Low-temperature demulsifier as well as preparation method and application thereof

Abstract

The invention relates to the technical field of demulsification, and discloses a low-temperature demulsifier as well as a preparation method and application thereof.The low-temperature demulsifier is prepared by mixing functional monomers, alkenyl polyether and the like for a polymerization reaction, the functional monomers comprise alkyl alkenyl sulfone and / or alkenyl acid, and the alkenyl polyether is vinyl polyether. The interaction between the functional monomer and water is stronger than that between heavy oil molecule groups and water, and the functional monomer and a main chain can form better water-oil balance, so that demulsification is promoted through the interaction between the functional monomer and oil at an emulsion interface; the low-temperature demulsifier prepared by the invention can be used for quickly demulsifying an oil-water emulsion at a low temperature, so that the demulsifying efficiency is improved, and the application of the demulsifier in a heavy oil emulsion is expanded.

Description

Technical Field

[0001] The present invention relates to the technical field of demulsification, and in particular to a low-temperature demulsifier, a preparation method thereof and an application thereof. Background Art

[0002] Conventional demulsification methods include gravity sedimentation, dissolved air flotation, biological treatment, electrochemistry, coagulation-flocculation, membrane treatment, etc. However, these treatment technologies generally have disadvantages such as low removal efficiency, long treatment cycle, large investment in infrastructure and equipment, large floor area, and easy to cause secondary pollution, and are not suitable for the demulsification environment of emulsions with high emulsified oil content and high heavy oil content.

[0003] The chemical demulsification method has high efficiency and strong practicability. By selecting a surfactant that can strongly adsorb on the oil-water interface to replace the emulsifier that forms a firm film in the emulsion, a new thin film is generated, and the demulsification occurs due to the significant reduction in the strength of the film.

[0004] Currently, conventional reverse demulsifiers mainly include polyethers, polysiloxanes, polyquaternary ammonium salts, etc., and these reverse demulsifiers have been applied in the field. However, the current demulsifiers have problems such as low demulsification efficiency, high demulsification temperature, and long time, resulting in high time cost and economic cost for demulsification.

[0005] Therefore, it is urgent to develop new demulsifiers to solve the bottleneck problems such as difficult demulsification of existing heavy oil emulsions and low separation efficiency, and improve the production efficiency of demulsification separation. Summary of the Invention

[0006] In view of the problems existing in the prior art, the present invention provides a low-temperature demulsifier, a preparation method thereof and an application thereof. The low-temperature demulsifier provided by the present invention can be used at normal temperature, has high demulsification efficiency and short demulsification time, and significantly reduces the cost of demulsification.

[0007] The present invention is achieved by the following technical solutions:

[0008] In the first aspect, the present invention provides a low-temperature demulsifier, and the structural formula is shown as Formula I:

[0009]

[0010] In Formula I, the value range of m is 1-15, the value range of n is 1-20, the value range of x is 5-24, the value range of y is 6-27, and the value range of k is 1-13; A is -SO2CH3 and / or -COOH; B and C are each independently one or more of H, alkyl and aryl.

[0011] The low-temperature demulsifier provided by the present invention has amphiphilicity for oil and water. Among them, -SO2CH3 and / or -COOH have strong interactions with water. The hydrogen bond energy formed between these two groups and the hydrogen in water molecules is greater than the hydrogen bond energy formed between asphaltene molecules and between asphaltene molecules and water molecules. Through hydrogen bond action, it adsorbs at the oil-water interface to stabilize the interfacial film, thereby replacing heavy oil such as asphaltene molecules and completing demulsification.

[0012] Preferably, the value of x is an integer from 5, 6, 7, 8, 9, 10, 11, 12, etc. to 24, and the value of y is an integer from 6, 7, 8, 9, 10, 11, 12, 13, 14, etc. to 27.

[0013] The selection of polyether in the low-temperature demulsifier provided by the present invention is also crucial. The value ranges of x and y need to be controlled within the above ranges. When x or y is too large, the carbon chain is too long, and there are two reasons for the adverse effect on the demulsifier effect: First, when the carbon chain is too long, the steric hindrance effect between the -SO2CH3 and / or -COOH groups increases. With strong activity, the -SO2CH3 and / or -COOH groups that can form hydrogen bonds have difficulty contacting the oil-water interface and are difficult to take effect, resulting in a decrease in demulsification efficiency. Second, when the carbon chain is too long, the molecular weight is too high, and the molecular diffusivity is poor. It cannot migrate from the oil phase to the oil-water interfacial film quickly to act, resulting in a decrease in demulsification efficiency; when x or y is too small, the carbon chain is too short, the molecular weight is small, and the ether bond oxygen in the polyether chain segment has weak interaction with water, resulting in difficulty for the -SO2CH3 and / or -COOH groups to adsorb at multiple points on the oil-water interface, and there are defects such as poor demulsification effect or no demulsification effect.

[0014] Preferably, the value of n is an integer from 1, 2, 3, 4, etc. to 20.

[0015] Preferably, B and C are each independently H. In the present invention, it is preferred that B and C are each independently H. Compared with alkyl groups, it has the advantage of enhancing the hydrophilicity of the demulsifier and facilitating the diffusion of the demulsifier in the oil-water two-phase.

[0016] Preferably, the number of carbon atoms of the alkyl group in B and C is each independently 1 to 10, and can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10.

[0017] Preferably, the value range of k is 1 to 6.

