A method for treating oil sludge / oil sand

Abstract

This invention belongs to the field of petrochemical and solid waste resource utilization technology, specifically relating to a method for treating oil sludge / oil sand. This invention creatively proposes a highly efficient separation method for oil sludge / oil sand based on pre-wetting with a surfactant-infused oil solution combined with water rinsing. In this invention, the oil sludge / oil sand is wetted with an oil solution pre-dissolved with a surfactant, significantly promoting the directional adsorption of the surfactant at the particle-oil phase interface and effectively reducing the adhesion work at the solid-oil interface. After the addition of an aqueous phase, driven by the interphase chemical potential difference and synergistic weak shearing action, the oil phase attached to the particle surface separates from the particles in the form of oil droplets. This invention not only achieves a high crude oil / asphalt recovery rate with a residual oil content of less than 0.5 wt% in the treated particles, but also yields high-quality recovered crude oil / asphalt, with a residual solid content of approximately 0.5 wt%, achieving the goal of "no oil in sand and no sand in oil," and has broad prospects for industrial application.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical and solid waste resource utilization technology, specifically relating to a method for treating oil sludge / oil sand. Background Technology

[0002] Oil sludge / oil sands is a complex three-phase system composed of crude oil / bitumen, water, and solid particles. The safe treatment and resource utilization of oil sludge, as well as the efficient extraction of oil sands, are of great significance in terms of energy security, economic benefits, and environmental protection. Conventional crude oil extraction, transportation, storage, and refining processes generate large amounts of crude oil sludge. Statistics show that oil sludge contains approximately 10-30% crude oil, which, if properly treated, can become an important energy supplement. More importantly, oil sludge has been classified as hazardous waste (No. HW08), and untreated oil sludge will cause serious pollution to soil, water, and the atmosphere. Furthermore, unconventional oil and gas resources, represented by Canadian oil sands, are a crucial pillar of the global energy structure, with oil sands production accounting for over 70% of Canada's total crude oil production. Therefore, overcoming the challenge of efficiently separating this three-phase system has become a research focus in the petroleum, petrochemical, and solid waste treatment fields.

[0003] Currently, the main processes for treating oil sludge / oil sands include hot alkaline water extraction, solvent extraction, and surfactant washing. In the commercial mining of Canadian oil sands, the hot alkaline water process is primarily used. This involves heating (50°C) and creating an alkaline environment to break down the bonds between bitumen and particles, followed by aeration flotation to recover the bitumen foam. However, the bitumen product produced by this process, known as bitumen foam, still contains 30% water and 10% solid particles, requiring secondary processing with solvents such as naphtha and n-heptane. Solvent extraction is based on the principle of "like dissolves like." Existing technologies use volatile solvents such as n-heptane and cyclohexane to extract oil sludge, recovering the solvent through distillation. Other existing technologies add particulate dispersants to the solvent to release the asphaltene bound by aggregated particles. However, current solvent extraction technologies are limited by the toxicity risks of volatile solvents and high operating costs, making large-scale industrial application difficult.

[0004] Surfactant-aqueous solution cleaning mainly relies on the directional adsorption of surfactants at the oil-water-solid interface, thereby altering the surface wettability of solid particles and stabilizing desorbed oil droplets. For example, existing technologies disclose a composite surfactant cleaning system, but this process requires treatment at 40-60°C for up to 2 hours, resulting in high energy and time costs. Other existing technologies disclose an oil sludge treatment method combining pretreatment with a dodecylbenzenesulfonic acid (DBSA) n-heptane solution with surfactant-aqueous solution cleaning, but this method has technical limitations such as excessive solvent consumption and cumbersome operation procedures. Summary of the Invention

[0005] The purpose of this invention is to provide a method for treating oil sludge / oil sand.

[0006] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a method for treating oil sludge / oil sand, comprising the following steps: The material to be treated is immersed in a surfactant oil solution to obtain an immersion system; the surfactant oil solution includes a surfactant and an external oil phase; the material to be treated is oil sludge or oil sand. After mixing the wetting system with the aqueous phase, the mixture is separated to obtain a mixed oil phase, an aqueous phase, and a solid phase. When the material to be processed is oil sludge, the mixed oil phase is a mixture of external oil phase and crude oil, and the solid phase is the processed oil sludge; the mixed oil phase is distilled to recover the external oil phase and crude oil; When the material to be processed is oil sand, the mixed oil phase is a mixture of external oil phase and bitumen, and the solid phase is the processed oil sand; the mixed oil phase is distilled to recover the external oil phase and bitumen; The surfactant comprises a hydrophobic alkyl chain, an intermediate segment, and a hydrophilic head group, wherein the intermediate segment comprises at least one of a polyoxypropylene segment and a polyoxyethylene segment.

