Dispersant compositions, their preparation methods and applications

Abstract

This invention relates to the field of dispersant technology, and discloses a dispersant composition, its preparation method, and its application. The composition comprises the following components in parts by weight: 100 parts linear paraffin, 10-30 parts water, 20-40 parts dispersing material, 8-10 parts emulsifier, and 3-5 parts solubilizer, wherein the dispersing material is selected from bicarbonates and / or carbonates. The dispersant composition provided by this invention is non-toxic and biodegradable. When used in polyacrylamide granulation, it results in polyacrylamide products with high hydrolytic uniformity and rapid hydrophilic solubility.

Description

Technical Field

[0001] This invention relates to the field of dispersant technology, and more specifically to a dispersant composition, its preparation method, and its application. Background Technology

[0002] Polyacrylamide is a general term for polymers obtained by homopolymerization or copolymerization of acrylamide monomers under the action of an initiator. It is an important water-soluble polymer with properties such as flocculation, thickening, shear resistance, drag reduction, and dispersibility. As a high-tech, high-value-added chemical product, it is widely used in oil extraction, chemical industry, papermaking, environmental protection and other fields, and is known as the "auxiliary agent for all industries".

[0003] Due to the diversity of monomer ratios and process parameters, polyacrylamide varies greatly in terms of molecular weight and solubility. Polyacrylamide used in the fracturing process for developing tight layers in oil fields mainly involves drag-reducing agents or thickeners with high viscosity, low frictional resistance, and good sand-carrying capacity. These are mainly copolymers of acrylamide and 2-acrylamide-2-methylpropanesulfonic acid or copolymers of acrylamide and functional monomers. Polymerized polyacrylamide blocks contain approximately 75% water, resembling gel and exhibiting strong viscoelasticity. During production, the water and volatile components must be removed to obtain a solid product with a certain solid content, which is then processed into 40-80 mesh granules. Since large blocks are difficult to dry, they must be broken down into smaller particles to increase the specific surface area and drying efficiency. Smaller particles have a larger specific surface area, making drying easier and more efficient. After granulation, the acrylamide copolymer particles have amide, carboxylic acid, sulfonic acid, hydrogen, and metal ions on their surface. These particles adhere to each other through surface polarity, hindering subsequent uniform hydrolysis, drying, grinding, and sieving, leading to uneven hydrolysis, clumping during drying, and other problems such as a "sugar core." The addition of dispersants effectively solves these problems. The diverse anchoring groups in the dispersant tightly anchor the oil film system to the polymer particle surface, forming a sufficiently thick protective layer that keeps the particles continuously loose, easy to flow, and facilitates rapid drying.

[0004] In the industrial production of polyacrylamide products for acid fracturing, mineral oil dispersants are required to reduce particle adhesion and improve the efficiency and effectiveness of subsequent drying and grinding. However, traditional mineral oil dispersants are non-biodegradable, causing pollution to the atmosphere, soil, and water. Furthermore, high-volume, high-displacement online, high-efficiency, continuous sand-adding fracturing fluids require polyacrylamide additives for acid fracturing to have rapid dissolution and viscous-inducing effects. Existing polyacrylamide materials suffer from water solubility issues due to the oil film barrier effect of traditional mineral oil dispersants. Therefore, there is an urgent need to develop a polyacrylamide granulation dispersant with good dispersibility and biodegradability to reduce environmental risks in the production process and further improve the water solubility of polyacrylamide. Summary of the Invention

[0005] The purpose of this invention is to overcome the pollution problems of polyacrylamide dispersants and the water solubility problems of polyacrylamide products in the prior art, and to provide a dispersant composition, its preparation method and application.

[0006] To achieve the above objectives, a first aspect of the present invention provides a dispersant composition comprising the following components in parts by weight:

[0007]

[0008] The dispersing material is selected from bicarbonates and / or carbonates.