[0018] In the second aspect, the present invention provides a preparation method of the low-temperature demulsifier. The preparation method includes the following steps:

[0019] Mix functional monomers, vinyl polyether, organic solvent and initiator, and carry out polymerization reaction on the obtained mixed material to prepare the low-temperature demulsifier. The structure of the vinyl polyether is shown in Formula II:

[0020]

[0021] In formula II, the numerical range of x is 5 to 24, and the numerical range of y is 6 to 27; B and C are each independently one or more of H, alkyl, and aryl;

[0022] The functional monomer includes alkyl vinyl sulfone and / or vinyl acid.

[0023] Preferably, the mass ratio of the vinyl polyether to the functional monomer is 25 to 100:1 to 10, for example, it can be 25:1, 30:1, 55:2, 60:2, 85:3, 100:3, 25:4, 40:5, 40:7, 40:8, 50:9, 60:10, or 100:10, etc.

[0024] Preferably, the organic solvent is one or more of toluene, n - heptane, tetrahydrofuran, DMF, DMSO, and xylene, and typical but non - restrictive combinations are the combination of toluene and n - heptane, the combination of toluene and DMF, the combination of DMF and n - heptane, the combination of DMSO and n - heptane, the combination of DMSO and xylene.

[0025] Preferably, the initiator is one or more of benzoyl peroxide, tert - butyl peroxybenzoate, methyl ethyl ketone peroxide, azobisisobutyronitrile, azobisisoheptonitrile, and dimethyl azobisisobutyrate.

[0026] Preferably, the ratio of the organic solvent to the functional monomer is 50 to 350 mL:1 to 5 g, for example, it can be 50 mL:1 g, 100 mL:1 g, 200 mL:2 g, 350 mL:3 g, 150 mL:4 g, or 350 mL:5 g, etc.

[0027] Preferably, the mass ratio of the initiator to the functional monomer is 0.15 to 3.1:1 to 5, for example, it can be 0.15:1, 1:1, 1.5:2, 2:3, 3.1:2.5, 2.5:2, 3:5, 2:3.5, 1.6:3.8, 2.7:4, or 3.1:5, etc.

[0028] Preferably, the alkyl vinyl sulfone is one or more of methyl vinyl sulfone, ethyl vinyl sulfone, methyl propenyl sulfone, ethyl propenyl sulfone, methyl butenyl sulfone, and ethyl butenyl sulfone, and typical but non - restrictive combinations are the combination of methyl vinyl sulfone and methyl propenyl sulfone, the combination of methyl butenyl sulfone and ethyl propenyl sulfone, the combination of methyl vinyl sulfone and ethyl vinyl sulfone.

[0029] Preferably, the alkenyl acid is one or more of acrylic acid, crotonic acid and pentenoic acid, and typical but non-limiting combinations are combinations of acrylic acid and crotonic acid, combinations of pentenoic acid and crotonic acid, and combinations of acrylic acid and pentenoic acid.

[0030] Preferably, when the functional monomer is alkyl alkenyl sulfone, the mixing includes: first mixing alkyl alkenyl sulfone, alkenyl polyether and a first portion of organic solvent to obtain a homogeneous first liquid phase; second mixing an initiator and a second portion of organic solvent to obtain a homogeneous second liquid phase; and third mixing the first liquid phase and the second liquid phase to complete the mixing.

[0031] Preferably, when the functional monomer is alkenyl acid, the mixing and the polymerization reaction include: first mixing alkenyl polyether and a first portion of organic solvent to obtain a homogeneous first liquid phase; second mixing an initiator and a second portion of organic solvent to obtain a homogeneous second liquid phase; third mixing the first liquid phase and the second liquid phase to obtain a third mixed material, heating the third mixed material to the reaction temperature first, and after introducing a protective atmosphere, slowly dropping the alkenyl acid while simultaneously carrying out the polymerization reaction.

[0032] Preferably, the first portion of organic solvent accounts for 80-98% of the total volume of the organic solvent, and can be, for example, 80%, 85%, 87%, 91%, 93%, 95% or 98%, etc.

[0033] Preferably, the temperature of the first mixing is 30-65°C, and can be, for example, 30°C, 35°C, 37°C, 40°C, 45°C, 50°C, 53°C, 55°C, 58°C, 60°C or 65°C, etc.

[0034] Preferably, the temperature of the second mixing is 30-65°C, and can be, for example, 30°C, 36°C, 39°C, 40°C, 43°C, 47°C, 51°C, 56°C, 59°C, 61°C or 65°C, etc.

[0035] Preferably, before slowly dropping the alkenyl acid, a protective atmosphere is introduced to remove air.

[0036] Preferably, the duration of removing air is 3-10 min, and can be, for example, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min or 10 min, etc.

[0037] Preferably, the dropping rate of the alkenyl acid is 10 to 30 mL / min, for example, it can be 10 mL / min, 12 mL / min, 14 mL / min, 15 mL / min, 17 mL / min, 20 mL / min, 22 mL / min, 25 mL / min, 26 mL / min, 28 mL / min, 30 mL / min, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable; the dropping duration is 5 to 20 min, for example, it can be 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, or 20 min, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0038] Preferably, the polymerization reaction includes: heating to the reaction temperature and reacting under a protective atmosphere.

[0039] Preferably, the heating rate of the stepwise heating is 1 to 10 °C / min, for example, it can be 1 °C / min, 2 °C / min, 3 °C / min, 4 °C / min, 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min or 10 °C / min, etc.

