Degreasing agent, preparation method therefor and use thereof

Abstract

The present invention relates to the field of oilfield chemicals; disclosed are a degreasing agent, a preparation method therefor, and a use thereof. The degreasing agent has a structural formula as shown in formula (I), R1 and R2 each being independently selected from -H, methyl or ethyl, and R3 being selected from a C4-C18 saturated or unsaturated hydrocarbon group. The degreasing agent is a reversible conversion degreasing agent, capable of switching between hydrophilicity and lipophilicity under external stimuli. The degreasing agent exhibits excellent extraction and degreasing effects, achieving an oil removal rate of over 97% for oily solid waste, while also possessing oil-displacing functionality. It has a low flash point, low volatility, mild odor irritation, high safety in use, and good environmental friendliness.

Description

Degreasing agents, their preparation methods and applications

[0001] Cross-references to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411801339.1, filed on December 09, 2024, entitled “Degreasing Agent and Preparation Method and Application Thereof”, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of oilfield chemicals technology, specifically to an oil removal agent, its preparation method, and its application. Background Technology

[0004] Oily solid waste is one of the main solid pollutants generated during oil and gas field development and refining processes. It exists in a solid or semi-fluid state, belonging to a heterogeneous multiphase dispersion system, and is mainly composed of crude oil, water, clay minerals, biological organic matter, and chemical additives. The oil content is generally around 10%, but can reach 20%-30% in some cases. Major oil and gas fields in my country are increasing their efforts in oily waste treatment. Currently, oily waste treatment technologies in the research stage or already in engineering application mainly include physical methods, chemical methods, biological methods, and combined treatment technologies. Currently, chemical, thermal, and biological methods are mainly used, which have achieved certain treatment effects, but also have the following technical limitations: (1) The oil content of the residue after chemical cleaning is still relatively high, above 5%; (2) Microbial treatment of solid waste, especially oily solid waste, takes a long time, generally 3-6 months, and the treatment area is large; (3) Thermal desorption technology uses high temperature to desorb petroleum from the sludge solid phase, and uses fuel or electromagnetic heating, which consumes a lot of energy and also needs to solve the problem of coking on the furnace wall. Domestic and foreign countries have carried out switch-type reversible conversion solvent extraction of oily solid waste, which can realize the reversible conversion of hydrophilicity and hydrophobicity after external response to stimulation, but these reversible conversion solvents usually have problems such as low flash point, high volatility, and irritating odor, and the oil removal rate is difficult to reach more than 95%. In addition, these reversible conversion solvents are often single-function and are usually only used for waste oil removal treatment.

[0005] Therefore, providing a new multifunctional reversible degreasing agent is of great significance for achieving safe and environmentally friendly efficient degreasing of oily solid waste and for expanding the application of degreasing agents. Summary of the Invention

[0006] This invention addresses the problems of insufficient oil removal effect, limited functionality, and inadequate safety and environmental protection of existing reversible degreasing agents by providing a degreasing agent, its preparation method, and its application.

[0007] To achieve the above objectives, a first aspect of the present invention provides a degreasing agent having the structural formula shown in formula (I).

[0008] R1 and R2 are each independently selected from -H, methyl, or ethyl; R3 is selected from C4-C. 18 Saturated or unsaturated hydrocarbon groups.

[0009] A second aspect of the present invention provides a method for preparing a degreasing agent, the method comprising:

[0010] In the presence of a water-carrying agent and a catalyst, the organic amine represented by formula (II) and the fatty acid represented by formula (III) are synthesized, and then the product system is separated to obtain an oil-removing agent.

[0011] R1 and R2 are each independently selected from -H, methyl, or ethyl; R3 is selected from C4-C. 18 Saturated or unsaturated hydrocarbon groups.

[0012] The third aspect of the present invention provides an oil remover prepared by the method described in the second aspect above.

[0013] The fourth aspect of the present invention provides the application of the oil-removing agent described in the first or third aspect above as an extractant in the treatment of oily waste, and / or as an oil displacement agent in reservoir development.

