阅读说明：本技术 一种柴油抗乳化剂的制备方法 (Preparation method of diesel oil anti-emulsifier ) 是由 谢天明 吴倩 张�浩 戴泽清 葛圣才 于 2019-10-28 设计创作，主要内容包括：本发明公开了一种柴油抗乳化剂的制备方法,具体涉及柴油抗乳化技术领域,先分别以烷基单元醇、烷基二元醇、烷基三元醇为起始剂制备三种分子量不同的聚醚；再使得三种聚醚分别通过改性剂改性扩链得到三种分子量更高的改性聚醚；最后将三种改性聚醚按照一定的质量比混合得到柴油抗乳化剂。本发明具有工艺简单、生产成本低、适温范围广、普适性强、加入量少、抗乳化性能强的特点,适用于柴油碱洗过程及储运、使用过程。(The invention discloses a preparation method of a diesel oil demulsifying agent, and particularly relates to the technical field of diesel oil demulsification, wherein three polyethers with different molecular weights are prepared by respectively taking alkyl monohydric alcohol, alkyl dihydric alcohol and alkyl trihydric alcohol as initiators; respectively modifying and chain extending the three kinds of polyether by using a modifier to obtain three kinds of modified polyether with higher molecular weight; and finally, mixing the three modified polyethers according to a certain mass ratio to obtain the diesel oil anti-emulsifier. The invention has the characteristics of simple process, low production cost, wide temperature range, strong universality, small addition amount and strong emulsification resistance, and is suitable for the diesel oil alkali washing process and the storage, transportation and use processes.)

1. The preparation method of the diesel oil anti-emulsifier is characterized by comprising the following steps:

s1, preparing three polyethers with different molecular weights by respectively taking alkyl monohydric alcohol, alkyl dihydric alcohol and alkyl trihydric alcohol as initiators;

s2, modifying and chain-extending the three polyethers obtained in the step S1 by using a modifier to obtain three modified polyethers with different molecular weights, wherein the molecular weight of the obtained modified polyether is larger than that of the polyether serving as the raw material;

s3, mixing the three modified polyethers obtained in the step S2 according to a certain mass ratio to obtain the diesel oil anti-emulsifier.

2. The method as claimed in claim 1, wherein in step S1, the molecular weights of the triblock polyethers prepared from alkyl monohydric alcohol, alkyl dihydric alcohol or alkyl trihydric alcohol as the initiator are respectively 800-3000, 1500-5000 and 2500-8000.

3. The method of claim 1, wherein in step S3, the molecular weights of the three modified polyethers prepared by using alkyl monohydric alcohol, alkyl dihydric alcohol or alkyl trihydric alcohol as the initiator are 1348-4657, 5458-12455 and 9645-18645 respectively, and the mass ratio is 100: 10-100: 5-90.

4. The method for preparing a diesel demulsifier according to claim 1, wherein in step S1, the triblock polyether prepared from an alkyl monol, an alkyl diol, or an alkyl triol as a starting material has molecular weights of 1972, 4125, and 6543, respectively; in step S3, the molecular weights of the three modified polyethers prepared by using alkyl monoalcohol, alkyl diol or alkyl triol as the initiator are 4657, 8564 and 13542, and the mass ratio is 100: 76: 85 when mixing.

5. The method for preparing a diesel demulsifier according to claim 1, wherein in step S1, the carbon chain of the alkyl monoalcohol is C1-C12, the carbon chain of the alkyl diol is C2-C10, and the carbon chain of the alkyl triol is C3-C8.

6. The method for preparing the diesel fuel demulsifier according to any one of claims 1 to 5, wherein the polyether is prepared in step S1 by: in a high-pressure reaction kettle, respectively taking alkyl monohydric alcohol, alkyl dihydric alcohol and alkyl trihydric alcohol as initiators and KOH as a catalyst at the temperature of 80-180 DEG^oC, under the reaction condition that the pressure is 0-1.0MPa, sequentially introducing propylene oxide, ethylene oxide and propylene oxide for reaction to obtain three triblock polyethers with different molecular weights;

the modifier in the step S2 is acrylic acid, and the specific method for obtaining the modified polyether comprises the following steps: adding the three polyethers obtained in the step S1 and acrylic acid into a reactor respectively, adding catalyst p-toluenesulfonic acid and solvent xylene, and reacting at 90-180 DEG C^oC, performing esterification reaction for 2-10h, and simultaneously dividing water by using a water separator; adding an initiator benzoyl peroxide into a reactor, 60-140%^oAnd (3) carrying out polymerization reaction for 2-10h under the condition of C, and carrying out reduced pressure distillation to remove xylene to respectively obtain three modified polyethers with higher molecular weights.

7. The method for preparing the diesel fuel demulsifier according to claim 6, wherein in step S1, the mass ratio of propylene oxide, ethylene oxide and propylene oxide introduced is 1 (0.2-8) to (0.1-5), and the amount of KOH is 0.05-1.5% of the mass of the polyether.