[0040] Preferably, the final temperature of the stepwise heating is 80 to 95 °C, for example, it can be 80 °C, 81 °C, 82 °C, 83 °C, 84 °C, 85 °C, 86 °C, 87 °C, 88 °C, 90 °C, 92 °C or 95 °C, etc.

[0041] Preferably, the protective atmosphere is a nitrogen atmosphere.

[0042] Preferably, the reaction is kept at the final temperature of the stepwise heating for 2 to 6 h, for example, it can be 2 h, 3 h, 3.2 h, 3.5 h, 4 h, 4.2 h, 4.5 h, 5 h, or 6 h, etc.

[0043] Preferably, the preparation method further includes: removing the solvent and drying the reaction material generated by the polymerization reaction to obtain the low-temperature demulsifier.

[0044] Preferably, the temperature for solvent removal is 66 to 155 °C, for example, it can be 66 °C, 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C or 155 °C, etc.

[0045] Preferably, the pressure for solvent removal is -0.1 to 0.1 MPa, for example, it can be -0.1 MPa, -0.05 MPa, 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa, 0.06 MPa, 0.07 MPa or 0.1 MPa, etc.

[0046] Preferably, the drying is vacuum drying.

[0047] Preferably, the drying temperature is 30 to 100 °C, for example, it can be 30 °C, 40 °C, 50 °C, 60 °C, 70 °C, 80 °C, 90 °C or 100 °C, etc.

[0048] Preferably, the drying time is 1.5 to 6 h, for example, it can be 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h or 6 h, etc.

[0049] In a third aspect, the present invention provides an application of the low-temperature demulsifier described above in emulsion demulsification. The application includes: mixing the demulsifier and the emulsion to be treated, and performing demulsification to obtain the demulsified material.

[0050] Preferably, the dosage of the demulsifier is 50 to 1000 ppm, for example, it can be 50 ppm, 150 ppm, 260 ppm, 360 ppm, 470 ppm, 570 ppm, 680 ppm, 780 ppm, 890 ppm or 1000 ppm, etc., but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0051] Preferably, the demulsification temperature is 20 to 70 °C, for example, it can be 20 °C, 30 °C, 35 °C, 39 °C, 45 °C, 48 °C, 50 °C, 55 °C, 62 °C, 66 °C or 70 °C, etc., but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0052] Preferably, the demulsification time is 5 to 120 min, for example, it can be 5 min, 18 min, 30 min, 40 min, 50 min, 60 min, 80 min, 95 min, 100 min or 120 min, etc., but is not limited to the listed values, and other unlisted values within this range are equally applicable.

[0053] Preferably, the emulsion to be treated is a water-in-oil emulsion.

[0054] Preferably, the water content in the emulsion to be treated is 1-50 wt%, for example, it can be 1 wt%, 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 28 wt%, 30 wt%, 35 wt%, 40 wt%, 45 wt% or 50 wt%, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0055] Preferably, the asphaltene content of the oil in the emulsion to be treated is 1-35 wt%, for example, it can be 1 wt%, 3 wt%, 7 wt%, 10 wt%, 15 wt%, 18 wt%, 20 wt%, 25 wt%, 30 wt% or 35 wt%, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0056] Preferably, the viscosity of the oil in the emulsion to be treated is 0.59-16600 mPa·s, for example, it can be 0.59 mPa·s, 1659.94 mPa·s, 3319.88 mPa·s, 4979.82 mPa·s, 6639.76 mPa·s, 8299.7 mPa·s, 11619.58 mPa·s, 13279.52 mPa·s, 14939.46 mPa·s or 16600 mPa·s, etc., but not limited to the listed values, and other unlisted values within this range are equally applicable.

[0057] The advantages and positive effects of the present invention are:

[0058] (1) The low-temperature demulsifier synthesized in the present invention is a non-ionic demulsifier. Compared with the ionic demulsifier in CN103421533A, it is acid and alkali resistant, has strong ion resistance, is not easily decomposed, has a small dosage, and has a wide application range and application fields; the synthesis route of the low-temperature demulsifier of the present invention is simpler, can be simply synthesized by a one-pot method, and can be adapted to industrial scale-up production;

[0059] (2) The low-temperature demulsifier provided by the present invention has high demulsification efficiency, short demulsification time and small dosage of the demulsifier, and the demulsification cost is low. It can achieve the effect that the demulsification efficiency reaches more than 97% under the condition of 40 °C, and basically reaches 100% demulsification efficiency at 50 °C. Description of the Drawings

[0060] Figure 1 is the nuclear magnetic resonance spectrum of the alkenyl polyether provided in Example 1 of the present invention;

[0061] Figure 2 is the nuclear magnetic resonance spectrum of the low-temperature demulsifier provided in Example 1 of the present invention;

[0062] Figure 3 is the infrared spectrum of the low-temperature demulsifier provided in Example 1 of the present invention;

[0063] Figure 4 It is a comparison diagram before and after demulsification of the demulsification application provided in Application Example 1 of the present invention;

[0064] Figure 5 It is the nuclear magnetic resonance spectrum of the low-temperature demulsifier provided in Example 6 of the present invention;

[0065] Figure 6 It is the infrared spectrum of the low-temperature demulsifier provided in Example 6 of the present invention;

[0066] Figure 7 It is a comparison diagram before and after demulsification of the demulsification application provided in Application Example 6 of the present invention. Detailed implementation manners

[0067] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation manners.

