LU102076B1

LU102076B1 - An Oil Sludge Demulsifier, A Preparation Method and Its Application

Info

Publication number: LU102076B1
Application number: LU102076A
Authority: LU
Inventors: Xinliang Liu; Chengrong Qin; Shuangxi Nie; Chen Liang; Zhiwei Wang; Shuangquan Yao; Xueping Song; Lianxin Luo; Jian Zhang; Jiulong Sha; Xusheng Li; Yongjun Yin; Wei Li; Hui He
Original assignee: Univ Guangxi
Priority date: 2020-09-24
Filing date: 2020-09-24
Publication date: 2021-03-25

Abstract

The invention discloses an oil sludge demulsifier, a preparation method and its application, which belongs to the field of demulsifier preparation technology. According to the mass percentage, the oil sludge demulsifier comprises the following raw materials: 30-40% amphoteric lignin, 10-20% sodium silicate, 4-5% sodium citrate, 2-3% alkyl polyglycoside, and the balance is water. The preparation method is to accurately weigh each raw material, mix the amphoteric lignin and alkyl polyglycoside with water, heat and stir evenly, then add sodium silicate and sodium citrate, and stir evenly. The oil sludge demulsifier of the invention can realize the demulsification of oil sludge at low temperature (60-70 °c), and has good demulsification effect for oil sludge with low oil content, separation, high oil recovery rate, low production cost and simple preparation method.

Description

An Oil Sludge Demulsifier, A Preparation Method and Its Application LU102076 Technical Field

[001] The invention relates to the field of demulsifier preparation technology, in particular to an oil sludge demulsifier, a preparation method and its application. Background Technology

[002] In the process of oil water injection and exploitation, a large amount of crude oil will mix with soil, sand, water and other substances to form oil sludge mixture, causing more and more serious environmental pollution. In addition, oil sludge has become an important source of pollution in oil fields and must be treated or recycled. Generally, the specific gravity of oil sludge is 1.5-1.8T/m°, the oil content is 5-50%, and the water content is 30-80%. The oil sludge can be treated by microbial degradation, landfill, combustion and brickmaking, etc. However, due to its certain water content and calcium, magnesium and other ions, it causes equipment corrosion and increases energy consumption costs, which brings great difficulties to its treatment or recovery. Chemical demulsifier is a common and rapid method of demulsification, but there are some problems such as low oil recovery, poor demulsification effect at low temperature, some demulsifiers are not environmentally friendly, and secondary pollution is caused by inflow into the environment.

[003] A large amount of demulsifiers are used in the process of crude oil demulsification and dehydration. Crude oil contains colloid, asphaltene and other natural emulsifiers, with strong emulsifying capacity. Coupled with the extensive use of various oilfield additives, chemical flooding, steam flooding and composite flooding, the water content of oil well produced fluids continues to rise, the composition and physical properties of crude oil produced liquids are more and more complex, and the stability of emulsions is enhanced, so the requirements for the performance of demulsifiers continue to increase. Therefore, the R&D, production and application of new and high efficiency crude oil demulsifiers are of great significance to the production of oil fields.

[004] Currently, there are many varieties of crude oil demulsifiers at home and abroad, but most of them are non-ionic demulsifiers, and their demulsification effects are also different. But in terms of its molecular composition, it is mainly the copolymer of ethylene oxide and propylene oxide. This kind of demulsifiers have obvious short-term demulsification effect, but the decrease in temperature during the demulsification process will increase the difficulty of demulsification of produced fluids, and the speed of 1 oil-water separation will slow down, resulting in a slowdown in dehydration efficiency. In addition, when this kind of demulsifiers are widely used, they will also have a negative 976 impact on the water quality of the oilfield and the surrounding environment, and the demulsifiers have strong specificity and have poor extended-spectrum adaptability to different crude oil products. Therefore, the existing crude oil demulsifiers can no longer meet the needs of oil fields. The search for a crude oil demulsifier with high efficiency, energy saving, environmental protection and low temperature resistance has become the current development direction of crude oil demulsifiers. Summary of the Invention

[005] The purpose of the invention is to provide an oil sludge demulsifier, a preparation method and its application, so as to solve the problems existing in the above existing technology, and provide an oil sludge demulsifier with high efficiency, energy saving, environmental protection, high oil recovery rate and good demulsification effect at low temperature.