[0007] Preferably, the hydrophobic alkyl chain has 10 to 20 carbon atoms and includes straight chains or isomer chains; The surfactant contains 1 to 20 polyoxypropylene segments. The surfactant contains 1 to 15 polyoxyethylene segments.

[0008] Preferably, the surfactant comprises at least one of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxypropylene polyoxyethylene ether, fatty alcohol polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether sulfonate, fatty alcohol polyoxyethylene ether phosphate, fatty alcohol polyoxypropylene ether sulfate, fatty alcohol polyoxypropylene ether sulfonate, fatty alcohol polyoxypropylene ether phosphate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfonate, and fatty alcohol polyoxypropylene ether polyoxyethylene ether phosphate.

[0009] Preferably, the fatty alcohol polyoxyethylene ether is lauryl alcohol polyoxyethylene ether AEO9; The fatty alcohol polyoxypropylene polyoxyethylene ether is a C16-C18 fatty alcohol polyoxyethylene polyoxypropylene ether. 16- 18 P6E9; The fatty alcohol polyoxyethylene ether carboxylic acid is oleyl alcohol polyoxyethylene ether carboxylic acid C.18:1 E5C; The fatty alcohol polyoxyethylene ether carboxylate is sodium oleyl alcohol polyoxyethylene ether carboxylate; the sodium oleyl alcohol polyoxyethylene ether carboxylate is C 18:1 E2C-Na or C 18:1 E5C-Na; The fatty alcohol polyoxypropylene ether carboxylate is lauryl polyoxypropylene ether carboxylate sodium C. 12 P5C-Na; The fatty alcohol polyoxyethylene ether sulfate is lauryl polyoxyethylene ether sulfate sodium C. 12 E3S; The fatty alcohol polyoxypropylene ether sulfate is lauryl polyoxypropylene ether sodium sulfate C. 12 P4S.

[0010] Preferably, the oil sludge / oil sand has an oil content of 5-30 wt%, a solid content of 50-95 wt%, and a water content of 0-20 wt%.

[0011] Preferably, the external oil phase includes at least one of kerosene, toluene, cyclohexane, cyclopentane, C7-C16 n-alkanes, and naphtha; The concentration of the surfactant in the surfactant oil solution is 0.01~0.5 mol / kg; The mass ratio of the oil sludge or oil sand to the surfactant oil solution is 1:4 to 10:1.

[0012] Preferably, the impregnation is carried out under stirring conditions, wherein the stirring speed is 100~2000 rpm and the time is 1~60 min.

[0013] Preferably, the mass ratio of the oil sludge or oil sand to the aqueous phase is 1:4 to 2:1; The mixing is carried out under stirring conditions, with a stirring speed of 100~2000 rpm and a stirring time of 1~60 min.

[0014] Preferably, the separation method is centrifugal separation, and the centrifugal separation speed is 100~7000 rpm.

[0015] Preferably, the distillation is vacuum distillation; The pressure of the vacuum distillation is 10~50 kPa and the temperature is 50~120℃.

[0016] Compared with the prior art, the beneficial effects of the present invention include: To address the aforementioned bottlenecks in existing technologies, this invention creatively proposes a highly efficient separation method for oil sludge / oil sand based on pre-wetting with a surfactant-infused oil solution combined with water rinsing. In this invention, an oil solution pre-dissolved with surfactants is used to wet the oil sludge / oil sand, significantly promoting the directional adsorption of surfactants at the particle-oil phase interface and effectively reducing the adhesion work at the solid-oil interface. After the addition of an aqueous phase, driven by the interphase chemical potential difference and synergistic weak shearing action, the oil phase adhering to the particle surface separates from the particles in the form of oil droplets. The processing method provided by this invention has the following advantages: it not only achieves a high crude oil / asphalt recovery rate with a residual oil content of less than 0.5 wt% in the treated particles, but also yields high-quality recovered crude oil / asphalt, with a residual solid content of approximately 0.5 wt%, achieving the goal of "no oil in sand and no sand in oil," and has broad prospects for industrial application.

[0017] This invention utilizes surfactants containing polyoxypropylene and / or polyoxyethylene segments to effectively stabilize O / W emulsions while exhibiting good oil solubility. When the surfactant oil solution is mixed with oil sludge / oil sands, the oil solution rapidly dilutes the crude oil / asphalt in the sludge / oil sands, reducing its viscosity. During this process, the surfactant is directionally adsorbed at the "particle-oil phase" interface, significantly reducing interfacial tension. Upon addition of the aqueous phase for rinsing, under the combined action of the chemical potential gradient and weak shear force, the surfactant pre-dissolved in the oil phase rapidly diffuses into the aqueous phase, carrying bound crude oil / asphalt molecules across the oil-water interface, promoting the dispersion of the oil phase into the aqueous phase, ultimately achieving separation from the solid particles. After separation, particles free of crude oil / asphalt settle to the bottom, oil droplets float to the top, and the aqueous phase remains in the middle, achieving three-phase separation of oil, water, and solid. Furthermore, the processing method provided by this invention can be carried out at room temperature and can reduce the consumption of surfactants and solvents, which is beneficial for cost reduction and efficiency improvement. Attached Figure Description

