Preparation method, demulsifier and application of biomass carbonization amination demulsifier

Abstract

The application discloses a preparation method, a demulsifier and application of a biomass carbonized aminated demulsifier. Cotton is hydrolyzed by phosphoric acid to obtain cellulose oligomers, and then the cellulose oligomers are treated by carbonization and then react with amino chemicals to obtain the biomass carbonized aminated demulsifier. The biomass carbonized aminated demulsifier is applied to oily wastewater, and after demulsification of the oily wastewater at room temperature for 30 min, the water phase transmittance reaches more than 82%, and the oil removal rate is as high as 99.24%. The demulsifier has the characteristics of cheap and easily available raw materials, small demulsifier dosage, high demulsification efficiency, short time, recycling of biomass waste, no pollution, easy degradation and simple preparation method, and is good in adaptability, and has good application and promotion prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of demulsifiers in the oil and gas industry, and particularly relates to a preparation method of a biomass carbonization amination demulsifier, the demulsifier and application. BACKGROUND

[0002] In the oil and gas industry, the oil-containing wastewater generated in the drilling, completion, production, transportation and refining processes contains fine clay suspended particles, oils and soluble treatment agents. These treatment agents, as a protective colloid, form a kind of polydispersed colloidal or emulsified solution with negative charge through functional groups and clay particles, and have high stability, which may last for several minutes to several years. The stable colloidal or emulsified solution has many adverse factors in the wastewater treatment process, including equipment corrosion, difficulty in dewatering, increased transportation costs, etc. Therefore, it is crucial to demulsify the colloidal or emulsified solution before treatment. The current emulsion demulsification methods mainly include chemical demulsification, membrane demulsification, electric field demulsification, heating demulsification and centrifugal demulsification. Among them, the chemical demulsification method is more commonly used, that is, a demulsifier is added to the emulsified oil-containing drilling wastewater, and through chemical action, other separation methods are used to achieve the purpose of oil-water separation by destabilizing and demulsifying the colloidal or emulsified solution.

[0003] Chemical demulsifiers are amphiphilic compounds with both hydrophilic and hydrophobic properties, which can be adsorbed at the oil-water interface. They can be generally divided into inorganic and organic types. Organic demulsifiers have more advantages than inorganic demulsifiers. For example, they have less dosage, strong demulsification ability, large and not easily broken flocculation, no increase in mud content, no corrosivity, and less influence of salt, pH value and temperature. They not only have the ability to remove suspended solids by adsorption, bridging and flocculation, but also have the functions of electric neutralization and demulsification of oil, and the ability to remove pollutants by electrostatic adsorption and flocculation between different molecules. Specifically, they are divided into synthetic organic high molecular flocculants and natural organic high molecular flocculants. For example, ethylene oxide-propylene oxide (EO-PO) block copolymers, silicon polyether, dendritic polymers, biodegradable polymer surfactants, ionic liquids and nanoparticle-based demulsifiers have attracted more and more attention in the industrial field. However, these demulsifiers have some inherent problems, such as complex and dangerous preparation process, high cost of raw materials, certain pollution to the environment, and serious waste of resources.

[0004] The Chinese patent document with the publication number CN105384927A and the publication date of March 9, 2016 discloses an oil-in-water emulsion demulsifier and a preparation method thereof. The oil-in-water emulsion demulsifier is prepared by sequentially preparing a bisamide, a chlorinated polyether and a cationic polyether. The preparation method comprises the following steps: 1) mixing an organic amine and a fatty acid in a proportion of 1:2-1:4 (molar ratio) under stirring, controlling the temperature of the reaction system at 50-170 DEG C, and reacting for 3-18 h to obtain the bisamide; 2) adding an organic solvent ethanol and the bisamide into a four-necked flask with a thermometer, a stirrer and a condenser tube in sequence, starting to drop polyepichlorohydrin at 20 DEG C-120 DEG C, stirring for 5 h, and cooling to obtain the chlorinated polyether which is a brownish red viscous liquid; 3) placing the chlorinated polyether and a dimethylamine aqueous solution synthesized above into a clean reaction kettle, purging air by introducing nitrogen, controlling the temperature at 50-80 DEG C, reacting for 5 h, continuously heating to 120 DEG C, and reacting for 6 h to obtain the brownish cationic polyether which is a water-soluble oil-in-water emulsion demulsifier. Although the organic demulsifier prepared by the method has high efficiency, the process is complex, the raw material cost is high, and the demulsifier remains in the oil phase or the water phase after demulsification, which causes environmental problems. Therefore, it is still a great challenge to seek a new demulsifier which is widely available, low in cost and excellent in performance. SUMMARY

