Multi-branched type crude oil demulsifier and preparation method thereof

Abstract

The invention relates to a multi-branched type crude oil demulsifier and a preparation method thereof. The structural general formula of the multi-branched type crude oil demulsifier is shown by formula I; the preparation method comprises the following steps: 1) performing acylation modification on chitosan to obtain N-acylated chitosan; 2) performing carboxyl alkylation on the N-acylated chitosanto obtain modified N-acylated carboxyl alkyl chitosan; 3) performing amination modification on the terminal hydroxyl of polyethylene glycol monomethyl ether to obtain aminated polyethylene glycol monomethyl ether; 4) enabling the modified polyethylene glycol monomethyl ether to react with the N-acylated carboxyl alkyl chitosan to obtain a target product polyethylene glycol monomethyl ether grafted N-acylated carboxyl alkyl chitosan. With chitosan type natural high-molecular compounds as raw materials, the multi-branched type crude oil demulsifier provided by the invention has the advantagesof wide source, natural property, no toxicity, high biocompatibility, degradability and the like. A series of efficient demulsifiers suitable for oil-in-water (O / W) type emulsion are obtained by introducing carboxyl alkyl, acyl and polyether side chain to a chitosan molecular chain and controlling the position and substitution degree of each substituent.

Description

technical field

[0001] The invention relates to a multi-branched crude oil demulsifier and a preparation method thereof, belonging to the field of petrochemical industry. Background technique

[0002] In the process of oilfield exploitation, with the implementation of oil recovery technologies such as steam flooding, surfactant, polymer and ASP flooding, the water content of crude oil emulsion increases, and the stability is enhanced, making it more difficult to break the emulsion of crude oil. The formation of emulsion will bring a series of serious hazards to the exploitation, transportation and processing of petroleum. The emulsification of crude oil and water will make the extraction of crude oil more difficult; when transporting water-containing crude oil by pipeline or tanker truck, it will increase the load of the pump and the transportation cost. Therefore, it is very necessary to desalt and dehydrate the crude oil emulsion before crude oil transportation and proces...

Examples

Embodiment 1

[0043] Prepare the N-n-butyrylation carboxymethyl chitosan of polyethylene glycol monomethyl ether graft, concrete steps are as follows:

[0044] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, degree of deacetylation >95%, viscosity 100-200mPa·s) dissolved in 40mL of 10% acetic acid aqueous solution, added 160mL of methanol to dilute, added 5.9mmol of n-butyric anhydride under stirring condition, left at room temperature for 24h, then added 260mL of acetone was used as precipitant, and the precipitate was washed three times with methanol and ether respectively, and freeze-dried to obtain white water-soluble solid N-n-butyrylated chitosan (A 4 CS).

[0045] Wherein the consumption of n-butyric anhydride is 0.5 times of the amount of amino substance contained in chitosan, and concrete calculation method is as follows:

[0046] The sugar unit of chitosan is glucosamine residue, and the molecular weight of this residue (sugar unit of chitosan) is 161, an...

Embodiment 2

[0051] Prepare the N-n-hexanoylated carboxymethyl chitosan grafted with polyethylene glycol monomethyl ether, and the specific steps are as follows:

[0052] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, deacetylation degree>95%, viscosity 100~200mPa·s) was dissolved in 40mL 10% acetic acid aqueous solution, added 160mL methanol to dilute, under stirring condition, add n-hexanoic anhydride 5.9mmol according to the amount of amino substance 0.5 times, in Placed at room temperature for 24 hours, 260 mL of acetone was added as a precipitant, the precipitate was washed three times with methanol and ether, and freeze-dried to obtain a white water-soluble solid N-n-hexanoylated chitosan (A 6 CS). Wherein the calculation method of n-hexanoic anhydride consumption is described in step (1) with reference to embodiment 1.

[0053] (2) Carboxymethylation of N-n-hexanoylated chitosan: get 1.128g A 6 Add 100mL of distilled water to CS in a 250mL three-neck flas...

