A high-efficiency crude oil desulfurizer and its synthesis method and application

Abstract

The present invention belongs to the field of oil production technology, and in particular to a kind of high-efficiency crude oil desulfurizer and its synthesis method and application. The synthesis method is as follows: cyanuric chloride and an alkaline organic solvent are added to a reactor, the temperature is lowered to below 20 DEG C, N, N dimethylbenzylamine is added, pH 9-10 is adjusted with sodium hydroxide solution, and the reaction is kept warm; the above-mentioned mixed solution is added to N-hydroxyethylpiperazine, heated to reflux, and pH 9-10 is maintained with sodium hydroxide solution during the reaction; the above-mentioned mixed solution is vacuum distilled to obtain a viscous solid, and the product desulfurizer is obtained by recrystallization with ethyl acetate. The desulfurizer of the present invention has the advantages that the raw material source is wide, the synthesis process is simple, the process is clean and pollution-free, and the sterilization and desulfurization effect is good.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum extraction, and in particular relates to a high-efficiency crude oil desulfurizer and a synthesis method and application thereof. Background Art

[0002] In the petroleum industry, crude oil desulfurization technology has long been a focus of research and development. Sulfur is a common associated element in petroleum and also a major harmful element. During the refining process of high-sulfur crude oil, sulfur not only causes severe corrosion to equipment, clogging pipelines and heat exchangers, but also poisons catalysts, impacting product quality. Furthermore, the presence of sulfides accelerates the corrosion of cyclohexanecarboxylic acids in high-temperature areas, generating harmful free radical reactions. More seriously, the sulfur in petroleum products, when burned, produces sulfur dioxide and sulfur trioxide, which are major sources of atmospheric pollution, contribute to the formation of acid rain, and cause severe environmental pollution.

[0003] In response to these challenges, crude oil desulfurization technology has emerged. As one of the important methods, crude oil desulfurizers have the advantages of small addition amount, easy operation, and significant desulfurization effect, and are widely used in the crude oil desulfurization process.

[0004] CN109593545A discloses a composite desulfurizer suitable for high oil content oil wells and its preparation method. The desulfurizer is composed of 20-27.5% formaldehyde by mass, 20-27.5% ethanolamine, 2-7% surfactant, 1-5% small molecule alcohols and the remainder of water. The desulfurizer has low viscosity and is fully in contact with crude oil. It has good mutual solubility effect, high antifreeze performance, short reaction time and is easy to prepare. The desulfurizer achieves the effect by reacting the reaction product of aldehyde and alcoholamine compound with hydrogen sulfide. The surfactant has an emulsifying effect, which makes the crude oil and desulfurizer have good mutual solubility effect. The small molecule alcohols serve as antifreeze fluid, so that the desulfurizer can still be used in sub-zero environments. However, the desulfurization principle of this patent is just the simple absorption of hydrogen sulfide by ethanolamine. The working principle is single and the desulfurization effect is limited.

[0005] CN116162068B discloses a triazine desulfurizer and its preparation method, belonging to the field of petroleum technology. This method involves reacting 2-aminoethanol and formaldehyde to produce intermediate A; reacting intermediate A with thionyl chloride to produce intermediate B; and reacting intermediate B with N-methylaniline to produce the triazine desulfurizer. The triazine desulfurizer produced by the present invention is stable in acidic environments, exhibits good stability, and has a prolonged service life. The triazine desulfurizer of the present invention has a high benzene ring content, which allows for mutual solubility with aromatic hydrocarbons in crude oil through π-π stacking, enhancing the solubility of the triazine desulfurizer, thereby promoting full contact with sulfur-containing substances and improving the desulfurization effect. The triazine desulfurizer of the present invention has excellent instantaneous desulfurization performance, and is therefore of great significance for suppressing hydrogen sulfide in oilfield crude oil storage and transportation systems, as well as achieving oilfield production safety, environmental protection, and energy conservation and emission reduction. However, the present invention has a complex synthesis process, high application costs, and is not economical. Summary of the Invention

[0006] The present invention addresses the deficiencies of the prior art and provides a highly efficient crude oil desulfurizer, a synthesis method thereof, and its application. The desulfurizer of the present invention has the advantages of a wide range of raw material sources, a simple synthesis process, a clean and pollution-free process, and good sterilization and desulfurization effects.