[006] In order to achieve the above purpose, the invention provides the following solutions:

[007] The invention provides an oil sludge demulsifier, according to the mass percentage, it comprises the following raw materials: 30-40% amphoteric lignin, 10-20% sodium silicate, 4-5% sodium citrate, 2-3% alkyl polyglycoside, and the balance is water.

[008] As a further improvement of the invention, the structural formula for amphoteric lignin is as follows: HO N A4

COOH TY oko jonin 7 Sal 0 N \ X OH , of which, Lignin is a lignin molecular fragment, R1, Ra, Ra CH CH NH —CH,CH NH and Ra are n, M or -NHz, of which, n and m are 1 or2.

[009] As a further improvement of the invention, the preparation method for amphoteric lignin comprises the following steps: 2

(1) With alkali lignin as raw material and potassium permanganate as oxidant, oxidize and prepare the lignin to obtain the oxidized lignin, of which, add 0.1-0.5g potassium 79/6 permanganate to per 1g of lignin; (2) Blend the oxidized lignin with alkali solution and absolute ethyl alcohol, with epichlorohydrin as halogenating agent, and react under stirring conditions to prepare and obtain the epoxidized lignin, add 0.5-1ml epichlorohydrin to per 1g of oxidized lignin; (3) Add the hyperbranched polyamine derivatives, alkali solution and formaldehyde to the epoxidized lignin, and react under stirring conditions to prepare and obtain the amphoteric lignin. The alkali solution is preferably sodium hydroxide solution, of which, add 0.2-0.5g hyperbranched polyamine derivatives to per 1g of epoxidized lignin, and add 0.1-1ml formaldehyde to per 1g of epoxidized lignin.

[0010] As a further improvement of the invention, the hyperbranched polyamine derivatives comprise diethylenetriamine, triethylenetetramine, tetraethylenepentamine and cross-linked derivatives formed by cross-linking of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

[0011] As a further improvement of the invention, the structural formula for alkyl polyglycoside is as follows:

HO od Ve n HO OH , of which, Ris the alkyl of C12-C1s, n is the degree of polymerization, andnis 1-3.

[0012] The invention also provides a preparation method for oil sludge demulsifier, which comprises the following steps: accurately weigh each raw material, mix the amphoteric lignin and alkyl polyglycoside with water, heat and stir evenly, then add sodium silicate and sodium citrate, and stir evenly to obtain the oil sludge demulsifier.

[0013] As a further improvement of the invention, it is heated to 40-60 °C in the preparation method for oil sludge demulsifier.

[0014] The invention also provides the application of the oil sludge demulsifier in oil sludge demulsification.

[0015] As a further improvement of the invention, the application method is to first add the oil sludge demulsifier to the oil sludge, of which, add the amount of 10ml of oil sludge demulsifier solution to per 80g of oil sludge, preferably add the oil sludge 3 demulsifier solution with a concentration of 11%, then fully mix the two, and then dehydrate the oil sludge demulsifier at 60-70°C 102076

[0016] The invention discloses the following technical effects:

[0017] Lignin is an aromatic superpolymer widely existing in plants, and its molecular structure contains the structural units of oxyphenylpropanol or its derivatives. Lignin is also a main by-product of pulp and paper industry. The most remarkably advantage of lignin is that it is rich in resources, renewable, cheap and easy to process. Lignin has abundant hydroxyl groups, phenolic hydroxyl groups and sites with high reactivity, so dispersants, surfactants and water treatment agents, etc. can be obtained by functionalizing lignin. The invention uses epichlorohydrin, hyperbranched polyamine and formaldehyde to modify lignin to prepare and obtain the modified lignin.

[0018] The lignin of the invention produces carboxyl anionic groups under the action of potassium permanganate, introduces active epoxy groups through epichlorohydrin epoxidation, and then forms cationic lignin under the action of hyperbranched polyamine, forms reticulated amphoteric modified lignin under cross-linking of formaldehyde. On the one hand, amphoteric lignin adsorbs heavy metal ions and inorganic salts in the oil sludge, on the other hand, it can reduce the viscosity of crude oil and accelerate the demulsification of oil sludge.

