阅读说明：本技术 一种劣质原油中有机氯的脱除方法 (Method for removing organic chlorine in inferior crude oil ) 是由 侯志忠 冯保杰 崔蕊 于焕良 刘嫘 于 2021-09-30 设计创作，主要内容包括：本发明涉及一种劣质原油中有机氯的脱除方法。对多种油相破乳剂进行筛选,选择脱盐率最高的油相破乳剂为最佳；对多种水相破乳剂进行筛选,选择脱盐率最高的水相破乳剂为最佳；在确定了最优的油相和水相破乳剂的基础上,确定油相破乳剂和水相破乳剂最佳的质量浓度；然后根据确定的油相和水相破乳剂最佳的质量浓度与氯转移剂进行电脱盐评价实验。该方法在不改变原有电脱盐装置的条件下,通过两种破乳剂和一种氯转移剂复配使用,并适当调整操作温度,使不容易破乳脱氯的劣质原油经过电脱盐单元后原油中的有机氯得以脱除,脱氯率可达到95％以上,操作简单,具有良好经济性。(The invention relates to a method for removing organic chlorine in inferior crude oil. Screening a plurality of oil phase demulsifiers, and selecting the oil phase demulsifier with the highest salt rejection rate as the best oil phase demulsifier; screening a plurality of water-phase demulsifiers, and selecting the water-phase demulsifier with the highest salt rejection rate as the best water-phase demulsifier; determining the optimal mass concentration of the oil phase demulsifier and the water phase demulsifier on the basis of determining the optimal oil phase demulsifier and water phase demulsifier; and then carrying out an electric desalting evaluation experiment with the chlorine transfer agent according to the determined optimal mass concentration of the demulsifier of the oil phase and the water phase. The method uses two demulsifiers and one chloride transfer agent in a compounding way without changing the original electric desalting device, and properly adjusts the operating temperature, so that organic chloride in the crude oil is removed after the inferior crude oil which is difficult to be demulsified and dechlorinated passes through the electric desalting unit, the dechlorination rate can reach more than 95 percent, the operation is simple, and the method has good economy.)

1. A method for removing organic chlorine in inferior crude oil is characterized by comprising the following steps:

1) screening various oil phase demulsifiers according to the demulsifiers actually used by the electric desalting unit in the crude oil processing technology, performing a desalting evaluation experiment on the various oil phase demulsifiers in the mixed crude oil, and selecting the oil phase demulsifier with the highest desalting rate as the best oil phase demulsifier;

2) screening various water-phase demulsifiers according to the demulsifiers actually used by the electric desalting unit in the crude oil processing technology, adding the optimal oil-phase demulsifier selected in the step (1) into the mixed crude oil, performing a desalting evaluation experiment on the various water-phase demulsifiers, and selecting the water-phase demulsifier with the highest desalting rate as the optimal demulsifier;

3) screening various chloride transfer agents according to the chloride transfer agents actually used by the electric desalting unit in the crude oil processing technology, adding the optimal oil phase demulsifier selected in the step (1) and the optimal water phase demulsifier selected in the step (2) into the mixed crude oil, performing a dechlorination evaluation experiment on the various chloride transfer agents, and selecting the chloride transfer agent with the highest dechlorination rate as the optimal chloride transfer agent;

4) on the basis of determining the optimal oil phase, water phase demulsifier and chlorine transfer agent, determining the optimal mass concentration of the oil phase demulsifier, on the basis, determining the optimal mass concentration of the water phase demulsifier, and on the basis of determining the optimal mass concentrations of the oil phase demulsifier and the water phase demulsifier, determining the optimal mass concentration of the chlorine transfer agent;

5) and (3) adding 5-10% of water into the mixed crude oil, fully stirring the oil phase with the optimal mass concentration, the water phase demulsifier and the chlorine transfer agent determined in the step (4), and then performing electric desalting treatment.

2. The dechlorination method of claim 1, wherein the oil phase demulsifier in step (4) is selected to have a mass concentration of 2-15 mg/kg; the mass concentration of the water phase demulsifier is 0.1-1.0 mg/kg; the mass concentration of the chlorine transfer agent is 5-30 mg/kg.

3. The dechlorination method of claim 1, wherein the oil phase demulsifier in step (4) is selected to have a mass concentration of 6-8 mg/kg; the mass concentration of the water phase demulsifier is 0.4-0.6 mg/kg; the mass concentration of the chlorine transfer agent is 14-16 mg/kg.

4. Dechlorination process according to claim 1, wherein the electric desalting in step (5) is carried out at 125-135 ℃.

5. The dechlorination process of claim 1, wherein the desalting evaluation test is according to QSH0236-2008 "requirements for crude oil demulsifier" standard.

Technical Field

The invention relates to a method for removing organic chlorine in inferior crude oil.