[0005] The present application aims at the defects and deficiencies of the prior art, and provides a preparation method of biomass carbonization amination demulsifier. The method can effectively solve the technical problems of high raw material cost, narrow source selection range and poor performance of the demulsifier in the prior art.

[0006] Another object of the present application is to provide a demulsifier prepared by the preparation method.

[0007] Still another object of the present application is to provide the application of the prepared demulsifier.

[0008] The present application is achieved by adopting the following technical scheme:

[0009] The preparation method of the biomass carbonization amination demulsifier comprises the following steps: hydrolyzing cotton by phosphoric acid to obtain cellulose oligomers, and then reacting the cellulose oligomers with an amino compound after carbonization treatment to obtain the biomass carbonization amination demulsifier.

[0010] The preparation method specifically comprises the following steps: adding cotton into phosphoric acid, dissolving sufficiently, then heating to 40-70℃ and stirring for 1-3h, then adding ethanol to regenerate the dissolved cellulose and obtain cellulose oligomers, uniformly dispersing the cellulose oligomers in an amino compound after carbonization treatment, adding sodium nitrite and stirring for 0.5-2h, then adding concentrated sulfuric acid, then stirring at 40-80℃ for 0.5-24h, finally centrifuging and washing to neutral, then freezing and drying the product to obtain the biomass carbonized amino compound demulsifier.

[0011] Further, the cotton is natural cotton.

[0012] Further, the cotton is a product taking cotton as raw material.

[0013] Further, the mass ratio of the cotton to phosphoric acid is 1-5:100.

[0014] Further, the mass ratio of the carbonized cellulose oligomers to sodium nitrite and concentrated sulfuric acid after addition is 1:10-30:35-60.

[0015] Further, the mass ratio of the amino compound to the carbonized cellulose oligomers is 20-50:1.

[0016] Further, the mass ratio of the carbonized cellulose oligomers to the amino compound aqueous solution is 2:40-50.

[0017] Further, the amino compound is at least one of ammonia, urea, ammonium bicarbonate, ethylenediamine, propylenediamine, polyethylene polyamine and polyethylene imine.

[0018] The biomass carbonized amino compound demulsifier prepared by the above preparation method of the biomass carbonized amino compound demulsifier.

[0019] The application of the biomass carbonized amino compound demulsifier prepared by the above preparation method of the biomass carbonized amino compound demulsifier in oil-containing wastewater emulsion.

[0020] Further, the application comprises the following steps: dispersing the biomass carbonized amino compound demulsifier in water to obtain a suspension, then mixing the suspension with the oil-containing wastewater emulsion at room temperature and standing for 10-30min.

[0021] After the demulsification is completed, most of the biomass carbonized amino compound demulsifier adsorbs oil and then floats on water together with the separated oil phase, and a small part of the biomass carbonized amino compound demulsifier settles in water, which can be separated by long-time sedimentation or centrifugal separation, and the separation is relatively simple.

[0022] Further, the mass fraction of the suspension is 0.01wt%-0.6wt%.

[0023] Further, the volume ratio of the suspension to the oily wastewater emulsion is 1:10-20.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1、The present application uses cotton as a precursor to prepare a biomass carbonized aminated demulsifier through steps, the biomass carbonized aminated demulsifier has a large number of active amino groups on the surface, and exhibits high interfacial activity, can quickly reduce the interfacial tension, and induce demulsification.