[0019] The oil sludge demulsifier of the invention uses lignin, sodium silicate, sodium citrate, alkyl polyglycoside and other environmental friendly raw materials as the main components, which is environmentally friendly and has little impact on the environment; it can realize demulsification of oil sludge at low temperature (60-70 °C), and has good demulsification effect for oil sludge with low oil content. For oil sludge containing 2-4% oil, the dehydration rate can reach 98%, separation, high oil recovery rate, low production cost and simple preparation method. Description of Drawings

[0020] In order to more clearly explain the embodiments of the invention or the technical solutions in the existing technology, the following will give a brief introduction to the drawings required in the embodiments. It is obvious that the drawings in the following description are only some embodiments of the invention. For those ordinary technical personnel in the field, without paying any creative work, they can also obtain other drawings according to these drawings.

[0021] Figure 1 is the infrared spectrogram of lignin and amphoteric lignin in Embodiment 1, of which, a is amphoteric modified lignin and b is lignin; 4

[0022] Figure 2 is the SEM diagram of amphoteric lignin in Embodiment 1;

[0023] Figure 3 is the SEM diagram of amphoteric lignin in Embodiment 2; HU102076

[0024] Figure 4 is the SEM diagram of amphoteric lignin in Embodiment 3; Detailed Description of the Presently Preferred Embodiments

[0025] Various exemplary embodiments of the invention are described in detail now. The detailed description should not be considered as a limitation of the invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the invention.

[0026] It should be understood that the terms described in the invention are only used to describe particular embodiments and are not used to limit the invention. In addition, for the numerical range in the invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any stated value or intermediate value within the stated range and any other stated value or intermediate value within the stated range is also included in the invention. The upper and lower limits of these smaller ranges can be independently included or excluded from the range.

[0027] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary technical personnel in the field of the invention. Although the invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein can also be used in the implementation or testing of the invention. All documents referred to in the descriptions are incorporated by reference to disclose and describe methods and/or materials related to the documents. In case of conflict with any incorporated documents, the contents of the descriptions shall prevail.

[0028] Without departing from the scope or spirit of the invention, various improvements and changes can be made to the specific embodiments of the descriptions of the invention, which is obvious to those technical personnel in the field. Other embodiments obtained from the descriptions of the invention are obvious to the technical personnel. The descriptions and embodiments of the application are only exemplary.

[0029] The terms “include”, “comprise”, “have”, “contain” and so on used in this article are all open terms, which means including but not limited to.

[0030] Embodiment 1

[0031] Preparation for Amphoteric Lignin: (1) Take 10g of paper industry alkali lignin, dissolve it in 50ml of NaOH solution with the concentration of 1mol/L, after stirring and dissolving, add 5g of potassium 5 permanganate, heat to 120°C, after reaction for 120min, filter out MnO, adjust pH to neutral, rotate and evaporate, and dry to obtain the oxidized lignin; 102076 (2) After drying the oxidized lignin, take 10g of oxidized lignin into a three-neck flask with a stirrer and a thermometer, and add 100mL of sodium hydroxide with the concentration of 10%, 5ml of epichlorohydrin, and 10ml of absolute ethyl alcohol, react at 70°C for 2h, filter, wash with water and acetone, and dry at 70°C to obtain the epoxidized lignin; (3) Take 10g of epoxidized lignin and put it into a three-neck flask with a stirrer and thermometer, add 5g of mixed solution of diethylenetriamine and triethylenetetramine (1:2, molar mass), 50mL of NaOH solution with the concentration of 40g/L and 10ml of formaldehyde in a three-neck flask, react at 80°C for 4h, filter, wash with water and ethanol three times, and dry at 70°Cto obtain the amphoteric lignin.

[0032] The epoxidation modification of amphoteric lignin in the embodiment can occur in the phenolic hydroxyl groups of lignin, including the free phenolic hydroxyl groups of syringyl, guaiacol and hydroxyphenyl in the lignin structure, and its structural formula is as follows: NH,

C NH, AN TI

HO _goox y Lignin NH, To +4 hw

[0033] Preparation for Oil Sludge Demulsifier:

[0034] According to the mass percentage, mix 35wt% of the above-mentioned synthetic amphoteric lignin, 2wt% alkyl polyglycoside and 38wt% water, heat to 50°C, and stir for 60 minutes; after mixing uniformly, add 20wt% sodium silicate, 5wt% sodium citrate, stir and react for 2h to obtain the liquid oil sludge demulsifier.

[0035] The alkyl polyglycoside in the embodiment is dodecyl polyglucoside APG1216.