[0009] A second aspect of the present invention provides a method for preparing the dispersant composition described in the first aspect, the method comprising:

[0010] Linear paraffin, water, and emulsifier are mixed and then subjected to shear emulsification. Dispersant and solubilizer are then added and ball-milled to obtain the dispersant composition.

[0011] The third aspect of the present invention provides the use of the composition described in the first aspect as a dispersant for granulation of polyacrylamide for acid fracturing.

[0012] The dispersant composition, its preparation method, and its application provided by the present invention, through the above technical solutions, have the following beneficial effects:

[0013] (1) The dispersant composition of the present invention includes linear paraffin, dispersing materials selected from bicarbonates and / or carbonates, etc., and uses linear paraffin to replace traditional mineral oil, thereby reducing the irreversible environmental pollution of soil, water and atmosphere by the dispersant.

[0014] (2) The dispersant composition of the present invention incorporates inert powders such as bicarbonate and / or carbonate as dispersing materials. In addition to the oil film anchoring and dispersing effect, it also increases the isolation and dispersing effect, making the colloidal particles dispersed better. At the same time, the inert powder dispersing material directly participates in the hydrolysis reaction of polyacrylamide in the post-hydrolysis process, promoting the improvement of static hydrolysis uniformity.

[0015] (3) In the preparation process of the dispersant, the present invention uses shear emulsification and ball milling dispersion processes. Shear emulsification is achieved by strong mechanical shearing force and strong mutual extrusion between materials, so that the oil and water phases are rapidly homogenized and emulsified, and the emulsified materials are more uniform and stable. The grinding balls of the ball milling process are used to uniformly disperse the materials to be ground, reduce the agglomeration of powder dispersion materials, improve the uniformity of the dispersion of powder dispersion materials and ensure their uniform particle size. The resulting microparticle dispersion system lays the foundation for promoting the uniformity of hydrolysis and improving the rapid water solubility of the product.

[0016] (4) The polyacrylamide prepared using the dispersant composition provided by the present invention has better rapid water solubility and no "fish eye" phenomenon occurs in the aqueous solution. Industrial tests have confirmed that the dispersant provided by the present invention has high industrial promotion value. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein 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 the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] A first aspect of the present invention provides a dispersant composition comprising the following components in parts by weight:

[0019]

[0020] The dispersing material is selected from bicarbonates and / or carbonates.

[0021] In this invention, linear paraffin wax is used instead of traditional mineral oil, reducing the irreversible environmental pollution of soil, water, and atmosphere caused by dispersants; an inert powder dispersing material is introduced, which, in addition to oil film anchoring dispersion, increases isolation dispersion, resulting in better dispersion of colloidal particles; in the post-hydrolysis process, the inert powder dispersing material directly participates in the hydrolysis reaction of polyacrylamide, promoting the improvement of static hydrolysis uniformity and enhancing the rapid water solubility of polyacrylamide;

[0022] The oil film dispersion refers to the dispersant's ability to disperse by relying on the oil phase. In the dispersant system provided by this invention, the oil and water phases are emulsified to form a uniform W / O emulsion system. The hydrophilic groups of the emulsifier combine with the polyacrylamide particles, while the lipophilic groups of the emulsifier combine with the oil in the emulsion system. In this way, the polyacrylamide particles are covered by an oil film and lose the possibility of sticking and agglomerating with each other.

[0023] Meanwhile, based on traditional oil film dispersion, this invention adds an inert dispersing material, adding carbonate or bicarbonate particles between the polyacrylamide particles wrapped by the oil film, reducing the possibility of polyacrylamide particles coming into contact with and sticking together, and further improving the dispersion effect, which is the so-called isolated dispersion.

[0024] In this invention, the oil-water emulsion system prepared by using the above-mentioned proportions has good stability, uniform dispersion effect, good particulate suspension stability of the dispersed material, and no sedimentation. At the same time, the addition of the aqueous phase further reduces the production cost of the dispersant.

