Quaternary ammonium salt ionic liquid microemulsions for heavy oil desorption, their methods and applications
The preparation and application of quaternary ammonium salt ionic liquid microemulsions have solved the problem that traditional microemulsion methods are difficult to effectively remove heavy oil, achieving efficient separation and low-cost processing of heavy oil and minerals, and has significant industrial application value.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SHANDONG UNIV OF TECH
- Filing Date
- 2023-01-10
- Publication Date
- 2026-06-30
AI Technical Summary
Existing technologies are insufficient for efficiently separating complex systems between heavy oil and minerals. Traditional microemulsion methods are ineffective at removing heavy oil, and existing technologies suffer from high costs and weak polarity, resulting in microemulsions that are not very effective at removing heavy oil.
A water-in-oil microemulsion was prepared by combining a quaternary ammonium salt ionic liquid surfactant, n-propanol, n-hexane, and water. The high polarity and low surface tension of the quaternary ammonium salt ionic liquid promoted the separation of heavy oil from minerals, reduced the oil-water interfacial tension, and enhanced the solubilization capacity.
It achieves efficient separation of heavy oil and minerals, reduces the residual amount of heavy oil, has mild processing conditions, low cost, and higher industrial application value.
Smart Images
Figure CN116120959B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of solid waste treatment technology, specifically relating to a quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption, its method, and its application. Background Technology
[0002] Petroleum, as one of the three major fossil fuels, plays a vital role in the development of human society and the economy. However, with the large-scale extraction of crude oil, conventional petroleum resources are gradually decreasing, which has become a significant factor affecting economic development. Meanwhile, the utilization of unconventional heavy oil sands resources, represented by oil sands, as an important component of fossil fuels, is receiving increasing attention. These unconventional heavy oil sands resources are a mixed system composed of heavy oil, water, and minerals. The heavy oil covering the mineral surface is a high-viscosity mixture composed of various organic components. The complex interactions between these components and between these components and the minerals enhance the stability of the heavy oil sands system and increase the difficulty of separating heavy oil, water, and slag. Therefore, to achieve the effective recovery and utilization of petroleum resources, it is necessary to explore a method for efficiently separating heavy oil sands.
[0003] Currently, conventional methods for processing oil resources mainly include thermal cracking, hot alkaline washing, ultrasonic-enhanced extraction, and microemulsion methods. Among these methods, microemulsion methods have shown significant advantages in oil resource processing due to their high solubilizing capacity and low interfacial tension. However, traditional microemulsions are ineffective at removing heavy oils. To address this issue, surfactants with strong interactions with heavy oils should be selected to construct microemulsions.
[0004] Patent CN107987867B discloses a microemulsion extractant for the separation of heavy oil, composed of a mixture of a eutectic solvent, a low-electrolyte alcohol, and a weakly polar solvent. The mass ratio of the eutectic solvent to the low-electrolyte alcohol to the weakly polar solvent is (1-2):(1-2):(2-4), resulting in an anhydrous, surfactant-free Winsor-I type microemulsion. The eutectic solvent is generated by reacting an amino acid ionic liquid with urea, with a molar ratio of 1:(2-4). The weakly polar solvent is an aromatic or chain hydrocarbon solvent. However, this patent uses the eutectic solvent as the polar phase of the microemulsion, requiring a large quantity, which significantly increases production costs.
[0005] Patent CN113772903A discloses a microemulsion for reducing the oil content of oily sludge. By weight, it comprises the following raw materials: 1 part ionic liquid surfactant, 25-30 parts co-surfactant, 20-25 parts oil-soluble component, and 45-50 parts water. The ionic liquid surfactant is 1-hexadecyl-3-methylimidazolium chloride or 1-hexadecyl-3-methylimidazolium bromide. However, the ionic liquid used in this patent is an imidazole-based ionic liquid, which has disadvantages such as high cost and weak polarity, resulting in a low removal rate of heavy oil in the prepared microemulsion.
[0006] Therefore, it is necessary to explore a novel microemulsion for the desorption of heavy oils. Summary of the Invention
[0007] The purpose of this invention is to provide a quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. This quaternary ammonium salt ionic liquid microemulsion features low surface tension, strong solubilizing ability, and recyclability. This invention also provides its preparation method and applications.
