Preparation of macromolecule / small molecule complex surfactant: HMPAM and TX100 are compounded according to a mass ratio of 2:1 to obtain a macromolecule / small molecule complex surfactant.

[0037] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt is placed in a reaction container, 600 g of the prepared macromolecule / small molecule complex surfactant is added, 600 g of sodium silicate is added, and 200 L of water is added. Subsequently, cleaning is performed at 75°C and 120 rpm for 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 72.5%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 78.3% and 80.7% respectively.

[0038] Example 5: The process of preparing the macromolecular surfactant of the present example is the same as that of Example 1, except that the hydrophobic monomer is methacrylic acid octadecyl ester, and the pH of the solution is adjusted to 6.0.

[0039] Preparation of macromolecule / small molecule complex surfactant: HMPAM and TX100 were mixed according to a mass ratio of 1:1 to obtain a macromolecule / small molecule complex surfactant.

[0040] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the prepared macromolecule / small molecule complex surfactant, 600 g of sodium silicate, and 200 L of pure water were added. Subsequently, cleaning was performed at 75°C and 120 rpm for 1 h. After the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 86.9% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 89.2% and 91.7%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0041] Example 6: In this example, the process of preparing the macromolecular surfactant was the same as that in Example 4, except that the macromolecule / small molecule complex surfactant was prepared by mixing HMPAM and TX100 according to a mass ratio of 3:1.

[0042] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the prepared macromolecule / small molecule complex surfactant, 600 g of sodium silicate, and 200 L of pure water were added. Subsequently, cleaning was performed at 75°C and 120 rpm for 1 h. After the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 82.7% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 85.5% and 90.6%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0043] Example 7: In this example, the process of preparing the macromolecular surfactant was the same as that in Example 1, except that the macromolecule / small molecule complex surfactant was prepared by mixing HMPAM and TX100 according to a mass ratio of 5:1.

[0044] The oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the macromolecular / small molecular composite surfactant prepared above was added, 600 g of sodium silicate was added, and 200 L of water was added. Subsequently, washing was performed at 75°C and 120 rpm for 1 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 78.7% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 83.1% and 86.5%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0045] Example 8 The macromolecular surfactant was prepared in the same manner as in Example 1, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and methyl methacrylate was 10:2:1, and the pH of the solution was adjusted to 7.0.

[0046] The macromolecular / small molecular composite surfactant was prepared by compounding HMPAM and TX100 at a mass ratio of 10:1.

[0047] The oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the macromolecular / small molecular composite surfactant prepared above was added, 600 g of sodium silicate was added, and 200 L of water was added. Subsequently, washing was performed at 75°C and 120 rpm for 1 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 78.7% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 83.1% and 86.5%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0048] Example 9 The macromolecular surfactant was prepared in the same manner as in Example 1, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and methyl methacrylate was 10:2:1, and the pH of the solution was adjusted to 7.0.

[0049] Example 10: The process of preparing the macromolecular surfactant and the macromolecule / small molecule composite surfactant in this example is the same as that in Example 1, except that the process of cleaning the oily sludge is as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt is placed in a reaction container, 1000 g of the macromolecule / small molecule composite surfactant prepared above is added, 600 g of sodium silicate is added, and 200 L of pure water is added. Then, cleaning is carried out at 75°C and 120 rpm for 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 87.9%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 90.8% and 93.9%, respectively.

[0050] Example 11 The process of preparing the macromolecular surfactant in this example is the same as that in Example 2, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and octadecyl methacrylate is 5:2:1, and the pH of the solution is adjusted to 7.5.

[0051] Preparation of macromolecule / small molecule composite surfactant: HMPAM and TX100 are compounded according to a mass ratio of 2:1 to obtain a macromolecule / small molecule composite surfactant.

[0052] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt is placed in a reaction container, 600 g of the macromolecule / small molecule composite surfactant prepared above is added, 600 g of sodium silicate is added, and 200 L of pure water is added. Then, cleaning is carried out at 50°C and 100 rpm for 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 88.3%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 90.5% and 92.1%, respectively.

[0053] Example 12 The process of preparing the macromolecular surfactant and the macromolecule / small molecule composite surfactant in this example is the same as that in Example 11, except that the pH of the solution is adjusted to 6.0.

