Polyether-based demulsifier for sludge with high water and oil content, manufacturing method and use

Abstract

To provide especially a polyether-base emulsion breaker for sludges with high water and oil contents, a manufacturing method, and use thereof in a technical field of sludge treatments.SOLUTION: A polyether-base emulsion breaker includes 4-20 pts.wt. of propylene glycol block polyether, 5-20 pts.wt. of ethylenediamine polyoxyethylene polyoxypropylene ether, 2-10 pts.wt. of a fatty alcohol polyoxyethylene ether, 1-5 pts.wt. of secondary alkyl sulfonate, and 60-90 pts.wt. of water. Propylene glycol block polyether, ethylenediamine polyoxyethylene polyoxypropylene ether, fatty alcohol polyoxyethylene ether, secondary alkyl sulfonate, and water are blended and a mass ratio is adjusted so as to improve emulsification destruction efficiency of the polyether-base emulsion breaker to oil-containing sludges with a high water content and containing sands.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to the technical field of sludge treatment, and more particularly to a polyether-based demulsifier for sludge with high water and oil content, its manufacturing method and use. [Background technology]

[0002] Solid waste generated in offshore oil and gas fields is primarily divided into two categories: municipal waste and hazardous waste. Municipal waste includes household waste, office waste, and construction waste, while hazardous waste includes oily sludge, chemical packaging barrels, and used lubricating oil. Oily sludge contains water-in-oil (W / O) or oil-in-water (O / W) emulsions, suspended solids, and other components. Oily sludge is listed on the National Hazardous Waste Catalog due to its complex composition and properties, including high levels of organic contaminants. Prior art techniques typically use demulsifiers to remove water from oily sludge. However, water-in-oil sludge generated in offshore oil fields is characterized by a high water content and low sediment content, sometimes exceeding 40% and approximately 5% sediment content. When the water content is high, the apparent viscosity of the water-in-oil oil-containing sludge increases, making it difficult for the demulsifier to diffuse into the oil sludge system. The solid sediment is adsorbed at the oil-water interface of the water-in-oil oil-containing sludge, playing a spatial stabilizing role and forming an interfacial film that is stronger than a simple oil-water interfacial film, thereby improving the stability of the oil sludge system and further increasing the difficulty of demulsification.

[0003] In the invention with application number 202110153456.1, a neutral oil-containing sludge cleaner was prepared by synthesizing and blending a non-polyether type demulsifier. The treatment system of this oil-containing sludge cleaner is close to neutral and environmentally friendly, but it has low demulsification efficiency and is difficult to apply to oil-containing sludge with a high water content and containing sediment. Summary of the Invention [Problem to be solved by the invention]

[0004] In response to the problem that the efficiency of non-polyether type demulsifiers in the prior art is low and they are difficult to apply to oil-containing sludge that has a high water content and contains sediment, the present invention provides a polyether-based demulsifier for sludge with high water and oil content, as well as a manufacturing method and use thereof, which is obtained by mixing propylene glycol block polyether, ethylenediamine polyoxyethylene polyoxypropylene ether, fatty alcohol polyoxyethylene ether, secondary alkyl sulfonate, and water and adjusting the mass ratio to improve the demulsification efficiency of the polyether-based demulsifier for oil-containing sludge that has a high water content and contains sediment.

[0005] In a first aspect, the present invention provides a polyether-based demulsifier for high water and oil content sludge, comprising 4 to 20 parts by weight of a propylene glycol block polyether, 5 to 20 parts by weight of an ethylenediamine polyoxyethylene polyoxypropylene ether, 2 to 10 parts by weight of a fatty alcohol polyoxyethylene ether, 1 to 5 parts by weight of a secondary alkyl sulfonate, and 60 to 90 parts by weight of water.