[0008] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention comprises, by weight, 0.1-0.8 parts of quaternary ammonium salt ionic liquid surfactant, 17.2-22.9 parts of n-propanol, 20-25 parts of n-hexane, and 56-59 parts of water; wherein the quaternary ammonium salt ionic liquid surfactant is 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0009] in:
[0010] 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride is synthesized from N,N-dimethylethanolamine and haloalkanes using ethanol as a solvent. It is either 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride or 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride, wherein: the haloalkanes are hexadecyl chloride or dodecyl chloride; the molar ratio of N,N-dimethylethanolamine to haloalkanes is 1:1-3; and the volume ratio of the mixture of N,N-dimethylethanolamine and haloalkanes to ethanol is 1:1-2.
[0011] Preferably, the molar ratio of N,N-dimethylethanolamine to haloalkanes is 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.5 or 1:3; more preferably, the molar ratio of N,N-dimethylethanolamine to haloalkanes is 1:1, which yields a high yield of quaternary ammonium salt ionic liquid surfactants.
[0012] Preferably, the volume ratio of the N,N-dimethylethanolamine mixture with haloalkanes to ethanol is 1:1, 1:1.3, 1:1.5, 1:1.7, or 1:2; more preferably, the volume ratio of the N,N-dimethylethanolamine mixture with haloalkanes to ethanol is 1:1.5. This volume ratio provides a sufficient reaction environment for the mixture and also reduces the waste of solvent.
[0013] The N,N-dimethylethanolamine in the raw materials for synthesizing the quaternary ammonium salt type ionic liquid surfactant provides a highly polar amine group, which, when combined with long-chain hexadecane or dodecane, exhibits better surface activity and can further reduce the oil-water interfacial tension.
[0014] Preferably, the preparation method of 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride comprises the following steps:
[0015] (1) Mix N,N-dimethylethanolamine with ethanol solvent and place it in a round-bottom flask. Add hexadecane or dodecane chlorodropwise and heat under reflux at 50-75°C for 12-36 hours to obtain a white crude product.
[0016] (2) After cooling the white crude product, add cyclohexane to crystallize and separate the lower layer of crude product. After recrystallization multiple times, use a rotary evaporator at 50°C for 20-30 min to remove the ethanol from the crude product. Dry the product under vacuum at 50-70°C for 12-24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride or 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0017] in:
[0018] The recrystallization process involves three recrystallizations.
[0019] The method for preparing the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption according to the present invention comprises the following steps:
[0020] (1) Dissolve the quaternary ammonium salt type ionic liquid surfactant in water, add n-propanol to it, mix evenly at 25°C to prepare a mixed solution;
[0021] (2) Add n-hexane dropwise to the mixture prepared in step (1) and mix it by hand until the mixture becomes clear and transparent, thus preparing the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0022] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention comprises the following steps:
[0023] (1) Heavy oil sands were pretreated with sodium carbonate solution to prepare pretreated oil sands;
[0024] (2) The quaternary ammonium salt ionic liquid microemulsion and the pretreated oil sand were heated and stirred at a certain volume-mass ratio, and then allowed to stand for 12 hours. The stirred mixture was then centrifuged to achieve the desorption treatment of heavy oil, and the residual oil in the bottom solid was analyzed.
[0025] in:
[0026] The sodium carbonate solution in step (1) has a mass fraction of 8%, and the volume ratio of sodium carbonate solution to heavy oil sand is 5:1-8:1 (ml:g). The pretreatment heating temperature is 40-50℃, the stirring rate is 100-300r / min, the stirring time is 5-15min, and after standing for 12 hours, pretreated oil sand with a residual oil content of less than 35% is obtained.
[0027] In step (2), the volume-to-mass ratio of the quaternary ammonium salt ionic liquid microemulsion to the pretreated oil sand is 2:2-6:2, with units of ml / g; the heating temperature is 20-40℃, the stirring rate is 50-300 r / min, and the stirring time is 5-20 min.