Embodiment 3

[0057] Prepare the N-n-octanoyl carboxymethyl chitosan of polyethylene glycol monomethyl ether graft, concrete steps are as follows:

[0058] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, degree of deacetylation>95%, viscosity 100-200mPa·s) dissolved in 40mL of 10% acetic acid aqueous solution, added 160mL of methanol for dilution, and added 5.9mmol of n-octylic anhydride according to 0.5 times the amount of amino substances under stirring conditions, After standing at room temperature for 24 h, 260 mL of acetone was added as a precipitating agent, and the precipitate was washed three times with methanol and ether, and freeze-dried to obtain a white water-soluble solid N-octanoyl chitosan (A 8 CS). Wherein the calculating method of n-octanoic anhydride consumption is described with reference to step (1) among the embodiment 1.

[0059] (2) Carboxymethylation of N-octanoyl chitosan: get 1.256g A 8Add 100mL of distilled water to CS in a 250mL three-n...

technical field

[0001] The invention relates to a multi-branched crude oil demulsifier and a preparation method thereof, belonging to the field of petrochemical industry. Background technique

[0002] In the process of oilfield exploitation, with the implementation of oil recovery technologies such as steam flooding, surfactant, polymer and ASP flooding, the water content of crude oil emulsion increases, and the stability is enhanced, making it more difficult to break the emulsion of crude oil. The formation of emulsion will bring a series of serious hazards to the exploitation, transportation and processing of petroleum. The emulsification of crude oil and water will make the extraction of crude oil more difficult; when transporting water-containing crude oil by pipeline or tanker truck, it will increase the load of the pump and the transportation cost. Therefore, it is very necessary to desalt and dehydrate the crude oil emulsion before crude oil transportation and proces...

Examples

Embodiment 1

[0043] Prepare the N-n-butyrylation carboxymethyl chitosan of polyethylene glycol monomethyl ether graft, concrete steps are as follows:

[0044] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, degree of deacetylation >95%, viscosity 100-200mPa·s) dissolved in 40mL of 10% acetic acid aqueous solution, added 160mL of methanol to dilute, added 5.9mmol of n-butyric anhydride under stirring condition, left at room temperature for 24h, then added 260mL of acetone was used as precipitant, and the precipitate was washed three times with methanol and ether respectively, and freeze-dried to obtain white water-soluble solid N-n-butyrylated chitosan (A 4 CS).

[0045] Wherein the consumption of n-butyric anhydride is 0.5 times of the amount of amino substance contained in chitosan, and concrete calculation method is as follows:

[0046] The sugar unit of chitosan is glucosamine residue, and the molecular weight of this residue (sugar unit of chitosan) is 161, an...

Embodiment 2

[0051] Prepare the N-n-hexanoylated carboxymethyl chitosan grafted with polyethylene glycol monomethyl ether, and the specific steps are as follows:

[0052] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, deacetylation degree>95%, viscosity 100~200mPa·s) was dissolved in 40mL 10% acetic acid aqueous solution, added 160mL methanol to dilute, under stirring condition, add n-hexanoic anhydride 5.9mmol according to the amount of amino substance 0.5 times, in Placed at room temperature for 24 hours, 260 mL of acetone was added as a precipitant, the precipitate was washed three times with methanol and ether, and freeze-dried to obtain a white water-soluble solid N-n-hexanoylated chitosan (A 6 CS). Wherein the calculation method of n-hexanoic anhydride consumption is described in step (1) with reference to embodiment 1.

[0053] (2) Carboxymethylation of N-n-hexanoylated chitosan: get 1.128g A 6 Add 100mL of distilled water to CS in a 250mL three-neck flas...

Embodiment 3

[0057] Prepare the N-n-octanoyl carboxymethyl chitosan of polyethylene glycol monomethyl ether graft, concrete steps are as follows:

[0058] (1) Synthesis of N-acylated chitosan: 2g chitosan (CS) (M w =179.17kDa, degree of deacetylation>95%, viscosity 100-200mPa·s) dissolved in 40mL of 10% acetic acid aqueous solution, added 160mL of methanol for dilution, and added 5.9mmol of n-octylic anhydride according to 0.5 times the amount of amino substances under stirring conditions, After standing at room temperature for 24 h, 260 mL of acetone was added as a precipitating agent, and the precipitate was washed three times with methanol and ether, and freeze-dried to obtain a white water-soluble solid N-octanoyl chitosan (A 8 CS). Wherein the calculating method of n-octanoic anhydride consumption is described with reference to step (1) among the embodiment 1.

[0059] (2) Carboxymethylation of N-octanoyl chitosan: get 1.256g A 8Add 100mL of distilled water to CS in a 250mL three-n...

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