阅读说明：本技术 一种咪唑啉天然气减阻剂及其合成方法及应用 (Imidazoline natural gas drag reducer and synthesis method and application thereof ) 是由 陈力群 韩跃旺 王凯 于 2020-03-26 设计创作，主要内容包括：本发明公开了一种咪唑啉型天然气减阻剂及其制备方法及应用,该减阻剂通过以下方法合成：将四口烧瓶固定在油浴锅中；称取一定量的长链羧酸与二乙烯三胺备用,将长链羧酸加入反应器中；将长链羧酸加热融化后,加入称量好的二乙烯三胺；继续升温到150℃,进行常压蒸馏,反应4h；当不再有水分流出时,切换为减压装置,控制真空度在2.67kPa左右,控制减环化温度至要考察的温度,控制减压环化时间至要考察的时长,所得产物用无水乙醇重结晶,将样品干燥后得到的淡黄色粉末状固体即为产品。本发明的减阻剂具有良好的吸附性能和优良的减阻増输效果。本发明合成工艺简单,条件温和,时间短,对设备要求低,易于实现大规模生产。(The invention discloses an imidazoline type natural gas drag reducer, a preparation method and application thereof, wherein the drag reducer is synthesized by the following method: fixing the four-mouth flask in an oil bath pan; weighing a certain amount of long-chain carboxylic acid and diethylenetriamine for later use, and adding the long-chain carboxylic acid into a reactor; heating and melting the long-chain carboxylic acid, and adding weighed diethylenetriamine; continuously heating to 150 ℃, and carrying out normal pressure distillation for reaction for 4 h; when no water flows out, switching to a pressure reduction device, controlling the vacuum degree to be about 2.67kPa, controlling the temperature of reduced cyclization to be the temperature to be examined, controlling the time of reduced cyclization to be the time to be examined, recrystallizing the obtained product with absolute ethyl alcohol, and drying the sample to obtain a light yellow powdery solid which is the product. The drag reducer disclosed by the invention has good adsorption performance and excellent drag reduction and transmission increasing effects. The invention has the advantages of simple synthesis process, mild condition, short time, low requirement on equipment and easy realization of large-scale production.)

1. An imidazoline natural gas drag reducer, characterized by the molecular structural formula as shown in the following formula:

wherein R is long-chain carboxylic acid, and R is C in the reaction of stearic acid imidazoline₁₇H₃₅Reaction of oleic imidazoline R is C₁₇H₃₃。

2. A method for synthesizing an imidazoline natural gas drag reducer, wherein the imidazoline natural gas drag reducer of claim 1 comprises the following steps:

fixing a four-mouth flask in an oil bath pan, respectively installing a water separator, a reflux condenser and a stirrer on three interfaces, and plugging the rest interfaces by using ground plugs;

according to the weight ratio of 1.7: 1, weighing a certain amount of long-chain carboxylic acid and diethylenetriamine for later use, adding the long-chain carboxylic acid into a reactor, and introducing nitrogen to discharge air in an instrument;

heating and melting carboxylic acid, adding weighed diethylenetriamine DETA, and continuing introducing nitrogen for protection to prevent the diethylenetriamine from being oxidized;

continuously heating to 150 ℃ for normal pressure distillation, and reacting for 4 h; when no water flows out, switching to a pressure reduction device, controlling the vacuum degree to be about 2.67kPa, controlling the temperature of reduced cyclization to be the temperature to be examined, controlling the time of reduced cyclization to be the time to be examined, recrystallizing the obtained product with a solvent, and drying the sample to obtain a light yellow powdery solid which is the product.

3. The method for synthesizing the imidazoline natural gas drag reducer of claim 2, wherein the long chain carboxylic acid is one of a fatty acid or oleic acid.

4. The method of synthesizing an imidazoline natural gas drag reducer of claim 2, wherein the reduced pressure cyclization temperature is controlled to a temperature to be investigated, the temperature being one of 150 ℃, 160 ℃, 170 ℃, 180 ℃, 220 ℃.

5. The method of synthesizing an imidazoline natural gas drag reducer of claim 2, wherein the depressurization loop time is controlled to a time period to be considered, the time period being one of 2h, 3h, 4h, 5h, and 6 h.

6. The method for synthesizing the imidazoline natural gas drag reducer of claim 2, wherein the solvent used for recrystallization is absolute ethanol or acetone.

