High-efficiency crude oil desulfurizing agent as well as synthesis method and application thereof

Abstract

The invention belongs to the technical field of oil exploitation, and particularly relates to an efficient crude oil desulfurizer and a synthesis method and application thereof. The synthesis method comprises the following steps: adding cyanuric chloride and an alkaline organic solvent into a reactor, cooling to 20 DEG C or below, adding N, N-dimethyl benzylamine, adjusting the pH value to 9-10 by using a sodium hydroxide solution, and carrying out heat preservation reaction; adding N-hydroxyethylpiperazine into the mixed solution, heating and refluxing, and maintaining the pH value to be 9-10 by using a sodium hydroxide solution during a reaction period; and carrying out reduced pressure distillation on the mixed solution to obtain a viscous solid, and recrystallizing with ethyl acetate to obtain the product desulfurizer. The desulfurizer disclosed by the invention has the advantages of wide raw material source, simple synthesis process, clean and pollution-free process and good sterilization and desulfurization effects.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum exploitation, 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, the desulfurization technology of crude oil has always been the focus of research and development. Sulfur is a common associated element in petroleum and is also the main harmful element. In the refining process of high-sulfur crude oil, sulfur will not only cause serious corrosion to equipment, block pipelines and heat exchange equipment, but also cause catalyst poisoning and affect product quality. In addition, the presence of sulfides will accelerate the corrosion of cyclohexane acid in high-temperature parts and produce harmful free radical reactions. What is more serious is that the sulfur in petroleum products will produce sulfur dioxide and sulfur trioxide when burned. These substances are one of the main sources of air pollution, which will promote the formation of acid rain and cause serious pollution to the environment.

[0003] In the face of these challenges, crude oil desulfurization technology came into being. As one of the important means, crude oil desulfurizer has the advantages of small addition amount, convenient operation, and significant desulfurization effect, and is widely used in the crude oil desulfurization process.

[0004] CN109593545A discloses a composite desulfurizer suitable for oil wells with high oil content and a preparation method thereof. The desulfurizer is composed of 20-27.5% formaldehyde by mass fraction, 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, 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 alcohol amine compounds with hydrogen sulfide. The surfactant has an emulsifying effect, so that the crude oil and the desulfurizer have a good mutual solubility effect. The small molecule alcohols are used as antifreeze fluids, so that the desulfurizer can still be used in a sub-zero environment. However, the desulfurization principle of this patent is just the simple absorption of hydrogen sulfide by ethanolamine, the action principle is single, and the desulfurization effect is limited.

[0005] CN116162068B discloses a triazine desulfurizer and a preparation method thereof, belonging to the field of petroleum technology. The method reacts 2-aminoethanol and formaldehyde to obtain an intermediate A; reacts the intermediate A with dichlorothionyl to obtain an intermediate B; and reacts the intermediate B with N-methylaniline to obtain a triazine desulfurizer. The triazine desulfurizer prepared by the present invention can stably exist in an acidic environment, has good stability, and prolongs the service life; the triazine desulfurizer of the present invention has a high benzene ring content, and can be mutually dissolved with aromatic hydrocarbons in crude oil through π-π stacking, thereby enhancing the solubility of the triazine desulfurizer, thereby promoting its 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 inhibiting hydrogen sulfide in the crude oil storage and transportation system of the oil field, and achieving oil field production safety, environmental protection, and energy conservation and emission reduction. However, the synthesis process of the present invention is complicated, the application cost is high, and it is not economical. Summary of the invention

[0006] The present invention aims to provide a high-efficiency crude oil desulfurizer and its synthesis method and application in view of the shortcomings of the prior art. The desulfurizer of the present invention has the advantages of wide sources of raw materials, simple synthesis process, clean and pollution-free process and good sterilization and desulfurization effect.

[0007] In order to achieve the above objectives:

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

[0009] (1) adding cyanuric chloride and an alkaline organic solvent into a reactor, cooling the reactor to below 20° C., adding N,N-dimethylbenzylamine, adjusting the pH to 9-10 with a sodium hydroxide solution, and keeping the temperature for reaction;

[0010] (2) adding N-hydroxyethylpiperazine to the mixed solution, 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 insulation 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 1-24h.

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

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

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

[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 the desulfurizer is as follows:

[0028]

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

[0030] The present invention uses cyanuric chloride to react with N, N-dimethylbenzylamine and N-hydroxyethylpiperazine to produce an acylation reaction, thereby obtaining a product having two-in-one functions of sterilization and desulfurization. The N-hydroxyethylpiperazine introduced by the substitution reaction of the present invention is a multifunctional desulfurization functional group, and piperazine can completely remove hydrogen sulfide. The product after piperazine desulfurization can absorb hydrogen sulfide, and the hydroxyethyl group has a large polarity and can also absorb hydrogen sulfide.