[0014] The degreasing agent provided by the present invention through the above technical solution has the following beneficial effects:

[0015] (1) The degreasing agent provided by this invention can achieve mutual conversion between hydrophilicity and lipophilicity under acid or alkali external stimulation, and has a very good extraction and degreasing effect. Using this degreasing agent to treat oily solid waste (such as oily drill cuttings), the degreasing rate of oily solid waste can reach more than 97% under conditions of non-high temperature and high pressure and without flash evaporation recovery agent.

[0016] (2) This degreasing agent is not only suitable for the harmless degreasing and resource recycling of oily solid waste in petroleum and petrochemical industries, but also has the function of oil displacement. It can be further used in the fields of oil displacement agent in petroleum extraction and oil and gas drilling fluid additive.

[0017] (3) Compared with the agents used in existing similar technologies, this degreasing agent has the advantages of low flash point, weak volatility, and low odor irritation. In addition, in addition to external stimulation from acids or alkalis, this degreasing agent can also achieve the interconversion of hydrophilicity and lipophilicity under external stimulation from CO2 or N2, so it is not necessary to use acids or alkalis to stimulate the degreasing agent. It is safe, environmentally friendly, and achieves green degreasing. Detailed Implementation

[0018] 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.

[0019] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0020] The first aspect of the present invention provides a degreasing agent having the structural formula shown in formula (I).

[0021] R1 and R2 are each independently selected from -H, methyl, or ethyl; R3 is selected from C4-C. 18 Saturated or unsaturated hydrocarbon groups.

[0022] The degreasing agent provided by this invention is a reversible degreasing agent with a specific structure. This degreasing agent has the structure shown in formula (I) above. Under normal conditions (without protonation), it exhibits excellent lipophilicity. In its molecular structure, an amino group connected to a six-membered ring, or at least one -H in the amino group being replaced by a methyl or ethyl group, allows the degreasing agent to convert to hydrophilicity upon contact with acid, and then back to lipophilicity upon contact with alkali. This conversion between hydrophilicity and lipophilicity enables the removal of oil from oily solid waste. The six-membered ring in the molecular structure makes the degreasing agent molecule nonpolar, enhancing the van der Waals forces between molecules and giving the degreasing agent excellent lipophilicity. It forms micelles at the water-oil interface, facilitating the stripping of oil from the surface of oily solid waste. The molecular structure of this degreasing agent features a specific long-chain hydrocarbon group attached to the carbonyl group, enhancing its solubility in water. This specific molecular structure results in excellent oil removal efficiency, achieving a high oil removal rate of over 97% when treating oily solid waste (e.g., oily drill cuttings). This degreasing agent also possesses oil displacement properties. Compared to similar agents, this degreasing agent has advantages such as a low flash point, low volatility, and minimal odor irritation. Furthermore, aside from acid or alkali irritation, it converts to hydrophilicity upon contact with CO2 and then reverts to lipophilicity upon contact with N2, eliminating the need for acid or alkali stimulation. This makes it safe and environmentally friendly.

[0023] According to the present invention, the degreasing agent can achieve both excellent extraction and degreasing effects and oil displacement effects as long as it satisfies the structural formula shown in formula (I) above, and has a low flash point, low volatility, and low odor irritation. For example, the degreasing agent can have the following structural formula: At least one of them.

[0024] According to the present invention, the degreasing agent having the above-mentioned structure preferably has R1 and R2 independently selected from methyl or ethyl in formula (I), which facilitates the ionization of proton hydrogen and bicarbonate ions, thereby promoting the hydrophilic-hydrophobic conversion.

[0025] Preferably, in formula (I), R3 is selected from C4-C 14 The saturated hydrocarbon groups can make the degreasing agent have good hydrophilicity after protonation.

[0026] According to a preferred embodiment of the present invention, the degreasing agent may have the following structural formula: At least one of the following. Degreasing agents with this structure can better achieve rapid hydrophilic-hydrophobic conversion.

[0027] According to the present invention, more preferably, in formula (I), R1 and R2 are the same, both being methyl groups, which can better ionize proton hydrogen and bicarbonate ions, thus promoting rapid hydrophilic-hydrophobic conversion.

[0028] More preferably, in formula (I), R3 is selected from saturated hydrocarbon groups of C6-C8, which can make the degreasing agent have better hydrophilicity after protonation.

[0029] According to a further preferred embodiment of the present invention, the degreasing agent may have the following structural formula: At least one of them.