7. The application of the imidazoline natural gas drag reducer is characterized in that the drag reducer is applied to natural gas pipeline transportation.

8. The use of an imidazoline natural gas drag reducer according to claim 7, wherein the imidazoline drag reducer is used by formulating into ethanol, gasoline, diesel or acetone solution.

9. The use of the imidazoline natural gas drag reducer of claim 8, wherein the imidazoline drag reducer is present in the formulated solution in an amount of 5 to 200 g/L.

Technical Field

The invention belongs to the technical field of drag reducers, and particularly relates to an imidazoline natural gas drag reducer as well as a synthesis method and application thereof.

Background

As an efficient and clean energy source, natural gas has become the best choice for improving the environment and promoting the sustainable development of economy in all countries of the world, and the demand of natural gas is increasing day by day.

The natural gas almost flows in the pipeline in a turbulent flow mode, a vortex is formed when the fluid flows through the rough surface of the inner wall of the pipeline, and the fluid before and after the vortex has certain pressure difference. The magnitude of the pressure difference (resistance loss) is related to the size of the vortex region and the strength of the vortex, and the size of the vortex region is related to the roughness of the inner wall of the pipe wall. When other conditions are unchanged, the larger the roughness is, the larger the eddy region is, and the larger the resistance loss is.

In view of the chemical composition and compound structure of the existing drag reducer, the existing drag reducer is basically based on the drag reduction mechanism that a polymer with the structural characteristics similar to a surfactant is firmly adhered to the inner surface of a pipeline at a polar end, and a long chain at a non-polar end is suspended in airflow near the wall of the pipeline downstream, or the polymer is fully dissolved in a certain solvent, the content of the polymer is adjusted, so that the solution has certain viscosity and elasticity, an elastic film is formed by coating the solution on the wall surface, and a gas-solid interface is changed into a gas-liquid interface. Because the roughness of the liquid surface is much smaller than that of the solid surface, the formed vortex area is much smaller, so that the frictional resistance between the natural gas and the inner wall of the pipeline can be greatly reduced, the pressure drop and the energy loss in the natural gas conveying process are reduced, and the gas transmission capacity of the pipeline is improved.

Disclosure of Invention

The invention aims to provide an imidazoline natural gas drag reducer, a synthetic method and application thereof, so as to solve the problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

an imidazoline natural gas drag reducer, the molecular structural formula is shown as the following formula:

wherein R is long-chain carboxylic acid, and R is C in the reaction of stearic acid imidazoline₁₇H₃₅Reaction of oleic imidazoline R is C₁₇H₃₃。

Further, the method for synthesizing the imidazoline natural gas drag reducer comprises the following steps:

fixing a four-mouth flask in an oil bath pan, respectively installing a water separator, a reflux condenser and a stirrer on three interfaces, and plugging the rest interfaces by using ground plugs;

according to the weight ratio of 1.7: 1, weighing a certain amount of long-chain carboxylic acid and diethylenetriamine for later use, adding the long-chain carboxylic acid into a reactor, and introducing nitrogen to discharge air in the instrument;

heating and melting carboxylic acid, adding weighed diethylenetriamine DETA, and continuing introducing nitrogen for protection to prevent the diethylenetriamine from being oxidized;

continuously heating to 150 ℃ for normal pressure distillation, and reacting for 4 h; when no water flows out, switching to a pressure reduction device, controlling the vacuum degree to be about 2.67kPa, controlling the temperature of reduced cyclization to be the temperature to be examined, controlling the time of reduced cyclization to be the time to be examined, recrystallizing the obtained product with a solvent, and drying the sample to obtain a light yellow powdery solid which is the product.

Further, the long-chain carboxylic acid is one of fatty acid or oleic acid.

Further, the reduced-pressure cyclization temperature is controlled to a temperature to be examined, which is one of 150 ℃, 160 ℃, 170 ℃, 180 ℃, 220 ℃.

Further, the pressure reducing ring time is controlled to a time period to be considered, which is one of 2h, 3h, 4h, 5h, and 6 h.

Further, the solvent used for recrystallization is absolute ethyl alcohol or acetone.

Further, an application of the imidazoline natural gas drag reducer, and an application of the drag reducer in natural gas pipeline transportation.