[0006] Here, the propylene glycol block polyether is preferably 4 to 10 parts by weight, the ethylenediamine polyoxyethylene polyoxypropylene ether is preferably 5 to 10 parts by weight, the fatty alcohol polyoxyethylene ether is preferably 2 to 5 parts by weight, and the secondary alkyl sulfonate is preferably 2 to 5 parts by weight.

[0007] The molecular formula of propylene glycol block polyether is HO(C2H4O) m (C3H6O) n H, the average molecular weight is 2000 to 3500, and the cloud point (1% aqueous solution) is 57 to 61°C. m and n are each 0 or a positive integer, and m+n≠0.

[0008] The molecular formula for ethylenediamine polyoxyethylene polyoxypropylene ether is (C3H6O-C2H8N2-C2H4O) x The average molecular weight is 200,000 or more, the pH value (1% aqueous solution) is 10-11, and the cloud point is 27-30E (25% BDG solution), where x is a positive integer.

[0009] The molecular formula of fatty alcohol polyoxyethylene ether is C 12 H 25 O(CH2CH2O) y H, the average molecular weight is 500 or more, the cloud point (1% aqueous solution) is 79°C, and y is a positive integer.

[0010] Secondary alkyl sulfonate is sodium secondary alkyl sulfonate, whose molecular formula is RSO3Na, where R is an alkyl group with 14 to 17 carbon atoms.

[0011] In a second aspect, the present invention provides a method for preparing the polyether demulsifier as described above, comprising mixing a propylene glycol block polyether, an ethylenediamine polyoxyethylene polyoxypropylene ether, a fatty alcohol polyoxyethylene ether, a secondary alkyl sulfonate, and water, followed by stirring to obtain the polyether demulsifier.

[0012] The stirring time is 28 to 32 minutes, and the stirring speed is 180 to 220 rpm.

[0013] The stirring temperature is 25 to 28°C.

[0014] In a third aspect, the present invention provides the use of a polyether demulsifier as described above in the treatment of high water and oil content sludge.

[0015] The sludge has an oil content of 55% to 60%, a water content of 38% to 43%, and a sand content of 4% to 6%. The dosage of the polyether demulsifier is 1000 to 5000 ppm. [Effects of the Invention]

[0016] The advantageous effects of the present invention are as follows: The present invention provides a polyether-based emulsifier for sludge with high water and oil content, as well as a manufacturing method and use thereof. The polyether-based emulsifier is prepared by stirring and mixing the raw materials propylene glycol block polyether, ethylenediamine polyoxyethylene polyoxypropylene ether, fatty alcohol polyoxyethylene ether, secondary alkyl sulfonate, and water, and is therefore simple to manufacture. In the present invention, by adjusting the dosage of each raw material in the polyether-based emulsifier, when the polyether-based emulsifier is applied to an oil-containing sludge system, its surface activity is higher than that of the film-forming material, allowing it to quickly diffuse to the interface. Therefore, it can replace or displace part of the natural emulsifier on the original interfacial film, reducing the oil-water interfacial tension and preventing the bulk phase active material molecules from migrating to the interface, forming an unstable mixed film. Eventually, the strength of the interfacial film is reduced, leading to its destruction and emulsification. This accelerates the three-phase separation of water, oil, and sand in oil-containing sludge with a high water content and sand content, significantly improving the emulsification efficiency of the polyether-based emulsifier. The polyether-based emulsifier provided by the present invention can achieve a dehydration rate of more than 90% for oil-containing sludge with a high water content and sand content, reducing the water content of the crude oil after separation to less than 3%, thereby meeting the requirements for crude oil export. DETAILED DESCRIPTION OF THE INVENTION

[0017] In order to allow those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are described below clearly and completely. It is clear that the described embodiments are only a part of the embodiments of the present invention, and are not all of the embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without making creative efforts shall fall within the protection scope of the present invention.

