CN110819381A - Demulsifier and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of petrochemical industry, and relates to a demulsifier and a preparation method thereof, wherein the technical scheme comprises the steps of firstly, utilizing triblock polyether to perform crosslinking esterification under a crosslinking agent to synthesize a high-molecular-weight demulsifier which can be used for dehydration and demulsification of crude oil, and synthesizing demulsifiers with different molecular weights which can be applied to demulsification of different types of crude oil.

Description

Demulsifier and preparation method thereof

Technical Field

The invention relates to the field of petrochemical industry, and particularly provides a demulsifier and a preparation method thereof.

Background

With the development of society, the oil is increasingly produced as a main energy source, a large amount of water is required to be added in the oil production process for oil extraction, so that the water content of the crude oil is obviously increased, and the crude oil exists basically in the form of oil-water emulsion. The crude oil contains a large amount of water and inorganic salts, and the components can seriously affect the processing and production process of the crude oil, corrode equipment, increase energy consumption and even block pipelines to cause shutdown, so the dehydration, desalination and demulsification of the crude oil become important in the further deep processing process of the crude oil.

The existing crude oil demulsification methods comprise a sedimentation method, a heating method, an electric dehydration method and a chemical method, and the demulsification of crude oil by adding a demulsifier is widely adopted at present; but with the continuous exploitation of crude oil with different properties, higher requirements are put on the quality of the demulsifier. Most of demulsifiers on the market at present are block polyether demulsifiers, but different types of demulsifiers need to be prepared because different crude oils are suitable for different demulsifiers, so that the prepared demulsifiers can be used for demulsifying better, but the demulsifiers on the market at present are difficult to be suitable for different types of crude oils, and therefore, whether a high-efficiency demulsifier with wider application can be obtained becomes one of the problems to be solved urgently in the field.

Disclosure of Invention

Aiming at various defects in the prior art, the inventor provides a demulsifier and a preparation method thereof, the technical scheme firstly utilizes triblock polyether to carry out crosslinking esterification under a crosslinking agent, the synthesized demulsifier with high molecular weight can be used for dehydration and demulsification of crude oil, and the synthesized demulsifier with different molecular weights can be applied to demulsification of different types of crude oil, the high-performance demulsifier can carry out rapid demulsification, and has the advantages of better crude oil adaptability and less consumption.

The purpose of the invention is realized by the following technical scheme:

the invention provides a brand-new triblock polyether demulsifier, which has high molecular weight and can be better paved on an interface, the occupied area on an oil-water interface is large, more natural emulsifier molecules are replaced, the demulsification effect is better, the branched chains of the demulsifier are increased by using crosslinking esterification, the molecular weight is obviously increased, and the specific preparation method is as follows:

(1) and (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure at 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; and after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing the kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, and adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished to obtain the diblock polyether with the structure of 'initiator-PO-EO'. Wherein the dosage of the catalyst is 0.3 percent of the total mass of the tetraethylenepentamine and the propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the condition that the pressure is 0.3 +/-0.05 MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:1-1:2,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 2:1-1:3,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1:1-1:2,

the triblock polyether demulsifier obtained by the preparation method has more branch structures, and the multi-branch structure has good wetting property, is easy to adsorb on the surfaces of solid ions and water drops, reduces the surface energy, and greatly reduces the strength of an interfacial film, thereby greatly improving the demulsification effect and playing a better demulsification effect; in addition, the adsorption capacity of the demulsifier on the interface is stronger than that of surface active substances in the crude oil, so that more demulsifier molecules can be adsorbed on the interface, but gaps exist among the demulsifier molecules, and the gaps of the demulsifier after crosslinking are greatly increased due to the branched chains, so that the probability that the surface active substances in the crude oil enter the gaps to form an adsorption film is reduced, and the strength of the oil-water interface is reduced to a greater extent.

After obtaining the triblock polyether demulsifier, the inventor further compounds the triblock polyether demulsifier, and the compound formula is as follows: the weight portion of the material is as follows:

20-30 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 40-60 parts of solvent oil;

wherein the viscosity reducer is selected from X-40 type viscosity reducer, and the solvent oil is D110 solvent oil on the market.