[0030] According to the present invention, the degreasing agent has a low flash point. The flash point of the degreasing agent is ≤140℃, which is beneficial to the safety of its use.

[0031] According to the present invention, preferably, the flash point of the degreasing agent is 50-140°C.

[0032] In this invention, the flash point of the degreasing agent is determined by the Binsky-Martin closed-cup method.

[0033] According to the present invention, the degreasing agent has low volatility, which is manifested in that the degreasing agent has a high boiling point. The boiling point of the degreasing agent is ≥150℃, which can reduce the volatilization of the agent during use.

[0034] According to the present invention, preferably, the boiling point of the degreasing agent is 150-230°C.

[0035] In this invention, the boiling point of the degreasing agent refers to the temperature at which the degreasing agent boils when its saturated vapor pressure is equal to the external pressure.

[0036] According to the present invention, the degreasing agent has a low odor irritation, is environmentally friendly, and is beneficial to the health of operators.

[0037] According to a preferred embodiment of the present invention, the degreasing agent has the following structural formula: and / or The oil removal agent of this embodiment has further improved the extraction and oil removal effect and the oil displacement effect. It has a low flash point, low volatility and low odor irritation, which can better recover oil resources from oily waste and play the role of oil displacement agent in oil reservoir development.

[0038] A second aspect of the present invention provides a method for preparing a degreasing agent, the method comprising:

[0039] In the presence of a water-carrying agent and a catalyst, the organic amine represented by formula (II) and the fatty acid represented by formula (III) are synthesized, and then the product system is separated to obtain an oil-removing agent.

[0040] R1 and R2 are each independently selected from -H, methyl, or ethyl; R3 is selected from C4-C. 18 Saturated or unsaturated hydrocarbon groups.

[0041] According to the present invention, in the method for preparing the degreasing agent, the organic amine has the structural formula shown in formula (II) above. In formula (II), preferably, R1 and R2 are each independently selected from methyl or ethyl, which facilitates the ionization of proton hydrogen and bicarbonate ions, thereby promoting the hydrophilic-hydrophobic conversion of the prepared degreasing agent under external stimulation.

[0042] According to the present invention, in the preparation method of the degreasing agent, in formula (II), R1 and R2 are the same, both being methyl, which can better ionize proton hydrogen and bicarbonate ions, and promote the degreasing agent to quickly achieve hydrophilic-hydrophobic conversion under external stimulation.

[0043] According to the present invention, in the method for preparing the degreasing agent, the fatty acid has the structural formula shown in formula (III) above. In formula (III), preferably, R3 is selected from C4-C6. 14 The saturated hydrocarbon groups can make the prepared degreasing agent have better hydrophilicity after protonation.

[0044] According to the present invention, in the preparation method of the degreasing agent, in formula (III), more preferably, R3 is selected from saturated hydrocarbon groups of C6-C8, which can make the prepared degreasing agent have better hydrophilicity after protonation.

[0045] According to the present invention, in the method for preparing the degreasing agent, the water-carrying agent can carry away the water generated in the reaction to promote the forward reaction. Preferably, the water-carrying agent can be selected from at least one of toluene, acetone, chloroform, and n-hexane.

[0046] According to a preferred embodiment of the present invention, the water-carrying agent is toluene.

[0047] According to the present invention, in the preparation method of the degreasing agent, preferably, the amount of water-carrying agent fed is such that the weight ratio of water-carrying agent to (organic amine + fatty acid) is 1:(4-13), which is more conducive to the co-evaporation of water-carrying agent and water and promotes the forward reaction.

[0048] According to the present invention, in the method for preparing the degreasing agent, the catalyst can facilitate the synthesis reaction between the organic amine and the fatty acid to obtain a compound having the structural formula shown in formula (I). Preferably, the catalyst may be selected from at least one of p-toluenesulfonic acid, citric acid, sodium hydroxide, and sulfuric acid.

[0049] According to a preferred embodiment of the present invention, the catalyst is p-toluenesulfonic acid.

[0050] According to the present invention, in the preparation method of the degreasing agent, preferably, the amount of catalyst fed is such that the weight ratio of catalyst to (organic amine + fatty acid) is 1:(40-130), more preferably 1:(80-120), which is more conducive to the rapid progress of the synthesis reaction.