[0036] Embodiment 2

[0037] Preparation for Amphoteric Lignin: (1) Take 10g of paper industry alkali lignin, dissolve it in 50ml of NaOH solution with the concentration of 1mol/L, after stirring and dissolving, add 2g of potassium 6 permanganate, heat to 150°C, after reaction for 180min, filter out MnO, adjust pH to neutral, rotate and evaporate, and dry to obtain the oxidized lignin; 102076 (2) After drying the oxidized lignin, take 10g of oxidized lignin into a three-neck flask with a stirrer and a thermometer, and add 100mL of sodium hydroxide solution with the concentration of 10%, 8ml of epichlorohydrin, and 10ml of absolute ethyl alcohol, react at 70°C for 2h, filter, wash with water and acetone, and dry at 70°C to obtain the epoxidized lignin; (3) Take 10g of epoxidized lignin and put it into a three-neck flask with a stirrer and thermometer, add 3g of mixed solution of diethylenetriamine and tetraethylenepentamine (1:2, molar mass), 50mL of sodium hydroxide solution with the concentration of 40g/L and 10ml of formaldehyde in a three-neck flask, react at 80°C for 4h, filter, wash with water and ethanol three times, and dry at 70°C to obtain the amphoteric lignin.

[0038] The epoxidation modification of amphoteric lignin in the embodiment can occur in the phenolic hydroxyl groups of lignin, including the free phenolic hydroxyl groups of syringyl, guaiacol and hydroxyphenyl in the lignin structure, and its structural formula is as follows: NH SNS SAN,

HO COOH y mn ST 0 a OH ha

[0039] Preparation for Oil Sludge Demulsifier: According to the mass percentage, mix 40wt% of the above-mentioned synthetic amphoteric lignin, 3wt% alkyl polyglycoside and 43wt% water, heat to 50°C, and stir for 60 minutes; after mixing uniformly, add 10wt% sodium silicate, 4wt% sodium citrate, stir and react for 2h to obtain the liquid oil sludge demulsifier.

[0040] The alkyl polyglycoside in the embodiment is dodecyl polyglucoside APG1214.

[0041] Embodiment 3

[0042] Preparation for Amphoteric Lignin: (1) Take 10g of paper industry alkali lignin, dissolve it in 50ml of NaOH solution with the concentration of 1mol/L, after stirring and dissolving, add 4g of potassium 7 permanganate, heat to 130°C, after reaction for 160min, filter out MnO, adjust pH to neutral, rotate and evaporate, and dry to obtain the oxidized lignin; 102076 (2) After drying the oxidized lignin, take 10g of oxidized lignin into a three-neck flask with a stirrer and a thermometer, and add 100mL of sodium hydroxide with the concentration of 10%, 8ml of epichlorohydrin, and 10ml of absolute ethyl alcohol, react at 70°C for 2h, filter, wash with water and acetone, and dry at 70°C to obtain the epoxidized lignin; (3) Take 10g of epoxidized lignin and put it into a three-neck flask with a stirrer and thermometer, add 2g of mixed solution of triethylenetetramine and tetraethylenepentamine (1:2, molar mass), 50mL of sodium hydroxide solution with the concentration of 40g/L and 8ml of formaldehyde in a three-neck flask, react at 80°C for 4h, filter, wash with water and ethanol three times, and dry at 70°C to obtain the amphoteric lignin.

[0043] The epoxidation modification of amphoteric lignin in the embodiment can occur in the phenolic hydroxyl groups of lignin, including the free phenolic hydroxyl groups of syringyl, guaiacol and hydroxyphenyl in the lignin structure, and its structural formula is as follows: NH Sy SAAL Dé Ba 47 O ve OH “TN,

[0044] Preparation for Oil Sludge Demulsifier:

[0045] According to the mass percentage, mix 30wt% of the above-mentioned synthetic amphoteric lignin, 2wt% alkyl polyglycoside and 48wt% water, heat to 50°C, and stir for 60 minutes; after mixing uniformly, add 15wt% sodium silicate, 5wt% sodium citrate, stir and react for 2h to obtain the liquid oil sludge demulsifier.

[0046] The alkyl polyglycoside in the embodiment is dodecyl polyglucoside APG1216.

[0047] Embodiment 4

[0048] The amphoteric lignin prepared in Embodiment 1 was adopted.