[0028] Preferably, in step (2), the volume-to-mass ratio of the quaternary ammonium salt ionic liquid microemulsion to the pretreated oil sand is 2 mL:2 g, 3 mL:2 g, 4 mL:2 g, 5 mL:2 g, or 6 mL:2 g.
[0029] Preferably, the heating temperature in step (2) is 20°C, 25°C, 30°C, 35°C or 40°C; the stirring rate is 50 r / min, 100 r / min, 150 r / min, 200 r / min, 250 r / min or 300 r / min; and the stirring time is 5 min, 8 min, 10 min, 15 min, 18 min or 20 min.
[0030] Compared with the prior art, the present invention has the following advantages:
[0031] (1) The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention uses a quaternary ammonium salt ionic liquid as a surfactant. This ionic liquid has high polarity and low toxicity, which can not only effectively prevent the aggregation of heavy oil components and promote the separation of heavy oil from minerals, but also reduce subsequent pollution to the environment. It is prepared by using quaternary ammonium salt ionic liquid surfactant, n-propanol, n-hexane and water as raw materials. The microemulsion is an oil-in-water type and has the characteristics of low surface tension, strong solubilization ability, small dosage, simple processing technology and recyclability.
[0032] (2) The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention relies on the synergistic effect of four raw materials: quaternary ammonium salt ionic liquid, n-propanol, n-hexane, and water. None of these components can be omitted. The quaternary ammonium salt ionic liquid, 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride, has strong polarity due to the presence of hydroxyl groups, exhibiting strong interaction with heavy oil components and easily penetrating to the oil-solid interface to promote the dissociation of heavy oil. n-Propanol enters the interfacial film, further reducing the oil-water interfacial tension and increasing the solubility of the microemulsion system. Simultaneously, since the solubility of the microemulsion decreases with the growth of the carbon chain of oil-soluble alkane, n-hexane is creatively added to reduce its impact on the solubility of the microemulsion.
[0033] (3) The method for preparing the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention is simple, the parameters are easy to control, and the prepared quaternary ammonium salt ionic liquid microemulsion has excellent performance and stable properties.
[0034] (4) The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in this invention is applied to the separation of heavy oil and minerals. The treatment effect is significant, the amount of heavy oil residue is small, the treatment conditions are mild, the cost is low, and it has higher industrial application value. Attached Figure Description
[0035] Figure 1 The infrared spectrum of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride synthesized in Example 1 is shown.
[0036] Figure 2 This is the 1H NMR spectrum of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride synthesized in Example 1;
[0037] Figure 3 The infrared spectrum of 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride synthesized in Example 6 is shown.
[0038] Figure 4 This is an appearance diagram of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption prepared in Example 1;
[0039] Figure 5 This is an image showing the effect of treating heavy oil sands in Example 1;
[0040] Figure 6 This is an image showing the effect of treating heavy oil sand in Example 2;
[0041] Figure 7 This is an image showing the effect of treating oil sand in Example 3;
[0042] Figure 8 This is a scanning electron microscope image of heavy oil sand particles processed in Example 3;
[0043] Figure 9 This is an image showing the effect of treating heavy oil sand in Example 4;
[0044] Figure 10 This is an image showing the effect of treating heavy oil sand in Example 5;
[0045] Figure 11 This is a diagram showing the effect of treating heavy oil sand in Example 6. Detailed Implementation
[0046] The present invention will be further described below with reference to embodiments.
[0047] Example 1
[0048] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 1 comprises the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 60 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of hexadecyl chloride is added dropwise. After heating and refluxing at 75°C for 36 hours, a white crude product is obtained. After cooling the white crude product, cyclohexane is added to crystallize and separate the lower crude product. After three recrystallizations, the ethanol in the crude product is removed by rotary evaporation at 50°C for 30 min. The product is then vacuum dried at 70°C for 24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride. Its infrared and nuclear magnetic resonance characterization are shown in the figures below. Figure 1 and Figure 2 .