[0018] Figure 1 The process flow for pre-wetting oil sludge / oil sand with surfactant oil solution provided in Example 1; Figure 2 The process flow for pre-wetting oil sludge / oil sand with pure oil phase provided for Comparative Example 1; Figure 3 The process flow for emulsion-type sludge / oil sand treatment provided for Comparative Example 2. Detailed Implementation

[0019] This invention provides a method for treating oil sludge / oil sand, comprising the following steps: The material to be treated is immersed in a surfactant oil solution to obtain an immersion system; the surfactant oil solution includes a surfactant and an external oil phase; the material to be treated is oil sludge or oil sand. After mixing the wetting system with the aqueous phase, the mixture is separated to obtain a mixed oil phase, an aqueous phase, and a solid phase. When the material to be processed is oil sludge, the mixed oil phase is a mixture of external oil phase and crude oil, and the solid phase is the processed oil sludge; the mixed oil phase is distilled to recover the external oil phase and crude oil; When the material to be processed is oil sand, the mixed oil phase is a mixture of external oil phase and bitumen, and the solid phase is the processed oil sand; the mixed oil phase is distilled to recover the external oil phase and bitumen; The surfactant comprises a hydrophobic alkyl chain, an intermediate segment, and a hydrophilic head group, wherein the intermediate segment comprises at least one of a polyoxypropylene segment and a polyoxyethylene segment.

[0020] The present invention involves immersing the material to be treated in a surfactant oil solution to obtain an immersion system.

[0021] In this invention, the oil (i.e., crude oil or bitumen) content of the oil sludge / oil sand is preferably 5-30 wt%, specifically 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, or 30 wt%; the solid content is preferably 50-95 wt%, specifically 50 wt%, 55 wt%, 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or 95 wt%; and the water content is preferably 0-20 wt%, specifically 0 wt%, 5 wt%, 10 wt%, 15 wt%, or 20 wt%. This invention does not impose any special limitations on the source of the oil sludge or oil sand; any source well known to those skilled in the art may be used.

[0022] In this invention, the surfactant oil solution comprises a surfactant and an external oil phase.

[0023] In this invention, the surfactant preferably comprises a hydrophobic alkyl chain, an intermediate segment, and a hydrophilic head group. The intermediate segment preferably comprises at least one of a polyoxypropylene segment and a polyoxyethylene segment. The hydrophobic alkyl chain preferably has 10 to 20 carbon atoms and preferably comprises a straight chain or an isomeric chain, specifically 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. The number of polyoxypropylene segments (PO) in the surfactant is preferably 1 to 20, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20. The number of polyoxyethylene segments (EO) in the surfactant is preferably 1 to 15, specifically 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15.

[0024] In this invention, the surfactant preferably comprises at least one of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxypropylene polyoxyethylene ether, fatty alcohol polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether sulfonate, fatty alcohol polyoxyethylene ether phosphate, fatty alcohol polyoxypropylene ether sulfate, fatty alcohol polyoxypropylene ether sulfonate, fatty alcohol polyoxypropylene ether phosphate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfonate, and fatty alcohol polyoxypropylene ether polyoxyethylene ether phosphate. In this invention, the fatty alcohol polyoxyethylene ether is preferably lauryl alcohol polyoxyethylene ether AEO9; the fatty alcohol polyoxypropylene polyoxyethylene ether is preferably C16-C18 fatty alcohol polyoxyethylene polyoxypropylene ether C... 16-18 P6E9; the fatty alcohol polyoxyethylene ether carboxylic acid is preferably oleyl alcohol polyoxyethylene ether carboxylic acid C. 18:1 E5C; the fatty alcohol polyoxyethylene ether carboxylate is preferably sodium oleyl alcohol polyoxyethylene ether carboxylate; sodium oleyl alcohol polyoxyethylene ether carboxylate is preferably C 18:1 E2C-Na or C 18:1 E5C-Na; the fatty alcohol polyoxypropylene ether carboxylate is preferably lauryl alcohol polyoxypropylene ether carboxylate sodium C 12 P5C-Na; the fatty alcohol polyoxyethylene ether sulfate is preferably lauryl alcohol polyoxyethylene ether sulfate sodium C 12 E3S; the fatty alcohol polyoxypropylene ether sulfate is preferably sodium lauryl alcohol polyoxypropylene ether sulfate C. 12 P4S.

[0025] In this invention, AEO9 and C 16-18 P6E9, C 12 P5C-Na, C 18:1 E5C, C 18:1 E2C-Na, C 18:1 E5C-Na, C 12 E3S and C 12 The structural formula of P4S is shown below: .

