Demulsifier using waste plastic bottles as raw materials, and preparation method and application thereof

Abstract

The application discloses a demulsifier taking waste plastic bottles as raw materials and a preparation method and application thereof. The preparation method of the demulsifier comprises the following steps: S1, taking waste PET plastics and dihydric alcohol as raw materials, and carrying out a hydrolysis reaction under the condition of acetate to obtain a glycolysis product; S2, carrying out a halogenation reaction on the glycolysis product and a halogenating reagent to obtain a halogenated product; and S3, reacting the halogenated product and an alkyl alcohol amine in a solvent to obtain an economical and environment-friendly demulsifier. The preparation method has a simple preparation process and is easy to implement. The demulsifier prepared by the application can quickly demulsify stable oil-water emulsions under low-temperature conditions, has a good demulsification effect, and the water phase is clear.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil-water emulsion treatment, and particularly relates to a demulsifier prepared from waste plastic bottles as raw materials and a preparation method and application thereof. BACKGROUND

[0002] The natural active substances such as colloid, asphaltene and resin in the crude oil emulsion make the existing form and structure of the crude oil emulsion tend to be complex, which causes the stable property of the emulsion, the difficulty in oil-water separation and the increase in the difficulty in demulsification and dehydration of the emulsion. In addition, the existence of the stable emulsion can also cause pipeline corrosion, catalyst deactivation in downstream refinery operation and increase in transportation cost. The commonly used methods for demulsification of crude oil currently include electricity, heat, biology, machinery, membrane separation and chemical demulsification. Among them, chemical demulsification has become one of the most popular demulsification methods due to its fast speed and low energy consumption.

[0003] The chemical demulsifiers mainly include polymer surfactants, nanoparticles and ionic liquids, for example, ethylene oxide-propylene oxide (EO-PO) block copolymer, silicon polyether, dendritic polymer, biodegradable polymer surfactant and nanoparticle-based demulsifier. The chemical demulsifier is an amphiphilic compound with hydrophilicity and hydrophobicity, which can be adsorbed on the oil-water interface, destroy the rigid interface film formed by the natural emulsifier and surfactant, and reduce the stability of the emulsion, so as to realize the separation of oil and water. The demulsifier usually shows similar behavior to the emulsifier, but can replace the emulsifier located at the oil-water interface in the water phase and oil phase, so as to make the liquid droplets flocculate and coalesce. In order to destroy the interface film formed by the emulsifier, the demulsifier usually needs to have stronger surface activity and lower interfacial tension than the emulsifier.

[0004] However, these demulsifiers have problems such as complex preparation process, high raw material cost, poor demulsification performance and potential pollution risk to the environment. SUMMARY

[0005] In view of the deficiencies in the prior art, the purpose of the present application is to provide a demulsifier prepared from waste plastic bottles as raw materials and a preparation method and application thereof. The demulsifier prepared by the present application has good demulsification performance and high demulsification efficiency.

[0006] The purpose of the present application is achieved by the following technical solutions.

[0007] A preparation method of a demulsifier prepared from waste plastic bottles as raw materials, comprising the following steps:

[0008] S1. mixing waste PET plastic, dihydric alcohol and acetate, then heating to 180-196 DEG C for glycolysis reaction, spinning off the dihydric alcohol after the reaction is completed, and crystallizing and purifying the remaining product to obtain a glycolysis product;

[0009] S2. mixing the glycolysis product with a halogenating agent, and performing a halogenation reaction at 50-65°C, after the reaction is completed, spinning out the excess halogenating agent to obtain a halogenated product;

[0010] S3. reacting the halogenated product with an alkyl alcohol amine in a solvent to obtain the demulsifier.

[0011] Preferably, in step S1, the mass ratio of the acetate to the waste PET plastic is 0.1:50.

[0012] Preferably, in step S1, the molar ratio of the waste PET plastic to the dihydric alcohol is 1:10-13.

[0013] Preferably, in step S1, the glycolysis reaction time is 8-12h.

[0014] Preferably, in step S1, the dihydric alcohol is at least one of ethylene glycol, propylene glycol and bisphenol A.

[0015] Preferably, in step S1, the acetate is at least one of potassium acetate, ammonium acetate, lead acetate and zinc acetate.

[0016] Preferably, in step S2, the mass ratio of the halogenating agent to the waste PET plastic of step S1 is 9:11 Preferably, in step S2, the halogenation reaction time is 4-8h.