[0051] According to the present invention, in the preparation method of the degreasing agent, preferably, the molar ratio of the organic amine to fatty acid is 1:(1-3), more preferably 1:(1.1-2), which is conducive to the full progress of the synthesis reaction.

[0052] According to the present invention, in the preparation method of the degreasing agent, during the synthesis reaction, the fatty acid and the organic amine undergo a condensation reaction. The conditions for the synthesis reaction include: being carried out under a protective atmosphere; a reaction temperature of 50-140°C, preferably 80-120°C; and a reaction time of 4-12 h, preferably 5-10 h.

[0053] According to the present invention, in the preparation method of the degreasing agent, the protective atmosphere is a gas that does not participate in the synthesis reaction and can release oxygen, such as helium, neon, argon, nitrogen, etc., and nitrogen is preferred.

[0054] According to the present invention, in the preparation method of the degreasing agent, after the synthesis reaction is completed, the obtained product system is separated to obtain the degreasing agent. In the present invention, the separation temperature is 120-210℃. To achieve better separation and purification to obtain the degreasing agent product, preferably, the separation can be divided into a first separation and a second separation performed sequentially. The first separation is performed at a temperature of 120-180℃, the purpose of which is to distill off the organic amines and water-carrying agents in the product system; the second separation is performed at a temperature of 160-210℃, and the temperature of the second separation is higher than that of the first separation, the distilled liquid being the degreasing agent product.

[0055] In this invention, the processes for the first and second separations are broadly defined, as long as the separation to obtain the corresponding products can be achieved under the aforementioned temperature conditions. Preferably, the first separation can be achieved by rotary evaporation purification. Preferably, the second separation can be achieved by rotary evaporation purification or vacuum distillation.

[0056] The preparation method provided by this invention involves synthesizing specific organic amines and fatty acids to obtain a product with the structural formula... (wherein, R1 and R2 are each independently selected from -H, methyl, or ethyl; R3 is selected from C8-C.) 18 This is a degreasing agent containing saturated or unsaturated hydrocarbon groups. It is a reversible degreasing agent, converting to hydrophilicity upon contact with acid and then reverting to lipophilicity upon contact with alkali. This hydrophilic-lipophilic conversion achieves degreasing of oily solid waste, combining excellent extraction and oil displacement effects. Using this agent to treat oily solid waste (e.g., oily drill cuttings) can achieve a degreasing rate of over 97%. Compared to similar agents, this degreasing agent has advantages such as low flash point, low volatility, and low odor irritation. Furthermore, besides external acid or alkali stimulation, it converts to hydrophilicity upon contact with CO2 and then reverts to lipophilicity upon contact with N2, eliminating the need for external acid or alkali stimulation, making it safe and environmentally friendly.

[0057] The third aspect of the present invention provides an oil remover prepared by the method described in the second aspect above.

[0058] According to the present invention, the degreasing agent prepared by the method described in the second aspect above has the same structure, composition and performance as the degreasing agent described in the first aspect above, and will not be repeated here.

[0059] The fourth aspect of the present invention provides the application of the oil-removing agent described in the first or third aspect above as an extractant in the treatment of oily waste, and / or as an oil displacement agent in reservoir development.

[0060] According to the present invention, the degreasing agent has a reversible conversion function of hydrophilicity and lipophilicity, and has excellent extraction and degreasing effect. It can well meet the requirements of harmless degreasing and resource recycling of oily solid waste in petroleum and petrochemical industries. It is safe and environmentally friendly in use and can achieve green degreasing.

[0061] According to the present invention, the oil removal agent also has the function of oil displacement, promoting crude oil displacement and recovery, and can be used as an oil displacement agent for oil extraction or an additive for oil and gas drilling fluid to realize the extraction of crude oil or the recovery of base mineral oil in drilling fluid.

[0062] The present invention will be described in detail below through examples. Unless otherwise specified, the following examples and comparative examples are all conventional methods; the reagents and materials used are commercially available unless otherwise specified.

[0063] Example 1

[0064] (1) Add n-heptanoic acid, toluene and p-toluenesulfonic acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing N,N-dimethylcyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the setup of the closed reaction apparatus.

