RU2206367C1 - Method of breaking stable concentrated oil-containing emulsions (options) - Google Patents

Abstract

FIELD: lubricants. SUBSTANCE: to emulsion in question (in particular spent cutting emulsion), 0.05-0.15 g/l of cationic polyelectrolyte is added or emulsion is first warmed and settled and then 2.0 g/l of flocculating sorbent (SF-A2) and acrylamide/sodium acrylate copolymer are added so that weight ratio of sorbent to copolymer reagent ranges from 600:1 to 6000:1. Duration of all emulsion breaking cycle is 1.5 h if electrolyte is utilized and 11 h without electrolyte and warming emulsion. When applying described methods, clarified water and oily slime are obtained, the former being reused in production purposes and the second is first compacted and then reused. EFFECT: increased purity of clarified water. 2 cl, 1 tbl, 6 ex

Description

 The invention relates to chemical methods for the destruction of emulsions, in particular lubricant-cooling technological means (SOTS), and can be used for their disposal.

 It is known that SOTS, due to its functional purpose, contains a large number of emulsifiers that prevent stratification of SOTS. At the same time, when solving tasks for the disposal of SOTS, the stability of emulsions is a negative factor.

 Particular difficulties arise with concentrated SOTS with a high (3-20 g / l) oil content.

 Currently, in industrial practice, there is a method of destroying stable concentrated emulsions (Technological instruction TI 101-II-HL-167-99, Magnitogorsk, 1999) [1].

According to the known method, the oil emulsion is heated to a temperature of 80-100 ^o With and at this temperature, stand for at least 10 hours. Then the mixture is fed into the reactor, in which it is treated with spent pickling sulfate solution with stirring with compressed air. Next, the mixture is defended for 18-20 hours.

 In the process of settling, the resulting mixture decomposes in such a way that free oil floats up, and the remaining decomposition products are neutralized with milk of lime.

 The resulting aqueous medium is an emulsion freed from part of the oil, containing a sufficiently large amount of residual oil products and suspended solids that do not allow it to be reused for production purposes.

 The known method is time consuming. The duration of one cycle of the decomposition of the emulsion is 20-30 hours. In addition, the use for the decomposition of the emulsion of the sulfuric acid pickling solution at elevated temperatures reduces the level of production safety and entails a deterioration in working conditions.

 The prior art method for the destruction of stable emulsions with a high oil content (RF patent 2095117, publ. 1997) [2]. The method includes processing the emulsion with a demulsifying composition, followed by settling and separation into oil and water.

 The demulsifying composition contains a micellar phase, consisting of water, an organic liquid and a surfactant with hydrophilic or hydrophobic properties with an excess of aqueous and organic phases that are not miscible with it, but are in equilibrium with this phase, and the sedimentation is carried out until separation into three phases . The demulsifying composition in this case is also an emulsion containing organic compounds - diesel fuel and surfactants.

 Using the known method in an industrial environment seems to be low-tech and unlikely for the following reasons.

 Firstly, it contains a complex operation for the preparation of a demulsifying composition, which is complicated by the selection of individual components - surface-active substances, moreover, expensive.

 Secondly, for each of the surfactants, it is required to provide optimal ratios and a temperature range in which the micellar phase will be stable. Moreover, the volume of the phase should exceed the volume of the destroyed by 3-4 times. When using the method for complete destruction of the emulsion requires repeated repetition of the introduction of the demulsifying composition, the presence of its excess in relation to the destroyed emulsion and the need to settle to determine the presence of excess micellar phase, indicating the end of the destruction of the emulsion.

 Thirdly, the product obtained as a result of the destruction of COTS emulsions by a known method is a mixture of organic substances with oil and residues of the components of the micellar phase extracted from the emulsion being destroyed. Such a product belongs to a higher hazard class than the destructible emulsion of SOTS and will require subsequent complex disposal technology.

 The claimed invention was created on the basis of simpler reagent methods for influencing an oil-containing emulsion. Moreover, the method according to option 1 is only reagent, and the method according to option 2 was created to improve the existing method [1].