[0026] 2、The raw material can be directly obtained from natural cotton or obtained from waste cotton fabric, can interact with asphaltene after modification, and is positively charged in the emulsion after modification to induce electrostatic neutralization with negatively charged oil droplets to promote demulsification. The present application makes full use of natural biomass, reduces the use of fossil raw materials, can be degraded in the natural environment, and has good application prospect.

[0027] 3、The biomass carbonized aminated demulsifier provided by the present application can realize normal temperature demulsification of the oily emulsion, realize effective separation of oil-water, and has the characteristics of small dosage and high demulsification efficiency, and the oil removal rate of 25mg / L of the demulsifier under normal temperature conditions for 30min can reach 99.24%. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The scanning electron microscope image of the biomass carbonized aminated demulsifier described in Example 1. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application, and are not used to limit the present application.

[0030] The cotton used in the examples is natural cotton. The concentrated sulfuric acid described in the examples is commercially available 98wt% concentrated sulfuric acid.

[0031] Example 1

[0032] As a preferred embodiment of the present application, a preparation method of a biomass carbonized aminated demulsifier is disclosed, which regenerates cellulose oligomers by hydrolyzing cotton with phosphoric acid, and then prepares the biomass carbonized aminated demulsifier by reacting the cellulose oligomers after carbonization treatment with an amino compound.

[0033] Example 2

[0034] As another preferred embodiment of the present application, a preparation method of the biomass carbonized aminated demulsifier is disclosed, which specifically comprises the following steps: adding cotton into phosphoric acid, dissolving sufficiently, then heating to 40-70℃ and stirring for 1-3h, then adding ethanol to regenerate the dissolved cellulose and obtain cellulose oligomers, uniformly dispersing the cellulose oligomers in an amino compound after carbonization treatment, adding sodium nitrite and stirring for 0.5-2h, then adding concentrated sulfuric acid, then stirring at 40-80℃ for 0.5-24h, finally centrifuging and washing to neutral, then freeze-drying the product to obtain the biomass carbonized aminated demulsifier. The cotton is natural cotton. The mass ratio of cotton to phosphoric acid is 3:100. The mass ratio of the carbonized cellulose oligomers to sodium nitrite and concentrated sulfuric acid is 1:20:50. The mass ratio of the amino compound to the carbonized cellulose oligomers is 35:1. The mass ratio of the carbonized cellulose oligomers to the aqueous solution of the amino compound is 2:45. The amino compound is at least one of ammonia, urea, ammonium bicarbonate, ethylenediamine, propylenediamine, polyethylene polyamine and polyethylene imine.

[0035] Example 3

[0036] The biomass carbonized aminated demulsifier prepared in Example 1 or 2 is applied in the oil-containing wastewater emulsion, which comprises the following steps: dispersing the biomass carbonized aminated demulsifier in water to obtain a suspension, then mixing the suspension with the oil-containing wastewater emulsion at room temperature and standing for 10-30min.

[0037] After the demulsification, most of the biomass carbonized aminated demulsifier adsorbs oil and then floats on the water together with the separated oil phase, and a small part of the biomass carbonized aminated demulsifier settles in the water, which can be separated by long-time sedimentation or centrifugation. The mass fraction of the suspension is 0.03wt%. The volume ratio of the suspension to the oil-containing wastewater emulsion is 1:15.

[0038] Example 4

[0039] The present example provides a biomass carbonized aminated demulsifier, which is obtained by the following steps:

[0040] 2g of cotton is added into 100ml of phosphoric acid, dissolved sufficiently, then heated to 50℃ and stirred for 2h, then 50ml of ethanol is added and stirred for 20min to regenerate the cellulose oligomers, then the product is centrifuged and washed to neutral, and finally freeze-dried.