[0017] Preferably, in step S2, the halogenating agent is at least one of a chlorinating agent, a brominating agent and an iodinating agent.

[0018] Preferably, the chlorinating agent is at least one of phosphorus pentachloride and dichlorosulfoxide.

[0019] Preferably, the brominating agent is at least one of carbon tetrabromide and dibromocyanoacetamide.

[0020] Preferably, the iodinating agent is at least one of phosphorus triiodide and hydriodic acid.

[0021] Preferably, in step S3, the mass ratio of the alkyl alcohol amine to the waste PET plastic of step S1 is 4-6:25.

[0022] Preferably, in step S3, the mass-volume ratio of the alkyl alcohol amine to the solvent is 0.17-0.25g / mL.

[0023] Preferably, in step S3, the solvent is xylene.

[0024] Preferably, in step S3, the reaction temperature is 120-130°C, and the reaction time is 8-10h.

[0025] Preferably, in step S3, the alkyl alcohol amine is at least one of butyldiethanolamine, dodecyldiethanolamine and octadecyldiethanolamine.

[0026] The demulsifier prepared by the preparation method of the demulsifier from waste plastic bottles.

[0027] Application of the demulsifier in demulsification of crude oil emulsion.

[0028] Preferably, the application comprises the following steps: dissolving the demulsifier in a solvent, and then mixing with the crude oil emulsion for demulsification; the solvent is at least one of water, ethanol and dimethylbenzene.

[0029] The reaction mechanism involved in the application is:

[0030] S1. The glycolysis reaction of PET, also known as alcoholysis reaction, is a nucleophilic substitution reaction. The electronegativity of metal ions promotes the reaction of acetate and alcohol to generate metal alcoholate, and then acetic acid is generated. Then, the metal on the metal alcoholate provides an empty orbital to combine with the lone pair of electrons of the carbonyl oxygen in PET (complexation), and the ester exchange reaction is completed. The chemical reaction process is as follows:

[0031]

[0032] S2. The glycolysis product reacts with a halogenation reagent to generate a halogenated product. The halogen in the halogenation reagent replaces the hydroxyl group in the product to generate a halogenated product. The chemical reaction formula is as follows:

[0033]

[0034] S3. The reaction of the halogenated product with the alkyl alcohol amine is a nucleophilic substitution reaction. The lone pair of electrons on the amino group and the oxygen group of the alkyl alcohol amine attacks the halogen atom (X) in the halogenated product, and X is removed to generate a hydrogen halide (HX) molecule. Then, the other ethoxyl group in the alkyl alcohol amine is transferred to the positive ion, eliminating its positive charge characteristics, and then the corresponding product is generated.

[0035] Compared with the prior art, the application has the following beneficial effects:

[0036] (1) The demulsifier prepared by the application has high surface activity, good thermal stability, good dispersibility in the oil phase, is suitable for petroleum crude oil emulsion, has high demulsification efficiency, requires small injection dose, has low demulsification temperature, and has fast demulsification rate; the preparation steps of the demulsifier are simple, the raw material cost is low, and the preparation is green and environmentally friendly.

[0037] (2) The demulsifier prepared by the application is a new type of green amphoteric surfactant, which can change wettability, surface tension and crude oil / water interfacial tension. And it is non-flammable. Compared with traditional demulsifiers, it has higher surface activity. Two long carbon chains make it have better dispersibility in oil phase and stronger force with natural interfacial active substances. Further destroy the interface film composed of asphaltene, promote the occurrence of demulsification process. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 The infrared spectrum of the demulsifier prepared in Example 1.

[0039] Figure 2 The actual photo of the demulsification results of experimental groups 6-11. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical scheme and advantages of the application more clear and obvious, the application will be further described in detail below in combination with examples. It should be understood that the specific examples described here are only used to explain the application and not to limit the application.

[0041] The commercial demulsifiers K3800, PDB9360, PDB9958 and DI-18 involved in the performance test were all purchased from BASF SE; the crude oil was sourced from Changqing Oilfield. The waste plastic bottles used in the examples were PET material, and the relative molecular weight was about 224.1.