[0018] The propylene glycol block polyether model used in Examples 1 and 5 is L64, with an average molecular weight of 2900 and a cloud point (1% aqueous solution) of 57-61°C. The molecular formula of ethylenediamine polyoxyethylene polyoxypropylene ether (EDEP) is (C3H6O-C2H8N2-C2H4O). x The average molecular weight is about 350,000, the pH value (1% aqueous solution) is about 10-11, and the cloud point is 27-30E (25% BDG solution). The fatty alcohol polyoxyethylene ether model is AEO-9, with an average molecular weight of 582 and a cloud point (1% aqueous solution) of 79°C. The secondary alkyl sulfonate model is SAS-60, with an average molecular weight of 300.

[0019] Example 1 The method for producing a polyether-based emulsifier for high-water and high-oil sludge is as follows: 5 parts by weight of propylene glycol block polyether, 5 parts by weight of ethylenediamine polyoxyethylene polyoxypropylene ether, 2 parts by weight of fatty alcohol polyoxyethylene ether, 5 parts by weight of secondary alkyl sulfonate, and 83 parts by weight of water are added to a stirring tank, stirred at 25°C and 200 rpm for 30 minutes, and then the material is discharged to obtain the polyether-based emulsifier for high-water and high-oil sludge.

[0020] <Examples 2 to 4> The polyether demulsifier obtained in Example 1 was used to treat oil-containing sludge with different water contents, and the treatment method included the following steps: Step 1: The polyether-based demulsifier obtained in Example 1 is mixed with oil-containing sludge to obtain a mixed system with a mass fraction of the polyether-based demulsifier of 3000 ppm. Step 2: The temperature of the mixed system is increased to 60°C, and the system is stirred at a constant temperature for 5 minutes at a stirring rate of 100 rpm to obtain a demulsified system. Step 3: Centrifuge the demulsified system at 4000 rpm for 6 minutes to obtain dehydrated crude oil. After centrifugation, record the amount of water removed and calculate the dehydration rate. Take a sample from the top layer of the demulsified and dehydrated crude oil and use Karl Fischer Coulomb titration (GB / T 11133-2015) to detect the water content of the demulsified crude oil. Take a sample from the mud at the bottom of the demulsified and dehydrated crude oil and use petroleum spectrophotometry (HJ 637-2012) to detect the oil content of the demulsified sediment.

[0021] In Examples 2 to 4, the water content of the oil-containing sludge before emulsification, the sediment content before emulsification, the dehydration rate, the water content of the crude oil after emulsification, and the oil content of the sediment after emulsification are as shown in Table 1.

[0022] JPEG0007829075000001.jpg30170

[0023] <Example 5> The method for producing a polyether-based emulsifier for high-water and high-oil sludge is as follows: 4 parts by weight of propylene glycol block polyether, 6 parts by weight of ethylenediamine polyoxyethylene polyoxypropylene ether, 2 parts by weight of fatty alcohol polyoxyethylene ether, 3 parts by weight of secondary alkyl sulfonate, and 85 parts by weight of water are added to a stirring tank, stirred at 25°C and 200 rpm for 30 minutes, and then the material is discharged to obtain the polyether-based emulsifier for high-water and high-oil sludge.

[0024] <Examples 6 to 8> The polyether-based demulsifier obtained in Example 5 was used to treat the above oil-containing sludge with different water contents, and the treatment method included the following steps: Step 1: The polyether-based demulsifier obtained in Example 5 is mixed with oil-containing sludge to obtain a mixed system with a mass fraction of the polyether-based demulsifier of 4000 ppm. Step 2: The temperature of the mixed system is increased to 60°C, and the system is stirred at a constant temperature for 5 minutes at a stirring rate of 100 rpm to obtain a demulsified system. Step 3: Centrifuge the demulsification system at 4000 rpm for 6 minutes to obtain dehydrated crude oil. After centrifugation, record the amount of water removed and calculate the dehydration rate. Sample the top layer of the demulsified and dehydrated crude oil and use Karl Fischer Coulomb titration (GB / T 11133-2015) to detect the water content of the demulsified crude oil. Sample the mud sample at the bottom of the demulsified and dehydrated crude oil and use petroleum spectrophotometry (HJ 637-2012) to detect the oil content of the sediment after demulsification.