[0026] In this invention, the external oil phase preferably includes at least one selected from kerosene, toluene, cyclohexane, cyclopentane, C7-C16 n-alkanes, and naphtha; the concentration of the surfactant in the surfactant oil solution is preferably 0.01-0.5 mol / kg, specifically 0.01 mol / kg, 0.02 mol / kg, 0.05 mol / kg, 0.1 mol / kg, 0.15 mol / kg, 0.20 mol / kg, 0.25 mol / kg, 0.30 mol / kg, 0.35 mol / kg, 0.40 mol / kg, 0.45 mol / kg, or 0.5 mol / kg; the mass ratio of the oil sludge or oil sand to the surfactant oil solution is preferably 1:4-10:1, specifically 1:4, 1:3, 1:2, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, or 10:1.

[0027] In this invention, the impregnation is preferably carried out under stirring conditions, the stirring speed is preferably 100~2000 rpm, specifically 100 rpm, 500 rpm, 1000 rpm, 1500 rpm, 2000 rpm; the time is preferably 1~60 min, specifically 1 min, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min.

[0028] After obtaining the wetting system, the present invention mixes the wetting system with the aqueous phase and then separates them to obtain a mixed oil phase, an aqueous phase and a solid phase respectively.

[0029] In this invention, the mass ratio of the oil sludge or oil sand to the aqueous phase is preferably 1:4 to 2:1, specifically 1:4, 1:3, 1:2, 1:1, or 2:1; the mixing is preferably carried out under stirring conditions, the stirring speed is preferably 100 to 2000 rpm, specifically 100 rpm, 500 rpm, 1000 rpm, 1500 rpm, or 2000 rpm; the stirring time is preferably 1 to 60 min, specifically 1 min, 10 min, 20 min, 30 min, 40 min, 50 min, or 60 min.

[0030] In this invention, the separation method is preferably centrifugal separation, and the centrifugal separation speed is preferably 100~7000 rpm, specifically 100 rpm, 500 rpm, 1000 rpm, 2000 rpm, 3000 rpm, 4000 rpm, 5000 rpm, 6000 rpm, or 7000 rpm; the time is preferably 5~30 min, specifically 5 min, 10 min, 15 min, 20 min, 25 min, or 30 min.

[0031] In this invention, when the material to be treated is oil sludge, the mixed oil phase is a mixture of external oil phase and crude oil, and the solid phase is the treated oil sludge; the mixed oil phase is distilled to recover the external oil phase and crude oil; when the material to be treated is oil sand, the mixed oil phase is a mixture of external oil phase and asphalt, and the solid phase is the treated oil sand; the mixed oil phase is distilled to recover the external oil phase and asphalt.

[0032] In this invention, the distillation is preferably vacuum distillation; the pressure of the vacuum distillation is preferably 10~50 kPa, specifically 10 kPa, 20 kPa, 30 kPa, 40 kPa, or 50 kPa; the temperature is preferably 50~120℃, specifically 50℃, 60℃, 70℃, 80℃, 90℃, 100℃, 110℃, or 120℃. In this invention, vacuum distillation can separate the external oil phase from the asphalt (i.e., the oil phase in oil sands) or the external oil phase from the crude oil (i.e., the oil phase in oil sludge). In this invention, the separated aqueous phase is preferably recycled back to the system before separation as a raw material; the external oil phase recovered by vacuum distillation is preferably recycled back to the surfactant oil solution.

[0033] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0034] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] Example 1 according to Figure 1 The processing flow shown is as follows: (1) Pre-wetting: The surfactant sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) was dissolved in kerosene to prepare a surfactant oil solution with a concentration of 0.1 mol / kg; 0.5 g of the oil solution and 2 g of high-quality Canadian oil sand (oil content of 14 wt%, water content of 0 wt%, solid content of 86 wt%) were accurately weighed and placed in a sample bottle and stirred at 500 rpm for 10 min. (2) Cleaning: Add 8g of water to the mixture obtained in step (1) and continue stirring at 500rpm for 5min; (3) Phase separation and characterization: After stirring, the resulting mixture was centrifuged at 7000 rpm for 5 min to separate the diluted asphalt (i.e. the mixed oil phase), water and solid particles; Diluted asphalt was subjected to vacuum distillation at 10 kPa and 110°C to remove and recover kerosene. The Dean-Stark method was used to test the amount of solid particles and aqueous phase residue in the asphalt. Simultaneously, bottom particles were removed, and 4 g of aqueous phase was added to remove trace amounts of surface oil. After drying at 100°C, the residual oil content of the particles was tested using an infrared oil analyzer. The final test results of this embodiment are summarized in Table 1.

