A cleaning agent for treating oily sludge, its preparation method and application

Abstract

This invention belongs to the field of environmental protection technology, specifically relating to a cleaning agent for treating oily sludge, its preparation method, and its application. The preparation method includes: a first substitution reaction of bis(3-trimethoxysilylpropyl)amine and a first epoxy halopropane in DMF to obtain an oiliness enhancer; a second substitution reaction of disodium 1,4-piperazine diethanesulfonate and a second epoxy halopropane in DMF to obtain a wateriness enhancer; and a first etherification reaction of sophorolipid with the oiliness enhancer in DMF, followed by a second etherification reaction with the wateriness enhancer to obtain the cleaning agent. The cleaning agent of this invention has the advantages of low dosage, good cleaning effect, and low oil content in the aqueous phase after cleaning.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection technology, specifically relating to a cleaning agent for treating oily sludge, its preparation method, and its application. Background Technology

[0002] Oily sludge is a hazardous waste generated during the extraction, refining, transportation, and storage of petroleum products, and its sources are widespread. During oil extraction, drilling mud and oily sludge discharged during well maintenance and cleaning accumulate continuously. Refineries also generate large amounts of oily sludge during crude oil processing, such as electrostatic desalting and dehydration, and tank cleaning. Furthermore, oily sludge is formed during the transportation and storage of petroleum products due to tank cleaning, leaks, and other accidents. This oily sludge has a complex composition, and if discharged directly without effective treatment, it will not only cause serious pollution to soil, water, and air, disrupting the ecological balance, but also threaten human health and safety.

[0003] Currently, the main methods for treating oily sludge include incineration, landfill, biological treatment, pyrolysis, and chemical cleaning. While incineration can rapidly remove oil, it is energy-intensive and produces large amounts of toxic and harmful gases, causing secondary pollution. Landfill requires significant land use, carries the risk of leakage, and places extremely high demands on landfill waterproofing, resulting in high treatment costs. Biological treatment utilizes microorganisms to degrade oil, which is environmentally friendly, but has a long treatment cycle, is greatly affected by environmental factors such as temperature and pH, and is ineffective for treating high-concentration oily sludge. Pyrolysis can recover some oil, but requires large equipment investments, operates under harsh conditions, and is prone to generating secondary pollutants.

[0004] Chemical cleaning, as a highly efficient and flexible treatment technology, breaks down the stable structure of oil sludge by adding cleaning agents, allowing oil to detach from the surface of solid particles and achieving oil-water separation. It has advantages such as high treatment efficiency, simple operation, and high oil recovery rate, and has become a research hotspot in recent years.

[0005] CN108298780A discloses a biological cleaning agent and its application method for treating oily sludge. Its active ingredient is monorhamnolipid, which has advantages such as being environmentally friendly, easy to prepare, and having a wide range of applications, including treating oily sludge generated during oil extraction, gathering, and refining processes. However, this method has a long treatment cycle, requires a large amount of cleaning agent, and has an oil washing efficiency of only 60%. After water washing, a large amount of oil remains on the surface of the mud and sand or is suspended in the aqueous phase, failing to meet the technical requirements for on-site application.

[0006] CN109179929A ​​discloses an oily sludge cleaning agent, comprising a primary cleaning agent and a secondary cleaning agent. The primary cleaning agent contains the following components: tea saponin, sodium silicate, fatty alcohol polyoxyethylene ether, and sodium bicarbonate; the secondary cleaning agent contains fatty alcohol polyoxyethylene ether and sodium bicarbonate. The primary cleaning agent is prepared by dissolving tea saponin, sodium silicate, fatty alcohol polyoxyethylene ether, and sodium bicarbonate in water. The secondary cleaning agent is prepared by dissolving fatty alcohol polyoxyethylene ether and sodium bicarbonate in water. This invention's oily sludge cleaning agent has high cleaning efficiency and low overall energy consumption. However, the cleaning process is relatively cumbersome, and the cleaning efficiency is only 80%, still failing to meet emission requirements for heavily polluted oily sludge. Summary of the Invention

[0007] This invention addresses the shortcomings of existing technologies by providing a cleaning agent for treating oily sludge, its preparation method, and its application. The cleaning agent of this invention has the advantages of requiring small dosage, achieving good cleaning results, and producing a low oil content in the aqueous phase after cleaning.