8. The preparation method of the diesel fuel demulsifier according to claim 6, wherein the mass ratio of the reagents added in step S2 is: polyether acrylic acid/p-toluenesulfonic acid/xylene/benzoyl peroxide (100: 10-60: 0.1-5: 5-100: 0.05-3).

9. The method for preparing a diesel demulsifier according to claim 6, wherein the esterification reaction temperature is from 90 to 180 ℃ in step S2^oAnd C, the reaction time is 2-8 h.

10. The method of claim 6The preparation method of the diesel oil anti-emulsifier is characterized in that in step S1, the polymerization reaction temperature is 90-180 DEG^oC, the pressure is 0-1.0 MPa; in step S2, the polymerization temperature is 70 to 120%^oAnd C, the reaction time is 2-10 h.

Technical Field

The invention belongs to the technical field of diesel oil demulsification, and particularly relates to a preparation method of a diesel oil demulsifying agent.

Background

The diesel oil obtained by processing and fractionating crude oil contains naphthenic acid and other corrosive substances, which affect the service life of an engine, and an oil refinery generally removes the corrosive substances by an alkali washing method, but sodium naphthenate, sodium fatty acid and phenolic substances generated in the alkali washing process are emulsifying agents with strong surface activity, so that the diesel oil is emulsified, the oil content of diesel oil alkali residue is increased, and the electric refining process is also affected. In addition, during storage, transportation and use of the diesel oil, the diesel oil is also subjected to emulsification phenomenon due to the influence of environmental change, vibration and additional components, so that the performance of the diesel oil is reduced. The addition of the demulsifier during the alkaline cleaning, storage and transportation and use of the diesel oil can effectively eliminate or reduce the influence caused by the emulsification.

① breaks the tension balance of oil-water interface to make the micro water drop in oil phase coalesce into small water drop quickly, ② replaces naphthenate radical which is absorbed on the oil-water interface and prevents the small water drop from coalescing, making the small water drop easy to gather, realizing oil-water separation under the action of gravity, ③ neutralizes the negative charge on the surface of the oil drop in the oil-water interface to make the oil drop coalesce quickly, thereby reducing the emulsion layer of the oil-water interface, Chinese patent CN101768463A discloses a diesel alkali washing anti-emulsifier composition and a synthesis method thereof, the composition is composed of amino-terminated polyether, quaternary ammonium derivative and alkyl-terminated polyether, because the average molecular weight of the components is smaller, the performance of the anti-emulsifier is general, Chinese patent CN103805231A discloses a diesel anti-emulsifier, the method is that polyether with the molecular weight of 5000-hazy 6000 is modified by diisocyanate to be chain extension to polyether with the molecular weight of 15000-cloudy 20000, the preparation process is simple, the oil-water separation is faster, but the problem of oil phase and oil-water interface exists.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of a diesel oil anti-emulsifier, wherein the prepared anti-emulsifier shows the anti-emulsifying performance of accelerating coalescence of water drops, quick separation of oil and water and clear oil-water interface under the synergistic action of three modified polyethers with different molecular weights, so that the problem of emulsification of diesel oil in the processes of alkali washing, storage and transportation and use is solved; has the advantages of simple process, low production cost, wide temperature range, strong universality, small addition amount and the like.

In order to achieve the purpose of the invention, the invention adopts the technical scheme that:

a preparation method of a diesel oil anti-emulsifier comprises the following steps:

s1, preparing three polyethers with different molecular weights by respectively taking alkyl monohydric alcohol, alkyl dihydric alcohol and alkyl trihydric alcohol as initiators;

s2, modifying and chain-extending the three polyethers obtained in the step S1 by using a modifier to obtain three modified polyethers with different molecular weights, wherein the molecular weight of the obtained modified polyether is larger than that of the polyether serving as the raw material;

s3, mixing the three modified polyethers obtained in the step S2 according to a certain mass ratio to obtain the diesel oil anti-emulsifier.

Preferably, in step S1, the triblock polyether prepared by using alkyl monol, alkyl diol or alkyl triol as the initiator has molecular weights of 800-. Wherein, the triblock polyether prepared by taking alkyl monohydric alcohol, alkyl dihydric alcohol or alkyl trihydric alcohol as an initiator has the molecular weight of 800-.

Preferably, in step S3, the molecular weights of the three modified polyethers prepared by using alkyl monohydric alcohol, alkyl dihydric alcohol or alkyl trihydric alcohol as the initiator are 1348-4657, 5458-12455 and 9645-18645 respectively, and the mass ratio is 100: 10-100: 5-90. Wherein, the mass ratio of the three modified polyethers prepared by taking alkyl monohydric alcohol, alkyl dihydric alcohol or alkyl trihydric alcohol as the initiator is 100: 20-100: 10-80, and the effect is better.