[0036] Comparative Example 1 according to Figure 2 The processing flow shown is as follows: (1) Pre-wetting: Weigh 0.5g of kerosene and 2g of high-grade Canadian oil sand (parameters refer to Example 1) and place them in a sample bottle. Stir at 500rpm for 10min to make them evenly mixed. (2) Cleaning: Sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) was pre-dissolved in 8g of water to prepare a surfactant aqueous solution with a concentration of 6.25mmol / kg (this concentration was set to ensure that the total amount of surfactant in the whole system was consistent with that in Example 1); then, the aqueous solution was added to the mixing system in step (1), and stirring was continued at 500rpm for 5min; (3) Phase separation and characterization: The mixture obtained in step (2) was centrifuged to obtain diluted asphalt, aqueous phase and solid particles; the specific operating conditions and the detection method of residual oil content in particles in this step were completely consistent with those in Example 1 above. The final test results of this comparative example are summarized in Table 1.

[0037] Comparative Example 2 according to Figure 3 The processing flow shown is as follows: (1) Emulsion preparation: Sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) was dissolved in kerosene to prepare a surfactant oil solution with a concentration of 0.1 mol / kg; then, 8 g of deionized water was added to 0.5 g of the above oil solution, and the mixture was stirred at 500 rpm for 10 min to prepare a homogeneous emulsion. (2) Cleaning: Weigh 2g of high-quality Canadian oil sand (parameters refer to Example 1) and place it in a sample bottle. Add the emulsion prepared in step (1) and stir at 500 rpm for 5 min. (3) Phase separation and characterization: The mixture obtained in step (2) was centrifuged to obtain diluted asphalt, aqueous phase and solid particles; the specific operating conditions and particle residual oil content detection methods of this step were completely consistent with those of Example 1 above. The final test results of this comparative example are summarized in Table 1.

[0038] Table 1 Comparison of relevant indicators after high-grade oil sand cleaning in Canada

[0039] The experimental results of Example 1 and Comparative Examples 1 and 2 show that, for high-grade Canadian oil sands, compared to the processes of pre-dissolving surfactants in the aqueous phase (Comparative Example 1) and emulsion washing (Comparative Example 2), the process of pre-dissolving surfactants in the oil phase for pre-wetting in Example 1 can reduce the residual oil content of the washed particles to below 0.5 wt%, meeting environmental emission standards. This comparative result proves that even if the total amount of surfactant and kerosene is exactly the same, the way the surfactant or oil phase is added will affect the separation of crude oil / asphalt from solid particles. Furthermore, Dean-Stark results show that the solid particle content in the recovered asphalt is only 0.57 wt%, and no water was detected, indicating the excellent quality of the recovered asphalt. The mechanism of effective separation of asphalt and particles is that when the oil phase pre-dissolved with surfactant comes into contact with water, the dual effects of interphase chemical potential difference and weak shear promote the emulsification of diluted asphalt, enhancing the separation of particles from diluted asphalt.

[0040] Example 2 The cleaning was performed in accordance with the method described in Example 1, except that the oil sand was replaced with low-grade Canadian oil sand (oil content 5 wt%, water content 4.5 wt%, solid content 90.5 wt%). The final test results of this example are summarized in Table 2.

[0041] Comparative Example 3 The cleaning process was carried out in accordance with Comparative Example 1, except that the oil sand was replaced with low-grade Canadian oil sand (oil content 5 wt%, water content 4.5 wt%, solid content 90.5 wt%). The final test results of this comparative example are summarized in Table 2.

[0042] Comparative Example 4 The cleaning process was carried out in accordance with Comparative Example 2, except that the oil sand was replaced with low-grade Canadian oil sand (oil content 5 wt%, water content 4.5 wt%, solid content 90.5 wt%). The final test results of this comparative example are summarized in Table 2.

[0043] Table 2 Comparison of relevant indicators after cleaning with low-grade oil sands in Canada

[0044] The experimental results of Examples 2 and Comparative Examples 3 and 4 show that the influence of the addition method of surfactant and oil phase on the residual oil content of particles is also applicable to low-grade Canadian oil sands. Compared with the processes of pre-dissolving surfactant in the aqueous phase (Comparative Example 3) and emulsion washing (Comparative Example 4), the process of pre-dissolving surfactant in the oil phase for pre-wetting in Example 2 reduces the residual oil content of particles after washing to below 0.5 wt%, meeting environmental emission standards. Furthermore, Dean-Stark results show that the solid particle content in the recovered asphalt is 1.52 wt%, and no water was detected, indicating that the process achieves good asphalt-particle separation. It is worth noting that compared with high-grade oil sands, the residual oil content of particles and the residual solid content of recovered asphalt are higher in Example 2, mainly because the low-grade oil sands have a higher content of fine particles. These fine particles easily combine with asphalt aggregates, increasing the difficulty of separating solid particles from asphalt.