[0025] In Examples 6 to 8, the water content of the oil-containing sludge before emulsification, the sediment content before emulsification, the dehydration rate, the water content of the crude oil after emulsification, and the oil content of the sediment after emulsification are as shown in Table 2.

[0026] JPEG0007829075000002.jpg30170

[0027] As can be seen from Tables 1 and 2, the polyether demulsifier prepared by the present invention can effectively remove water from oil-containing sludge with a high original water content, and obtain crude oil with a water content of less than 2.076% after demulsification.

[0028] <Comparative Examples 1 to 3> The only difference between Comparative Examples 1 to 3 and Examples 2 to 4 is that in Comparative Examples 1 to 3, a commercially available non-polyether-based demulsifier M550 was used to treat oil-containing sludge with water contents of 38.67%, 39.85%, and 42.61%, respectively.

[0029] In Comparative Examples 1 to 3, the water content of the oil-containing sludge before emulsification breaking, the sediment content before emulsification breaking, the dehydration rate, the water content of the crude oil after emulsification breaking, and the oil content of the sediment after emulsification breaking are as shown in Table 3.

[0030] JPEG0007829075000003.jpg30170

[0031] <Comparative Examples 4 to 6> The only difference between Comparative Examples 4 to 6 and Examples 2 to 4 is that in Comparative Examples 4 to 6, a commercially available non-polyether-based demulsifier, LAS-30, was used to treat oil-containing sludge with water contents of 38.67%, 39.85%, and 42.61%, respectively.

[0032] In Comparative Examples 4 to 6, the water content of the oil-containing sludge before emulsification breaking, the sediment content before emulsification breaking, the dehydration rate, the water content of the crude oil after emulsification breaking, and the oil content of the sediment after emulsification breaking are as shown in Table 4.

[0033] JPEG0007829075000004.jpg30170

[0034] As can be seen from Tables 3 and 4, in Comparative Examples 1 to 3 and Comparative Examples 4 to 6, when the same oil-containing sludge was treated using the commercially available non-polyether demulsifiers M550 and LAS-30, respectively, the water content of the crude oil after emulsification was significantly higher than that of the crude oil after emulsification in Examples 2 to 4, and the oil content of the sediment after emulsification was significantly higher than that in Examples 2 to 4. This demonstrates that the polyether demulsifiers produced by the present invention can achieve better separation of water, oil, and sediment in the treatment of oil-containing sludge than the commercially available non-polyether demulsifiers.

[0035] <Comparative Examples 7 to 9> The difference between Comparative Examples 7 to 9 and Examples 2 to 4 is that the demulsifier used in Comparative Examples 7 to 9 is prepared from 2 parts by weight of propylene glycol block polyether, 3 parts by weight of ethylenediamine polyoxyethylene polyoxypropylene ether, 1 part by weight of fatty alcohol polyoxyethylene ether, 6 parts by weight of secondary alkyl sulfonate, and 88 parts by weight of water.

[0036] In Comparative Examples 7 to 9, the water content of the oil-containing sludge before emulsification, the sediment content before emulsification, the dehydration rate, the water content of the crude oil after emulsification, and the oil content of the sediment after emulsification are as shown in Table 5.

[0037] JPEG0007829075000005.jpg30170

[0038] <Comparative Examples 10 to 12> The only difference between Comparative Examples 10-12 and Examples 2-4 is that the demulsifier used in Comparative Examples 10-12 was prepared using 5 parts by weight of propylene glycol block polyether, 5 parts by weight of disodium ethylenediaminetetraacetate, 5 parts by weight of fatty alcohol polyoxyethylene ether, 6 parts by weight of sodium dodecylbenzenesulfonate, and 80 parts by weight of water. Here, the propylene glycol block polyether model was L65 with an average molecular weight of 3500, the fatty alcohol polyoxyethylene ether model was AEO-3 with a molecular weight of 318.56, and the sodium dodecylbenzenesulfonate model was LAS-30.