[0008] One objective of this invention is to disclose a method for preparing a cleaning agent for treating oily sludge. The preparation method includes: (1) a first substitution reaction of bis(3-trimethoxysilylpropyl)amine and a first epoxy halopropane in a first DMF to obtain an oiliness enhancer; (2) a second substitution reaction of disodium 1,4-piperazine diethanesulfonate and a second epoxy halopropane in a second DMF to obtain a wateriness enhancer; (3) a first etherification reaction of sophorolipid with the oiliness enhancer in a third DMF, followed by a second etherification reaction with the wateriness enhancer to obtain a cleaning agent.

[0009] The molecular structural formula of the oiliness enhancer is as follows:

[0010]

[0011] The molecular structural formula of the water-based reinforcing agent is as follows:

[0012] .

[0013] In this invention, preferably, the weight ratio of the first epoxy halide, the second epoxy halide, the disodium salt of 1,4-piperazine diethanesulfonate, the sophorose ester, and the di(3-trimethoxysilylpropyl)amine is 0.22-0.48:2.2-6:5-8:100-220:1.

[0014] More preferably, the weight ratio of the first epoxy halide, the second epoxy halide, the disodium salt of 1,4-piperazine diethanesulfonate, the sophorose ester and the di(3-trimethoxysilylpropyl)amine is 0.25-0.44:3-5:5.5-7.5:120-200:1.

[0015] In this invention, preferably, the epoxy halopropane is epichlorohydrin or epibromopropane.

[0016] In this invention, preferably, the weight ratio of the first DMF, the second DMF, the third DMF to di(3-trimethoxysilylpropyl)amine is 6-10:30-50:25-50:1.

[0017] In this invention, preferably, the temperature of the first substitution reaction is 60-90°C and the time is 2-6 hours.

[0018] In this invention, preferably, the temperature of the second substitution reaction is 80-100°C and the time is 6-24h.

[0019] In this invention, preferably, the temperature of the first etherification reaction is 70-90°C and the time is 1-4 hours.

[0020] In this invention, preferably, the temperature of the second etherification reaction is 70-90°C and the time is 2-6 hours.

[0021] According to a more specific preferred embodiment, the preparation method of the cleaning agent for treating oily sludge specifically includes the following steps:

[0022] (1) Di(3-trimethoxysilylpropyl)amine, first epoxy halopropane and first DMF are added to the first reactor to carry out the first substitution reaction, with triethylamine as an acid-binding agent. The reaction temperature is 60-90℃ and the time is 2-6h to obtain an oiliness enhancer.

[0023] (2) Add disodium salt of 1,4-piperazine diethanesulfonate, second epoxy halopropane and second DMF to the second reactor to carry out the second substitution reaction. The reaction temperature is 80-100℃ and the time is 6-24h to obtain the water-based reinforcing agent.

[0024] (3) Add the third DMF and sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor to carry out the first etherification reaction, the reaction temperature is 70-90℃ and the time is 1-4h; add the mixture from the second reactor to carry out the second etherification reaction, the reaction temperature is 70-90℃ and the time is 2-6h, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0025] Preferably, the weight ratio of triethylamine to di(3-trimethoxysilylpropyl)amine is 1-2:1.

[0026] Secondly, the present invention discloses a cleaning agent for treating oily sludge prepared by the above preparation method.

[0027] Thirdly, this invention discloses the application of the above-mentioned cleaning agent in the treatment of oily sludge.