[0065] The weight ratio of toluene to (N,N-dimethylcyclohexylamine + n-heptanoic acid) is 1:13.

[0066] The weight ratio of p-toluenesulfonic acid to (N,N-dimethylcyclohexylamine + n-heptanoic acid) is 1:110;

[0067] The molar ratio of N,N-dimethylcyclohexylamine to n-heptanoic acid is 1:1.1;

[0068] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add N,N-dimethylcyclohexylamine dropwise into the three-necked flask. After the N,N-dimethylcyclohexylamine has been completely added, close the valve. Set the target temperature of the oil bath to 80°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 8 hours.

[0069] (3) The product system obtained after the reaction was transferred to a round bottom flask and purified by rotary evaporation at 120°C to remove N,N-dimethylcyclohexylamine and toluene from the product system; then the product system was distilled at 160°C and the liquid distilled out was the degreasing agent (i.e., P1).

[0070] The structural formula of P1 is: The flash point, boiling point and odor of P1 are shown in Table 1.

[0071] Example 2

[0072] (1) Add octanoic acid, toluene and sulfuric acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing N,N-dimethylcyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0073] The weight ratio of toluene to (N,N-dimethylcyclohexylamine + octanoic acid) is 1:10.

[0074] The weight ratio of sulfuric acid to (N,N-dimethylcyclohexylamine + octanoic acid) is 1:80;

[0075] The molar ratio of N,N-dimethylcyclohexylamine to octanoic acid is 1:1.5;

[0076] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add N,N-dimethylcyclohexylamine dropwise into the three-necked flask. After the N,N-dimethylcyclohexylamine has been completely added, close the valve. Set the target temperature of the oil bath to 100°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 6 hours.

[0077] (3) The product system obtained after the reaction was transferred to a round-bottom flask and purified by rotary evaporation at 120°C to remove N,N-dimethylcyclohexylamine and toluene from the product system; then the product system was distilled at 170°C and the distilled liquid was the degreasing agent (i.e., P2).

[0078] The structural formula of P2 is: The flash point, boiling point and odor of P2 are shown in Table 1.

[0079] Example 3

[0080] (1) Add valeric acid, acetone and p-toluenesulfonic acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing N,N-diethylcyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the upper end of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0081] The weight ratio of acetone to (N,N-diethylcyclohexylamine + n-valeric acid) is 1:8.

[0082] The weight ratio of p-toluenesulfonic acid to (N,N-diethylcyclohexylamine + n-valeric acid) is 1:130;

[0083] The molar ratio of N,N-diethylcyclohexylamine to n-valeric acid is 1:1.5;

[0084] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add N,N-diethylcyclohexylamine dropwise into the three-necked flask. After the N,N-diethylcyclohexylamine has been completely added, close the valve. Set the target temperature of the oil bath to 140°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 4 hours.

[0085] (3) Transfer the product system obtained after the reaction to a round bottom flask and perform rotary evaporation purification at 130°C to remove N,N-diethylcyclohexylamine and acetone from the product system; then distill the product system at 190°C and the distilled liquid is the degreasing agent (i.e., P3).

[0086] The structural formula of P3 is: The flash point, boiling point, and odor of P3 are shown in Table 1.

[0087] Example 4

[0088] (1) Add pentadecanoic acid, acetone and p-toluenesulfonic acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing N,N-diethylcyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the setup of the closed reaction apparatus.

[0089] The weight ratio of acetone to (N,N-diethylcyclohexylamine + pentadecanoic acid) is 1:7.

[0090] The weight ratio of p-toluenesulfonic acid to (N,N-diethylcyclohexylamine + pentadecanoic acid) is 1:80;

[0091] The molar ratio of N,N-diethylcyclohexylamine to pentadecanoic acid is 1:2.5;

[0092] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add N,N-diethylcyclohexylamine dropwise into the three-necked flask. After the N,N-diethylcyclohexylamine has been completely added, close the valve. Set the target temperature of the oil bath to 90°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 12 hours.

[0093] (3) The product system obtained after the reaction was transferred to a round-bottom flask and purified by rotary evaporation at 140°C to remove N,N-diethylcyclohexylamine and acetone from the product system; then the product system was distilled at 210°C and the liquid distilled out was the degreasing agent (i.e., P4).