[0007] To achieve the above objectives:

[0008] In a first aspect, the present invention discloses a method for synthesizing a high-efficiency crude oil desulfurizer, the synthesis method being as follows:

[0009] (1) Add cyanuric chloride and an alkaline organic solvent to a reactor, cool to below 20°C, add N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the temperature for reaction;

[0010] (2) adding N-hydroxyethylpiperazine to the above mixture, heating to reflux, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[0011] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0012] In the present invention, preferably, the molar ratio of N,N-dimethylbenzylamine, N-hydroxyethylpiperazine, and cyanuric chloride is 0.8-2.2:1-2.4:1.

[0013] More preferably, the molar ratio of N,N-dimethylbenzylamine, N-hydroxyethylpiperazine and cyanuric chloride is 0.9-2.1:1.1-2.3:1.

[0014] In the present invention, preferably, the alkaline organic solvent is one of ethanol, propanol, isopropanol, isobutanol and tert-butanol with a pH of 9-10.

[0015] More preferably, the alkaline organic solvent is one of ethanol and isopropanol with a pH of 9-10.

[0016] In the present invention, preferably, the mass ratio of the alkaline organic solvent to cyanuric chloride is 20-40:1.

[0017] More preferably, the mass ratio of the alkaline organic solvent to cyanuric chloride is 30-40:1.

[0018] In the present invention, preferably, the temperature of the heat preservation reaction is 30-70°C.

[0019] More preferably, the temperature of the insulation reaction is 50-70°C.

[0020] In the present invention, preferably, the insulation reaction time is 1-24 hours.

[0021] More preferably, the insulation reaction time is 6-24 hours.

[0022] In the present invention, preferably, the heating reflux time is 4-24 hours.

[0023] More preferably, the heating reflux time is 12-24 hours.

[0024] The synthesis reaction equation of the high-efficiency crude oil desulfurizer of the present invention is as follows:

[0025]

[0026]

[0027] In another aspect, the present invention discloses a high-efficiency crude oil desulfurizer, the molecular structure of which is as follows:

[0028]

[0029] In a third aspect, the present invention discloses the application of the above-mentioned desulfurizer in the treatment of oil wells with high hydrogen sulfide content.

[0030] The present invention produces a product with two-in-one sterilization and desulfurization functions by acylation reaction of cyanuric chloride with N,N-dimethylbenzylamine and N-hydroxyethylpiperazine. The N-hydroxyethylpiperazine introduced by the substitution reaction is a multifunctional desulfurization functional group. Piperazine can completely remove hydrogen sulfide, and the product after piperazine desulfurization can adsorb hydrogen sulfide. The hydroxyethyl group has a high polarity and can also adsorb hydrogen sulfide.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The raw materials for the desulfurization agent of the present invention are widely available, the synthesis process is simple, and the process is clean and pollution-free;

[0033] (2) The desulfurizer of the present invention has a good bactericidal effect, and the bactericidal rate at a concentration of 15 mg / L is 100%;

[0034] (3) The desulfurizer of the present invention has a good desulfurization effect, and the sulfur capacity reaches more than 33.5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The invention discloses a device for measuring the sulfur content of a high-efficiency desulfurizing agent. DETAILED DESCRIPTION

[0036] The endpoints of the ranges and any values ​​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 endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0037] The present invention will be further described below with reference to specific embodiments:

[0038] Example 1

[0039] (1) Add 0.05 mol of cyanuric chloride and 184.4 g of propanol to a reactor, cool to below 20°C, add 0.04 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 30°C for 24 hours;

[0040] (2) Add 0.12 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 4 h. During the reaction, use sodium hydroxide solution to maintain the pH at 9-10.

[0041] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0042] Example 2

[0043] (1) Add 0.05 mol of cyanuric chloride and 217 g of isobutanol to the reactor, cool to below 20°C, add 0.06 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 40°C for 18 hours;

[0044] (2) Add 0.11 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 8 h. During the reaction, maintain the pH at 9-10 with sodium hydroxide solution;

[0045] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0046] Example 3

[0047] (1) Add 0.05 mol of cyanuric chloride and 264 g of tert-butyl alcohol to the reactor, cool to below 20°C, add 0.07 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 40°C for 12 hours;

[0048] (2) Add 0.1 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 12 h. During the reaction, use sodium hydroxide solution to maintain the pH at 9-10.