[0039] In Comparative Examples 10 to 12, the water content of the oil-containing sludge before emulsification, the sediment content before emulsification, the dehydration rate, the water content of the crude oil after emulsification, and the oil content of the sediment after emulsification are as shown in Table 6.

[0040] JPEG0007829075000006.jpg30170

[0041] As can be seen from Tables 5 and 6, the demulsifiers of Comparative Examples 7 to 9, which were not prepared according to the ratios provided by the present invention, failed to effectively separate the water, oil, and sediment in the oil-containing sludge, because the water content of the crude oil after demulsification was higher than 11% and the oil content of the sediment after demulsification was higher than 15%. In Comparative Examples 10 to 12, AEO-3, which has similar effects and molecular weight, was used instead of AEO-9, and LAS-30 was used instead of SAS-60. The water content of the crude oil after demulsification was higher than 10%, and the oil content of the sediment after demulsification was higher than 14%, failing to effectively separate the water, oil, and sediment in the oil-containing sludge. The polyether-based demulsifier used in Examples 2 to 4 showed significant separation effects for sludge with an oil content of 55% to 60%, a water content of 38% to 43%, and a sediment content of 4% to 6% compared to Comparative Examples 7 to 12.

[0042] Although the present invention has been described in detail by preferred embodiments, the present invention is not limited thereto. Those skilled in the art can make various equivalent modifications or substitutions to the embodiments of the present invention without departing from the spirit and essence of the present invention, and these modifications or substitutions shall fall within the scope of the present invention. Those skilled in the art can easily think of modifications or substitutions within the technical scope disclosed in the present invention, and these shall fall within the protection scope of the present invention.

Claims

1. A polyether-based demulsifier for sludge with high water and oil content, 4 to 20 parts by weight of a propylene glycol block polyether, 5 to 20 parts by weight of an ethylenediamine polyoxyethylene polyoxypropylene ether, 2 to 10 parts by weight of a fatty alcohol polyoxyethylene ether, 1 to 5 parts by weight of a secondary alkyl sulfonate, and 60 to 90 parts by weight of water; The molecular formula of propylene glycol block polyether is HO(C 2 H 4 O) m (C 3 H 6 O) n H, with an average molecular weight of 2000 to 3500; The molecular formula of fatty alcohol polyoxyethylene ether is C 12 H 25 O (CH 2 CH 2 O) y H, and the average molecular weight is 500 or more; Secondary alkyl sulfonate is sodium secondary alkyl sulfonate, and the molecular formula of sodium secondary alkyl sulfonate is RSO 3 Na, R is an alkyl group having 14 to 17 carbon atoms, The molecular formula of ethylenediamine polyoxyethylene polyoxypropylene ether is (C 3 H 6 O-C 2 H 8 N 2 -C 2 H 4 O) x and an average molecular weight of 200,000 or more.

2. A method for producing the polyether-based demulsifier according to claim 1, comprising: Propylene glycol block polyether, ethylenediamine polyoxyethylene polyoxypropylene ether, fatty alcohol polyoxyethylene ether, secondary alkyl sulfonate and water are mixed and then stirred to obtain a polyether-based demulsifier; The method for producing a polyether-based demulsifier according to claim 1, wherein the stirring temperature is 25 to 28°C.

3. 3. The method according to claim 2, wherein the stirring time is 28 to 32 minutes and the stirring speed is 180 to 220 rpm.

4. The polyether-based demulsifier according to claim 1, which is used for treating sludge having a high water and oil content.

5. A polyether-based emulsifier as described in claim 4, characterized in that the sludge has an oil content of 55% to 60%, a water content of 38% to 43%, and a soil and sand content of 4% to 6%.

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