The preparation method of the compound demulsifier comprises the steps of directly adding the components into a reaction kettle, heating to 60 ℃, stirring for 2 hours, and obtaining a product which is the compound demulsifier after the reaction is finished;

the isopropanol in the compound demulsifier is favorable for dissolving the block polyether with high molecular weight, the X-40 type viscosity reducer is a dispersive viscosity reducer, the mixing of the dispersive viscosity reducer and the demulsifier is favorable for dispersing and separating water drops in crude oil, and the solvent oil promotes the dissolution of the whole demulsifier.

In a further application process, the inventor further provides a more accurate technical scheme:

when tetraethylenepentamine: step (1) propylene oxide: the triblock polyether demulsifier (with the minimum molecular weight) obtained by the mol ratio of the ethylene oxide to the propylene oxide in the step (1) is 1:1:3:1, and the formula of the compound demulsifier is as follows: 35-40 parts of triblock polyether demulsifier, 10 parts of isopropanol, 15-20 parts of viscosity reducer and 30-40 parts of solvent oil;

when tetraethylenepentamine: step (1) propylene oxide: the triblock polyether demulsifier (with a smaller molecular weight) obtained by the mol ratio of the ethylene oxide to the propylene oxide in the step (1) being 1:2:2:2, and the formula of the compound demulsifier is as follows: 30-40 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 30-50 parts of solvent oil.

When tetraethylenepentamine: step (1) propylene oxide: ethylene oxide, the mole ratio of the propylene oxide in the step (1) is 1:2:1:2, and the formula of the compound demulsifier is as follows: 20-30 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 40-60 parts of solvent oil.

When tetraethylenepentamine: step (1) propylene oxide: ethylene oxide, the mole ratio of the propylene oxide in the step (1) is 1:2:1:4, and the triblock polyether demulsifier (with the largest molecular weight) is obtained, and the formula of the compound demulsifier is as follows: 20-25 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10 parts of viscosity reducer and 55-60 parts of solvent oil.

The technical scheme is that the optimal implementation scheme is preferably selected according to the molecular weight of the block polyether and the proportion of the block polyether in the compound demulsifier, the effect of the compounded demulsifier is obviously better than that of the demulsifier using the triblock polyether alone, and the demulsifying effect of the demulsifier compounded by the technical scheme is better than that of the demulsifier on the market.

Compared with the prior art, the viscosity reducer is added in the compound demulsifier obtained by the technical scheme, the thick oil with high asphaltene and colloid contents can be effectively and rapidly demulsified, and the dehydration demulsification effect of the thick oil is greatly improved.

Detailed Description

The present invention will be described in further detail with reference to the following examples, but it should not be construed that the scope of the above subject matter is limited to the following examples. All the technologies realized based on the above contents of the present invention belong to the scope of the present invention, and the following embodiments are all completed by adopting the conventional prior art except for the specific description.

Example 1

1. Preparation of block polyethers

(1) And (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure at 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; and after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing the kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, and adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished to obtain the diblock polyether with the structure of 'initiator-PO-EO'. The dosage of the catalyst is 0.3 percent of the total mass of the tetraethylenepentamine and the propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the pressure of (0.3 +/-0.05) MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:1,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 1:3,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1: 1;

2. preparation of compound demulsifier

The compound demulsifier comprises the following components in parts by weight: 35-40 parts of triblock polyether demulsifier, 10 parts of isopropanol, 15-20 parts of viscosity reducer and 30-40 parts of solvent oil,

wherein the viscosity reducer is selected from X-40 type (the X-40 type viscosity reducer is a dispersive viscosity reducer, and is mixed with a demulsifier to be beneficial to dispersing and separating water drops in crude oil) solvent oil, and D110 solvent oil on the market is selected.

The preparation method of the compound demulsifier comprises the steps of directly adding the components into a reaction kettle, heating to 60 ℃, stirring for 2 hours, and obtaining a product after the reaction is finished, namely the compound demulsifier.