Preferably, in step S1, the triblock polyether prepared with alkyl monol, alkyl diol or alkyl triol as initiator has molecular weights of 1972, 4125 and 6543, respectively; in step S3, the molecular weights of the three modified polyethers prepared by using alkyl monoalcohol, alkyl diol or alkyl triol as the initiator are 4657, 8564 and 13542, and the mass ratio is 100: 76: 85 when mixing.

Preferably, in step S1, the carbon chain of the alkyl monoalcohol is C1-C12, the carbon chain of the alkyl diol is C2-C10, and the carbon chain of the alkyl triol is C3-C8. Wherein the carbon chain of the alkyl unit alcohol is C1-C10; the carbon chain of the alkyl dihydric alcohol is C2-C8; the carbon chain of the alkyl triol is more effective when the carbon chain is C3-C6.

Preferably, the polyether is prepared in step S1 by: in a high-pressure reaction kettle, respectively taking alkyl monohydric alcohol, alkyl dihydric alcohol and alkyl trihydric alcohol as initiators and KOH as a catalyst at the temperature of 80-180 DEG^oC, under the reaction condition that the pressure is 0-1.0MPa, sequentially introducing propylene oxide, ethylene oxide and propylene oxide for reaction to obtain three triblock polyethers with different molecular weights;

the modifier in the step S2 is acrylic acid, and the specific method for obtaining the modified polyether comprises the following steps: adding the three polyethers obtained in the step S1 and acrylic acid into a reactor respectively, adding catalyst p-toluenesulfonic acid and solvent xylene, and reacting at 90-180 DEG C^oC, performing esterification reaction for 2-10h, and simultaneously dividing water by using a water separator; adding an initiator Benzoyl Peroxide (BPO) into a reactor, 60-140%^oAnd (3) carrying out polymerization reaction for 2-10h under the condition of C, and carrying out reduced pressure distillation to remove xylene to respectively obtain three modified polyethers with higher molecular weights.

Preferably, in step S1, the mass ratio of Propylene Oxide (PO), Ethylene Oxide (EO) and Propylene Oxide (PO) is 1 (0.2-8) to (0.1-5), and KOH is used in an amount of 0.05-1.5% by mass based on the mass of the polyether. Wherein, the mass ratio of the introduced PO, EO and PO is 1 (0.2-5) to (0.1-4), and the effect is better when the using amount of KOH is 0.1-1 percent of the mass of the prepared polyether.

Preferably, the adding mass ratio of each reagent in the step S2 is as follows: polyether acrylic acid/p-toluenesulfonic acid/xylene/benzoyl peroxide (100: 10-60: 0.1-5: 5-100: 0.05-3). Wherein the polyether-acrylic acid-p-toluenesulfonic acid-xylene-BPO addition mass ratio is 100: 10-40: 0.1-3: 10-80: 0.05-1, and the effect is better.

Preferably, in step S2, the esterification reaction temperature is 90-180 deg.C^oC，The reaction time is 2-8 h. Wherein the esterification reaction temperature is 100-160-^oC, the reaction time is 3-8h, and the effect is better.

Preferably, in step S1, the polymerization temperature is 90 to 180%^oC, the pressure is 0-1.0 MPa; in step S2, the polymerization temperature is 70 to 120%^oAnd C, the reaction time is 2-10 h.

Has the advantages that:

① the diesel oil anti-emulsifier prepared by the invention solves the problem of emulsification of diesel oil in the processes of alkali washing, storage, transportation and use;

② the diesel oil anti-emulsifier prepared by the invention contains three polyethers with different average molecular weights, and in the anti-emulsifying process, the effects of accelerated coalescence of water drops, rapid separation of oil and water and clear oil-water interface can be realized under the synergistic effect of the three modified polyethers;

③ the invention has the advantages of simple process, low production cost, wide temperature range, strong universality, small addition amount, strong emulsification resistance, etc.

Detailed Description

The average molecular weight (number average molecular weight) of the polyether was measured using an Agilent PL-GPC model 220 high temperature gel permeation chromatograph.

The diesel oil anti-emulsifier performance evaluation method comprises the steps of adding 20ml of sodium phosphate solution with the concentration of 40g/L and 80ml of diesel oil into a 100ml measuring cylinder for standby use, preparing solution by taking 8g of sodium naphthenate, 11.5g C10 solvent and 0.5g of diesel oil anti-emulsifier, transferring 32uL of the prepared solution into the measuring cylinder with the plug by using a liquid transfer gun, starting timing after the measuring cylinder with the plug is held by a hand and shaken up and down for 100 times, recording ① water yield after 15 minutes, determining whether ② oil phase is clear, and determining whether ③ oil-water interface is clear, wherein the water yield is the most important index, the oil phase is turbid, the oil-water interface is unclear, the water yield is less in the same time, the water yield reaches 18ml in 15 minutes, and the diesel oil is a qualified product if the oil phase is clear and the oil-water interface is clear.

The synthesis of the triblock polyethers is a common procedure, and the specific reaction conditions are not described in detail.