Background

With the increasing variety and proportion of imported inferior crude oil (generally, crude oil with relative density of more than 0.95, sulfur content of more than 2.0% and colloid content of more than 15%), crude oil processed by an atmospheric and vacuum distillation unit tends to be diversified and inferior, and the proportion of high-sulfur and high-chlorine crude oil continuously increases, so that the unit faces unprecedented equipment corrosion problems. The chlorides and sulfides contained in the crude oil are heated to decompose or hydrolyze in the distillation process to generate hydrogen chloride and hydrogen sulfide, which cause serious corrosion to equipment and pipelines together with organic acid in the crude oil, thereby influencing the normal operation of the device. Therefore, it is essential to remove the salts and chlorides to the maximum possible extent in the electro-desalination unit.

In recent years, with the trend of diversification and deterioration of domestic crude oil, the conditions of low-temperature corrosion and salt deposition of a fractionating tower top system are very prominent, and the problems become common problems of domestic oil refining enterprises. The corrosion is serious not only in the three tower tops (including top circulation) of a distillation device, the top of a catalytic fractionating tower, the top of a coking fractionating tower, a hydrogen sulfide removing stripping tower of a hydrogenation device and a condensation cooling system thereof, but also in the salt deposition condition of a high-pressure air cooler and a high-pressure heat exchanger of a hydrogenation reaction effluent, such as the dew point corrosion and the ammonium salt deposit corrosion of a tower top system of a fractionating tower of an atmospheric and vacuum device.

As the content of chlorine in crude oil is increased along with the heavy and inferior crude oil and the large amount of injected chemical additives in the process of extracting the crude oil, particularly the content of organic chlorine is increased, the content of the organic chlorine of the oil extraction additives reaches dozens of to hundreds of thousands of mu g/g, so that the content of the organic chlorine in the crude oil is 5 to 30 mu g/g, the chlorine corrosion of a refining unit is increased, and especially the chlorine corrosion of H in the presence of sulfur and chlorine is increased₂S+H₂The corrosion type of the O + HCl corrosion can cause obvious corrosion to common carbon steel or alloy steel, and particularly, the corrosion type of the O + HCl corrosion and the alloy steel can also mutually play an accelerating role under high concentration, so that the low-temperature part of the device is corroded and perforated, and the production safety is seriously influenced. Generally, chlorine in each narrow fraction below 350 ℃ in crude oil is mainly organic chlorine, wherein chlorine content in each narrow fraction below 150 ℃ is higher.

When the electric desalting unit is normally operated, only one demulsifier is added to desalt the mixed crude oil, the salt content of the crude oil after the desalting can meet the index requirement, but when the crude oil with poor quality is processed, the salt content of the crude oil after the desalting exceeds the standard, and organic chlorine in the crude oil is difficult to remove, so that the conditions of low-temperature corrosion and salt deposition of a fractionating tower top system are caused.

In order to improve the desalting effect of the electric desalting, particularly the removal effect of organic chlorine, a water-soluble demulsifier and a chlorine transfer agent are added on the basis of the original electric desalting oil-soluble demulsifier, the effect of desalting and removing the organic chlorine is inspected, and finally the effective control on the corrosion of ammonium salt can be realized.

Disclosure of Invention

The invention utilizes the oil phase demulsifier, the water phase demulsifier and the chlorine transfer agent to be compounded for use, removes salts and organic chloride in the crude oil to the maximum extent, and improves the dechlorination effect of the inferior crude oil.

A method for removing organic chlorine in inferior crude oil comprises the following steps:

1) screening various oil phase demulsifiers according to the demulsifiers actually used by the electric desalting unit in the crude oil processing technology, performing a desalting evaluation experiment on the various oil phase demulsifiers in the mixed crude oil, and selecting the oil phase demulsifier with the highest desalting rate as the best oil phase demulsifier;

2) screening various water-phase demulsifiers according to the demulsifiers actually used by the electric desalting unit in the crude oil processing technology, adding the optimal oil-phase demulsifier selected in the step (1) into the mixed crude oil, performing a desalting evaluation experiment on the various water-phase demulsifiers, and selecting the water-phase demulsifier with the highest desalting rate as the optimal demulsifier;

3) screening various chloride transfer agents according to the chloride transfer agents actually used by the electric desalting unit in the crude oil processing technology, adding the optimal oil phase demulsifier selected in the step (1) and the optimal water phase demulsifier selected in the step (2) into the mixed crude oil, performing a dechlorination evaluation experiment on the various chloride transfer agents, and selecting the chloride transfer agent with the highest dechlorination rate as the optimal chloride transfer agent;

4) on the basis of determining the optimal oil phase, water phase demulsifier and chlorine transfer agent, determining the optimal mass concentration of the oil phase demulsifier, on the basis, determining the optimal mass concentration of the water phase demulsifier, and on the basis of determining the optimal mass concentrations of the oil phase demulsifier and the water phase demulsifier, determining the optimal mass concentration of the chlorine transfer agent;

5) and (3) adding 5-10% of water into the mixed crude oil, fully stirring the oil phase with the optimal mass concentration, the water phase demulsifier and the chlorine transfer agent determined in the step (4), and then performing electric desalting treatment.

