A demulsifier for oily wastewater treatment and its synthesis method and application

Abstract

The present invention belongs to the technical field of sewage treatment, and specifically relates to a demulsifier for oily sewage treatment and its synthesis method and application. The synthesis method is as follows: tributylaminomethylsilane, potassium hydroxide, 4-chloro-1-butanol are added to the reactor, stirred at room temperature, heated, and kept warm for reaction; the above mixture is transferred to an autoclave, potassium hydroxide is added again, vacuumed, filled with nitrogen, repeated three times, then slowly heated, vacuumed, passed through propylene oxide, heated up, kept warm for reaction, when the pressure no longer changes, passed through ethylene oxide, heated up, kept warm for reaction, when the pressure no longer changes, the system is cooled to room temperature using circulating cooling water, adjusted, and a product demulsifier is obtained. The demulsifier of the present invention has the advantages of a wide source of raw materials, a simple synthesis process, and low-concentration and high-efficiency demulsification.

Description

Technical Field

[0001] The invention belongs to the technical field of sewage treatment, and specifically relates to a demulsifier for oily sewage treatment and a synthesis method and application thereof. Background Art

[0002] During the oil extraction process, a large amount of formation water is also extracted along with the crude oil, and the produced fluid contains crude oil to form an oil-water mixture. In the oil refining process, the dehydration of crude oil and the washing of oil products will also produce oily wastewater. In the chemical industry, chemical production processes using petroleum as raw materials, such as the production of synthetic rubber and plastics, will also produce oily wastewater.

[0003] If oily wastewater is discharged directly without effective treatment, it will cause serious harm to the aquatic environment. Oil substances will form an oil film on the water surface, blocking oxygen from entering the water, causing aquatic organisms to die of lack of oxygen. At the same time, some harmful substances in oil, such as polycyclic aromatic hydrocarbons, will accumulate in water bodies and sediments, enrich through the food chain, and have long-term adverse effects on the ecosystem and human health.

[0004] Oil droplets in oily wastewater often exist in an emulsified state. The stability of emulsified oil droplets is due to the adsorption of a layer of surfactant molecules on the surface of the oil droplets. The hydrophilic groups of these molecules face the water phase, and the hydrophobic groups face the oil phase, forming a stable interface structure. The particle size of such emulsified oil droplets is small, usually between a few microns and tens of microns, and they have high stability, making it difficult to achieve oil-water separation by simple physical methods.

[0005] Traditional demulsifiers such as inorganic acids, alkalis, and salts are not effective in treating complex oily wastewater. Although some simple surfactant demulsifiers can destroy the stability of emulsified oil droplets to a certain extent, they have problems such as low demulsification efficiency and narrow application range.

[0006] CN104291412A discloses a method for preparing a reverse demulsifier for treating polymer-containing oil production wastewater. The method first uses epichlorohydrin as a raw material to synthesize polyepichlorohydrin PECH through a self-polymerization reaction, and then reacts with an organic amine and carbon disulfide to obtain a brown-red viscous liquid. The present invention also provides a reverse demulsifier prepared by the method, which is an anionic polymer with a network structure, a brown-red viscous liquid, and a rotational viscosity of 120 to 140CP under the conditions of 30°C and a rotation speed of 100r / min. Evaluation tests show that the network anionic reverse demulsifier product prepared by the method has a good water purification effect, dense flocs, and clear water quality, and is particularly suitable for treating polymer-containing oil production wastewater. However, the composition of the reverse demulsifier of the invention is single, the principle of reverse demulsification is simple, and the treatment of complex oilfield oily wastewater is limited, and it cannot meet the needs of oilfield production.