[0094] The structural formula of P4 is: The flash point, boiling point, and odor of P4 are shown in Table 1.

[0095] Example 5

[0096] (1) Add valeric acid, chloroform and sodium hydroxide (solid) to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing cyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0097] The weight ratio of chloroform to (cyclohexylamine + n-valeric acid) is 1:11.

[0098] The weight ratio of sodium hydroxide to (cyclohexylamine + valerate) is 1:40;

[0099] The molar ratio of cyclohexylamine to valerate is 1:3;

[0100] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add cyclohexylamine dropwise into the three-necked flask. After it has been completely added, close the valve. Set the target temperature of the oil bath to 140°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 4 hours.

[0101] (3) Transfer the product system obtained after the reaction to a round bottom flask and purify it by rotary evaporation at 150°C to remove cyclohexylamine and chloroform from the product system; then distill the product system at 190°C and the distilled liquid is the degreasing agent (i.e., P5).

[0102] The structural formula of P5 is: The flash point, boiling point, and odor of P5 are shown in Table 1.

[0103] Example 6

[0104] (1) Add nonadecanoic acid, n-hexane and sulfuric acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing cyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the setup of the closed reaction apparatus.

[0105] The weight ratio of n-hexane to (cyclohexylamine + nonadecanoic acid) is 1:10.

[0106] The weight ratio of sulfuric acid to (cyclohexylamine + nonadecanoic acid) is 1:130;

[0107] The molar ratio of cyclohexylamine to nonadecanoic acid is 1:3;

[0108] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add cyclohexylamine dropwise into the three-necked flask. After it has been completely added, close the valve. Set the target temperature of the oil bath to 100°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 8 hours.

[0109] (3) Transfer the product system obtained after the reaction to a round bottom flask and purify it by rotary evaporation at 120°C to remove cyclohexylamine and n-hexane from the product system; then distill the product system at 160°C and the distilled liquid is the degreasing agent (i.e., P6).

[0110] The structural formula of P6 is: The flash point, boiling point, and odor of P6 are shown in Table 1.

[0111] Example 7

[0112] (1) Add linolenic acid, n-hexane and citric acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing cyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0113] The weight ratio of n-hexane to (cyclohexylamine + linolenic acid) is 1:4.

[0114] The weight ratio of citric acid to (cyclohexylamine + linolenic acid) is 1:70;

[0115] The molar ratio of cyclohexylamine to linolenic acid is 1:1;

[0116] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add cyclohexylamine dropwise into the three-necked flask. After it has been completely added, close the valve. Set the target temperature of the oil bath to 100°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 7 hours.

[0117] (3) Transfer the product system obtained after the reaction to a round bottom flask and purify it by rotary evaporation at 140°C to remove cyclohexylamine and n-hexane from the product system; then distill the product system at 200°C and the liquid distilled out is the degreasing agent (i.e., P7).

[0118] The structural formula of P7 is: The flash point, boiling point, and odor of P7 are shown in Table 1.

[0119] Comparative Example 1

[0120] (1) Add hexanoic acid, chloroform and silicon dioxide to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing n-propylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the top of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0121] The weight ratio of chloroform to (n-propylamine + n-hexanoic acid) is 1:10.

[0122] The weight ratio of silicon dioxide to (n-propylamine + n-hexanoic acid) is 1:140;

[0123] The molar ratio of n-propylamine to n-hexanoic acid is 1:4;

[0124] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add n-propylamine dropwise into the three-necked flask. After the propylamine has been completely added, close the valve. Set the target temperature of the oil bath to 110°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 4 hours.

[0125] (3) Transfer the product system obtained after the reaction to a round bottom flask and purify it by rotary evaporation at 120°C to remove n-propylamine and chloroform from the product system; then distill the product system at 140°C and the distilled liquid is the degreasing agent (i.e., DP1).

[0126] The structural formula of DP1 is The flash point, boiling point and odor of DP1 are shown in Table 1.