In the step (4), the mass concentration of the oil phase demulsifier is selected to be 2-15 mg/kg; the mass concentration of the water phase demulsifier is 0.1-1.0 mg/kg; the mass concentration of the chlorine transfer agent is 5-30 mg/kg.

Preferably, in the step (4), the mass concentration of the oil phase demulsifier is selected to be 6-8 mg/kg; the mass concentration of the water phase demulsifier is 0.4-0.6 mg/kg; the mass concentration of the chlorine transfer agent is 14-16 mg/kg.

The electric desalting operation temperature of the step (5) is 125-135 ℃.

The multiple steps (1), (2) or (3) are preferably four.

The desalting evaluation experiment of the dechlorination method is according to the standard of QSH0236-2008 technical requirements on crude oil demulsifiers.

The using effect of the chlorine transfer agent is inspected through the chlorine content and the dechlorination rate of the crude oil after the dechlorination, so that the dechlorination rate reaches more than 60 percent.

The method uses two demulsifiers and one chloride transfer agent in a compounding way without changing the original electric desalting device, and properly adjusts the operating temperature, so that organic chloride in the crude oil is removed after the inferior crude oil which is difficult to be demulsified and dechlorinated passes through the electric desalting unit, the dechlorination rate can reach more than 95 percent, the operation is simple, and the method has good economy.

Detailed Description

The invention is further illustrated by the following examples. Evaluation methods adopted in the experiment:

the salt rejection calculation method is adopted:

the method for calculating the dechlorination rate comprises the following steps:

firstly, screening a plurality of oil phase demulsifiers, and according to QSH0236-2008 technical requirements on crude oil demulsifiers, namely the enterprise standards of China petrochemical group companies, performing desalination evaluation experiments on the plurality of oil phase demulsifiers in mixed crude oil by using an electric desalination experimental instrument capable of simulating an industrial electric desalter, and selecting the oil phase demulsifier with the highest desalination rate as the best oil phase demulsifier under the same conditions that the adding concentration of the demulsifier is 7mg/kg and the operating temperature is 130 ℃;

secondly, screening a plurality of water-phase demulsifiers, adding the optimal oil-phase demulsifier selected in the step (1) into the mixed crude oil by using an electric desalting tester capable of simulating an industrial electric desalting device according to QSH0236-2008 technical requirements on crude oil demulsifiers-enterprise standards of China petrochemical group company, performing desalting evaluation experiments on the plurality of water-phase demulsifiers, and selecting the water-phase demulsifier with the highest desalting rate as the optimal water-phase demulsifier under the same conditions that the adding concentration of the demulsifier is 0.5mg/kg and the operating temperature is 130 ℃;

finally, screening a plurality of chloride transferants, according to QSH0236-2008 technical requirements on crude oil demulsifiers-China enterprises standards of petrochemical group companies, using an electric desalting tester capable of simulating an industrial electric desalting device to add the optimal oil phase demulsifier selected in the step (1) and the optimal water phase demulsifier selected in the step (2) into the mixed crude oil, and performing evaluation experiments on the plurality of chloride transferants, wherein the chloride transferant with the highest dechlorination rate is selected as the optimal chloride transferant under the conditions that the adding concentration of the chloride transferants is 15mg/kg and the operating temperature is 130 ℃;

on the basis of determining the optimal oil phase, water phase demulsifier and chlorine transfer agent, according to QSH0236-2008 technical requirement of crude oil demulsifier-enterprise standard of China petrochemical group company, an electric desalting experimental instrument capable of simulating an industrial electric desalting device is utilized to determine the optimal mass concentration of the oil phase demulsifier, determine the optimal mass concentration of the water phase demulsifier on the basis, and finally determine the optimal mass concentration of the chlorine transfer agent on the basis of determining the optimal mass concentrations of the oil phase demulsifier and the water phase demulsifier.

And (3) adding 5-10% of water into the mixed crude oil, fully stirring the oil phase, the water phase demulsifier and the chlorine transfer agent with the optimal mass concentration determined in the step (4), and performing electric desalting treatment.

In the step (4), the mass concentration of the oil phase demulsifier is 2-15 mg/kg; the mass concentration of the water phase demulsifier is 0.1-1.0 mg/kg; the mass concentration of the chlorine transfer agent is 5-30 mg/kg.

Preferably, in the step (4), the mass concentration of the oil phase demulsifier is selected to be 6-8 mg/kg; the mass concentration of the water phase demulsifier is 0.4-0.6 mg/kg; the mass concentration of the chlorine transfer agent is 14-16 mg/kg.