[0068] The present invention will be further described in detail below. However, the following examples are merely simple examples of the present invention and do not represent or limit the scope of the protection of the rights of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0069] The general structural formula of the low-temperature demulsifier involved in the following examples and comparative examples is shown in Formula I:

[0070]

[0071] The general structural formula of the alkenyl polyether used for preparing the low-temperature demulsifier is shown in Formula II:

[0072]

[0073] Examples 1 to 3 and Comparative Examples 1 to 5

[0074] A low-temperature demulsifier has a structure as shown in Formula I. The specific values of m, n, x, y, k and the functional groups A, B, and C in Formula I are shown in Table 1.

[0075] Table 1 Specific structures of the low-temperature demulsifiers in Examples 1 to 3 and Comparative Examples 1 to 5

[0076]

[0077]

[0078] "Same as 1" in Table 1 indicates the same setting as in Example 1.

[0079] The preparation methods adopted in the above examples and comparative examples include the following steps:

[0080] At 50 °C, the first mixed functional monomers (methyl vinyl sulfone, pentene, acrylamide, and styrene respectively), the alkenyl polyether, and the first part of the organic solvent (toluene), and the first part of the organic solvent accounts for 90% of the total volume of the organic solvent. Wait for the materials to dissolve to obtain a homogeneous first liquid phase; the alkenyl polyether is shown in Formula II, and its 400 MHz nuclear magnetic resonance hydrogen spectrum is as Figure 1 shown.

[0081] At 50 °C, the second mixed initiator (benzoyl peroxide) and the second part of the organic solvent (toluene), and the ratio of the organic solvent to the functional monomer is 160 mL:1 g; the mass ratio of the initiator to the functional monomer is 0.2:1; the materials are dissolved to obtain a homogeneous second liquid phase;

[0082] The third step is to mix the first liquid phase and the second liquid phase to complete the mixing. The obtained mixed material is gradually heated at 5 °C / min to ensure that the temperature is 85 °C, and the polymerization reaction is carried out for 4 h under a nitrogen atmosphere;

[0083] The reaction material produced by the polymerization reaction is subjected to solvent removal at 55 °C and -0.1 MPa and vacuum drying at 80 °C and -0.1 MPa for 4 h to obtain the low-temperature demulsifier.

[0084] The 400 MHz nuclear magnetic resonance hydrogen spectrum of the low-temperature demulsifier prepared in Example 1 is as Figure 2 shown, and the infrared spectrum is as Figure 3 shown. From Figures 2 - 3 it can be seen that the S=O sulfone asymmetric stretching vibration peak near 1300 cm -1 comes from -SO2CH3, and the low-temperature demulsifier obviously has a sulfonyl group. And the broad peak at 3500 cm -1 in the infrared comes from the -OH at the end of the polyether chain segment, and the stretching vibration peak near 1084 cm -1 comes from the ether bond in the molecule. The absorption peak with a chemical shift between 1.07 and 1.13 ppm in the nuclear magnetic resonance hydrogen spectrum corresponds to the hydrogen of the methyl group on the propylene oxide block, and the peak with a chemical shift between 3 and 3.15 ppm corresponds to the methylene hydrogen on the ethylene oxide of the polyether structure. The above indicates that the demulsifier structure has an ethylene oxide-propylene oxide polyether chain segment.

[0085] Example 4

[0086] A low-temperature demulsifier, whose structure is shown in Formula I. In Formula I, m is 2, n is 3, x is 9, y is 13, and k is 2; the A is -SO2CH3; the B and C are both -CH3.

[0087] This example also provides a preparation method for the above demulsifier. The preparation method includes the following steps:

[0088] At 45°C, first mix methyl vinyl sulfone, vinyl polyether and the first part of the organic solvent (DMF), where the first part of the organic solvent accounts for 96% of the total volume of the organic solvent. Wait for the materials to dissolve to obtain a homogeneous first liquid phase;

[0089] At 55°C, second mix the initiator (azobisisobutyronitrile) and the second part of the organic solvent (DMF). The ratio of the organic solvent to methyl vinyl sulfone is 180 mL:1 g; the mass ratio of the initiator to methyl vinyl sulfone is 0.62:1. The materials dissolve to obtain a homogeneous second liquid phase;

[0090] Third mix the first liquid phase and the second liquid phase to complete the mixing. The resulting mixed material is gradually heated at 3°C / min to ensure the temperature is at 85°C, and polymerize under nitrogen atmosphere for 3 h;

[0091] Perform solvent removal on the reaction material produced by the polymerization reaction at 55°C and -0.1 MPa, and vacuum dry at 100°C and -0.1 MPa for 1.5 h to obtain the low-temperature demulsifier.

[0092] Example 5

[0093] This example provides a low-temperature demulsifier with a structural formula as shown in Formula I. In Formula I, m is 3, n is 2, x is 9, y is 11, and k is 8; A is -SO2CH3CH3; both B and C are -CH2CH3.