[0042] Example 1

[0043] A demulsifier using waste plastic bottles as raw materials, the demulsifier is obtained by the following steps:

[0044] Uniformly mix 50g of waste PET plastic and 150g of ethylene glycol solution at room temperature, then add 0.1g of zinc acetate, after mixing, heat to 186℃ and react for 8h, after the reaction is completed, spin off the ethylene glycol, then crystallize and purify the product. Then add 45g of dichloro sulfoxide to react at 65℃ for 4h, after the reaction is completed, spin off the excess dichloro sulfoxide, then add 11.9g of dodecyl diethanolamine in xylene to mix, react at 120℃ for 8h, after the reaction is completed, spin off the xylene, and the demulsifier is obtained.

[0045] Figure 1 The infrared spectrum of the demulsifier prepared in Example 1. By Figure 1 It can be seen that: the wide absorption band at 3380cm -1 is related to the stretching of O-H. The peak at 2925cm -1 is the stretching vibration of C-H. The peak at 1722cm -1The peak at 1710 cm"1is associated with C=0 group, which indicates the presence of -COOH group in the sample. The planar bending vibration of -OH shows at 1451 cm -1 The representative peak at 1268 cm -1 The peak at 1058 cm -1 The peak at 1058 cm

[0046] Example 2

[0047] A demulsifier using waste plastic bottles as raw materials, the demulsifier is obtained by the following steps:

[0048] Under normal temperature conditions, 50 g of waste PET plastic and 150 g of ethylene glycol solution are uniformly mixed, then 0.1 g of lead acetate is added, after mixing, the temperature is raised to 186°C and reacted for 8 h, after the reaction is completed, the ethylene glycol is rotary evaporated, then the product is crystallized and purified. Then add 45 g of dichloro sulfide at 65°C for 4 h, after the reaction is completed, the excess dichloro sulfide is rotary evaporated, then 11.9 g of dodecyl diethanolamine is added to the product and mixed in xylene, reacted at 120°C for 8 h, after the reaction is completed, the xylene is rotary evaporated, to obtain the demulsifier.

[0049] Example 3

[0050] A demulsifier using waste plastic bottles as raw materials, the demulsifier is obtained by the following steps:

[0051] Under normal temperature conditions, 50 g of waste PET plastic and 150 g of ethylene glycol solution are uniformly mixed, then 0.1 g of zinc acetate is added, after mixing, the temperature is raised to 186°C and reacted for 8 h, after the reaction is completed, the ethylene glycol is rotary evaporated, then the product is crystallized and purified. Then add 45 g of carbon tetrabromide at 65°C for 4 h, after the reaction is completed, the excess carbon tetrabromide is rotary evaporated, then 11.9 g of dodecyl diethanolamine is added to the product and mixed in xylene, reacted at 120°C for 8 h, after the reaction is completed, the xylene is rotary evaporated, to obtain the demulsifier.

[0052] Example 4

[0053] A demulsifier using waste plastic bottles as raw materials, the demulsifier is obtained by the following steps:

[0054] Under normal temperature conditions, 50 g of waste PET plastic and 150 g of ethylene glycol solution were uniformly mixed, then 0.1 g of lead acetate was added, after mixing, the temperature was raised to 186°C for 8 h of reaction, after the reaction was completed, the ethylene glycol was rotary evaporated, then the product was crystallized and purified. Then 45 g of dichloro sulfide was added at 65°C for 4 h of reaction, after the reaction was completed, the excess dichloro sulfide was rotary evaporated, then 8.9 g of octadecyl diethanolamine was added to the product and mixed in xylene, reacted at 120°C for 8 h, after the reaction was completed, the xylene was rotary evaporated, to obtain the demulsifier.

[0055] Example 5

[0056] A demulsifier using waste plastic bottles as raw materials, the demulsifier is obtained by the following steps:

[0057] Under normal temperature conditions, 50 g of waste PET plastic and 150 g of ethylene glycol solution were uniformly mixed, then 0.1 g of zinc acetate was added, after mixing, the temperature was raised to 186°C for 8 h of reaction, after the reaction was completed, the ethylene glycol was rotary evaporated, then the product was crystallized and purified. Then 45 g of dichloro sulfide was added at 65°C for 4 h of reaction, after the reaction was completed, the excess dichloro sulfide was rotary evaporated, then 8.9 g of octadecyl diethanolamine was added to the product and mixed in xylene, reacted at 120°C for 8 h, after the reaction was completed, the xylene was rotary evaporated, to obtain the demulsifier.