[0028] The cleaning agent for treating oily sludge of the present invention is a composite surfactant obtained by chemically modifying the nonionic biosurfactant sophorolipid. Based on sophorolipid, an oil-containing siloxane lipophilic group is introduced, which can quickly penetrate into the interior of the oily sludge. The sulfonic acid quaternary ammonium salt amphoteric surfactant is introduced, which can quickly strip the oil from the oily sludge and collect it on the surface of the aqueous solution. The present invention combines the advantages of chemical and biosurfactants, and is used in a lower amount and is environmentally friendly.

[0029] The beneficial effects and advantages of this invention compared with the prior art are as follows:

[0030] (1) The cleaning agent for treating oily sludge of the present invention has a good cleaning effect on oily sludge. When 150g and 200g of the aqueous solution (400mg / L) of the present invention are used to clean 40g of oily soil, the oil washing rate reaches up to 97% and 97.5% respectively.

[0031] (2) The cleaning agent of the present invention has a low oil content in the aqueous phase after cleaning the oily sludge. When 150g and 200g of the aqueous solution (400mg / L) of the present invention are used to clean 40g of oily soil, the oil content in the aqueous phase is as low as 17 and 16.5mg / L, respectively. Attached Figure Description

[0032] Figure 1 The reaction equation for preparing the oiliness enhancer of the present invention is as follows;

[0033] Figure 2 The reaction equation for preparing the water-based reinforcing agent of the present invention is as follows;

[0034] Figure 3 Comparison of 200g SDBS and 200g of oily sludge from Example 7. Detailed Implementation

[0035] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0036] The present invention will be further described below with reference to specific embodiments:

[0037] Example 1

[0038] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 1.1g of epichlorohydrin, 5g of triethylamine, and 30g of DMF to the first reactor, heat to 60°C, keep warm for 6h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0039] (2) Add 25g of disodium 1,4-piperazine diethanesulfonate, 11g of second epichlorohydrin and 150g of DMF to the second reactor, heat to 80°C, keep warm for 24h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0040] (3) Add 125g DMF and 500g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 70°C, keep the reaction temperature for 4h to carry out the first etherification reaction, add the mixture from the second reactor, heat to 70°C, keep the reaction temperature for 6h to carry out the second etherification reaction, and distill under reduced pressure to obtain the solid, which is the product cleaning agent.

[0041] Example 2

[0042] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 1.25g of epichlorohydrin, 7g of triethylamine, and 35g of DMF to the first reactor, heat to 60°C, keep warm for 5h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0043] (2) Add 40g of disodium 1,4-piperazine diethanesulfonate, 25g of second epichlorohydrin and 250g of DMF to the second reactor, heat to 80℃, keep warm for 24h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0044] (3) Add 250g DMF and 1100g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 75℃, keep the reaction temperature for 3h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 90℃, keep the reaction temperature for 2h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0045] Example 3

[0046] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 1.55g of epichlorohydrin, 7.5g of triethylamine, and 45g of DMF to the first reactor, heat to 90°C, keep warm for 2h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0047] (2) Add 30g of disodium 1,4-piperazine diethanesulfonate, 20g of epichlorohydrin, and 180g of DMF to the second reactor, heat to 90°C, keep warm for 12h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0048] (3) Add 180g DMF and 1000g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 80℃, keep the reaction temperature for 3h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 80℃, keep the reaction temperature for 4h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0049] Example 4

[0050] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 2.4g of first-epoxybromopropane, 10g of triethylamine, and 50g of DMF to the first reactor, heat to 80°C, keep warm for 3h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0051] (2) Add 35g of disodium 1,4-piperazine diethanesulfonate, 27.7g of second epoxide bromopropane and 232g of DMF to the second reactor, heat to 90℃, keep warm for 16h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0052] (3) Add 200g DMF and 910g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 90℃, keep the reaction temperature for 1h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 85℃, keep the reaction temperature for 5h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0053] Example 5