[0094] This example also provides a preparation method for the above demulsifier. The preparation method includes the following steps:

[0095] At 45°C, first mix ethyl vinyl sulfone, vinyl polyether and the first part of the organic solvent (n-heptane). The first part of the organic solvent accounts for 92% of the total volume of the organic solvent. Wait for the materials to dissolve to obtain a homogeneous first liquid phase;

[0096] At 55°C, second mix the initiator (BPO) and the second part of the organic solvent (n-heptane). The ratio of the organic solvent to ethyl vinyl sulfone is 150 mL:1 g; the mass ratio of the initiator to ethyl vinyl sulfone is 0.40:1. The materials dissolve to obtain a homogeneous second liquid phase;

[0097] Third mix the first liquid phase and the second liquid phase to complete the mixing. The resulting mixed material is gradually heated at 9°C / min to ensure the temperature is at 82°C, and polymerize under nitrogen atmosphere for 5 h;

[0098] Perform solvent removal on the reaction material produced by the polymerization reaction at 80°C and 0 MPa, and vacuum dry at 70°C and 0 MPa for 4 h to obtain the low-temperature demulsifier.

[0099] Application Example 1

[0100] Taking the low-temperature demulsifier in Example 1 as an example, the low-temperature demulsifier prepared in Example 1 was applied in emulsion demulsification. The application method includes: mixing 0.0005 - 0.05 mg of the low-temperature demulsifier and 10 - 50 mL of the emulsion to be treated (water-in-oil emulsion, the water content in the emulsion is 20 wt%, the asphaltene content in the oil of the emulsion is 20 wt%, and the viscosity of the oil is 8863 mPa·s), and carrying out demulsification to obtain the demulsified material.

[0101] Specific parameters of the demulsification rate at different demulsification temperatures, demulsifier concentrations, and demulsification times are shown in Table 2.

[0102] Table 2 Demulsification rate at different demulsification temperatures, demulsifier concentrations, and demulsification times

[0103]

[0104]

[0105] The experimental diagrams before and after demulsification in this application example with a dosage of 600 ppm and demulsification for 62.5 min at 50 °C are as Figure 4 shown (the left figure is before demulsification, and the right figure is after demulsification). It can be seen from Figure 4 this that after demulsification with this demulsifier, the oil and water are completely separated, and the demulsification efficiency reaches 100%.

[0106] Application Examples 2 - 3 and Application Comparative Examples 1 - 7

[0107] The low-temperature demulsifiers prepared in Examples 2 - 3 and Comparative Examples 1 - 7 were respectively applied in emulsion demulsification. The application method includes: mixing the low-temperature demulsifier and the emulsion to be treated (the same water-in-oil emulsion as in Application Example 1), carrying out demulsification to obtain the demulsified material. The addition amount of the demulsifier is 600 ppm, the demulsification temperature is 50 °C, and the demulsification time is 120 min.

[0108] Application Example 4

[0109] This application example provides the application of the low-temperature demulsifier in Example 4 in emulsion demulsification. The application method includes:

[0110] Mixing 0.02 mg of the demulsifier and 20 mL of the emulsion to be treated (water-in-oil emulsion, the water content in the emulsion is 25%, the asphaltene content in the oil of the emulsion is 5%, and the viscosity of the oil is 5838 mPa·s), carrying out demulsification to obtain the demulsified material. The addition amount of the demulsifier is 1000 ppm, the demulsification temperature is 70 °C, and the demulsification time is 30 min.

[0111] Application Example 5

[0112] This application example provides the application of the low-temperature demulsifier in Example 5 in emulsion demulsification. The application method includes:

[0113] Mix 0.0128 mg of the demulsifier and 16 mL of the emulsion to be treated (water-in-oil emulsion, the water content in the emulsion is 15%, the asphaltene content of the oil in the emulsion is 3%, and the viscosity of the oil is 2609.3 mPa·s) for demulsification to obtain the demulsified material. The dosage of the demulsifier is 800 ppm, the demulsification temperature is 65 °C, and the demulsification time is 60 min.

[0114] Use the bottle test method to test the demulsification dehydration efficiency D of the demulsifier r , and calculate the demulsification rate through the formula. In the formula, V is the volume of the water phase separated after demulsification (mL); V0 is the volume of the water phase contained in the emulsion (mL).

[0115] The demulsification data of Application Examples 2 to 5 and Application Comparative Examples 1 to 7 are shown in Table 3.

[0116] Table 3 Demulsification data of Application Examples 2 to 5 and Application Comparative Examples 1 to 7

[0117] Demulsification and dehydration efficiency (%) Application Example 2 100 Application Example 3 99 Application Example 4 86.05 Application Example 5 95.56 Application Comparative Example 1 0 Application Comparative Example 2 0 Application Comparative Example 3 0 Application Comparative Example 4 19.18 Application Comparative Example 5 12.90 Application Comparative Example 6 13.70 Application Comparative Example 7 18.07

[0118] In Application Comparative Example 1, since the A group is -CH3, the content of the hydrophilic group in the molecule is small, the hydrophilic-lipophilic balance value is low, and the overall molecule tends to be oil-soluble and is not easily soluble in water, making it difficult or impossible to reach the oil-water interfacial film to act, resulting in no demulsification effect at all. In Application Comparative Example 2, since the A group is -CONH2, although this group is also a polar group, it leads to too high a hydrophilic-lipophilic balance value of the molecule, poor solubility in the oil phase, and inability to diffuse to the oil-water interfacial film to take effect, ultimately resulting in no demulsification effect at all; in Application Comparative Example 3, since the A group is -C6H6, the phenyl group is non-polar, and the addition of the phenyl group has a similar effect to that caused by -CH3, increasing the lipophilicity of the molecule and resulting in poor hydrophilicity, making it difficult for the demulsifier molecule to be transferred to the interface, ultimately resulting in no demulsification effect at all.