[0025] In a preferred embodiment of the present invention, the composition comprises the following components in parts by weight:

[0026]

[0027] In this invention, by using the above-mentioned preferred composition and raw material ratio, the dispersion effect of the dispersant can be further improved, while the static hydrolysis uniformity of polyacrylamide and the water solubility of the obtained polyacrylamide product can be further promoted.

[0028] In a preferred embodiment of the present invention, the linear paraffin is Yanshan Petrochemical Type I linear paraffin and / or Yanshan Petrochemical Type II linear paraffin.

[0029] In a preferred embodiment of the invention, the emulsifier is selected from Tween and / or Span.

[0030] In a preferred embodiment of the present invention, the emulsifier is Tween 80 and Span 80.

[0031] In a preferred embodiment of the present invention, the mass ratio of Tween 80 to Span 80 is 1:15-20.

[0032] In this invention, the Tween 80 and Span 80 emulsifiers used in the above-mentioned mass ratio have high stability of the emulsion system and moderate emulsion viscosity, which has a positive promoting effect on improving the suspension stability of the dispersed material particles in the dispersant.

[0033] In a preferred embodiment of the present invention, the solubilizer is selected from at least one of polysorbate compounds, polyoxyethylene fatty alcohol ether compounds, and sodium dodecyl sulfate.

[0034] In a preferred embodiment of the present invention, the polysorbate compound is Tween 60.

[0035] In a preferred embodiment of the present invention, the polyoxyethylene fatty alcohol ether compound is AEO-3.

[0036] In a preferred embodiment of the present invention, the dispersing material is sodium bicarbonate and sodium carbonate.

[0037] In a preferred embodiment of the present invention, the mass ratio of sodium bicarbonate to sodium carbonate is 1:0.5-5.

[0038] In a preferred embodiment of the present invention, the particle size of the sodium bicarbonate and the sodium carbonate is independently 40-100 mesh.

[0039] Using sodium bicarbonate and sodium carbonate with the above-mentioned ratio and particle size as dispersing materials has the effect of good hydrolysis uniformity and high stability of suspension system.

[0040] A second aspect of the present invention provides a method for preparing the dispersant composition described in the first aspect, the method comprising:

[0041] Linear paraffin, water, and emulsifier are mixed and then subjected to shear emulsification. Dispersant and solubilizer are then added and ball-milled to obtain the dispersant composition.

[0042] In this invention, linear paraffin, emulsifier, and water are emulsified into a W / O type emulsion system using a shear emulsification method. The composition containing the dispersing material, solubilizer, and W / O emulsion system is ball-milled to stably suspend and disperse the powdered dispersing material within the emulsion system, thereby obtaining a dispersant composition for polyacrylamide. Compared to traditional mineral oil dispersants, this composition exhibits excellent biodegradability and dispersibility. When the dispersant prepared using the method provided in this invention is used in polyacrylamide granulation, the resulting polyacrylamide product exhibits high and rapid hydrolysis uniformity, good water solubility, and no "fish-eye" phenomenon occurs in the aqueous solution.

[0043] In a preferred embodiment of the present invention, the shear emulsification treatment time is 10-30 min and the stirring speed is 2500-3000 rpm.

[0044] In a preferred embodiment of the present invention, the ball milling process is performed using a vertical stirred ball mill.

[0045] In a preferred embodiment of the present invention, the ball milling process takes 20-40 minutes and rotates at 80-100 rpm.

[0046] The third aspect of the present invention provides the use of the composition described in the first aspect as a dispersant for granulation of polyacrylamide for acid fracturing.

[0047] In a preferred embodiment of the present invention, the granulation process of the polyacrylamide for acid fracturing includes:

[0048] (1) A first solution is obtained by mixing acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and water. Sodium hydroxide is added to adjust the pH of the first solution to 6-8 to obtain a second solution.