[0049] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 1 consists of 0.01g of quaternary ammonium salt ionic liquid surfactant, 2.29g of n-propanol, 2.00g of n-hexane, and 5.7g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0050] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 1 consists of the following steps: Weigh 0.01g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.7g of water at room temperature, then add 2.29g of n-propanol, mix thoroughly at 25°C to obtain a mixture. Add 2.00g of n-hexane dropwise to the above mixture, and mix by hand until the mixture becomes clear and transparent to obtain the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. The appearance of the microemulsion is shown in the figure below. Figure 4 As shown.
[0051] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 1 consists of the following steps:
[0052] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0053] (2) Weigh 2g of pretreated oil sand and mix it with 2ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 250r / min for 20min at 35℃. After standing for 12 hours, centrifuge to separate the contents. Figure 5 The residual oil content was 1.98% when the bottom solids were measured.
[0054] Example 2
[0055] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 2 consists of the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 60 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of hexadecyl chloride is added dropwise. After heating and refluxing at 75°C for 36 hours, a white crude product is obtained. After cooling the white crude product, cyclohexane is added to crystallize and separate the lower crude product. After recrystallization three times, the ethanol in the crude product is removed by rotary evaporation at 50°C for 30 min. The product is then vacuum dried at 70°C for 24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride. Its infrared and nuclear magnetic resonance characterization are shown in the figures below. Figure 1 and Figure 2 .
[0056] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 2 consists of 0.02g of quaternary ammonium salt ionic liquid surfactant, 2.08g of n-propanol, 2.10g of n-hexane, and 5.80g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0057] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 2 comprises the following steps: Weigh 0.02 g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.80 g of water at room temperature, then add 2.08 g of n-propanol, mix thoroughly at 25°C to obtain a mixture. Add 2.10 g of n-hexane dropwise to the above mixture, and mix by hand until the mixture becomes clear and transparent, thus preparing a quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0058] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 2 consists of the following steps:
[0059] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0060] (2) Weigh 2g of pretreated oil sand and mix it with 4ml of quaternary ammonium salt ionic liquid microemulsion. Stir at 250r / min for 18min at 40℃. After standing for 12 hours, centrifuge to separate the contents. Figure 6 The residual oil content was 1.85% when the bottom solids were measured.
[0061] Example 3
[0062] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 3 consists of the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 60 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of hexadecyl chloride is added dropwise. After heating and refluxing at 75°C for 36 hours, a white crude product is obtained. After cooling the white crude product, cyclohexane is added to crystallize and separate the lower crude product. After recrystallization three times, the ethanol in the crude product is removed by rotary evaporation at 50°C for 30 min. The product is then vacuum dried at 70°C for 24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride. Its infrared and nuclear magnetic resonance characterization are shown in the figures below. Figure 1 and Figure 2 .
[0063] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 3 consists of 0.08g of quaternary ammonium salt ionic liquid surfactant, 1.72g of n-propanol, 2.30g of n-hexane, and 5.90g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0064] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 3 consists of the following steps:
[0065] Weigh 0.08 g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.90 g of water at room temperature, then add 1.72 g of n-propanol and mix thoroughly at 25 °C to prepare a mixture. Add 2.30 g of n-hexane dropwise to the above mixture, shaking by hand until the mixture becomes clear and transparent, obtaining a quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0066] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 3 consists of the following steps:
[0067] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0068] (2) Weigh 2g of pretreated oil sand and mix it with 6ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 300r / min for 20min at 40℃. After standing for 12 hours, centrifuge to separate the contents. Figure 7 The scanning electron microscope image of the bottom solid after drying is shown below. Figure 8 The residual oil rate was measured to be 1.05%.
[0069] Example 4
[0070] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 4 consists of the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 60 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of hexadecyl chloride is added dropwise. After heating and refluxing at 75°C for 36 hours, a white crude product is obtained. After cooling the white crude product, cyclohexane is added to crystallize and separate the lower crude product. After recrystallization three times, the ethanol in the crude product is removed by rotary evaporation at 50°C for 30 min. The product is then vacuum dried at 70°C for 24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride. Its infrared and nuclear magnetic resonance characterization are shown in the figures below. Figure 1 and Figure 2 .