[0041] 2g of cellulose oligomer was carbonized at 400℃, then 1g of the carbonized product was uniformly dispersed in 22.5ml of an amino compound, 23g of sodium nitrite was added and stirred for 10min, then 21ml of concentrated sulfuric acid was added dropwise, after that the paste sample was placed in 60℃ and stirred for 1h, after the reaction was completed, it was washed by centrifugation until neutral, and the product was freeze-dried to obtain a biomass carbonized amino demulsifier.

[0042] Example 5

[0043] The present example provides a biomass carbonized amino demulsifier, which is obtained by the following steps:

[0044] 2g of cotton was added to 100ml of phosphoric acid, after fully dissolved, the temperature was raised to 60℃ and stirred for 2h, then 50ml of ethanol was added and stirred for 20min to regenerate the cellulose oligomer, after that it was washed by centrifugation until neutral, and the product was freeze-dried.

[0045] 2g of cellulose oligomer was carbonized at 400℃, then 1g of the carbonized product was uniformly dispersed in 22.5ml of an amino compound, 23g of sodium nitrite was added and stirred for 10min, then 21ml of concentrated sulfuric acid was added dropwise, after that the paste sample was placed in 60℃ and stirred for 1h, after the reaction was completed, it was washed by centrifugation until neutral, and the product was freeze-dried to obtain a biomass carbonized amino demulsifier.

[0046] Example 6

[0047] The biomass carbonized amino demulsifier prepared in Example 4 was prepared into suspensions of different concentrations, which were used to characterize the demulsification performance of amino demulsifiers of different concentrations in oil-containing wastewater emulsion.

[0048] 5 parts by weight of crude oil was added to 495 parts by weight of deionized water and stirred to mix, heated to 60℃, then stirred at a speed of 11000r / min for 20min to obtain a stable oil-containing wastewater emulsion (oil-in-water emulsion).

[0049] Different parts by weight of the amino demulsifier prepared in Example 4 were added to water to prepare amino demulsifier suspensions with mass fractions of 0.06%, 0.05%, 0.04%, 0.03%, 0.02%, and 0.01%, respectively, and the obtained samples were marked as experimental groups 1-6; the blank group was water, and the sample was marked as experimental group 7.

[0050] 1 volume part of the above experimental groups 1-6 was added to 20 volume parts of oil-containing wastewater emulsion, then mixed uniformly by shaking thoroughly, and then placed at room temperature for 30min, the transmittance and oil removal rate were measured, and the results are shown in Table 1.

[0051] Table 1 Demulsification results of experimental groups 1-7

[0052] Group CN1 (mg / L) Transmittance (%) Oil removal rate (%) Experimental group 1 30 81.70 99.02 Experimental group 2 25 82.0 99.24 Experimental group 3 20 57.7 98.26 Experimental group 4 15 31.1 97.30 Experimental group 5 10 23.4 97.16 Experimental group 6 5 0.3 91.60 Experimental group 7 0 0 0.5

[0053] Note: The "amino demulsifier (mg / L)" in the table refers to the concentration of the amino demulsifier in the oil-containing wastewater emulsion.

[0054] As can be seen from Table 1, the biomass carbonized amino demulsifier provided by the present application has good demulsification performance, and the transmittance of the oil-containing wastewater emulsion can reach 82.0% and the oil removal rate can reach 99.24% after 30 min of settling at room temperature at a concentration of 25 mg / L.

[0055] Example 7

[0056] Based on the biomass carbonized amino demulsifier prepared in Example 4, experimental groups 8-12 were sequentially established to characterize the demulsification performance of the amino demulsifier at different pH values.

[0057] 5 parts by weight of crude oil was added to 495 parts by weight of deionized water and stirred to mix, the pH value was adjusted by adding hydrochloric acid or sodium hydroxide, heated to 60°C, and then stirred at a speed of 11000 r / min for 20 minutes to obtain a stable oil-containing wastewater emulsion (oil-in-water emulsion).

[0058] The amino demulsifier prepared in Example 4 was added to water to prepare amino demulsifier suspensions with mass fractions of 0.05%, 0.1% and 0.15%, respectively, and the samples were recorded as experimental groups 8-12.