 As the closest in technical essence to the claimed invention according to option 1, you can take "Method of wastewater treatment" (RF Patent 2064445, publ. 1996) [3]. The known method relates to reagents and consists in the fact that coagulant-montmorillonite clay with an absorption capacity of at least 90 mEq / 100g is introduced into the wastewater, and at the same time a flocculant is introduced - a copolymer of acrylamide, sodium acrylate and butadiene styrene in proportion to the coagulant ( 20-100): 1.

 The essence of the known method is the joint use of high-quality montmorillonite clays, characterized by good adsorption properties, and the flocculant SAAB, which allows to obtain a high degree of wastewater treatment.

 The known method is used for wastewater with a low content of petroleum products from 0.0482 to 0.3284 g / l (as follows from table 1 of the description of the patent). In addition, it should be noted that, unlike SOTS, wastewater containing oil products are not stable stabilized emulsions.

 As the closest in technical essence analogue to the claimed invention according to option 2, you can take the known method [1].

 The objective of the present invention is to create a productive industrial method for the destruction of stable concentrated emulsions with the formation of the product in the form of a utilized oil sludge and recycled water.

 To solve the problem in the method according to option 1, including the introduction of reagents, a cationic type polyelectrolyte in the amount of 0.05-0.15 g / l, the flocculating sorbent "Reagent SF-A2" - aluminosilicate activated by alkaline reagents and derivatives of alkaline hydrolysis of (co) polymers of acrylamide in an amount of at least 2.0 g / l and the polymer reagent is a copolymer of acrylamide and sodium acrylate, while the flocculating sorbent and the polymer reagent are introduced in the ratio (600-6000): 1.

To solve the problem in the method according to option 2, which includes heating the emulsion to a temperature of 80-100 ^o C, settling at this temperature, separating the pop-up oil and introducing reagents, after separating the pop-up oil, the flocculating sorbent "Reagent SF-A2" is successively introduced into the emulsion - aluminosilicate activated with alkaline reagents and derivatives of alkaline hydrolysis of (co) acrylamide polymers in an amount of at least 2.0 g / l and a polymer reagent is a copolymer of acrylamide and sodium acrylate, while the flocculating sorbent and the polymer reagent is introduced in the ratio (600-6000): 1.

 In this case, the reagents are introduced in the indicated amount in terms of dry matter.

 The essence of the invention according to option 1 is a reagent treatment of the emulsion, in which in a certain sequence enter these reagents in a certain amount. Using the cationic polyelectrolyte, the electrokinetic potential of the emulsion droplets is changed. In this case, the dose of the introduced electrolyte allows partial demulsification of the emulsion at the time of reaching the isoelectric point. The stability of the emulsion is maintained, but conditions are created for the destructive effect of the flocculating sorbent.

 The flocculating sorbent separates the emulsion into water and oil sludge, which is an organomineral complex in the form of oil and sorbent particles combined into macro flakes capable of sedimentation separation with a liquid medium. However, part of the flocculating sorbent, exerting an effect on the complex of emulsion stabilizers, is itself partially stabilized by surfactants - emulsifiers of the initial emulsion and, thus, makes it possible to have a small amount of colloid-dissolved sorbent in the processed system that is not bound to sedimentary macro flakes.

 The colloidal dissolved flocculating sorbent is removed from the system as a result of the subsequent introduction of a polymer reagent into it.

 The polymer reagent is a copolymer of polyacrylamide and sodium acrylate, obtained by partial hydrolysis of polyacrylamide followed by precipitation.

 Being introduced into the system in the stated ratio with respect to the flocculating sorbent, the polymer reagent intensifies the process of separating the dispersed phase in an already separated emulsion and flocculates the remainder of the stabilized colloid-dissolved flocculating sorbent. In this case, the destruction of such a complex emulsion as concentrated SOTS occurs as a result of the mutual action of the introduced reagents and represents a change in the electrokinetic potential of the system, aggregation and removal of the oils, stabilizers, surface-active and other substances contained in it and flocculation of possible excess reagents.