The electric desalting operation temperature of the step (5) is 125-135 ℃.

Example 1

Carrying out an oil-soluble demulsifier evaluation experiment by using a mixed crude oil of Ba, Yi and Kas as a raw material, wherein the oil-soluble demulsifier is Narcico-1, Narcico-2, Narcico-3 and Narcico-4, the addition concentration is 7mg/kg, the operation temperature is 130 ℃, and the optimal desalination rate of the Narcico-3 demulsifier is 78.58%; carrying out an evaluation experiment of matching the water-soluble demulsifiers with the Nalter-3 oil-soluble demulsifiers (the addition concentration is 7mg/kg), wherein the water-soluble demulsifiers are Guangdong head-1, Guangdong head-2, Guangdong head-3 and Guangdong head-4, the addition concentration is 0.5mg/kg, the operating temperature is 130 ℃, and the optimal desalination rate of the Guangdong head-3 demulsifiers is 90.71%; finally, a chlorine transfer agent is added on the basis of mixing the Naerceae-3 oil-soluble demulsifier (the adding concentration is 7mg/kg) and the Guangdong first-3 water-soluble demulsifier (the adding concentration is 0.5mg/kg), the chlorine transfer agent is Xinchang-1, Xinchang-2, Xinchang-3 and Xinchang-4, the adding concentration is 15mg/kg, the operating temperature is 130 ℃, and the dechlorination rate of the Xinchang-2 chlorine transfer agent is the best and is 95.92%.

Example 2

Taking mixed crude oil of light weight, heavy weight and Kass as raw materials, carrying out an oil solubility, water solubility demulsifier and chlorine transfer agent optimal matching concentration evaluation experiment, adding 5% of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naercao-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 2mg/kg, 0.1mg/kg and 10mg/kg, and the electric desalting operation temperature is 125 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the best matching concentration is considered, and the dechlorination rate is 95.18%.

Example 3

Taking mixed crude oil of light weight, heavy weight and Kass as raw materials, carrying out an oil solubility, water solubility demulsifier and chlorine transfer agent optimal matching concentration evaluation experiment, adding 5% of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naercao-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 12mg/kg, 0.8mg/kg and 20mg/kg, and the electric desalting operation temperature is 130 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the optimal matching concentration is inspected, and the dechlorination rate is 96.93 percent.

Example 4

Taking mixed crude oil of light weight, heavy weight and Kass as raw materials, carrying out an oil solubility, water solubility demulsifier and chlorine transfer agent optimal matching concentration evaluation experiment, adding 5 percent of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naercao-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 15mg/kg, 1.0mg/kg and 30mg/kg, and the electric desalting operation temperature is 135 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the optimal matching concentration is considered, and the dechlorination rate is 97.78%.

Example 5

Taking mixed crude oil of Ba light, Yi heavy and Kas as raw materials, carrying out the evaluation experiment of the optimal matching concentration of an oil-soluble demulsifier, a water-soluble demulsifier and a chlorine transfer agent, adding 5 percent of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naerce-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 5mg/kg, 0.4mg/kg and 25mg/kg, and the electric desalting operation temperature is 125 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the optimal matching concentration is inspected, and the dechlorination rate is 96.89%.

Example 6

Taking mixed crude oil of Ba light, Yi heavy and Kas as raw materials, carrying out the evaluation experiment of the optimal matching concentration of an oil-soluble demulsifier, a water-soluble demulsifier and a chlorine transfer agent, adding 5 percent of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naerce-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 7mg/kg, 0.5mg/kg and 15mg/kg, and the electric desalting operation temperature is 130 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the best matching concentration is considered, and the dechlorination rate is 95.68%.

Example 7

Taking mixed crude oil of light weight, heavy weight and Kass as raw materials, carrying out an oil solubility, water solubility demulsifier and chlorine transfer agent optimal matching concentration evaluation experiment, adding 5% of purified water into the mixed crude oil, carrying out high-speed emulsification, taking 50.0g of a sample, sequentially adding a Naercao-3 oil phase demulsifier, a Guangdong first-3 water phase demulsifier and a Xinchang-2 chlorine transfer agent, wherein the mass concentrations are respectively 10mg/kg, 0.6mg/kg and 5mg/kg, and the electric desalting operation temperature is 135 ℃. After the mixture was sufficiently stirred, an evaluation experiment of electric desalting was carried out according to actual operating conditions. The using effect of the demulsifier and the chloride transfer agent with the optimal matching concentration is inspected, and the dechlorination rate is 96.30 percent.

While the methods and techniques of the present invention have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations and/or modifications of the methods and techniques described herein may be made without departing from the spirit and scope of the invention. It is expressly intended that all such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and content of the invention. The invention belongs to the known technology.