[0049] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0050] Example 4

[0051] (1) Add 0.05 mol of cyanuric chloride and 278 g of isopropyl alcohol to the reactor, cool to below 20°C, add 0.08 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 50°C for 6 hours;

[0052] (2) Add 0.09 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 12 h. During the reaction, maintain the pH at 9-10 with sodium hydroxide solution;

[0053] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0054] Example 5

[0055] (1) Add 0.05 mol of cyanuric chloride and 300 g of ethanol to the reactor, cool to below 20°C, add 0.09 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 60°C for 1 hour;

[0056] (2) Add 0.08 mol of N-hydroxyethylpiperazine to the above mixture, heat and reflux for 16 h, and maintain the pH at 9-10 with sodium hydroxide solution during the reaction;

[0057] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0058] Example 6

[0059] (1) Add 0.05 mol of cyanuric chloride and 317 g of ethanol to the reactor, cool to below 20°C, add 0.1 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 70°C for 2 h;

[0060] (2) Add 0.06 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 20 h. During the reaction, use sodium hydroxide solution to maintain the pH at 9-10.

[0061] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0062] Example 7

[0063] (1) Add 0.05 mol of cyanuric chloride and 368.8 g of isopropyl alcohol to the reactor, cool to below 20°C, add 0.11 mol of N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep the reaction at 70°C for 4 hours;

[0064] (2) Add 0.05 mol of N-hydroxyethylpiperazine to the above mixture and heat under reflux for 24 h. During the reaction, maintain the pH at 9-10 with sodium hydroxide solution;

[0065] (3) The mixed solution is distilled under reduced pressure to obtain a viscous solid, which is then recrystallized from ethyl acetate to obtain a desulfurizing agent.

[0066] Example 8 Evaluation of Sterilization Effect

[0067] Take a sample of produced water from an oil well in Shengli Oilfield and divide it into a series of 500ml narrow-necked bottles. Add 5, 10 and 15mg / L concentrations of the desulfurizer of the present invention, shake well, place in a 60℃ oven, take samples after 1 hour, test the SRB content by the extinction dilution method, and calculate the bactericidal rate.

[0068] Conventional oilfield fungicide 1227 was used as comparative example 1. The test results are shown in Table 1.

[0069] From Table 1 we can see that:

[0070] (1) The desulfurizers of the present invention (Examples 1-7) all achieved a sterilization rate of 90% or more when used at a concentration of 5 mg / L, with the highest reaching 99.7% (Example 7). However, the sterilization rate of Comparative Example 1227 was 33.3%, which was significantly lower than that of the present invention.

[0071] (2) The desulfurizer of the present invention (Examples 1-7) has a sterilization rate of more than 99% when used at a concentration of 10 mg / L, with the highest reaching 100%. The sterilization rate of Comparative Example 1227 is 55.1%, which is significantly lower than that of the present invention.

[0072] (3) The desulfurizers of the present invention (Examples 1-7) all achieved a sterilization rate of 100% when used at a concentration of 15 mg / L, while the sterilization rate of Comparative Example 1227 was 94.1%, which was significantly lower than that of the present invention.

[0073] Example 9 Sulfur Capacity Test

[0074] Sulfur capacity is one of the most important indicators for evaluating the performance of a desulfurizer. The sulfur capacity of the present invention was tested with reference to Q / SH10202872-2021 "General Technical Conditions for Desulfurizers". The triazine desulfurizer of Shengli Oilfield Jindao Petroleum Engineering Technology Co., Ltd. was used as comparative example 2. The test results are shown in Table 1.

[0075] (1) Absorption of hydrogen sulfide

[0076] according to Figure 1 According to the requirements, the device connections are carried out in a fume hood. Weigh 10g of the desulfurizer to be tested and add it to the hydrogen sulfide absorption reaction bottle. Add 400g of distilled water, put in a sintered filter element so that it is placed close to the bottom (3-5mm) of the absorption reaction bottle, and connect it to the outlet of the hydrogen sulfide cylinder through a pipeline. Make sure the filter element is completely immersed in the liquid and the top of the filter element is less than 15mm from the liquid level of the desulfurizer dilution liquid. Add a rubber stopper to the upper part of the absorption tube, leaving a gas outlet, which is connected to the silver nitrate solution and sodium hydroxide solution in turn. Weigh the mass of the hydrogen sulfide absorption reaction bottle and the sintered filter element, which is m0.