[0054] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 1.85g of first-epoxybromopropane, 9g of triethylamine, and 40g of DMF to the first reactor, heat to 70°C, keep warm for 4h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0055] (2) Add 30g of disodium 1,4-piperazine diethanesulfonate, 24g of second epoxide bromopropane and 214g of DMF to the second reactor, heat to 100℃, keep warm for 6h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0056] (3) Add 175g DMF and 820g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 90℃, keep the reaction temperature for 2h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 85℃, keep the reaction temperature for 4h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0057] Example 6

[0058] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 2.2g of first-epoxybromopropane, 9g of triethylamine, and 45g of DMF to the first reactor, heat to 80°C, keep warm for 3h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0059] (2) Add 35g of disodium 1,4-piperazine diethanesulfonate, 30g of second epoxide bromopropane and 198g of DMF to the second reactor, heat to 90℃, keep warm for 8h, carry out the second substitution reaction, and obtain the water-based reinforcing agent.

[0060] (3) Add 183g DMF and 730g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 88℃, keep the reaction temperature for 3h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 80℃, keep the reaction temperature for 4h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0061] Example 7

[0062] (1) Add 5g of di(3-trimethoxysilylpropyl)amine, 2.12g of epichlorohydrin, 10g of triethylamine, and 45g of DMF to the first reactor, heat to 80°C, keep warm for 4h, carry out the first substitution reaction, and obtain the oiliness enhancer.

[0063] (2) Add 33g of disodium 1,4-piperazine diethanesulfonate, 26.3g of epichlorohydrin and 204g of DMF to the second reactor, heat to 95°C, keep warm for 8h, carry out the second substitution reaction, and obtain the water-based reinforcing agent;

[0064] (3) Add 195g DMF and 635g sophorolipid to the third reactor, stir and slurry, add the mixture from the first reactor, heat to 90℃, keep the reaction temperature for 3h, carry out the first etherification reaction, add the mixture from the second reactor, heat to 88℃, keep the reaction temperature for 6h, carry out the second etherification reaction, and obtain the solid by vacuum distillation, which is the product cleaning agent.

[0065] Example 8: Evaluation of Cleaning Effect

[0066] The cleaning agent of this invention (Examples 1-7) was prepared with water at 55°C to a concentration of 400 mg / L. 40 g of soil (containing 13.8 wt% oil) spilled at an oil well in Shengli Oilfield was placed in a beaker, and 150 g and 200 g of the diluted cleaning agent of this invention were added. The mixture was stirred for 5 minutes, allowed to stand, and the cleaned soil was separated. The oil content was then tested. The oil washing rate (%) was calculated.

[0067] Oil washing rate η = (Soil oil content - Soil oil content after washing) / Soil oil content × 100%

[0068] The oil washing efficiencies of 150g and 200g of the cleaning agent of this invention are η1 and η2, respectively.

[0069] The test method was based on HJ 1051-2019, "Determination of Petroleum Carbonates in Soil - Infrared Spectrophotometry". The test results are shown in Table 1. A comparative experiment was conducted using sodium dodecylbenzenesulfonate (SDBS).

[0070] As can be seen from Table 1:

[0071] (1) When the cleaning agent of the present invention (Examples 1-7) is used at a concentration of 400 mg / L and a dosage of 150 g, it can clean 40 g of oily soil with an oil washing efficiency of 95% or more, and the highest efficiency is 97% (Example 6); while the oil washing efficiency of the comparative example sodium dodecylbenzene sulfonate (SDBS) is 53.8%, which is significantly lower than that of the present invention;

[0072] (2) When the cleaning agent of the present invention (Examples 1-7) is used at a concentration of 400 mg / L and a dosage of 200 g, it can clean 40 g of oily soil with an oil washing efficiency of 95.7% or higher, and the highest is 97.5% (Example 6); while the oil washing efficiency of the comparative example sodium dodecylbenzenesulfonate (SDBS) is 60.5%, which is significantly lower than that of the present invention.