[0127] Comparative Example 2

[0128] (1) Add acetic acid, toluene and sulfuric acid to a three-necked flask; then place the three-necked flask in an oil bath, insert a condenser into the middle opening of the three-necked flask, insert a constant pressure dropping funnel containing cyclohexylamine into the right opening, and connect the N2 gas tube to the left opening. Purge N2 for 5 minutes to purge air; after the N2 is purged, pull out the gas tube and immediately plug the upper end of the condenser and the vent to complete the construction of the closed reaction apparatus.

[0129] The weight ratio of toluene to (cyclohexylamine + acetic acid) is 1:4.

[0130] The weight ratio of sulfuric acid to (cyclohexylamine + acetic acid) is 1:100;

[0131] The molar ratio of cyclohexylamine to acetic acid is 1:1;

[0132] (2) Turn on the cooling water and simultaneously turn on the heating and magnetic stirring of the oil bath. When the temperature reaches 50°C, wait for 5 minutes and then open the valve of the constant pressure dropping funnel to add cyclohexylamine dropwise into the three-necked flask. After it has been completely added, close the valve. Set the target temperature of the oil bath to 80°C. When the temperature reaches the target temperature, start timing to carry out the synthesis reaction for 4 hours.

[0133] (3) Transfer the product system obtained after the reaction to a round bottom flask and purify it by rotary evaporation at 90°C to remove cyclohexylamine and toluene from the product system; then distill the product system at 110°C and the distilled liquid is the degreasing agent (i.e., DP2).

[0134] The structural formula of DP2 is The flash point, boiling point and odor of DP2 are shown in Table 1.

[0135] Comparative Example 3

[0136] Commercially available reversible degreasing agent (N,N-dimethylcyclohexylamine) is designated DP3.

[0137] Table 1

[0138] As shown in Table 1, the degreasing agent provided by this invention has a flash point not higher than 140℃, a boiling point not lower than 150℃, and a mild odor. Compared with the degreasing agents in the comparative example, it is safer and more environmentally friendly.

[0139] Test case

[0140] 1. Conductivity test

[0141] The conductivity of the above-mentioned degreasing agent P2 was tested, and the process is as follows:

[0142] Take 20 mL of degreasing agent and 40 mL of deionized water. Pour the deionized water into a beaker, and place the degreasing agent on top of the water layer. Then, purge CO2 at 0.2 L / min for 60 min. Starting from the time CO2 is introduced, insert a conductivity meter into the aqueous phase and measure the change trend of the aqueous phase conductivity during this 60 min period to characterize the protonation process. Afterward, place the beaker containing the protonated degreasing agent aqueous solution on a magnetic stirrer, heat at 60°C, and purge with N2 for 60 min to remove CO2 to characterize the deprotonation process. During this 60 min period, insert a conductivity meter to measure the change in the conductivity of the degreasing agent in the aqueous solution. The conductivity test results for the total 120 min period are shown in Table 2.

[0143] Table 2

[0144] As shown in Table 2, CO2 acts on the degreasing agent, causing it to undergo a protonation reaction, resulting in a gradual increase in conductivity. Conversely, the introduction of N2 and heating causes the CO2 to be rapidly expelled, leading to a deprotonation reaction, which results in a rapid decrease in conductivity. This test demonstrates that the degreasing agent provided by this invention is responsive to CO2 and can achieve a reversible conversion between hydrophilic and lipophilic properties during the degreasing process.

[0145] 2. Evaluation of oil removal efficiency for oily solid waste

[0146] Oily drill cuttings were used as test samples (taken from the Southwest Oil and Gas Field, with an oil content of 23.74% by weight based on the dry basis of the drill cuttings). 10g of the test sample was placed in a 500mL beaker, and 20mL of the above-mentioned degreasing agents P1-P7 and DP1-DP3 were added respectively under a 60℃ water bath. After stirring at 300 rpm for 30min, the samples were centrifuged to separate the oil content of the drill cuttings after degreasing. The degreasing rate was calculated, and the results are shown in Table 3.

[0147] Oil removal rate (%) = (P0 - V0) / P0 × 100%;

[0148] Where P0 represents the original oil content of the drill cuttings, %; and V0 represents the oil content of the drill cuttings after treatment, %.

[0149] Table 3

[0150] As shown in Table 3, the degreasing agents P1-P7 provided by this invention have high-efficiency degreasing performance for oily solid waste, and the degreasing rate can reach more than 97%.