[0077] Place the hydrogen sulfide absorption reaction flask in a constant-temperature water bath at 60°C ± 1°C, ensuring the bath's liquid level is at least 20 mm above the level of the desulfurizer dilution solution. After maintaining the constant temperature for at least 15 minutes, begin injecting hydrogen sulfide or hydrogen sulfide gas balanced with inert gas into the absorption tube. Use a flowmeter to control the gas injection rate to no more than 20 mL / min. Weigh the mass of the hydrogen sulfide absorption reaction flask (including the desulfurizer, distilled water, and filter element) every 30 minutes until the mass of the absorption reaction flask stops increasing. Record this as m1.

[0078] At the same time, the mass of the absorption reaction bottle (including distilled water and filter element) n0 and n1 before and after the reaction was measured when only 400g of distilled water was added without adding desulfurizer.

[0079] (2) Calculation of sulfur capacity

[0080] The sulfur capacity is calculated according to formula (1):

[0081]

[0082] Where:

[0083] X—sulfur content of desulfurizer, %;

[0084] m0—weight of the absorption reaction bottle before the experiment (including desulfurizer, distilled water and filter element), g;

[0085] m1—mass of the absorption reaction bottle after the experiment (including desulfurizer, distilled water and filter element), g;

[0086] m—mass of the desulfurizer to be tested, g;

[0087] n0—mass of the absorption reaction bottle before the experiment (including distilled water and filter element), g;

[0088] n1—The mass of the absorption reaction bottle after the experiment (including distilled water and filter element), g.

[0089] Table 1 Sterilization effect test (sterilization rate, %)

[0090]

[0091]

[0092] As can be seen from Table 1, the sulfur capacity of the desulfurizer of the present invention (Examples 1-7) is greater than 33.5%, with the highest reaching 52.4% (Example 1); while the sulfur capacity of Comparative Example 2 is 26.6%. The desulfurization effect of the desulfurizer of the present invention is significantly better than that of the comparative example.

[0093] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A high-efficiency crude oil desulfurizer, characterized in that: The molecular structural formula of the desulfurizer is as follows: or .

2. A method for synthesizing a high-efficiency crude oil desulfurizer as claimed in claim 1, characterized in that: The synthesis method is as follows: (1) Add cyanuric chloride and alkaline organic solvent to the reactor, cool to below 20°C, add N,N-dimethylbenzylamine, adjust the pH to 9-10 with sodium hydroxide solution, and keep warm for reaction; (2) Add N-hydroxyethylpiperazine to the above mixture, heat to reflux, and maintain the pH at 9-10 with sodium hydroxide solution during the reaction; (3) distilling the mixed solution under reduced pressure to obtain a viscous solid, which was then recrystallized from ethyl acetate to obtain the product desulfurizer; The molar ratio of the N,N-dimethylbenzylamine, N-hydroxyethylpiperazine and cyanuric chloride is 0.8-2.2:1-2.4:

1.

3. The synthesis method according to claim 2, characterized in that The molar ratio of the N,N-dimethylbenzylamine, N-hydroxyethylpiperazine and cyanuric chloride is 0.9-2.1:1.1-2.3:

1.

4. The synthesis method according to claim 3, wherein The alkaline organic solvent is one of ethanol, propanol, isopropanol, isobutanol and tert-butanol with a pH of 9-10.

5. The synthesis method according to claim 2 or 4, characterized in that The mass ratio of the alkaline organic solvent to cyanuric chloride is 20-40:

1.

6. The synthesis method according to claim 2, characterized in that The temperature of the heat preservation reaction is 30-70° C. and the time is 1-24 hours.

7. The synthesis method according to claim 6, characterized in that The temperature of the heat preservation reaction is 50-70° C. and the time is 6-24 hours.

8. The synthesis method according to claim 2, characterized in that The heating reflux time is 4-24h.

9. The synthesis method according to claim 8, characterized in that The heating reflux time is 12-24h.

10. Use of the desulfurizer according to claim 1 in the treatment of oil wells with high hydrogen sulfide content.

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