[0059] 1 volume part of the above amino demulsifier suspension was added to 20 volume parts of oil-containing wastewater emulsion with different pH values, then fully oscillated and mixed uniformly, and then placed at room temperature for 30 min, and the transmittance and oil removal rate were measured, and the results are shown in Table 2.

[0060] Table 2 Demulsification results of experimental groups 8-12

[0061] Group pH Transmittance % Oil removal rate % Experimental group 8 4 5.2 95.81 Experimental group 9 6 59.7 98.35 Experimental group 10 7 82.0 99.24 Experimental group 11 8 62 98. 47 Experimental group 12 10 2.6 97.78

[0062] As can be seen from Table 2, the biomass carbonized amino demulsifier provided by the present application can achieve higher demulsification efficiency near neutral.

[0063] The present application provides a biomass carbonized amino demulsifier suitable for demulsification of oil-containing wastewater emulsion, and has the characteristics of simple preparation method, wide source of raw materials, no pollution, easy degradation, excellent demulsification performance, etc.

[0064] The specific embodiments of the present application described above do not constitute a limitation on the scope of protection of the present application. Any various other corresponding changes and modifications made in accordance with the technical concept of the present application shall be included in the scope of protection of the claims of the present application.

Claims

1. A method of preparing a biomass carbonization aminization demulsifier, characterized by: The biomass carbonized aminated demulsifier is prepared by hydrolyzing cotton in phosphoric acid to obtain cellulose oligomers, and then reacting the cellulose oligomers with an amino compound after carbonization treatment. The preparation method specifically comprises the following steps: adding cotton into phosphoric acid, dissolving sufficiently, and then heating to 40-70 DEG C and stirring for 1-3 h, then adding ethanol to regenerate the dissolved cellulose and obtain cellulose oligomers, uniformly dispersing the cellulose oligomers in an amino compound after carbonization treatment, adding sodium nitrite and stirring for 0.5-2 h, then adding concentrated sulfuric acid, stirring at 40-80 DEG C for 0.5-24 h, and finally centrifuging and washing to neutral, and then freeze-drying the product to obtain the biomass carbonized aminated demulsifier.

2. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The cotton is natural cotton.

3. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The cotton is a product taking cotton as raw material.

4. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The mass ratio of the cotton to phosphoric acid is 1-5:

100.

5. The method for preparing a biomass carbonization and amination demulsifier according to claim 1, characterized in that: The mass ratio of the cellulose oligomers after carbonization to sodium nitrite and concentrated sulfuric acid is 1:10-30:35-60.

6. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The mass ratio of the amino compound to the cellulose oligomers after carbonization is 20-50:

1.

7. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The mass ratio of the cellulose oligomers after carbonization to the amino compound aqueous solution is 2:40-50.

8. The method for preparing a biomass carbonization amination demulsifier according to claim 1, characterized in that: The amino compound is at least one of ammonia, urea, ammonium bicarbonate, ethylenediamine, propylenediamine, polyethylene polyamine and polyethylene imine. 9.A biomass carbonized aminated demulsifier prepared by the preparation method of the biomass carbonized aminated demulsifier according to claim 1. 10.The application of the biomass carbonized aminated demulsifier prepared by the preparation method of the biomass carbonized aminated demulsifier according to claim 1 in oil-containing wastewater emulsion.

11. Use of the biomass carbonization aminization demulsifier according to claim 10 in oil-containing wastewater emulsions, characterized in that: The method comprises the following steps: dispersing the biomass carbonized aminated demulsifier in water to obtain a suspension, and then mixing the suspension with the oil-containing wastewater emulsion at room temperature and standing for 10-30 min.

12. Use of the biomass carbonization aminization demulsifier according to claim 11 in oil-containing wastewater emulsions, characterized in that The mass fraction of the suspension is 0.01wt%-0.6wt%.

13. Use of the biomass carbonization aminization demulsifier according to claim 12 in oil-containing wastewater emulsions, characterized in that: The volume ratio of the suspension to the oil-containing wastewater emulsion is 1:10-20.

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