[0045] Example 3 The cleaning was performed in accordance with the method of Example 1, except that the oil sand was replaced with Shengli oil sludge (oil content of 28wt%, water content of 15wt%, and solid content of 57wt%). At the same time, CO2 was introduced into the mixture obtained in step (2) before the centrifugation operation in step (3). The final test results of this example are summarized in Table 3.

[0046] Comparative Example 5 The cleaning process was carried out in accordance with Comparative Example 1, except that the oil sand was replaced with Shengli oil sludge (oil content 28 wt%, water content 15 wt%, solid content 57 wt%). Simultaneously, CO2 was introduced into the mixture obtained in step (2) before the centrifugation operation in step (3). The final test results of this comparative example are summarized in Table 3. Comparative Example 6 The cleaning process was carried out in accordance with Comparative Example 2, except that the oil sand was replaced with Shengli oil sludge (oil content 28 wt%, water content 15 wt%, solid content 57 wt%). Furthermore, CO2 was introduced into the mixture obtained in step (2) before the centrifugation operation in step (3). The final test results of this comparative example are summarized in Table 3.

[0047] Table 3 Comparison of relevant indicators after Shengli oilsand cleaning

[0048] The experimental results of Examples 3 and Comparative Examples 5 and 6 show that the influence of the method of adding surfactants and the oil phase on the residual oil content of particles is also applicable to Shengli oil sludge. Compared with the processes of pre-dissolving surfactants in the aqueous phase (Comparative Example 3) and emulsion washing (Comparative Example 4), the process of pre-dissolving surfactants in the oil phase for pre-wetting in Example 3 reduced the residual oil content of particles after washing to below 0.5 wt%, meeting environmental emission standards. Furthermore, Dean-Stark results showed that no solid particles or water were detected in the recovered crude oil, indicating that the process achieved good asphalt-particle separation. In this example and the comparative examples, centrifugation alone could not achieve effective separation of diluted crude oil and the aqueous phase. This is presumably due to the presence of surfactants added during the previous oil displacement process remaining in the oil sludge, thereby enhancing emulsion stability. Therefore, in these examples, CO2 was introduced to induce C 18:1 The responsive structural transformation of E2C-Na promotes the separation of diluted crude oil from the aqueous phase.

[0049] Example 4 The cleaning was performed in accordance with the method described in Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with sodium lauryl polyoxyethylene ether sulfate (C) 12 E3S). The final test results of this embodiment are summarized in Table 4.

[0050] Comparative Example 7 The cleaning was performed in accordance with the method described in Comparative Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with sodium lauryl polyoxyethylene ether sulfate (C) 12 E3S). The final test results for this comparative example are summarized in Table 4.

[0051] Comparative Example 8 The cleaning was performed in accordance with the method described in Comparative Example 2, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with sodium lauryl polyoxyethylene ether sulfate (C) 12 E3S). The final test results for this comparative example are summarized in Table 4.

[0052] Example 5 The cleaning was performed in accordance with the method described in Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with sodium lauryl polyoxypropylene sulfate (C 12 P4S). The final test results of this embodiment are summarized in Table 4.

[0053] Comparative Example 9 The cleaning was performed in accordance with the method described in Comparative Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1E2C-Na) is replaced with sodium lauryl polyoxypropylene sulfate (C 12 P4S). The final test results for this comparative example are summarized in Table 4.

[0054] Comparative Example 10 The cleaning was performed in accordance with the method described in Comparative Example 2, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with sodium lauryl polyoxypropylene sulfate (C 12 P4S). The final test results for this comparative example are summarized in Table 4.

[0055] Example 6 The cleaning was performed in accordance with the method described in Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with fatty alcohol polyoxypropylene polyoxyethylene ether (C 16-18 P6E9). The final test results of this embodiment are summarized in Table 4.

[0056] Comparative Example 11 The cleaning was performed in accordance with the method described in Comparative Example 1, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with fatty alcohol polyoxypropylene polyoxyethylene ether (C 16-18 P6E9). The final test results for this comparative example are summarized in Table 4.

[0057] Comparative Example 12 The cleaning was performed in accordance with the method described in Comparative Example 2, wherein sodium oleyl alcohol polyoxyethylene ether carboxylate (C 18:1 E2C-Na) is replaced with fatty alcohol polyoxypropylene polyoxyethylene ether (C 16-18 P6E9). The final test results for this comparative example are summarized in Table 4.

[0058] Table 4 Comparison of relevant indicators of different surfactants after cleaning with high-quality Canadian oil sands

[0059] The experimental results of Examples 4-6 and Comparative Examples 7-12 show that, for high-grade Canadian oil sands, this invention investigated various types of surfactants and obtained similar cleaning effects. Compared to the processes of pre-dissolving surfactants in the aqueous phase (Comparative Examples 7, 9, and 11) and emulsion cleaning (Comparative Examples 8, 10, and 12), the process of pre-dissolving surfactants in the oil phase and pre-wetting the oil phase used in Examples 4-6 reduced the residual oil content of the cleaned particles to below 0.5 wt%, meeting environmental emission standards. Furthermore, Dean-Stark results showed that the solid particle content in the recovered crude oil was consistently around 0.5 wt%, and no water was detected, indicating that the process achieved good bitumen-particle separation.