[0054] The oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the macromolecular / small molecular composite surfactant prepared above was added, 600 g of sodium silicate was added, and 200 L of pure water was added. Subsequently, washing was performed at 90°C and 150 rpm for 1 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 89.7% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 91.6% and 94.2%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0055] Example 13 In this example, the macromolecular surfactant was prepared in the same manner as in Example 2, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and methacrylic acid octadecyl ester was 5:2:1, and the solution pH was adjusted to 7.5.

[0056] Preparation of macromolecular / small molecular composite surfactant: HMPAM and TX100 were compounded in a mass ratio of 2:1 to obtain a macromolecular / small molecular composite surfactant.

[0057] The oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction container, 600 g of the macromolecular / small molecular composite surfactant prepared above was added, 600 g of sodium silicate was added, and 200 L of pure water was added. Subsequently, washing was performed at 75°C and 120 rpm for 0.5 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was 83.3% as calculated by the gravimetric method, and the removal rates of colloid and asphaltene were 86.7% and 90.1%, respectively, as measured by the stepwise solvent extraction-chromatographic column method.

[0058] Example 14 In this example, the macromolecular surfactant was prepared in the same manner as in Example 2, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, and methacrylic acid octadecyl ester was 5:2:1, and the solution pH was adjusted to 8.0.

[0059] Preparation of macromolecular / small molecular composite surfactant: HMPAM and TX100 were compounded in a mass ratio of 2:1 to obtain a macromolecular / small molecular composite surfactant.

[0060] The oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction vessel, 600 g of the above-prepared macromolecular / small-molecule composite surfactant was added, 600 g of sodium silicate was added, and 200 L of pure water was added. Subsequently, washing was performed at 75°C and 120 rpm for 2 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was calculated to be 84.4% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 89.5% and 93.1%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0061] Example 15 The macromolecular surfactant and the macromolecular / small-molecule composite surfactant were prepared as in Example 14, except that the oily sludge was washed as follows: 10 kg of oily sludge with an oil content of 20%wt and a water content of 45%wt was placed in a reaction vessel, 600 g of the above-prepared macromolecular / small-molecule composite surfactant was added, 600 g of sodium silicate was added, and 200 L of water was added. Subsequently, washing was performed at 75°C and 120 rpm for 1 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was calculated to be 80.9% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 87.7% and 89.2%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0062] Example 16 The macromolecular surfactant and the macromolecular / small-molecule composite surfactant were prepared as in Example 1, except that the macromolecular / small-molecule composite surfactant was first mixed with water to obtain a composite surfactant solution with a concentration of 1 g / L, and the volume ratio of the composite surfactant solution to the mass of the oily sludge was 20 L:1 kg. Then, the composite surfactant solution was added to the oily sludge with an oil content of 15%wt for washing. The washing conditions were as follows: a washing temperature of 75°C, a rotation speed of 120 rpm, and a washing time of 1 h. After the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was calculated to be 75.3% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 82.9% and 85.9%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0063] Example 17 The preparation process of the macromolecular surfactant and the macromolecule / small molecule composite surfactant in this example is the same as that in Example 1, except that the macromolecule / small molecule composite surfactant is first mixed with water to obtain a composite surfactant solution with a concentration of 5 g / L, and then the composite surfactant solution is added to the oily sludge with an oil content of 15%wt for cleaning, and the volume ratio of the composite surfactant solution to the mass of the oily sludge is 20 L:1 kg; the cleaning conditions are: cleaning temperature 75°C, rotation speed 120 rpm, cleaning time 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, and the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 85.1%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 90.6% and 91.5%, respectively.

[0064] Example 18: The preparation process of the macromolecular surfactant in this example is the same as that in Example 1, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and methacrylic acid octadecyl ester is 8:2:1, and the solution pH is adjusted to 7.0.

[0065] Preparation of macromolecule / small molecule composite surfactant: HMPAM and Tween 60 are compounded in a mass ratio of 2:1 to obtain a macromolecule / small molecule composite surfactant.

[0066] Cleaning of oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt is placed in a reaction container, 600 g of the above-prepared macromolecule / small molecule composite surfactant is added, 600 g of sodium silicate is added, and 200 L of water is added. Subsequently, it is cleaned at 75°C and 120 rpm for 1 h, after the reaction is completed, the soil solid is collected by centrifugal separation and naturally air-dried, and the TPH removal rate in the oily sludge is calculated by the gravimetric method to be 84.9%, and the removal rates of colloid and asphaltene are measured by the stepwise solvent extraction-chromatographic column method to be 89.5% and 92.3%, respectively.