[0071] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 4 consists of 0.06g of quaternary ammonium salt ionic liquid surfactant, 1.84g of n-propanol, 2.50g of n-hexane, and 5.60g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0072] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 4 consists of the following steps: Weigh 0.06 g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.60 g of water at room temperature, then add 1.84 g of n-propanol, mix thoroughly at 25°C to obtain a mixture. Add 2.50 g of n-hexane dropwise to the above mixture, and mix by hand until the mixture becomes clear and transparent to obtain the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0073] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 4 consists of the following steps:
[0074] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0075] (2) Weigh 2g of pretreated oil sand and mix it with 5ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 200r / min for 18min at 30℃, let stand for 12 hours, and then centrifuge to separate the contents. Figure 9 The residual oil content was 1.68% when the bottom solids were measured.
[0076] Example 5
[0077] The preparation method of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 5 consists of the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 60 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of hexadecyl chloride is added dropwise. After heating and refluxing at 75°C for 36 hours, a white crude product is obtained. After cooling the white crude product, cyclohexane is added to crystallize and separate the lower crude product. After recrystallization three times, the ethanol in the crude product is removed by rotary evaporation at 50°C for 30 min. The product is then vacuum dried at 70°C for 24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride. Its infrared and nuclear magnetic resonance characterization are shown in the figures below. Figure 1 and Figure 2 .
[0078] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 5 consists of 0.04 g of quaternary ammonium salt ionic liquid surfactant, 1.96 g of n-propanol, 2.20 g of n-hexane, and 5.80 g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0079] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 5 comprises the following steps: Weigh 0.04 g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.80 g of water at room temperature, then add 1.96 g of n-propanol, mix thoroughly at 25°C to obtain a mixture. Add 2.20 g of n-hexane dropwise to the above mixture, and mix by hand until the mixture becomes clear and transparent to obtain the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0080] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 5 consists of the following steps:
[0081] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0082] (2) Weigh 2g of pretreated oil sand and mix it with 3ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 250r / min for 15min at 40℃, let stand for 12 hours, and then centrifuge to separate the contents. Figure 10 The residual oil content was 1.89% when the bottom solids were measured.
[0083] Example 6
[0084] The preparation method of 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride described in Example 6 comprises the following steps: 0.1 mol of N,N-dimethylethanolamine is mixed with 55 ml of ethanol solvent and placed in a round-bottom flask. 0.1 mol of dodecyl chloride is added dropwise, and the mixture is heated under reflux at 65°C for 24 hours to obtain a white crude product. After cooling the white crude product, cyclohexane is added to allow the lower layer of crude product to crystallize and separate. After three recrystallizations, the ethanol in the crude product is removed by rotary evaporation at 50°C for 25 min. The product is then vacuum dried at 60°C for 15 hours to obtain 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride, the infrared spectrum of which is shown below. Figure 3 .
[0085] The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 6 consists of 0.03g of quaternary ammonium salt ionic liquid surfactant, 1.97g of n-propanol, 2.40g of n-hexane, and 5.60g of water by weight; wherein the quaternary ammonium salt ionic liquid surfactant is 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0086] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 6 comprises the following steps: Weigh 0.03 g of 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid, dissolve it in 5.60 g of water at room temperature, then add 1.97 g of n-propanol, mix thoroughly at 25°C to obtain a mixture. Add 2.40 g of n-hexane dropwise to the above mixture, and mix by hand until the mixture becomes clear and transparent to obtain the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
[0087] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Example 6 consists of the following steps:
[0088] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0089] (2) Weigh 2g of pretreated oil sand and mix it with 6ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 200r / min for 20min at 35℃, let stand for 12 hours, and then centrifuge to separate the contents. Figure 11 The residual oil content was 1.65% when the bottom solids were measured.
[0090] Comparative Example 1
[0091] The preparation method of the emulsion for heavy oil desorption described in Comparative Example 1 consists of the following steps: Span80 and P123 are compounded in a mass ratio of 1:1 to obtain a mixed surfactant; 0.4g of the mixed surfactant, 3g of n-hexane, and 7g of water are weighed and homogenized using a homogenizing stirrer at a speed of 10000r / min to obtain a milky white, opaque emulsion for heavy oil desorption.