[0058] Performance test:

[0059] Commercial demulsifier K3800 was used as Comparative Example 1, PDB9360 was used as Comparative Example 2, PDB9958 was used as Comparative Example 3, DI-18 was used as Comparative Example 4, and the demulsifiers prepared in Examples 1-5 were compared in terms of demulsification performance in crude oil emulsion, the specific steps were as follows:

[0060] 150 parts by weight of crude oil was added to 350 parts by weight of deionized water and stirred and mixed, heated to 60°C, then stirred at a speed of 11000 r / min for 20 minutes, and this process was repeated three times until a stable water-in-oil emulsion, i.e. crude oil emulsion, was obtained.

[0061] The demulsifiers prepared in Examples 1-5 were added to xylene / ethanol (volume ratio 75:25) respectively to prepare a solution with a mass fraction of 0.5%, i.e. Experimental Groups 1-5; commercial demulsifier K3800 was used as Comparative Example 1, PDB9360 was used as Comparative Example 2, PDB9958 was used as Comparative Example 3, and DI-18 was used as Comparative Example 4, which were used as Comparative Examples 1-4 for comparison experiments, the commercial demulsifiers in the comparative examples were added to xylene / ethanol (volume ratio 75:25) to prepare a solution with a mass fraction of 0.5%, i.e. Comparative Groups 1-4.

[0062] The experimental groups 1-5 and the comparative groups 1-4 are added to the above crude oil emulsion in a volume ratio of 1:20, then fully oscillated and mixed uniformly, and then transferred to a 40℃ water bath for 2h, and the dehydration rate is measured, and the results are shown in Table 1.

[0063] Table 1 demulsification results of experimental groups 1-5

[0064]

[0065]

[0066] Note: "demulsifier (mg / L)" in the table refers to the concentration of the demulsifier in the crude oil emulsion.

[0067] From Table 1, it can be seen that the demulsifiers prepared in Examples 1-3 all have very good demulsification performance, but the demulsification efficiency will be different due to different preparation conditions. The reason why the demulsifiers prepared in Examples 4 and 5 have lower efficiency is that the hydrophobicity of the hydrophobic end is weaker, and cannot better interact with natural interfacial active substances to destroy the interfacial film. Compared with the commercial demulsifiers in the comparative groups, the demulsification ability of the demulsifiers provided in the present scheme also has good effect.

[0068] Based on the demulsifier prepared in Example 1, different concentrations of solutions are used to characterize the demulsification performance of different concentrations of demulsifiers in the crude oil emulsion.

[0069] 150 parts by weight of crude oil is added to 350 parts by weight of deionized water and stirred and mixed, heated to 60℃, then stirred at a speed of 11000r / min for 20 minutes, and this process is repeated three times until a stable water-in-oil emulsion is obtained.

[0070] Different weights of the demulsifier prepared in Example 1 are added to dimethylbenzene / ethanol (volume ratio 75:25) to prepare demulsifiers with mass fractions of 0.5%, 0.4%, 0.3%, 0.2%, and 0.1%, respectively, and the obtained samples are respectively recorded as experimental groups 6-10; the blank group is 0%, and the sample is recorded as experimental group 11.

[0071] 1 part by volume of the above experimental groups 6-11 is added to 20 parts by volume of the crude oil emulsion, then fully oscillated and mixed uniformly, and then transferred to a 40℃ water bath for 2h, and the dehydration rate is measured, and the results are shown in Table 2.

[0072] Table 2 demulsification results of experimental groups 6-11

[0073]

[0074]

[0075] Note: The "demulsifier (mg / L)" in the table refers to the concentration of the demulsifier in the crude oil emulsion.

[0076] As shown in Table 2, the demulsifier provided by the application has good demulsification performance, and a demulsification efficiency of 93.02% can be achieved with 150 mg / L of the demulsifier, the demulsification efficiency reaches 95.36% when the concentration is 200 mg / L, and the demulsification efficiency is 96.7% when the concentration is 250 mg / L.

[0077] Figure 2 The demulsification results of experimental groups 6-11 are shown in the physical photo graph. Figure 2 It can be seen that the demulsifier provided by the application has good demulsification performance and can form a clear oil-water interface.

[0078] Based on the demulsifier prepared in Example 1, experimental groups 11-15 are sequentially established to characterize the demulsification performance of the demulsifier under different temperatures and times.

[0079] 150 parts by weight of crude oil is added to 350 parts by weight of deionized water and stirred and mixed, heated to 60℃, then stirred at a speed of 11000 r / min for 20 minutes, and this process is repeated three times until a stable water-in-oil emulsion is obtained.