[0060] Comparative Example 13 The cleaning was performed in accordance with the method described in Example 1, without the addition of surfactant C. 18:1 E2C-Na, meaning pre-wetting with only pure kerosene. The final test results for this comparative example are summarized in Table 5.

[0061] Example 7 The cleaning was performed in accordance with the method described in Example 1, wherein the concentration of the surfactant oil solution was adjusted to 0.05 mol / kg during the pre-wetting process. The final test results of this example are summarized in Table 5.

[0062] Example 8 The cleaning was performed in accordance with the method described in Example 1, wherein the concentration of the surfactant oil solution was adjusted to 0.15 mol / kg during the pre-wetting process. The final test results of this example are summarized in Table 5.

[0063] Table 5. Effect of surfactant concentration on residual oil content in particles after washing with high-grade Canadian oil sands.

[0064] The experimental results of Examples 1, 7-8, and Comparative Example 13 show that for high-grade Canadian oil sands, if pre-wetting with pure kerosene followed by rinsing with water is used, the particle residue rate is as high as 5.31 wt%; however, when a surfactant oil solution with a concentration of only 0.05 mol / kg is used during pre-wetting, the particle residue rate drops instantly to 0.37 wt%. Furthermore, as the surfactant concentration increases, the residual oil content of the particles continues to decrease. This result confirms the crucial role of surfactants in the efficient removal of bitumen. Based on the experimental data, in practical industrial applications, only 5 kg of surfactant C is needed to treat 1 ton of oil sands. 18:1 E2C-Na can meet environmental emission standards, demonstrating the excellent economic feasibility and broad industrial prospects of this process.

[0065] Comparative Example 14 The cleaning was performed in accordance with the method described in Example 1, except that the amount of surfactant oil solution added was adjusted to 0.05 g. The final test results of this comparative example are summarized in Table 6.

[0066] Comparative Example 15 The cleaning was performed in accordance with the method described in Example 1, except that the amount of surfactant oil solution added was adjusted to 0.15 g. The final test results of this comparative example are summarized in Table 6.

[0067] Example 9 The cleaning was performed in accordance with the method described in Example 1, except that the amount of surfactant oil solution added was adjusted to 0.3g. The final test results of this example are summarized in Table 6.

[0068] Table 6. Effect of surfactant oil solution dosage on residual oil content in particles after washing with high-grade Canadian oil sands.

[0069] The experimental results of Examples 1 and 9, and Comparative Examples 14-15 show that, for high-grade Canadian oil sands, the particle residue rate gradually decreases with the increase of the amount of surfactant oil solution added during the pre-impregnation process. When 0.3 g of surfactant oil solution with a concentration of 0.1 mol / kg is added, the particle residue rate drops to below 0.5 wt%, meeting the environmental emission standards.

[0070] Example 10 The cleaning was performed in accordance with the method described in Example 1, except that during the pre-wetting process, the oil phase used to prepare the surfactant was replaced with n-heptane. The final test results of this example are summarized in Table 7.

[0071] Example 11 The cleaning was performed in accordance with the method described in Example 1, except that during the pre-wetting process, the oil phase used to prepare the surfactant was replaced with n-tetradecane. The final test results of this example are summarized in Table 7.

[0072] Example 12 The cleaning was performed in accordance with the method described in Example 1, except that during the pre-wetting process, the oil phase used to prepare the surfactant was replaced with naphtha. The final test results of this example are summarized in Table 7.

[0073] Table 7. Effect of surfactant oil solution oil phase type on residual oil content of particles after Canadian high-grade oil sand cleaning.

[0074] The experimental results of Examples 1 and 10-13 show that, for high-grade Canadian oil sands, when n-heptane, n-tetradecane, kerosene, or naphtha are used as the surfactant in the dissolved oil phase during pre-wetting, the residual oil content of the particles is less than 0.5 wt%. These results fully demonstrate that the process proposed in this invention has extremely wide applicability to various types of dissolved oil phases.

[0075] Comparative Example 16 The cleaning process was performed in accordance with Example 1, except that the water rinsing step was omitted; instead, the phase separation process was initiated directly after pre-impregnation and mixing, and solid particles and diluted asphalt were separated by centrifugation. The final test results of this comparative example are summarized in Table 8. Table 8. Effect of rinsing steps on residual oil content of particles after cleaning with high-quality Canadian oil sands.

[0076] The experimental results of Example 1 and Comparative Example 16 show that for high-grade Canadian oil sands, if only pre-wetting with a surfactant oil solution is performed without subsequent aqueous rinsing (Comparative Example 16), the residual oil content of the particles is as high as 4.15 wt%; however, when an aqueous rinsing step is added, the residual oil content of the particles instantly drops to 0.17 wt%. This comparative result fully demonstrates the importance of the water rinsing process in separating particles and bitumen.