[0073] Example 9 Oil content test of aqueous phase

[0074] The oil content of the intermediate aqueous phase of the sample from Example 8 was tested. 150g of the aqueous phase after cleaning according to the present invention contained oil C1, and 200g of the aqueous phase after cleaning according to the present invention contained oil C2. The test results are shown in Table 1. A comparative experiment was also conducted using sodium dodecylbenzenesulfonate (SDBS).

[0075] Table 1. Cleaning efficiency of cleaning agents and oil content in aqueous phase.

[0076] η1, % η2, % C1, mg / L C2, mg / L Example 1 95.4 96 17.3 17 Example 2 95 95.7 19.8 19.4 Example 3 95.1 96 18.8 18.2 Example 4 96.1 96.6 18 17.7 Example 5 96 96.6 17.6 17 Example 6 97 97.5 17 16.5 Example 7 96.7 97.2 17.2 16.8 SDBS 53.8 60.5 558 536

[0077] As can be seen from Table 1:

[0078] (1) When the cleaning agent of the present invention (Examples 1-7) was used at a concentration of 400 mg / L and a dosage of 150 g to clean 40 g of oily soil, the oil content in the aqueous phase was as low as 17 mg / L (Example 6); while the oil content in the aqueous phase of the comparative example sodium dodecylbenzenesulfonate (SDBS) was 558 mg / L, which was significantly higher than that of the present invention;

[0079] (2) When the cleaning agent of the present invention (Examples 1-7) was used at a concentration of 400 mg / L and a dosage of 200 g to clean 40 g of oily soil, the oil content in the aqueous phase was as low as 16.5 mg / L (Example 6); while the comparative example sodium dodecylbenzenesulfonate (SDBS) had an oil content of 536 mg / L in the aqueous phase, which was significantly higher than that of the present invention.

[0080] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a cleaning agent for treating oily sludge, characterized in that, The preparation method includes: (1) bis(3-trimethoxysilylpropyl)amine and a first epoxy halide undergo a first substitution reaction in a first DMF to obtain an oily strengthening agent; (2) disodium 1,4-piperazine diethanesulfonate and a second epoxy halide undergo a second substitution reaction in a second DMF to obtain an aqueous strengthening agent; (3) sophorolipid undergoes a first etherification reaction with the oily strengthening agent in a third DMF, and then undergoes a second etherification reaction with the aqueous strengthening agent to obtain a cleaning agent; The molecular structural formula of the oiliness enhancer is as follows: ； The molecular structural formula of the water-based reinforcing agent is as follows: ； The weight ratio of the first epoxy halide, the second epoxy halide, disodium 1,4-piperazine diethanesulfonate, sophoryl ester, and di(3-trimethoxysilylpropyl)amine is 0.22-0.48:2.2-6:5-8:100-220:

1.

2. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The weight ratio of the first epoxy halide, the second epoxy halide, disodium 1,4-piperazine diethanesulfonate, sophoryl ester, and di(3-trimethoxysilylpropyl)amine is as follows: 0.25-0.44：3-5：5.5-7.5：120-200：1。 3. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The epoxy halopropane is epichlorohydrin or epibromopropane.

4. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The weight ratio of the first DMF, second DMF, and third DMF to di(3-trimethoxysilylpropyl)amine is 6-10:30-50:25-50:

1.

5. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The temperature of the first substitution reaction is 60-90℃, and the time is 2-6h.

6. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The second substitution reaction is carried out at a temperature of 80-100℃ for 6-24 hours.

7. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The temperature of the first etherification reaction is 70-90℃ and the time is 1-4h.

8. The method for preparing the cleaning agent for treating oily sludge according to claim 1, characterized in that, The second etherification reaction is carried out at a temperature of 70-90℃ for 2-6 hours.

9. A cleaning agent for treating oily sludge prepared by the preparation method according to any one of claims 1-8.

10. The application of the cleaning agent as described in claim 9 in the treatment of oily sludge.

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