The invention according to option 2 is identical to the invention according to option 1. According to option 2, to partially change the electrokinetic potential of the droplets of the emulsion, its heating to 80-100 ^{° C.} and settling at this temperature are used. At the same time, as with the introduction of the cationic polyelectrolyte, partial emulsification of the emulsion droplets occurs, and conditions are created for the destructive sorption-flocculation effect of the flocculating sorbent. Further, as in option 1.

 The claimed method is illustrated by examples.

 As objects for testing the proposed method used emulsion SOTS based on the emulsol ET-2u and Quakerol-1914.

The processing of emulsions was carried out under stationary conditions. The working temperature of the emulsion ranged from 25 to 87 ^o C, pH 6.3-7.6. Correction of the parameters of the method depending on the temperature of the emulsion and the pH was not performed. The introduced reagents were not heated.

 The mechanical mixing time of the emulsion with each of the introduced reagents was 1.5-3 minutes. In industrial conditions, the optimal mixing time can be 15-20 minutes after the introduction of each of the reagents.

 As the cationic polyelectrolyte used cationic type polyelectrolyte brand VPK-402 TU 6-05-2009-86. You can use the product of the interaction of polyethylene polyamine and urea - flocculant FS-413 TU 6-05751768-58-93. However, the FS-413 flocculant is hydrolyzed in a short period of time and, as a result, quickly loses its properties.

 As a flocculating sorbent, Reagent SF-A2 was used in accordance with TU 2164-004-36614963-01.

 As a polymer reagent used reagent "Aquapol-FT2" according to TU 2216-003-36614963-99. It is possible to use a polymer reagent brand "Fennopol" (Production of Finland).

 Quantitative characteristics of the introduced reagents and the results of processing the destructible emulsion are shown in the table for the method / 1 / and for the claimed (examples 1-6). In this case, examples 1-3 correspond to the claimed method according to option 1, and examples 4-6 correspond to the method according to option 2. Moreover, the lower dosage limits of the introduced reagents are determined by obtaining the necessary technical result, and the upper ones are economically justified. The amount of reagents is given in terms of dry matter per 1 liter of destructible emulsion.

 In industrial conditions, it is justifiable to use aqueous solutions of reagents, while their concentrations are determined by the hardware design of the technological scheme and the technical capabilities of metering pumps.

Method / 1 /. Emulsion based on Quulsol-1914 emulsol. The total oil content of 18.4 g / l; pH 7.2; temperature 25 ^o C. The data are based on the results of industrial use.

Example 1. An emulsion based on Quulsol-1914 emulsol. The total oil content of 18.4 g / l; pH 7.2; temperature 25 ^o C. Processing was carried out with reagents: VPK-402 in an amount of 0.05 g / l; SF-A2 - 6.0 g / l; Aquapol-FT2 - 0.001 g / l.

Example 2. An emulsion based on emulsol ET-2u. The total oil content of 20.5 g / l; pH 7.6; temperature 38 ^o C. Processing was performed with reagents: FS-413 in an amount of 0.15 g / l; SF-A2 -2.0 g / l; Aquapol-FT2 - 0.0033 g / l.

Example 3. An emulsion based on Quulsol-1914 emulsol. The total oil content of 15.2 g / l; pH 6.3; temperature 50 ^o C. Processing was carried out with reagents: VPK-402 in an amount of 0.09 g / l; SF-A2 in an amount of 4.2 g / l; Aquapol-FT2 in an amount of 0.005 g / l.

Example 4. An emulsion based on emulsol "Quakerol-1914". Destructible emulsion was heated to 90 ^o C and without adding etching sulfate solution was defended for 10 hours. The floating oil was separated, and the partially clarified aqueous medium had the following characteristics: total oil content 4.6 g / l; pH 7.0; temperature 87 ^° C. The partially clarified aqueous medium was treated with the following reagents: SF-A2 in an amount of 3.2 g / l; Aquapol-FT2 in an amount of 0.001 g / l.