[0067] Example 19: The preparation process of the macromolecular surfactant in this example is the same as that in Example 1, except that the mass ratio of acrylamide, 2-acrylamido-2-methylpropanesulfonic acid and methacrylic acid hexadecyl ester is 6:2:1, and the solution pH is adjusted to 7.0.

[0068] Preparation of macromolecule / small molecule composite surfactant: HMPAM and Tween 80 are compounded in a mass ratio of 2:1 to obtain a macromolecule / small molecule composite surfactant.

[0069] Washing oily sludge: 10 kg of oily sludge with an oil content of 15%wt and a water content of 45%wt was placed in a reaction vessel, 600 g of the above-prepared macromolecular / small-molecular composite surfactant was added, 600 g of sodium silicate was added, and 200 L of water was added. Subsequently, washing was carried out at 75°C and 120 rpm for 1 h, and after the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was calculated to be 85.5% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 90.4% and 91.2%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0070] Example 20: The macromolecular surfactant preparation and the macromolecular / small-molecular composite surfactant preparation in this example were the same as in Example 5, except that HMPAM and TX100 were compounded in a mass ratio of 2:1, the macromolecular / small-molecular composite surfactant was first mixed with water to obtain a composite surfactant solution with a concentration of 3 g / L, and then the composite surfactant solution was added to oily sludge with an oil content of 15%wt for washing, with a volume ratio of composite surfactant solution to oily sludge of 20 L:1 kg. The washing conditions were: washing temperature 75°C, rotation speed 120 rpm, washing time 1 h. After the reaction was completed, the soil solids were collected by centrifugal separation and naturally air-dried. The TPH removal rate in the oily sludge was calculated to be 87.5% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 89.5% and 93.2%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0071] Comparative Example 1: The steps for preparing the macromolecular surfactant in this comparative example were the same as in Example 4, except that the hydrophobic monomer was octyl methacrylate and the hydrophilic monomer was sodium a-olefin sulfonate.

[0072] The process for preparing the macromolecular / small-molecular composite surfactant and washing oily sludge was the same as in Example 4. The difference was that the hydrophilic monomer and the hydrophobic monomer used to prepare the macromolecular surfactant were different. The TPH removal rate in the oily sludge was calculated to be 45.6% by the gravimetric method, and the removal rates of colloid and asphaltene were measured to be 32.3% and 40.5%, respectively, by the stepwise solvent extraction-chromatographic column method.

[0073] Comparative Example 2: The steps for preparing the macromolecular surfactant in this comparative example were the same as in Example 4, except that the hydrophobic monomer was hexyl methacrylate and the hydrophilic monomer was sodium a-olefin sulfonate.

[0074] The preparation of the macromolecule / small molecule complex surfactant and the process of cleaning the oily sludge are the same as those in Example 4. The difference lies in that the hydrophilic monomer and the hydrophobic monomer used for preparing the macromolecule surfactant are different. The removal rate of TPH in the oily sludge is 40.1% by weight calculation, and the removal rates of colloid and asphaltene are 28.8% and 33.7% respectively by the step-by-step solvent extraction-chromatographic column method.

[0075] Comparative Example 3 The preparation of the macromolecule surfactant in the present comparative example is the same as that in Example 4, except that the hydrophobic monomer is octyl methacrylate.

[0076] The preparation of the macromolecule / small molecule complex surfactant and the process of cleaning the oily sludge are the same as those in Example 4. The difference lies in that the hydrophilic monomer and the hydrophobic monomer used for preparing the macromolecule surfactant are different. The removal rate of TPH in the oily sludge is 40.1% by weight calculation, and the removal rates of colloid and asphaltene are 28.8% and 33.7% respectively by the step-by-step solvent extraction-chromatographic column method.

[0077] Under the same conditions, the macromolecule surfactant prepared in Example 4 has a better effect on cleaning the oily sludge than the macromolecule surfactants prepared in Comparative Examples 1-3 when combined with the small molecule surfactant. The removal rate of TPH in the example is stably above 65%, and the removal rate of heavy components (colloid and asphaltene) also breaks through 70%. The present application has a more obvious effect on cleaning heavy components.

[0078] The unmentioned parts of the present application are applicable to the prior art.