[0049] (2) After cooling the second solution to 5-10℃, transfer it to a polymerization bottle, add the functional monomer urea, introduce nitrogen into the polymerization bottle, add ammonium persulfate and sodium bisulfite as composite initiators, continue to introduce nitrogen until the reaction system begins to heat up, and the polymerization reaction begins.

[0050] (3) After the polymerization reaction has been carried out for 10-15 hours, the polymer block is taken out and granulated. During the granulation process, a dispersant (3-10 wt% of the polymer block mass) and a hydrolysant (0.5-3 wt% of the polymer block mass) are added to make the granules fully dispersed and adhere to the dispersant. Then, the granules are placed in a constant temperature oven at 40-60℃ for hydrolysis. After drying and pulverizing, the polyacrylamide product for acid fracturing is obtained.

[0051] The mass ratio of acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), water, urea, ammonium persulfate, and sodium bisulfite is 2000-2200:550-650:1400-1600:20-25:0.5-2:0.5-2.

[0052] The dispersant is the dispersant composition provided in the first aspect of the present invention.

[0053] In this invention, there is no particular limitation on the type of hydrolysing agent, and conventional types of hydrolysing agents in the art can be used.

[0054] The present invention will be described in detail below through embodiments.

[0055] In the following examples and comparative examples, the biotoxicity of the dispersant was determined according to the national standard "Biotoxicity of Pollutants from Marine Oil Exploration and Development: Part 2: Test Methods" (GB / T 18420.2-2009). Artemia larvae hatched for 20-24 hours were used as the experimental subjects, and their median lethal concentration (LC50) within 96 hours was measured. 50 );

[0056] The method for determining the water solubility of polyacrylamide products used in acid fracturing is as follows: prepare an aqueous solution of 4‰ polyacrylamide product, stir at high speed at 600 rpm, and record the dissolution time and dissolution state.

[0057] The method for determining the uniformity of hydrolysis is as follows: Polyacrylamide samples are selected from the upper, middle and lower parts of the dried polyacrylamide silo. The degree of hydrolysis of the samples is determined according to GB / T 12005.6-1989 "Determination of Degree of Hydrolysis of Partially Hydrolyzed Polyacrylamide". The difference between the highest degree of hydrolysis and the lowest degree of hydrolysis is used to characterize the uniformity of hydrolysis.

[0058] Examples 1-10 and Comparative Examples 1-7 illustrate the preparation of the dispersant compositions.

[0059] Example 1

[0060] (1) Take 100 parts by weight of Yanshan Petrochemical Type I linear paraffin, 20 parts by weight of water and 9 parts by weight of emulsifier, mix them and then perform shear emulsification treatment to obtain W / O type emulsion; wherein, the emulsifier is composed of Tween 80 and Span 80 in a mass ratio of 1:17, the shear emulsification treatment time is 20 min and the stirring speed is 2880 rpm;

[0061] (2) The W / O type emulsion, 30 parts by mass of dispersing material and 4 parts by mass of solubilizer are mixed and ball-milled to obtain dispersant composition 1; wherein the dispersing material is a mixture of 100 mesh sodium bicarbonate and 100 mesh sodium carbonate in a mass ratio of 1:1, the solubilizer is AEO-3, the ball milling time is 30 min, and the ball milling speed is 90 rpm.

[0062] Example 2-10

[0063] Following the same method as in Example 1, different compositional compositions and proportions, as well as preparation conditions (see Tables 1 and 2), were used to obtain dispersant compositions 2-10.

[0064] Comparative Examples 1-4

[0065] Following the same method as in Example 1, different compositional compositions and proportions, as well as preparation conditions (see Tables 1 and 2), were used to obtain dispersant compositions 11-14.

[0066] Comparative Example 5

[0067] Following the same method as in Example 1, except that the Yanshan Petrochemical Type I linear paraffin in step (1) was replaced with white oil, dispersant composition 15 was obtained.