[0151] 3. Evaluation of oil displacement effect

[0152] Oil displacement tests were conducted using the aforementioned oil removers P1-P7 and DP1-DP3, as follows:

[0153] (1) Saturated oil sand: Select laboratory 70 mesh quartz sand, put 200g of quartz sand into a 500mL beaker, add 150g of crude oil, and then age it in a 50℃ oven for 24h; filter out the oil-containing quartz sand, continue aging at room temperature for 24h, and seal for later use.

[0154] (2) Prepare 6 20mL glass stoppered centrifuge tubes (each group consists of 2 tubes, divided into three groups: oil displacement agent oil displacement group, surfactant oil displacement group and blank water sample oil displacement group). Add 1mL of crude oil to the bottom of each of the 6 centrifuge tubes, then add 5g of aged quartz sand from step (1), and finally add 9mL of water sample.

[0155] (3) Add 1 mL of the above-mentioned oil removal agents P1-P7 and DP1-DP3 to the oil displacement group of the high-efficiency recyclable oil displacement agent prepared in step (2);

[0156] (4) After slight shaking, let stand, observe the oil displacement effect between each sample and record the experimental phenomena.

[0157] The results of the oil displacement test are shown in Table 4.

[0158] Table 4

[0159] As shown in Table 4, the oil removal agents P1-P7 provided by this invention have a rapid and significant oil displacement effect, a long duration, and no wall adhesion. Their oil displacement effect is significantly better than that of DP1-DP3.

[0160] 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. An oil removing agent, characterized by comprising: The oil removing agent has a structural formula shown in formula (I), wherein R1, R2are each independently selected from -H, methyl or ethyl; R3is selected from a C4-C 18 saturated or unsaturated hydrocarbon group.

2. The oil removal agent according to claim 1, wherein R1, R2are each independently selected from methyl or ethyl; and / or, R3is selected from C4-C 14 saturated hydrocarbon groups.

3. The oil removal agent according to claim 2, wherein R1, R2are the same and each is methyl; and / or, R3is selected from C6-C8saturated hydrocarbon group.

4. The oil removal agent according to any one of claims 1 to 3, wherein The flash point of the oil removing agent is ≤140℃.

5. The oil removal agent according to any one of claims 1 to 3, wherein The boiling point of the oil removing agent is ≥150℃.

6. A method for producing a deoiling agent, characterized by, The method comprises: The organic amine shown in formula (II) is subjected to a synthesis reaction with the fatty acid shown in formula (III) in the presence of a water-carrying agent and a catalyst, and then the product system is separated to obtain the oil removal agent; wherein R1, R2are each independently selected from -H, methyl or ethyl; R3is selected from a C4-C 18 saturated or unsaturated hydrocarbon group.

7. The production method according to claim 6, wherein R1, R2are each independently selected from methyl or ethyl; and / or R3is selected from C4-C 14 saturated hydrocarbon groups.

8. The production method according to claim 7, wherein R1, R2are the same and each is methyl; and / or, R3is selected from C6-C8saturated hydrocarbon group.

9. The production process according to any one of claims 6 to 8, wherein The water carrying agent is selected from at least one of toluene, acetone, chloroform and n-hexane; and / or, the catalyst is selected from at least one of p-toluene sulfonic acid, citric acid, sodium hydroxide and sulfuric acid.

10. The method of making according to any one of claims 6-8, wherein, The weight ratio of the water carrying agent:(organic amine + fatty acid) is 1:(4-13); and / or, the weight ratio of the catalyst:(organic amine + fatty acid) is 1:(40-130); and / or, the molar ratio of the organic amine:fatty acid is 1:(1-3).

11. The method of making according to any one of claims 6-8, wherein, The conditions of the synthetic reaction comprise: being carried out under a protective atmosphere, the reaction temperature is 50-140℃, and the reaction time is 4-12h; and / or, the temperature used for the separation is 120-210℃.

12. The oil removing agent prepared by the method of any one of claims 6-11.

13. The use of the oil removing agent of any one of claims 1-5 and 12 as an extractant in the treatment of oil-containing waste, and / or as a flooding agent in the development of oil reservoirs.

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