[0119] Examples 6 to 8 and Comparative Examples 8 to 12

[0120] The structures of the low-temperature demulsifiers in the above Examples 6 to 8 and Comparative Examples 8 to 12 are shown in Formula I. The specific values of m, n, x, y, k and the functional groups A, B, C in Formula I are shown in Table 4.

[0121] Table 4 Specific structures of the low-temperature demulsifiers in Examples 6 to 8 and Comparative Examples 8 to 12

[0122] A B C m n x y k Example 6 -COOH -H -H 2 2 10 11 1 Example 7 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 4 Example 8 Same as 6 Same as 6 <![CDATA[-(CH2)7CH3]]> Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Comparative Example 8 <![CDATA[-(CH2)2CH3]]> Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Comparative Example 9 <![CDATA[-CONH2]]> Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Comparative Example 10 <![CDATA[-C6H6]]> Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Comparative Example 11 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 27 Same as 6 Same as 6 Comparative Example 12 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 3 Same as 6 Same as 6 Comparative Example 13 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 4 Same as 6 Comparative Example 14 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 Same as 6 30 Same as 6

[0123] In Table 4, "Same as 6" means the same settings as in Example 6.

[0124] The preparation methods used in Examples 6 - 8 and Comparative Examples 8 - 12 include the following steps:

[0125] At 50°C, the first mixed vinyl polyether and the first part of the organic solvent (toluene), and the first part of the organic solvent accounts for 90% of the total volume of the organic solvent. Wait for the material to dissolve to obtain a homogeneous first liquid phase; the vinyl polyether is as shown in Formula II.

[0126] At 50°C, the second mixed initiator (benzoyl peroxide) and the second part of the organic solvent (toluene); the mass ratio of the initiator to the functional monomer is 0.2:1; the material dissolves to obtain a homogeneous second liquid phase.

[0127] The third step is to mix the first liquid phase and the second liquid phase. After mixing, the obtained mixed material is gradually heated at 5°C / min to ensure the temperature is 85°C. Nitrogen is introduced for 5 minutes to remove air, and then the functional monomers (acrylic acid, pentene, acrylamide, styrene respectively) are dropped into the mixed material at a dropping rate of 15 mL / min within 8 minutes. The ratio of the organic solvent to the functional monomer is 160 mL:1 g, and the polymerization reaction is carried out under nitrogen atmosphere for 4 h while maintaining the temperature.

[0128] The reaction material produced by the polymerization reaction is subjected to solvent removal at 55°C and -0.1 MPa and vacuum drying at 80°C and -0.1 MPa for 4 h to obtain the low-temperature demulsifier.

[0129] The 400 MHz nuclear magnetic resonance hydrogen spectrum of the low-temperature demulsifier prepared in Example 6 is as Figure 5 shown, and the infrared spectrum is as Figure 6 shown. From Figures 5 - 6 it can be seen that the peak at 9 - 12 ppm in chemical shift in the nuclear magnetic resonance hydrogen spectrum is the hydrogen on the carboxyl group, and the demulsifier obviously has a carboxyl group. And the broad peak at 3500 cm -1 in the infrared spectrum comes from the -OH at the end of the polyether chain segment, and the stretching vibration peak near 1084 cm -1 comes from the ether bond in the molecule. The absorption peak between 1.07 - 1.13 ppm in chemical shift in the nuclear magnetic resonance hydrogen spectrum corresponds to the hydrogen on the methyl group of the propylene oxide block, and the peak between 3 - 3.15 ppm in chemical shift corresponds to the methylene hydrogen on the ethylene oxide of the polyether structure. The above shows that the demulsifier molecular structure contains an ethylene oxide - propylene oxide block polyether chain segment.

[0130] Example 9

[0131] A low-temperature demulsifier, the structural formula is as shown in Formula I, where m is 2, n is 3, x is 10, y is 13, k is 7; A is -COOH; B and C are both -CH3.

[0132] This embodiment also provides a preparation method of the above demulsifier, and the preparation method includes the following steps:

[0133] At 48 °C, the first mixture of alkenyl polyether and the first part of the organic solvent (DMF), and the first part of the organic solvent accounts for 96% of the total volume of the organic solvent. Wait for the materials to dissolve to obtain a homogeneous first liquid phase;

[0134] At 50 °C, the second mixture of initiator (azobisisobutyronitrile) and the second part of the organic solvent (DMF), and the mass ratio of the initiator to the acrylic acid is 0.60:1. The materials dissolve to obtain a homogeneous second liquid phase;

[0135] The third step is to mix the first liquid phase and the second liquid phase, complete the mixing, and gradually heat up the obtained mixed materials at 5 °C / min to ensure that the temperature is 89 °C. Introduce nitrogen for 5 minutes to remove air, and then slowly drop the acrylic acid into the mixed materials at a dropping rate of 20 mL / min within 8 minutes. The ratio of the organic solvent to the functional monomer is 190 mL:1 g, and keep warm under a nitrogen atmosphere for 3 h for the polymerization reaction;

[0136] Perform solvent removal on the reaction materials produced by the polymerization reaction at 50 °C and -0.1 MPa, and vacuum dry at 90 °C and -0.1 MPa for 2 h to obtain the low-temperature demulsifier.

[0137] Example 10

[0138] This embodiment provides a low-temperature demulsifier, and the structural formula is shown in Formula I. In Formula I, m is 2, n is 3, x is 9, y is 10, and k is 10; A is -COOH; both B and C are -CH2CH3.