[0068] Comparative Example 6

[0069] Following the same method as in Example 1, except that the ball milling process in step (2) was replaced with ordinary stirring process, the ordinary stirring process lasting for 30 minutes and the stirring speed being 70 rpm, to obtain dispersant composition 16.

[0070] Comparative Example 7

[0071] 100 parts by weight of Yanshan Petrochemical Type I linear paraffin, 20 parts by weight of water, 9 parts by weight of emulsifier, 30 parts by weight of dispersant and 4 parts by weight of solubilizer were mixed and subjected to shear emulsification to obtain dispersant composition 17; wherein, the emulsifier was composed of Tween 80 and Span 80 in a mass ratio of 1:17, the dispersant was composed of 100 mesh sodium bicarbonate and 100 mesh sodium carbonate in a mass ratio of 1:1, the solubilizer was AEO-3, the shear emulsification time was 20 min, and the stirring speed was 2880 rpm.

[0072] Table 1

[0073]

[0074]

[0075]

[0076] Table 2

[0077]

[0078]

[0079] Application Example 1

[0080] (1) A first solution is obtained by mixing acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and water. Sodium hydroxide is added to adjust the pH of the first solution to 7 to obtain the second solution.

[0081] (2) After cooling the second solution to 8°C, transfer it to a polymerization bottle, add urea, introduce nitrogen into the polymerization bottle, add ammonium persulfate and sodium bisulfite, and continue to introduce nitrogen until the reaction system begins to heat up and the polymerization reaction begins.

[0082] (3) After the polymerization reaction has been going on for 12 hours, the polymer block is taken out and granulated. During the granulation process, dispersant composition 1 (5 wt% of the polymer block mass) is added to make the dispersant composition 1 uniformly dispersed on the surface of the polymer granules. NaOH solid (1 wt% of the polymer block mass) is added to make the granules fully dispersed and adhere to the dispersant. The dispersion effect and the adhesion state of the granules are observed and recorded. Then, the granules are placed in a 60℃ constant temperature oven for hydrolysis. After drying and pulverizing, the polyacrylamide product for acid fracturing is obtained. Two points are taken from the top, middle and bottom of the polyacrylamide product for six-point sampling to determine the degree of hydrolysis.

[0083] The mass ratio of acrylamide (AM), 2-acrylamide-2-methylpropanesulfonic acid (AMPS), water, urea, ammonium persulfate, and sodium bisulfite is 2100:600:1500:22:1:1.

[0084] Application Example 2-17

[0085] The method is the same as in Application Example 1, except that dispersant composition 1 is replaced by dispersant compositions 2-17 respectively.

[0086] Application Example 18

[0087] The method is the same as in Application Example 1, except that the dispersant composition 1 is replaced with white oil.

[0088] The results of the biotoxicity test of dispersant compositions 1-17 and white oil dispersant are shown in Table 3. The results of the dispersing effect of the dispersants in application examples 1-18 and the hydrolytic uniformity and water solubility of the prepared acid fracturing polyacrylamide products are shown in Table 4.

[0089] Table 3

[0090]

[0091]

[0092] Table 4

[0093]

[0094]

[0095] As can be seen from the data in Table 3, the dispersant composition provided by the present invention has lower biotoxicity compared to traditional white oil dispersants.

[0096] According to the data in Table 4, when the dispersant composition provided by the present invention is used for polyacrylamide granulation, the resulting polyacrylamide product has high hydrolysis uniformity, fast water solubility, and no "fish eye" phenomenon occurs in the aqueous solution.

[0097] A comparison of the data from Application Examples 1-2 and 3-5 shows that limiting the proportions of each component in the composition to a preferred range can further promote the uniformity of polyacrylamide hydrolysis and the rapid water solubility of the polyacrylamide product.

[0098] A comparison of the data from Application Examples 1-2 and 6-7 shows that limiting the proportion of the dispersing material in the composition to a preferred range can improve the dispersion effect of the dispersant, while further promoting the hydrolysis uniformity of polyacrylamide and the rapid water solubility of the polyacrylamide product.