[0080] The demulsifier prepared in Example 1 is added to dimethylbenzene / ethanol (volume ratio 75:25) to prepare a solution with a mass fraction of 0.5%.

[0081] 1 part by volume of the above demulsifier is added to 20 parts by volume of the crude oil emulsion, then thoroughly shaken and mixed, and then transferred to a water bath set at different temperatures and left to stand for 3 hours, and the dehydration rate is measured, and the results are shown in Table 3.

[0082] Table 3: Demulsification results of experimental groups 12-15

[0083]

[0084] As shown in Table 3, the demulsifier provided by the application can achieve a demulsification efficiency of 90.8% at 40℃ for 150 minutes, and a demulsification efficiency of 93.02% at 50℃ for 90 minutes.

[0085] In summary, the demulsifier described in the application has the advantages of simple synthesis steps, low demulsification temperature, fast demulsification rate, and high demulsification efficiency.

[0086] The specific embodiments of the application described above do not constitute a limitation on the scope of protection of the application. Any various other corresponding changes and modifications made in accordance with the technical concept of the application should be included in the scope of protection of the claims of the application.

Claims

1. A method for preparing a demulsifier using waste plastic bottles as raw material, characterized in that, Includes the following steps: S1. Waste PET plastic, diol and acetate are mixed, and then heated to 180~196℃ to carry out glycolysis reaction. After the reaction is completed, the diol is evaporated by rotary evaporation, and the remaining product is crystallized and purified to obtain the glycolysis product. S2. Mix the glycolysis product with the halogenating agent and carry out the halogenation reaction at 50~65℃. After the reaction is completed, evaporate the excess halogenating agent to obtain the halogenated product. S3. The demulsifier is prepared by reacting the halogenated product with an alkyl alcohol amine in a solvent; The alkyl alcoholamine mentioned in step S3 is at least one of butyl diethanolamine, dodecyl diethanolamine, and octadecyl diethanolamine.

2. The method for preparing a demulsifier using waste plastic bottles as raw material according to claim 1, characterized in that, The mass ratio of acetate to waste PET plastic in step S1 is 0.1:50; The molar ratio of waste PET plastic and diol in step S1 is 1:10~13.

3. The method for preparing a demulsifier using waste plastic bottles as raw material according to claim 2, characterized in that, The mass ratio of the halogenating agent in step S2 to the waste PET plastic in step S1 is 9:11; The mass ratio of the alkylolamine in step S3 to the waste PET plastic in step S1 is 4~6:25; The mass-to-volume ratio of the alkyl alcohol amine to the solvent in step S3 is 0.17~0.25 g / mL.

4. A method for preparing a demulsifier using waste plastic bottles as raw material according to any one of claims 1 to 3, characterized in that, The glycolysis reaction in step S1 takes 8-12 hours; The halogenation reaction in step S2 takes 4-8 hours; The reaction temperature in step S3 is 120℃~130℃, and the reaction time is 8h~10h.

5. The method for preparing a demulsifier using waste plastic bottles as raw material according to claim 4, characterized in that, The diol mentioned in step S1 is at least one of ethylene glycol, propylene glycol, and bisphenol A; The acetate in step S1 is at least one of potassium acetate, ammonium acetate, lead acetate, and zinc acetate.

6. The method for preparing a demulsifier using waste plastic bottles as raw material according to claim 5, characterized in that, The halogenating agent mentioned in step S2 is at least one of chlorinating agent, brominating agent, and iodizing agent; The solvent in step S3 is xylene.

7. The method for preparing a demulsifier using waste plastic bottles as raw material according to claim 6, characterized in that, The chlorinating agent is at least one of phosphorus pentachloride and thionyl chloride; The brominating agent is at least one of carbon tetrabromide and dibromocyanoacetamide; The iodizing agent is at least one of phosphorus triiodide and hydroiodic acid.

8. The demulsifier prepared by the method of preparing a demulsifier using waste plastic bottles as raw material as described in any one of claims 1 to 7.

9. The application of the demulsifier according to claim 8 in the demulsification of crude oil emulsions.

10. The application according to claim 9, characterized in that, The process includes the following steps: dissolving a demulsifier in a solvent and then mixing it with a crude oil emulsion to demulsify; the solvent is at least one of water, ethanol, and xylene.

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