[0139] This embodiment also provides a preparation method of the above demulsifier, and the preparation method includes the following steps:

[0140] At 45 °C, the first mixture of alkenyl polyether and the first part of the organic solvent (n-heptane), and the first part of the organic solvent accounts for 92% of the total volume of the organic solvent. Wait for the materials to dissolve to obtain a homogeneous first liquid phase;

[0141] At 55 °C, the second mixture of initiator (BPO) and the second part of the organic solvent; the mass ratio of the initiator to the acrylic acid is 1.4:3. The materials dissolve to obtain a homogeneous second liquid phase;

[0142] Mix the third mixture of the first liquid phase and the second liquid phase to complete the mixing. The obtained mixed material is gradually heated at 8 °C / min to ensure the temperature is 90 °C, and nitrogen is introduced for 6 min to remove air. Then, the acrylic acid is slowly dropped into the mixed material at a dropping rate of 16 mL / min within 10 min. The ratio of the organic solvent to the functional monomer is 260 mL:1.6 g, and the polymerization reaction is carried out under a nitrogen atmosphere for 5 h while maintaining the temperature.

[0143] The reaction material produced by the polymerization reaction is subjected to solvent removal at 80 °C and 0.01 MPa and vacuum drying at 70 °C and -0.1 MPa for 4 h to obtain the low-temperature demulsifier.

[0144] Application Example 6

[0145] Taking the low-temperature demulsifier in Example 6 as an example, the low-temperature demulsifier prepared in Example 6 is applied in emulsion demulsification. The application method includes:

[0146] Mix 0.002 - 0.1 mg of the demulsifier and 10 - 100 mL of the emulsion to be treated (water-in-oil emulsion, the water content in the emulsion is 18 wt%, the asphaltene content of the oil in the emulsion is 15 wt%, and the viscosity of the oil is 6754 mPa·s) for demulsification to obtain the demulsified material. The specific parameters of the demulsification rate at different demulsification temperatures, demulsifier concentrations, and demulsification times are shown in Table 5.

[0147] Table 5 Demulsification Rates at Different Demulsification Temperatures, Demulsifier Concentrations, and Demulsification Times

[0148] Serial number Demulsification temperature / °C Demulsifier concentration / ppm Demulsification time / min Demulsification rate / % 1 70 50 62.5 100 2 70 1000 62.5 100 3 70 525 5 79.0698 4 50 1000 5 68.8889 5 30 525 5 23.2558 6 30 50 62.5 53.6585 7 50 525 5 62.7907 8 50 50 120 97.561 9 30 1000 62.5 55.5556 10 50 525 30 93.0233 11 30 525 120 55.814 12 70 525 120 100 13 50 525 62.5 100 14 50 525 62.5 100 15 50 50 30 58.5366 16 50 525 62.5 100 17 50 1000 120 100 18 50 50 5 26.8293

[0149] The experimental diagrams before and after demulsification in this application example at a dosage of 525 ppm and a demulsification temperature of 50 °C for 62.5 min are as Figure 7 shown (the left figure is before demulsification, and the right figure is after demulsification). It can be seen from Figure 7 this that after this demulsification, the oil and water are completely separated, and the demulsification efficiency reaches 100%.

[0150] Application Examples 7 - 8 and Application Comparative Examples 8 - 14

[0151] The low-temperature demulsifiers prepared in Examples 7 - 8 and Comparative Examples 8 - 14 are respectively used in emulsion demulsification. The application method includes:

[0152] Mix 0.03 mg of the demulsifier and 30 mL of the emulsion to be treated (the same as the water-in-oil emulsion in Application Example 6) for demulsification to obtain the demulsified material. The addition amount of the demulsifier is 1000 ppm, the demulsification temperature is 50 °C, and the demulsification time is 62.5 min.

[0153] Application Example 9

[0154] This application example provides the application of the low-temperature demulsifier in Example 9 in emulsion demulsification. The application method includes:

[0155] Mix 0.005 mg of the demulsifier and 10 mL of the emulsion to be treated (water-in-oil emulsion, with 30% water content in the emulsion, 8% asphaltene content in the oil of the emulsion, and the viscosity of the oil being 4214.79 mPa·s) for demulsification to obtain the demulsified material. The addition amount of the demulsifier is 500 ppm, the demulsification temperature is 40 °C, and the demulsification time is 60 min.

[0156] Application Example 10

[0157] This application example provides the application of the low-temperature demulsifier in Example 10 in emulsion demulsification. The application method includes:

[0158] Mix 0.02 mg of the demulsifier and 20 mL of the emulsion to be treated (water-in-oil emulsion, with 15% water content in the emulsion, 3% asphaltene content in the oil of the emulsion, and the viscosity of the oil being 2780.7 mPa·s) for demulsification to obtain the demulsified material. The addition amount of the demulsifier is 1000 ppm, the demulsification temperature is 75 °C, and the demulsification time is 60 min.

[0159] The bottle test method is used to test the demulsification dehydration efficiency D of the demulsifier r , and the demulsification rate is calculated by the formula . In the formula, V is the volume of the separated aqueous phase (mL) after demulsification is completed, and V0 is the volume of the aqueous phase contained in the emulsion (mL). The demulsification data of Application Examples 7-10 and Application Comparative Examples 8-14 are shown in Table 6.