[0099] A comparison of the data from Application Examples 1-2 and 8-9 shows that using Tween 80 and Span 80 as emulsifiers results in a highly stable emulsion system with moderate viscosity. This has a positive effect on improving the suspension stability of the dispersed material particles in the dispersant, thereby improving the dispersion effect of the dispersant, promoting the hydrolysis uniformity of polyacrylamide, and enhancing the rapid water solubility of the polyacrylamide product.

[0100] A comparison of the data from Application Examples 1-2 and 10 shows that using Tween 80 and Span 80 in the preferred mass ratio as emulsifiers can further improve the suspension stability of the dispersed material particles in the dispersant, thereby improving the dispersion effect of the dispersant, promoting the hydrolysis uniformity of polyacrylamide, and improving the rapid water solubility of polyacrylamide products.

[0101] A comparison of the data from Application Examples 1-2 and Application Examples 11-14 shows that the dispersant composition prepared by using the proportions of the components in the composition provided by the present invention has a good dispersion effect. At the same time, the hydrolysis uniformity of polyacrylamide is good during the granulation process, and the final polyacrylamide product has better rapid water solubility.

[0102] A comparison of the data from Application Examples 1-2 and Application Example 15 shows that the dispersant composition using linear paraffin provided by the present invention as the oil phase component has a better dispersing effect than white oil as the oil phase component in traditional dispersants. At the same time, the hydrolysis uniformity of polyacrylamide is better during the granulation process, and the final polyacrylamide product has better rapid water solubility.

[0103] A comparison of the data from Application Examples 1-2 and 16 shows that ball milling in the preparation of the dispersant composition results in a more uniform and stable dispersant composition, thereby improving its dispersion effect, promoting the hydrolysis uniformity of polyacrylamide, and enhancing the rapid water solubility of the polyacrylamide product.

[0104] A comparison of the data from Application Examples 1-2 and Application Example 17 shows that, in the preparation of the dispersant composition, compared with directly performing shear emulsification after mixing all components, the dispersant composition prepared by the method provided by this invention has better dispersion effect, better hydrolysis uniformity of polyacrylamide during granulation, and better rapid water solubility of the final polyacrylamide product.

[0105] A comparison of the data from Application Examples 1-2 and Application Example 18 shows that the dispersant composition provided by the present invention significantly improves the hydrolytic uniformity of polyacrylamide during granulation and the rapid water solubility of the final polyacrylamide product compared to traditional white oil dispersants.

[0106] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A dispersant composition, characterized in that, The composition comprises the following components in parts by weight: 100 parts linear paraffin 12-25 parts water 24-36 parts of dispersion material, 9-10 parts emulsifier 4-5 parts of solubilizer; The dispersing materials are sodium bicarbonate and sodium carbonate; The emulsifiers are Tween 80 and Span 80; the mass ratio of Tween 80 to Span 80 is 1:15-20; Linear paraffin, water, and emulsifier are mixed and then subjected to shear emulsification. Then, dispersant and solubilizer are added and ball milling is performed to obtain the dispersant composition. The particle size of the sodium bicarbonate and the sodium carbonate is independently 40-100 mesh.

2. The composition according to claim 1, wherein, The solubilizer is selected from at least one of polysorbate compounds, polyoxyethylene fatty alcohol ether compounds, and sodium dodecyl sulfate.

3. The composition according to claim 1 or 2, wherein, The mass ratio of sodium bicarbonate to sodium carbonate is 1:0.5-5.

4. The dispersant composition according to claim 1 or 2, wherein, The shear emulsification process takes 10-30 minutes and the stirring speed is 2500-3000 rpm.

5. The dispersant composition according to claim 1 or 2, wherein, The ball milling process takes 20-40 minutes and rotates at 80-100 rpm.

6. The use of the composition according to any one of claims 1-5 as a dispersant for granulation of polyacrylamide for acid fracturing.

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