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

[0032] (1) The raw materials for preparing the desulfurizer 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 desulfurizing agent of the present invention has a good desulfurizing 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 capacity of a high-efficiency desulfurizing agent. DETAILED DESCRIPTION

[0036] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the 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 as specifically disclosed in this article.

[0037] The present invention will be further described below in conjunction with specific embodiments:

[0038] Example 1

[0039] (1) Add 0.05 mol of cyanuric chloride and 184.4 g of propanol into 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) adding 0.12 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 4 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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 isobutyl alcohol 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) adding 0.11 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 8 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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 a 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) adding 0.1 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 12 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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 isopropanol into a 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) adding 0.09 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 12 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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) adding 0.08 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 16 h, and maintaining 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 into a 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 hours;

[0060] (2) adding 0.06 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 20 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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 isopropanol into a 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) adding 0.05 mol N-hydroxyethylpiperazine to the above mixture, heating and reflux for 24 h, and maintaining the pH at 9-10 with sodium hydroxide solution during the reaction;

[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, divide it into a series of 500 ml narrow-mouth bottles, add 5, 10, 15 mg / L concentrations of the desulfurizer of the present invention, shake well, place in a 60°C 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, and the test results are shown in Table 1.

[0069] From Table 1 we can see that:

[0070] (1) The desulfurizer of the present invention (Examples 1-7) has a sterilization rate of 90% or more when used at a concentration of 5 mg / L, with the highest reaching 99.7% (Example 7), while the sterilization rate of Comparative Example 1227 is 33.3%, which is 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 desulfurizer of the present invention (Examples 1-7) has a sterilization rate of 100% when the concentration is 15 mg / L, while the sterilization rate of Comparative Example 1227 is 94.1%, which is 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 is tested with reference to Q / SH10202872-2021 "General Technical Conditions for Desulfurizers". The triazine desulfurizer of Shengli Oilfield Jindao Petroleum Engineering Technology Co., Ltd. is 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 is connected in a fume hood. Weigh 10g of the desulfurizer to be tested, add it to the hydrogen sulfide absorption reaction bottle, add 400g of distilled water, put in a sintered filter element so that it is 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, so that the filter element is completely immersed in the liquid, and the top of the filter element is 15mm below 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 the 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 bottle in a constant temperature water bath at 60℃±1℃, and make the liquid level of the water bath higher than the level of the desulfurizer dilution liquid by more than 20mm. After keeping the constant temperature for at least 15 minutes, start injecting hydrogen sulfide or hydrogen sulfide gas balanced by inert gas into the absorption tube, and control the gas injection speed to no more than 20mL / min through the flow meter. Weigh the mass of the hydrogen sulfide absorption reaction bottle (including the desulfurizer, distilled water and filter element) every 30 minutes until the mass of the absorption reaction bottle does not increase, recorded 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—the 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] It can be seen from Table 1 that 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 are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for synthesizing a high-efficiency crude oil desulfurizer, characterized in that: The synthesis method is as follows: (1) adding cyanuric chloride and an alkaline organic solvent into a reactor, cooling the reactor to below 20° C., adding N,N-dimethylbenzylamine, adjusting the pH to 9-10 with a sodium hydroxide solution, and keeping the temperature for reaction; (2) adding N-hydroxyethylpiperazine to the mixed solution, heating to reflux, and maintaining 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, and recrystallizing it with ethyl acetate to obtain a product desulfurizer; The molar ratio of the N,N-dimethylbenzylamine, N-hydroxyethylpiperazine and cyanuric chloride is 0.8-2.2:1-2.4:

1.

2. The synthesis method according to claim 1, 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.

3. The synthesis method according to claim 1, characterized in that: The alkaline organic solvent is one of ethanol, propanol, isopropanol, isobutanol and tert-butanol with a pH of 9-10.

4. The synthesis method according to claim 1 or 3, characterized in that: The mass ratio of the alkaline organic solvent to cyanuric chloride is 20-40:

1.

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

6. The synthesis method according to claim 5, characterized in that: The temperature of the heat preservation reaction is 50-70°C and the time is 6-24h.

7. The synthesis method according to claim 1, characterized in that: The heating reflux time is 4-24h.

8. The synthesis method according to claim 7, characterized in that: The heating reflux time is 12-24h.

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

10. Use of the desulfurizing agent according to claim 9 in the treatment of oil wells with high hydrogen sulfide content.

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