[0007] CN106565007B discloses a deoiling agent for produced water from ternary composite flooding. The deoiling agent is prepared by reacting 2,5-pyridinediamine with formaldehyde and formic acid to generate an intermediate, which is then reacted with sodium chlorododecanoate to generate a zwitterionic deoiling agent. The molar ratio of 2,5-pyridinediamine, formaldehyde, formic acid and sodium chlorododecanoate is 1:2.5-6:2.5-5.5:0.8-2.5, preferably 1:3:3:1.5. The deoiling agent of the invention has the characteristics of simple preparation, strong adaptability, low cost, strong salt resistance and good oil removal effect, and the salt resistance reaches 2.3×10 4 mg / L, the oil removal rate of produced water from ASP flooding is over 97%. And the recovered oil produced by separation does not affect the subsequent dehydration of crude oil. However, the pyridine monomer in the deoiling agent of the invention is highly toxic and easily causes environmental pollution. Summary of the invention

[0008] The present invention aims at the above-mentioned deficiencies of the prior art and provides a demulsifier for oily wastewater treatment and its synthesis method and application. The demulsifier of the present invention has the advantages of wide raw material sources, simple synthesis process and low-concentration high-efficiency demulsification.

[0009] In order to achieve the above objectives:

[0010] In a first aspect, the present invention discloses a method for synthesizing a demulsifier for treating oily wastewater, and the specific steps of the synthesis method are as follows:

[0011] (1) Add tributylaminomethylsilane, potassium hydroxide and 4-chloro-1-butanol into a reactor, stir at room temperature for 20-30 minutes, heat to 100-105° C., and keep warm for 20-30 minutes;

[0012] (2) The mixture is transferred to a high-pressure reactor, potassium hydroxide is added again, the pipeline and the reactor are purged with nitrogen, vacuumized, filled with nitrogen, and vacuumized again, and the process is repeated three times, followed by slow heating to 85-90° C., vacuumization is stopped, propylene oxide is introduced, the temperature is raised to 130-160° C., and the reaction is carried out at the temperature. When the pressure no longer changes, ethylene oxide is introduced, the temperature is raised to 160-190° C., and the reaction is carried out at the temperature. When the pressure no longer changes, the system is cooled to room temperature using circulating cooling water, and the pH is adjusted to 7-8 using hydrochloric acid to obtain a demulsifier product.

[0013] Based on 1 mole part of tributylaminomethylsilane, the usage amounts of 4-chloro-1-butanol, propylene oxide and ethylene oxide are 2.7-3.9 mole parts, 15-60 mole parts and 30-150 mole parts respectively.

[0014] More preferably, based on 1 mole part of tributylaminomethylsilane, the amounts of 4-chloro-1-butanol, propylene oxide and ethylene oxide are 3-3.6 mole parts, 30-60 mole parts and 60-150 mole parts respectively.

[0015] Preferably, in step (1), the weight ratio of potassium hydroxide to tributylaminomethylsilane is 0.6-0.7:1.

[0016] Preferably, in step (2), the weight ratio of potassium hydroxide to tributylaminomethylsilane is 0.2-0.4:1.

[0017] The synthetic reaction equation of the demulsifier for oily wastewater treatment of the present invention is as follows:

[0018]

[0019] In another aspect, the present invention discloses a demulsifier for treating oily wastewater, wherein the molecular structure of the demulsifier is as follows:

[0020]

[0021] Wherein, m = 5-20;

[0022] n=10-50.

[0023] In a third aspect, the present invention discloses the application of the above-mentioned demulsifier in the treatment of oily wastewater.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] (1) The raw materials of the demulsifier of the present invention are widely available and the synthesis process is simple;

[0026] (2) The demulsifier of the present invention has the advantage of high efficiency demulsification at low concentration. When the concentration is 10 mg / L, the oil removal rate reaches more than 92%. DETAILED DESCRIPTION

[0027] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0028] The present invention will be further described below in conjunction with specific embodiments:

[0029] Example 1

[0030] (1) Add 0.05 mol tributylaminomethylsilane, 7.8 g potassium hydroxide, and 0.135 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 20 min, heat to 100° C., and keep the temperature for 20 min;

[0031] (2) The mixture was transferred to an autoclave, 2.6 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 85° C., stopping vacuuming, introducing 0.75 mol of propylene oxide, raising the temperature to 130° C., and reacting at the temperature. When the pressure no longer changed, 1.5 mol of ethylene oxide was introduced, and the temperature was raised to 160° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 with hydrochloric acid to obtain a demulsifier product.