[0092] The application of the emulsion for heavy oil desorption described in Comparative Example 1 comprises the following steps:
[0093] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0094] (2) Weigh 2g of pretreated oil sand and mix it with 12ml of emulsion for heavy oil desorption. Stir at 40℃ for 30min, let stand for 24 hours and then centrifuge. The bottom solid was taken and the residual oil rate was measured to be 6.23%.
[0095] Comparative Example 2
[0096] The preparation method of the 1-hexadecyl-3-methylimidazolium chloride ion liquid described in Comparative Example 2 comprises the following steps: 0.2 mol of N-methylimidazolium is mixed with 160 ml of ethyl acetate solvent and placed in a round-bottom flask. 0.3 mol of hexadecyl chloride is added dropwise. After heating under reflux at 80 °C for 30 hours, a golden-yellow crude product is obtained. The ethyl acetate in the crude product is removed by rotary evaporation at 50 °C for 40 min. The product is then vacuum dried at 80 °C for 16 hours to obtain the 1-hexadecyl-3-methylimidazolium chloride ion liquid.
[0097] The preparation method of the ionic liquid microemulsion for heavy oil desorption described in Comparative Example 2 comprises the following steps: Weighing 0.10 g of 1-hexadecyl-3-methylimidazolium chloride ionic liquid, dissolving it in 4.80 g of water at room temperature, and then adding 2.90 g of n-propanol to obtain a mixture. Adding 2.30 g of n-hexane dropwise to the above mixture yields a clear and transparent ionic liquid microemulsion for heavy oil desorption.
[0098] The application of the ionic liquid microemulsion for heavy oil desorption described in Comparative Example 2 consists of the following steps:
[0099] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0100] (2) Weigh 2g of pretreated oil sand and mix it with 17.5ml of ionic liquid microemulsion. Stir at 500r / min for 40min at 60℃. After standing for 24 hours, centrifuge and separate the bottom solid. The residual oil rate was 1.33%.
[0101] Comparative Example 3
[0102] The preparation method of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Comparative Example 3 is the same as that in Example 3. The only difference is that the raw material composition of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption is different. The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Comparative Example 3 is composed of 0.08 g of quaternary ammonium salt type ionic liquid surfactant, 1.72 g of ethylene glycol, 2.30 g of n-hexane, and 5.90 g of water by weight. Among them, the quaternary ammonium salt type ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0103] A quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption was prepared according to the preparation method in Example 3: 0.08 g of 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride ionic liquid was weighed and dissolved in 5.90 g of water at room temperature. Then, 1.72 g of ethylene glycol was added, and the mixture was stirred evenly at 25°C to obtain a mixture. 2.30 g of n-hexane was added dropwise to the above mixture. It was found that the formed microemulsion was unstable and easily demulsified, making it unsuitable for heavy oil desorption.
[0104] Comparative Example 4
[0105] The preparation method and application of the ionic liquid microemulsion for heavy oil desorption described in Comparative Example 4 are the same as those in Example 3. The only difference is that the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Comparative Example 3 is composed of 0.08 g of quaternary ammonium salt type ionic liquid surfactant, 1.72 g of n-propanol, 2.30 g of n-octane, and 5.90 g of water by weight; wherein the quaternary ammonium salt type ionic liquid surfactant is 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride.
[0106] The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption described in Comparative Example 4 consists of the following steps:
[0107] (1) 1g of heavy oil sand was mixed with 8ml of sodium carbonate aqueous solution with a mass fraction of 8%, stirred at 300r / min for 15min at 50℃, and left to stand for 12 hours to obtain pretreated oil sand. The residual oil rate of the oil sand was measured to be 28.75%.
[0108] (2) Weigh 2g of pretreated oil sand and mix it with 6ml of quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption. Stir at 300r / min for 20min at 40℃. After standing for 12 hours, centrifuge and separate the bottom solid. The residual oil rate was 3.25% after drying.