Example 2

1. Preparation of block polyethers

(1) And (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure at 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; and after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing the kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, and adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished to obtain the diblock polyether with the structure of 'initiator-PO-EO'. The dosage of the catalyst is 0.3 percent of the total mass of the tetraethylenepentamine and the propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the pressure of (0.3 +/-0.05) MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:2,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 1:1,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1:1,

2. preparation of compound demulsifier

The compound demulsifier comprises the following components in parts by weight: 30-40 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 30-50 parts of solvent oil,

wherein the viscosity reducer is selected from X-40 type (the X-40 type viscosity reducer is a dispersive viscosity reducer, and is mixed with a demulsifier to be beneficial to dispersing and separating water drops in crude oil) solvent oil, and D110 solvent oil on the market is selected.

The preparation method of the compound demulsifier comprises the steps of directly adding the components into a reaction kettle, heating to 60 ℃, stirring for 2 hours, and obtaining a product after the reaction is finished, namely the compound demulsifier.

Example 3

1. Preparation of block polyethers

(1) And (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure of 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; and after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing the kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, and adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished to obtain the diblock polyether with the structure of 'initiator-PO-EO'. The dosage of the catalyst is 0.3 percent of the total mass of the tetraethylenepentamine and the propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the pressure of (0.3 +/-0.05) MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:2,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 2:1,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1:1,

2. preparation of compound demulsifier

The compound demulsifier comprises the following components in parts by weight: 20-30 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 40-60 parts of solvent oil,

wherein the viscosity reducer is selected from X-40 type (the X-40 type viscosity reducer is a dispersive viscosity reducer, and is mixed with a demulsifier to be beneficial to dispersing and separating water drops in crude oil) solvent oil, and D110 solvent oil on the market is selected.

The preparation method of the compound demulsifier comprises the steps of directly adding the components into a reaction kettle, heating to 60 ℃, stirring for 2 hours, and obtaining a product after the reaction is finished, namely the compound demulsifier.

Example 4

1. Preparation of block polyethers

(1) And (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure at 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; and after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing the kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, and adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished to obtain the diblock polyether with the structure of 'initiator-PO-EO'. The dosage of the catalyst is 0.3 percent of the total mass of the tetraethylenepentamine and the propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the pressure of (0.3 +/-0.05) MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:2,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 2:1,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1:2,

2. preparation of compound demulsifier

The compound demulsifier comprises the following components in parts by weight: 20-25 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10 parts of viscosity reducer and 55-60 parts of solvent oil,

wherein the viscosity reducer is selected from X-40 type (the X-40 type viscosity reducer is a dispersive viscosity reducer, and is mixed with a demulsifier to be beneficial to dispersing and separating water drops in crude oil) solvent oil, and D110 solvent oil on the market is selected.

The preparation method of the compound demulsifier comprises the steps of directly adding the components into a reaction kettle, heating to 60 ℃, stirring for 2 hours, and obtaining a product after the reaction is finished, namely the compound demulsifier.

Examples of the experiments

The product triblock polyether demulsifier, the compound demulsifier and the demulsifier on the market in the above examples were tested for demulsification performance. Adding 80mL of simulated crude oil solution (crude oil density is 875 kg/L) into a 100mL volumetric flask, and then adding 0.8mL of 0.01g/mL demulsifier solution; after oscillating and mixing uniformly, placing the mixture in a constant-temperature water bath kettle at 75 ℃, respectively recording the dehydration amount of 30min and 90min, and calculating the dehydration rate, wherein the experimental result is shown in the following table 1;

preparation of the simulated crude oil: weighing a crude oil sample with a certain mass, adding 40% of water, placing the crude oil sample in a water bath kettle at 50 +/-5 ℃, keeping the temperature for 30min, placing the crude oil sample under a high-speed shearing machine at the rotating speed of 2000r/min, and stirring for 8min to prepare a crude oil sample which is a simulated crude oil.