[0032] Example 2

[0033] (1) Add 0.05 mol tributylaminomethylsilane, 8 g potassium hydroxide, and 0.145 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 25 min, heat to 103° C., and keep warm for 25 min;

[0034] (2) The mixture was transferred to an autoclave, 2.9 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 85° C., stopping vacuuming, introducing 1 mol of propylene oxide, raising the temperature to 140° C., and reacting at the temperature. When the pressure no longer changed, 2.8 mol of ethylene oxide was introduced, raising the temperature to 165° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 with hydrochloric acid to obtain a demulsifier product.

[0035] Example 3

[0036] (1) Add 0.05 mol tributylaminomethylsilane, 9.1 g potassium hydroxide, and 0.195 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 30 min, heat to 105° C., and keep warm for 30 min;

[0037] (2) The mixture was transferred to an autoclave, 3.4 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 90° C., vacuuming was stopped, 1.3 mol of propylene oxide was introduced, the temperature was raised to 145° C., and the reaction was carried out at the temperature. When the pressure no longer changed, 4.5 mol of ethylene oxide was introduced, the temperature was raised to 180° C., and the reaction was carried out at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 with hydrochloric acid to obtain a demulsifier product.

[0038] Example 4

[0039] (1) Add 0.05 mol tributylaminomethylsilane, 8.3 g potassium hydroxide, and 0.155 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 25 min, heat to 103° C., and keep warm for 25 min;

[0040] (2) The mixture was transferred to an autoclave, 3.7 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 88° C., stopping vacuuming, introducing 1.6 mol of propylene oxide, raising the temperature to 150° C., and reacting at the temperature. When the pressure no longer changed, 5 mol of ethylene oxide was introduced, and the temperature was raised to 185° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 using hydrochloric acid to obtain a demulsifier product.

[0041] Example 5

[0042] (1) Add 0.05 mol tributylaminomethylsilane, 8.6 g potassium hydroxide, and 0.165 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 28 min, heat to 102° C., and keep warm for 30 min;

[0043] (2) The mixture was transferred to an autoclave, 4.2 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 90° C., stopping vacuuming, introducing 2 mol of propylene oxide, raising the temperature to 155° C., and reacting at the temperature. When the pressure no longer changed, introducing 5.5 mol of ethylene oxide, raising the temperature to 185° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 using hydrochloric acid to obtain a demulsifier product.

[0044] Example 6

[0045] (1) Add 0.05 mol of tributylaminomethylsilane, 8.8 g of potassium hydroxide, and 0.175 mol of 4-chloro-1-butanol into a reactor, stir at room temperature for 26 min, heat to 103° C., and keep warm for 28 min;

[0046] (2) The mixture was transferred to an autoclave, 4.6 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 90° C., stopping vacuuming, introducing 2.3 mol of propylene oxide, raising the temperature to 155° C., and reacting at the temperature. When the pressure no longer changed, introducing 5.5 mol of ethylene oxide, raising the temperature to 190° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 with hydrochloric acid to obtain a demulsifier product.

[0047] Example 7

[0048] (1) Add 0.05 mol tributylaminomethylsilane, 8.8 g potassium hydroxide, and 0.17 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 20 min, heat to 105° C., and keep warm for 25 min;

[0049] (2) The mixture was transferred to an autoclave, 4.9 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 85° C., stopping vacuuming, introducing 2.8 mol of propylene oxide, raising the temperature to 160° C., and reacting at the temperature. When the pressure no longer changed, introducing 6.8 mol of ethylene oxide, raising the temperature to 190° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 using hydrochloric acid to obtain a demulsifier product.

[0050] Example 8

[0051] (1) Add 0.05 mol tributylaminomethylsilane, 9 g potassium hydroxide, and 0.18 mol 4-chloro-1-butanol into a reactor, stir at room temperature for 30 min, heat to 104° C., and keep warm for 28 min;

[0052] (2) The mixture was transferred to an autoclave, 5.2 g of potassium hydroxide was added again, the pipeline and the autoclave were purged with nitrogen, vacuumed, filled with nitrogen, and vacuumed again, and the process was repeated three times, followed by slow heating to 88° C., stopping vacuuming, introducing 3 mol of propylene oxide, raising the temperature to 160° C., and reacting at the temperature. When the pressure no longer changed, introducing 7.5 mol of ethylene oxide, raising the temperature to 95° C., and reacting at the temperature. When the pressure no longer changed, the system was cooled to room temperature using circulating cooling water, and the pH was adjusted to 7-8 with hydrochloric acid to obtain a demulsifier product.