Claims

1. A macromolecular / small molecule composite surfactant for enhancing the cleaning of oily sludge, characterized in that, A macromolecular surfactant is obtained by a free radical polymerization reaction with acrylamide as a main monomer, 2-acrylamido-2-methylpropanesulfonic acid as a hydrophilic monomer, and a long-chain alkyl methacrylate as a hydrophobic monomer; the macromolecular surfactant and a non-ionic surfactant are prepared according to a mass ratio of 1:1-10:1 to obtain the macromolecule / small molecule composite surfactant.

2. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 1, characterized by, In the preparation process of the macromolecular surfactant, the mass fraction of acrylamide in the total monomers is 60%-80%, the mass fraction of 2-acrylamido-2-methylpropanesulfonic acid in the total monomers is 10%-30%, and the mass fraction of the long-chain alkyl methacrylate in the total monomers is 5%-20%, and the total monomers are the sum of the main monomer, the hydrophilic monomer and the hydrophobic monomer, and the total mass fraction of the three monomers is 100%.

3. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 1, characterized by, The structural formula of the macromolecular surfactant is: ， In the formula, x=60-70%, y=15-25%, z=5-15%, x+y+z=1, and a=10-16.

4. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 1, characterized by, The long-chain alkyl methacrylate is at least one of octadecyl methacrylate, dodecyl methacrylate, tetradecyl methacrylate or hexadecyl methacrylate; and the non-ionic surfactant is at least one of Triton 100, Tween 60 or Tween 80.

5. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 1, characterized by, The preparation process of the macromolecular surfactant is as follows: First, the main monomer acrylamide and the hydrophilic monomer 2-acrylamido-2-methylpropanesulfonic acid are weighed according to a mass ratio of 6:1-6:3, mixed in deionized water, and adjusted to weak alkalinity; Then, the hydrophobic monomer long-chain alkyl methacrylate is added after stirring to complete dissolution, wherein the mass ratio of the emulsifier to the main monomer acrylamide is 1:1000-10:1000, and the mass ratio of the main monomer acrylamide to the long-chain alkyl methacrylate is 6:0.5-6:2; Next, the system is purged and deoxygenated by nitrogen, and then the initiator ammonium persulfate is slowly added dropwise, and the mass ratio of the initiator ammonium persulfate to the main monomer acrylamide is 3:1000-9:1000, and after the dropwise addition is completed, the stirring is continued for 25-40 min; After the stirring is completed, the system is heated to 60-90℃, and the reaction is carried out under stirring for 4-6 h, and after the reaction is completed, the product is collected and dried at 30-80℃ for 20-36 h to obtain the macromolecular surfactant HMPAM.

6. The macromolecule / low molecule complex surfactant for enhanced washing of oil sludge according to any one of claims 1 to 5, characterized by, The macromolecule / small molecule composite surfactant is used for cleaning oily sludge.

7. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 6, characterized by, The process for using the macromolecule / small molecule composite surfactant to clean oily sludge is as follows: oily sludge with an oil content of 15%wt-20%wt is taken into a reactor, and the macromolecule / small molecule composite surfactant and water are added for cleaning, wherein the mass ratio of the composite surfactant to the oily sludge is 1:100-10:100, the cleaning temperature is 50-90℃, the rotation speed is 100-150 rpm, and the cleaning time is 0.5-2 h. Or the macromolecule / small molecule complex surfactant is first mixed with water to obtain a complex surfactant solution with a concentration of 1-5 g / L, and then the complex surfactant solution is added to the oily sludge with an oil content of 15%-20% wt for cleaning, and the cleaning conditions are as follows: a cleaning temperature of 50-90 ℃, a rotating speed of 100-150 rpm, and a cleaning time of 0.5-2 h.

8. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 7, characterized by, During the cleaning process, an additive is added, and the additive is at least one of sodium carbonate, sodium bicarbonate or sodium silicate, and the additive is added in an amount of 1-5 g / L.

9. The macromolecule / low molecule complex surfactant for enhanced cleaning of oil sludge according to claim 7, characterized by, After the oily sludge is cleaned, the total petroleum hydrocarbon removal rate in the oily sludge is calculated by using the gravimetric method, and the removal rates of resin and asphaltene are measured by using the stepwise solvent extraction-chromatographic column method; the total petroleum hydrocarbon removal rate is stably controlled at more than 65%, and the removal rates of heavy components including resin and asphaltene are controlled at more than 70%.

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