Example 5. Emulsion based on ET-2u emulsol. After heating and settling, as in Example 4, the partially clarified aqueous medium had the following characteristics: total oil content of 6.4 g / l; pH 6.9; temperature 85 ^° C. The partially clarified aqueous medium was treated with the following reagents: SF-A2 in an amount of 2.0 g / l; Aquapol-FT2 - 0.002 g / l.

Example 6. The emulsion based on the emulsol "Quakerol-1914". After heating and settling, as in examples 4, 5, partially clarified aqueous medium had the following characteristics: total oil content of 3.8 g / l; pH 6.3; temperature 85 ^° C. The partially clarified aqueous medium was treated with the following reagents: SF-A2 in an amount of 3.6 g / l; Aquapol-FT2 - 0.003 g / l.

 The end of the destruction of the emulsion was judged by the formation of large aggregated flakes of oil sludge and the clarified water contained between them. This method of controlling the end of the process of destruction of the emulsion was tested in laboratory conditions for the analytical determination of the amount of oil products and suspended solids in samples of clarified water.

 The separation of the mixture obtained after the reagent treatment as in option 1, and option 2, is possible by sedimentation, filtration, centrifugation or flotation. Using any of these methods results in a product in the form of oil sludge and clarified water. The humidity of the structured compacted sludge after settling for 1.5 hours is 86-92%, the volume of sludge is 18-20% of the volume of the separated emulsion. When filtering through TLF-5 mylar filter cloth, humidity is respectively 35%, sludge volume 3-5%, while centrifugation humidity 28-32%, sludge volume 2-3%. Depending on the method of disposal, you can choose a method of compacting sludge. At the same time, clarified water is suitable for reuse in the technology for preparing a working emulsion or other technological solutions. Compacted sludge can be disposed of by burning or used as a plasticizer in the manufacture of reinforced concrete products.

 From the data given in the table shows that the clarified water obtained as a result of the destruction of the emulsion according to the claimed method, has good performance in terms of the amount of residual content of oil products and suspended solids and can be re-returned to the production cycle. The duration of one general cycle of the decomposition of the emulsion (without the operation of compaction of the precipitate) in comparison with the existing method [1] is approximately 20 times less when using the method according to option 1 and about 3 times less when using the method according to option 2.

 Thus, the claimed method of destroying stable concentrated emulsions of COTS allows you to create a simple, productive, suitable for different types of COTS, regardless of their temperature and pH, technology. At the same time, the technology excludes the operations of heating, acidification, neutralization, long-term sedimentation.

 According to the second option, this technology can be integrated into an existing production process in which there is heating of the emulsion with subsequent sedimentation, but acidification and long-term sedimentation operations are excluded. The method can be implemented in an industrial environment with the formation of a recyclable product.

Claims (3)

 1. A method of destroying stable concentrated oil-containing emulsions, including the introduction of reagents, characterized in that the cationic type polyelectrolyte is introduced into the emulsion in an amount of 0.05-0.15 g / l, flocculating sorbent "Reagent SF-A2" - alkaline aluminosilicate activated reagents and derivatives of alkaline hydrolysis of (co) polymers of acrylamide in an amount of at least 2.0 g / l and the polymer reagent is a copolymer of acrylamide and sodium acrylate, while the flocculating sorbent and the polymer reagent are introduced in a mass ratio (600-6000): 1. 2. A method of destroying stable concentrated oil-containing emulsions, comprising heating the emulsion to a temperature of 80-100 ^° C, settling at this temperature, separating the pop-up oil, introducing reagents, characterized in that after separating the pop-up oil, the flocculating sorbent "Reagent SF- A2 "- aluminosilicate activated by alkaline reagents and derivatives of alkaline hydrolysis of (co) acrylamide polymers in an amount of at least 2.0 g / l and a polymer reagent - a copolymer of acrylamide and sodium acrylate, etc. This sorbent and polymeric flocculating agent are administered in a weight ratio (600-6000): 1.  3. The method according to any one of claim 1 or 2, characterized in that the reagents are introduced in the specified amount in terms of dry substance per 1 liter of destructible emulsion.

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