[0109] Compared to Comparative Example 1, which used a mixture of surfactants Span80 and P123, and Comparative Example 2, which used 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride, the microemulsions prepared in Examples 1-5 of this invention exhibit milder treatment conditions and better treatment effects. Compared to Comparative Example 3, which used ethylene glycol, the microemulsion system in Examples 1-5 using n-propanol is more stable. Compared to Comparative Example 4, which used n-octane, the microemulsion system constructed with n-hexane in Examples 1-5 has stronger solubilizing ability. In Examples 1-5, the high polarity and low surface tension of the quaternary ammonium salt ionic liquid hindered the aggregation of heavy crude oil, promoting the detachment of heavy oil from the mineral surface and reducing the residual oil content of the minerals. The combination of the microemulsion of this invention with the heavy oil sands treatment process of this invention improves the desorption efficiency of heavy oil and realizes the resource recovery and utilization of heavy oil.
Claims
1. A quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption, characterized in that: It is composed of 0.1-0.8 parts by weight of quaternary ammonium salt type ionic liquid surfactant, 17.2-22.9 parts of n-propanol, 20-25 parts of n-hexane, and 56-59 parts of water; wherein: the quaternary ammonium salt type ionic liquid surfactant is 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride; 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride is synthesized from N,N-dimethylethanolamine and haloalkanes using ethanol as a solvent. It comprises either 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride or 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride, wherein: the haloalkanes are hexadecyl chloride or dodecyl chloride; the molar ratio of N,N-dimethylethanolamine to haloalkanes is 1:1-3; and the volume ratio of the mixture of N,N-dimethylethanolamine and haloalkanes to ethanol is 1:1-2. The preparation method of 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride comprises the following steps: (1) Mix N,N-dimethylethanolamine with ethanol solvent and place it in a round-bottom flask. Add hexadecane or dodecane chlorodropwise and heat under reflux at 50-75°C for 12-36 hours to obtain a white crude product. (2) After cooling the white crude product, add cyclohexane to crystallize and separate the lower layer of crude product. After recrystallization multiple times, use a rotary evaporator at 50°C for 20-30 min to remove the ethanol from the crude product. Dry the product under vacuum at 50-70°C for 12-24 hours to obtain 1-hexadecyl-(2-hydroxyethyl)-dimethylammonium chloride or 1-dodecyl-(2-hydroxyethyl)-dimethylammonium chloride.
2. The quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption according to claim 1, characterized in that: The number of recrystallizations in step (2) of the preparation method of 1-alkyl-(2-hydroxyethyl)-dimethylammonium chloride is 3.
3. A method for preparing the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption as described in claim 1, characterized in that: It consists of the following steps: (1) Dissolve the quaternary ammonium salt type ionic liquid surfactant in water, add n-propanol to it, mix evenly at 25°C to prepare a mixed solution; (2) Add n-hexane dropwise to the mixture prepared in step (1) and mix it by hand until the mixture becomes clear and transparent, thus preparing the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption.
4. The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption as described in claim 1, characterized in that: It consists of the following steps: (1) Pretreatment of heavy oil sands with sodium carbonate solution was carried out to prepare pretreated oil sands; (2) The quaternary ammonium salt ionic liquid microemulsion and the pretreated oil sand were heated and stirred at a certain volume-mass ratio, and then left to stand for 12 hours. The mixture was then centrifuged to achieve desorption treatment of heavy oil, and the residual oil in the bottom solid was analyzed.
5. The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption according to claim 4, characterized in that: In step (1), the mass fraction of sodium carbonate solution is 8%, the volume mass ratio of sodium carbonate solution to heavy oil sand is 5:1-8:1 (unit: ml:g), the pretreatment heating temperature is 40-50℃, the stirring rate is 100-300 r / min, the stirring time is 5-15 min, and after standing for 12 hours, pretreated oil sand with a residual oil content of less than 35% is obtained.
6. The application of the quaternary ammonium salt ionic liquid microemulsion for heavy oil desorption according to claim 4, characterized in that: In step (2), the volume-to-mass ratio of the quaternary ammonium salt ionic liquid microemulsion to the pretreated oil sand is 2:2-6:2, with units of ml / g; the heating temperature is 20-40℃, the stirring rate is 50-300r / min, and the stirring time is 5-20min.