[0053] Example 9 Demulsification Performance Test

[0054] Take the water after oil-water separation of the produced fluid of a block in Shengli Oilfield, the oil content is 240 mg / L, add 500 ml of the separated water into a series of beakers, add 10, 20, and 30 mg / L of the demulsifier of the present invention, respectively, stir for 60 seconds at a stirring speed of 200 rpm, let it stand for 15 minutes, take the lower layer of water to test the oil content, and calculate the oil removal rate.

[0055] A comparative experiment was conducted using polyoxyethylene polyoxypropylene glycol ether, and the test results are shown in Table 1.

[0056] Table 1 Demulsification performance test results

[0057]

[0058]

[0059] As can be seen from Table 1, the demulsifiers of the present invention (Examples 1-8) have the advantages of low concentration and high efficiency demulsification:

[0060] (1) When the concentration is 10 mg / L, the oil removal rate reaches more than 92%, and the highest reaches 97.17% (Example 8). The oil removal rate of the comparative example polyoxyethylene polyoxypropylene glycol ether is 83.33%, which is significantly lower than that of the present invention;

[0061] (2) When the concentration is 20 mg / L, the oil removal rate reaches 95% or more, and the highest reaches 97.54% (Example 8). The oil removal rate of the comparative example polyoxyethylene polyoxypropylene glycol ether is 88.33%, which is significantly lower than that of the present invention;

[0062] (3) When the concentration is 30 mg / L, the oil removal rate reaches more than 96%, and the highest reaches 97.75% (Example 8). The oil removal rate of the comparative example polyoxyethylene polyoxypropylene glycol ether is 91.67%, which is significantly lower than that of the present invention.

[0063] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0064] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0065] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for synthesizing a demulsifier for oily wastewater treatment, characterized in that: The specific steps of the synthetic method are as follows: (1) Add tributylaminomethylsilane, potassium hydroxide and 4-chloro-1-butanol into a reactor, stir at room temperature for 20-30 minutes, heat to 100-105° C., and keep warm for 20-30 minutes; (2) The mixture is transferred to a high-pressure reactor, potassium hydroxide is added again, the pipeline and the reactor are purged with nitrogen, vacuumized, filled with nitrogen, and vacuumized again, and the process is repeated three times, followed by slow heating to 85-90° C., vacuumization is stopped, propylene oxide is introduced, the temperature is raised to 130-160° C., and the reaction is carried out at the temperature. When the pressure no longer changes, ethylene oxide is introduced, the temperature is raised to 160-190° C., and the reaction is carried out at the temperature. When the pressure no longer changes, the system is cooled to room temperature using circulating cooling water, and the pH is adjusted to 7-8 using hydrochloric acid to obtain a demulsifier product.

2. The synthesis method according to claim 1, characterized in that Based on 1 mole part of tributylaminomethylsilane, the usage amounts of 4-chloro-1-butanol, propylene oxide and ethylene oxide are 2.7-3.9 mole parts, 15-60 mole parts and 30-150 mole parts respectively.

3. The synthesis method according to claim 2, characterized in that Based on 1 mole part of tributylaminomethylsilane, the amounts of 4-chloro-1-butanol, propylene oxide and ethylene oxide are 3-3.6 mole parts, 30-60 mole parts and 60-150 mole parts respectively.

4. The synthesis method according to claim 1, characterized in that In step (1), the weight ratio of potassium hydroxide to tributylaminomethylsilane is 0.6-0.7:

1.

5. The synthesis method according to claim 1, characterized in that In step (2), the weight ratio of potassium hydroxide to tributylaminomethylsilane is 0.2-0.4:

1.

6. The demulsifier prepared by the synthesis method according to any one of claims 1 to 5, characterized in that: The molecular structural formula of the demulsifier is as follows: Wherein, m = 5-20; n＝10-50。 7. Use of the demulsifier according to claim 6 in the treatment of oily wastewater.

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