TABLE 1 results of demulsification Performance of different triblock polyether demulsifiers

The data in table 1 show that the demulsification effect of example 4 is better. According to the technical scheme, different types of demulsifiers can be prepared, and different types of demulsifiers can be obtained by controlling the mass ratio of the initiator, the head PO, the EO and the tail PO.

TABLE 2 results of demulsification Performance of different compounded demulsifiers

The demulsifier block polyether compounded in example 4 in table 2 is used in a small amount and has a demulsifying effect superior to that of the market demulsifier. The technical scheme realizes that by controlling the initial agent: head PO: EO and tail PO realize the synthesis of block polyether products with different molecular weights, and the demulsification effect of the compounded block polyether is better than that of the demulsifier only using triblock polyether. The triblock polyether demulsifier prepared by the technical scheme is partially superior to the demulsifiers on the market, and the compounded demulsifiers have better effects than the demulsifiers on the market;

meanwhile, the dosage of the demulsifier in the experiment is the same, so that the dosage of the triblock polyether in the compound demulsifier is far lower than that of the triblock polyether demulsifier which is independently adopted, but according to the experimental result, the effect is better and better than that of the prior art when the compound demulsifier is adopted, and unexpected technical effect is obtained on the basis of reducing the dosage of the triblock polyether, which is not possessed by the prior art.

Claims (3)

1. A demulsifier, characterized by: in particular to a triblock polyether demulsifier, which comprises the following steps:

(1) and (3) taking tetraethylenepentamine, an alkaline catalyst and propylene oxide, putting into a reaction kettle, closing the reaction kettle, purging for 2-5min by using nitrogen, and then closing a gas inlet valve and a gas outlet valve. Stirring and heating, maintaining the surface pressure at 0.3 + -0.05 Mpa, heating to 120 deg.C within 1-1.5h, and reacting for 1h under the pressure and temperature conditions; after the reaction is finished, introducing cooling water to cool to room temperature, then adding ethylene oxide, closing a kettle cover, removing air, continuously heating to 120 ℃, reacting for 1h at the temperature, adding glacial acetic acid to neutralize the alkaline catalyst after the reaction is finished, and obtaining diblock polyether with an initiator-PO-EO structure, wherein the dosage of the catalyst is 0.3% of the total mass of tetraethylenepentamine and propylene oxide at the beginning of the reaction;

(2) taking the synthesized diblock polyether to synthesize triblock polyether: and (2) adding the diblock polyether synthesized in the step (1) into a reaction kettle, adding propylene oxide into the reaction kettle, heating to 120 ℃, and reacting for 0.5h under the condition that the pressure is 0.3 +/-0.05 MPa to obtain a product, namely triblock polyether. The obtained product is triblock polyether with an initiator-PO-EO-PO structure;

(3) crosslinking the triblock polyether synthesized in the step (2) with toluene diisocyanate, wherein the dosage of the toluene diisocyanate is 1.5% of the total mass of the triblock polyether obtained in the step (2), the temperature is maintained at 110 ℃, and the stirring is carried out for 1.5h at normal temperature and normal pressure, so as to obtain a crosslinked product, namely the triblock polyether demulsifier;

in the step (1), the mol ratio of tetraethylenepentamine to propylene oxide is as follows: 1:1-1:2,

the mol ratio of the propylene oxide to the ethylene oxide in the step (1) is; 2:1-1:3,

the mol ratio of the propylene oxide in the step (1) to the propylene oxide in the step (2) is as follows: 1:1-1:2.

2. The demulsifier of claim 1, wherein:

the alkaline catalyst in the step (1) is potassium hydroxide or sodium hydroxide.

3. A compound demulsifier is characterized in that: the formula comprises the following components in parts by weight:

20-30 parts of triblock polyether demulsifier, 10 parts of isopropanol, 10-20 parts of viscosity reducer and 40-60 parts of solvent oil;

wherein the viscosity reducer is selected from X-40 type viscosity reducers; mineral spirit is mineral spirit D110.