[0049] Preparation for Oil Sludge Demulsifier: 8

[0050] According to the mass percentage, mix 25wt% of the above-mentioned synthetic amphoteric lignin, 5wt% alkyl polyglycoside and 38wt% water, heat to 50°C, and stir for 102076 60 minutes; after mixing uniformly, add 25wt% sodium silicate, 7wt% sodium citrate, stir and react for 2h to obtain the liquid oil sludge demulsifier.

[0051] The alkyl polyglycoside in the embodiment is dodecyl polyglucoside APG1216.

[0052] Comparative Example 1

[0053] Same as the Embodiment 1, the difference is only that the lignin is not cyclized and modified.

[0054] Comparative Example 2

[0055] Same as the Embodiment 1, the difference is only that the lignin is not oxidized and modified by potassium permanganate.

[0056] Application: The above oil sludge demulsifier is used to the actual oil sludge demulsification. Oil sludge composition: oil content is 46.38%, water content is 49.40% and solid content is 5.22%. Take 80g of oil sludge and inject 0.8mL of demulsifier solution. After fully stirring, add it to a 100mL of mixing cylinder with stopper. After fully mixing, let it stand for 120min at room temperature to determine the water content of the dehydrated oil sludge, so as to calculate the dehydration rate. The results are shown in Table 1.

[0057] Table 1 [ew mere

[0058] Note: The oil sludge with oil content of 2.6%, water content of 89.38% and solid content of 8.02% was used for demulsification test.

[0059] The above described embodiments are only to describe the preferred methods of the invention, but not to limit the scope of the invention. On the premise of not departing from the design spirit of the invention, various deformations and improvements made by those ordinary technical personnel in the field to the technical solutions of the invention shall fall within the protection scope determined by the claims of the invention.

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Claims

CLAIMS - LU102076

1. An oil sludge demulsifier, which is characterized in that, according to the mass percentage, it comprises the following raw materials: 30-40% amphoteric lignin, 10-20% sodium silicate, 4-5% sodium citrate, 2-3% alkyl polyglycoside, and the balance is water.

2. An oil sludge demulsifier as described in Claim 1, which is characterized in that, the structural formula for amphoteric lignin is as follows: HO N AR4

COOH TY

O Lignin gnin | Ry /

O N \ \ OH , of which, Lignin is a lignin molecular fragment, Rı, —CH,CH NH —CH,CH NH Ra, Rs and Ra are n , mor -NHa, of which, n and m areior2.

3. An oil sludge demulsifier as described in Claim 2, which is characterized in that, the preparation method for amphoteric lignin comprises the following steps: (1) With alkali lignin as raw material and potassium permanganate as oxidant, oxidize and prepare the lignin to obtain the oxidized lignin; (2) Blend the oxidized lignin with alkali solution and absolute ethyl alcohol, with epichlorohydrin as halogenating agent, and react under stirring conditions to prepare and obtain the epoxidized lignin; (3) Add the hyperbranched polyamine derivatives, alkali solution and formaldehyde to the epoxidized lignin, and react under stirring conditions to prepare and obtain the amphoteric lignin.

4. An oil sludge demulsifier as described in Claim 3, which is characterized in that, the hyperbranched polyamine derivatives comprise diethylenetriamine, triethylenetetramine, tetraethylenepentamine and cross-linked derivatives formed by cross-linking of diethylenetriamine, triethylenetetramine and tetraethylenepentamine.

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5. An oil sludge demulsifier as described in Claim 1, which is characterized in that, LU102076

HO Ho 0-R n the structural formula for alkyl polyglycoside is as follows: HO OH , of which, R is the alkyl of C12-C1s, n is the degree of polymerization, and n is 1-3.

6. A preparation method for oil sludge demulsifier as described in any one of Claims 1-5, which is characterized in that, it comprises the following steps: accurately weigh each raw material, mix the amphoteric lignin and alkyl polyglycoside with water, heat and stir evenly, then add sodium silicate and sodium citrate, and stir evenly to obtain the oil sludge demulsifier.

7. The preparation method for oil sludge demulsifier as described in Claim 6, which is characterized in that, it is heated to 40-60 °C

8. An application of the oil sludge demulsifier as described in any one of Claims 1-5 in oil sludge demulsification.

9. The application as described in Claim 8, which is characterized in that, the application method is to first add the oil sludge demulsifier to the oil sludge, of which, add the amount of 10ml of oil sludge demulsifier solution to per 80g of oil sludge, then fully mix the two, and then dehydrate the oil sludge demulsifier at 60-70°C.

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