[0077] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for treating oil sludge / oil sand, characterized in that, Includes the following steps: The material to be treated is immersed in a surfactant oil solution to obtain an immersion system; the surfactant oil solution includes a surfactant and an external oil phase; the material to be treated is oil sludge or oil sand. After mixing the wetting system with the aqueous phase, the mixture is separated to obtain a mixed oil phase, an aqueous phase, and a solid phase. When the material to be processed is oil sludge, the mixed oil phase is a mixture of external oil phase and crude oil, and the solid phase is the processed oil sludge; The mixed oil phase is distilled to recover the external oil phase and crude oil; When the material to be processed is oil sand, the mixed oil phase is a mixture of externally added oil phase and bitumen, and the solid phase is the processed oil sand; The mixed oil phase is distilled to recover the external oil phase and asphalt; The surfactant comprises a hydrophobic alkyl chain, an intermediate segment, and a hydrophilic head group, wherein the intermediate segment comprises at least one of a polyoxypropylene segment and a polyoxyethylene segment.

2. The processing method according to claim 1, characterized in that, The hydrophobic alkyl chain has 10 to 20 carbon atoms and includes straight chains or isomer chains; The surfactant contains 1 to 20 polyoxypropylene segments. The surfactant contains 1 to 15 polyoxyethylene segments.

3. The processing method according to claim 1, characterized in that, The surfactant includes at least one of fatty alcohol polyoxyethylene ether, fatty alcohol polyoxypropylene polyoxyethylene ether, fatty alcohol polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene ether carboxylic acid and its salt, fatty alcohol polyoxypropylene polyoxyethylene ether carboxylic acid and its salt, fatty alcohol polyoxyethylene ether sulfate, fatty alcohol polyoxyethylene ether sulfonate, fatty alcohol polyoxyethylene ether phosphate, fatty alcohol polyoxypropylene ether sulfate, fatty alcohol polyoxypropylene ether sulfonate, fatty alcohol polyoxypropylene ether phosphate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfate, fatty alcohol polyoxypropylene ether polyoxyethylene ether sulfonate, and fatty alcohol polyoxypropylene ether polyoxyethylene ether phosphate.

4. The processing method according to claim 3, characterized in that, The fatty alcohol polyoxyethylene ether is lauryl alcohol polyoxyethylene ether AEO9; The fatty alcohol polyoxypropylene polyoxyethylene ether is a C16-C18 fatty alcohol polyoxyethylene polyoxypropylene ether. 16-18 P6E9; The fatty alcohol polyoxyethylene ether carboxylic acid is oleyl alcohol polyoxyethylene ether carboxylic acid C. 18:1 E5C; The fatty alcohol polyoxyethylene ether carboxylate is sodium oleyl alcohol polyoxyethylene ether carboxylate; the sodium oleyl alcohol polyoxyethylene ether carboxylate is C 18:1 E2C-Na or C 18:1 E5C-Na; The fatty alcohol polyoxypropylene ether carboxylate is lauryl polyoxypropylene ether carboxylate sodium C. 12 P5C-Na; The fatty alcohol polyoxyethylene ether sulfate is lauryl polyoxyethylene ether sulfate sodium C. 12 E3S; The fatty alcohol polyoxypropylene ether sulfate is lauryl polyoxypropylene ether sodium sulfate C. 12 P4S.

5. The processing method according to claim 1, characterized in that, The oil sludge / oil sand has an oil content of 5-30 wt%, a solid content of 50-95 wt%, and a water content of 0-20 wt%.

6. The processing method according to claim 1, characterized in that, The external oil phase includes at least one of kerosene, toluene, cyclohexane, cyclopentane, C7-C16 n-alkanes, and naphtha; The concentration of the surfactant in the surfactant oil solution is 0.01~0.5 mol / kg; The mass ratio of the oil sludge or oil sand to the surfactant oil solution is 1:4 to 10:

1.

7. The processing method according to claim 1, characterized in that, The impregnation is carried out under stirring conditions, with a stirring speed of 100~2000 rpm and a time of 1~60 min.

8. The processing method according to claim 1, characterized in that, The mass ratio of the oil sludge or oil sand to the aqueous phase is 1:4 to 2:1; The mixing is carried out under stirring conditions, with a stirring speed of 100~2000 rpm and a stirring time of 1~60 min.

9. The processing method according to claim 1, characterized in that, The separation method is centrifugal separation, and the centrifugal separation speed is 100~7000 rpm.

10. The processing method according to claim 1, characterized in that, The distillation is vacuum distillation; The pressure of the vacuum distillation is 10~50 kPa and the temperature is 50~120℃.

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