[0160] Table 6 Demulsification data of Application Examples 7-10 and Application Comparative Examples 8-14

[0161] Demulsification and dehydration efficiency (%) Application Example 7 100 Application Example 8 100 Application Example 9 97.78 Application Example 10 100 Application Comparative Example 8 0 Application Comparative Example 9 0 Application Comparative Example 10 0 Application Comparative Example 11 37.21 Application Comparative Example 12 33.33 Application Comparative Example 13 24.39 Application Comparative Example 14 40

[0162] It should be noted that the above embodiments are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A low-temperature demulsifier, characterized in that The structure is as shown in Formula I: In Formula I, the value range of m is 1 - 15, the value range of n is 1 - 20, the value range of x is 5 - 24, and the value range of y is 6 - 27; the value range of k is 1 - 13; A is -SO2CH3 and / or -COOH; B and C are each independently one or more of H, alkyl, and aryl.

2. The demulsifier for low temperature according to claim 1, wherein The number of carbon atoms of the alkyl in B and C is each independently 1 - 10.

3. A preparation method of the demulsifier at low temperature according to claim 1 or 2, characterized in that, The preparation method includes the following steps: Mix a functional monomer, an alkenyl polyether, an organic solvent, and an initiator, and subject the obtained mixed material to a polymerization reaction to obtain the low-temperature demulsifier. The structure of the alkenyl polyether is as shown in Formula II: In Formula II, the value range of x is 5 - 24, and the value range of y is 6 - 27; B and C are each independently one or more of H, alkyl, and aryl; The functional monomer includes an alkyl vinyl sulfone and / or an alkenyl acid.

4. The preparation method according to claim 3, characterized in that, The mass ratio of the alkenyl polyether to the functional monomer is 25 - 100:1 - 10; the ratio of the organic solvent to the functional monomer is 50 - 350 mL:1 - 5 g; the mass ratio of the initiator to the functional monomer is 0.15 - 3.1:1 - 5; Preferably, the organic solvent is one or more of toluene, n-heptane, tetrahydrofuran, DMF, DMSO, and xylene; Preferably, the initiator is one or more of benzoyl peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, azobisisobutyronitrile, azobisisoheptonitrile, and dimethyl azobisisobutyrate; Preferably, the alkyl vinyl sulfone is one or more of methyl vinyl sulfone, ethyl vinyl sulfone, methyl propenyl sulfone, ethyl propenyl sulfone, methyl butenyl sulfone, and ethyl butenyl sulfone; the alkenyl acid is one or more of acrylic acid, crotonic acid, and pentenoic acid.

5. The preparation method according to claim 3, characterized in that, When the functional monomer is an alkyl vinyl sulfone, the mixing includes: first mixing the alkyl vinyl sulfone, the alkenyl polyether, and a first portion of the organic solvent to obtain a homogeneous first liquid phase; second mixing the initiator and a second portion of the organic solvent to obtain a homogeneous second liquid phase; third mixing the first liquid phase and the second liquid phase to complete the mixing; Preferably, when the functional monomer is an alkenyl acid, the mixing and the polymerization reaction include: first mixing the alkenyl polyether and a first portion of the organic solvent to obtain a homogeneous first liquid phase; second mixing the initiator and a second portion of the organic solvent to obtain a homogeneous second liquid phase; third mixing the first liquid phase and the second liquid phase to obtain a third mixed material, heating the third mixed material to the reaction temperature first, and after introducing a protective atmosphere, slowly dropping the alkenyl acid while simultaneously performing a polymerization reaction; Preferably, the first portion of the organic solvent accounts for 80 - 98% of the total volume of the organic solvent; Preferably, the temperature of the first mixing is 30 - 65 °C; Preferably, the temperature of the second mixing is 45 - 55 °C; Preferably, before slowly dropping the alkenyl acid, a protective atmosphere is introduced to remove air; Preferably, the duration of removing air is 4 - 10 min; Preferably, the dropping duration of the alkenyl acid is 5 - 20 min.

6. The preparation method according to claim 3, characterized in that, The polymerization reaction includes: heating to the reaction temperature and carrying out the reaction under a protective atmosphere; Preferably, the heating rate of the heating is 1 to 10 °C / min; Preferably, the final temperature of the heating is 80 to 95 °C; Preferably, the protective atmosphere is a nitrogen atmosphere; Preferably, the reaction is kept at the reaction temperature for 2 to 6 h. When the functional monomer is vinyl acid, the reaction is kept at the reaction temperature for 2 to 6 h after the vinyl acid is completely added dropwise.

7. The preparation method according to claim 3, wherein The preparation method further includes: removing the solvent from and drying the reaction material produced by the polymerization reaction to obtain the low-temperature demulsifier; preferably, the temperature for solvent removal is 66 to 155 °C, and the pressure is -0.1 to 0.1 MPa; the drying is vacuum drying; the temperature of the drying is 30 to 100 °C, and the time is 1.5 to 6 h.

8. An application of the low-temperature demulsifier according to claim 1 or 2 in emulsion demulsification.

9. The application according to claim 8, wherein The application includes: mixing the low-temperature demulsifier and the emulsion to be treated and carrying out demulsification to obtain the demulsified material; preferably, the addition amount of the demulsifier is 50 to 1000 ppm; the temperature of the demulsification is 20 to 70 °C; the time of the demulsification is 5 to 120 min.

10. The application according to claim 8, characterized in that, The emulsion to be treated is a water-in-oil emulsion; preferably, the water content in the emulsion to be treated is 1 to 50 wt%; the asphaltene content of the oil in the emulsion to be treated is 1 to 35 wt%; the viscosity of the oil in the emulsion to be treated is 0.59 to 16600 mPa·s.

Images