Furthermore, the imidazoline drag reducer is prepared into ethanol, gasoline, diesel oil or acetone solution for use.

Furthermore, the content of the imidazoline drag reducer in the prepared solution is 5-200 g/L.

Compared with the prior art, the invention has the following technical effects:

the imidazoline natural gas drag reducer has the main advantages that: under the protection of imidazoline solution, the surface of the metal pipe can form an imidazoline adsorbed film in the environment of acid medium, the film can change the oxidation-reduction potential of hydrogen ions, and the adsorbed imidazoline compound can be partially mixed with the solution. The oxidant forms a complex, thereby achieving the purposes of reducing the potential and slowing down the corrosion. The synthesis method is simple, the reaction time is short, and the solvent is low in toxicity and pollution-free.

The product of the invention is used as a natural gas drag reducer, and is generally prepared into solutions of ethanol, gasoline, diesel oil, acetone or the like for drag reduction and transportation enhancement of natural gas pipelines. Besides, the product of the invention also has a certain corrosion inhibition function on the natural gas pipeline.

The product of the invention is white solid, is convenient to use, and overcomes the defects of poor adsorptivity and short duration of drag reduction effect of the existing natural gas drag reducer. The product has good adsorption performance and excellent resistance reduction and transmission increasing effects on the metal surface.

The synthesis process of the natural gas drag reducer is simple, the reaction condition is mild, and the reaction time is short; meanwhile, the method has low requirement on equipment, the yield is over 70 percent, and large-scale industrial production is easy to realize.

Drawings

FIGS. 1 and 2 are an infrared spectrum of the product obtained in example 1 and an infrared spectrum of a raw material fatty acid, respectively.

FIG. 3 is an SEM of the surface of a blank steel sheet and a steel sheet coated with a drag reducer obtained in example 1. Wherein, (a) is a blank steel surface; (b) the steel surface is the steel surface after film forming.

Fig. 4 is an electrochemical polarization curve of the electrode and the blank electrode after the film formation of the drag reducer obtained in example 1.

Detailed Description

The invention is further described below with reference to the accompanying drawings:

referring to fig. 1 to 4, an imidazoline natural gas drag reducer has a molecular formula shown as follows:

wherein R is long-chain carboxylic acid, and R is C in the reaction of stearic acid imidazoline₁₇H₃₅Reaction of oleic imidazoline R is C₁₇H₃₃。

A method for synthesizing an imidazoline natural gas drag reducer, based on the imidazoline natural gas drag reducer of claim 1, comprising the following steps:

fixing a four-mouth flask in an oil bath pan, respectively installing a water separator, a reflux condenser and a stirrer on three interfaces, and plugging the rest interfaces by using ground plugs;

according to the weight ratio of 1.7: 1, weighing a certain amount of long-chain carboxylic acid and diethylenetriamine for later use, adding the long-chain carboxylic acid into a reactor, and introducing nitrogen to discharge air in the instrument;

heating and melting carboxylic acid, adding weighed diethylenetriamine DETA, and continuing introducing nitrogen for protection to prevent the diethylenetriamine from being oxidized;

continuously heating to 150 ℃ for normal pressure distillation, and reacting for 4 h; when no water flows out, switching to a pressure reduction device, controlling the vacuum degree to be about 2.67kPa, controlling the temperature of reduced cyclization to be the temperature to be examined, controlling the time of reduced cyclization to be the time to be examined, recrystallizing the obtained product with a solvent, and drying the sample to obtain a light yellow powdery solid which is the product.

The synthetic route of the imidazoline natural gas drag reducer is as follows:

the long-chain carboxylic acid is one of fatty acid or oleic acid.

The reduced pressure cyclization temperature is controlled to a temperature to be examined, which is one of 150 ℃, 160 ℃, 170 ℃, 180 ℃, 220 ℃.

And controlling the decompression ring time to a time length to be considered, wherein the time length is one of 2h, 3h, 4h, 5h and 6 h.

The solvent used for recrystallization is absolute ethyl alcohol or acetone.

An application of imidazoline natural gas drag reducer, and an application of the drag reducer in natural gas pipeline transportation.

The imidazoline drag reducer is prepared into ethanol, gasoline, diesel oil or acetone solution for use.

The content of the imidazoline drag reducer in the prepared solution is 5-200 g/L.