JPH0734071A - Contamination preventing agent for petroleum refining or petrochemical process - Google Patents

Abstract

PURPOSE:To obtain a preventing agent having excellent contamination preventing effect especially at high temperature and useful for effectively preventing the contamination of a process fluid in a petroleum refining plant by combining a specific polyoxythiophosphonic acid ester with a dispersing agent. CONSTITUTION:This preventing agent contains (A) a polyoxythiophosphonic acid ester of the formula (R<1> is 3-30C alkyl or alkenyl; R<2> and R<3> are a 2-5C alkylene or alkenylene; (n) and (m) are 1-5) and (B) a dispersing agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel antifouling agent for petroleum refining or petrochemical processes, and more particularly to fouling of process fluids in petroleum refining plants and petrochemical plants, particularly to fouling mainly composed of organic matter. The present invention relates to a stain preventive agent which has an action of suppressing generation of a stain component and dispersing the generated stain.

[0002]

2. Description of the Related Art Conventionally, various processes such as atmospheric distillation, vacuum distillation, hydrodesulfurization, catalytic cracking, catalytic reforming and isomerization have been adopted in petroleum refining processes.
Each petroleum-based raw material oil is repeatedly subjected to treatments such as heating, cooling, decomposition, and separation, and is introduced into various petroleum products. In addition, coal-based feedstock oil such as coal carbonized oil is treated alone or in a mixture with petroleum-based feedstock oil and subjected to the same treatment. on the other hand,
In petrochemical processes, such as naphtha cracking and ethylene plants, various treatments such as heating, distillation, and cooling are performed before products are made from raw materials. In such a petroleum refining or petrochemical process, when the process fluid is heated by, for example, a preheat heat exchanger or a reboiler, it undergoes thermal denaturation to generate sludge, which is transferred to the preheat heat exchanger or the reboiler. It is unavoidable that dirt adheres to the hot surface or piping.
The following is known as a mechanism for generating such dirt. That is, in petroleum refining processes and petrochemical processes, easily oxidizable organic substances such as unsaturated hydrocarbons in the process fluid are first led to hydroperoxide by dissolved oxygen, and then, by heat, they exert catalytic ability especially on metals. In the presence of the substance that it has, it decomposes into ketones, aldehydes, carboxylic acids, etc., which then polymerize to form oligomers and polymers to form sludge.
Therefore, in order to prevent such dirt, conventionally,
In petroleum refining and petrochemical processes, antioxidants and antioxidants to suppress the formation of hydroperoxides, metal deactivators that deactivate catalytically active substances such as metals, and sludge formation and A dispersant for preventing deposits from adhering, or an antifouling agent combining these is used. Examples of the stain preventive agent include (1) polyalkenyl succinimide,
(2) An antifouling agent containing an alkyl- or alkenyl-substituted organic carboxylic acid, a polyalkylenepolyamine copolymer and phosphite (Japanese Patent Publication No. 46-6503),
(3) Antifouling agent comprising a composition containing a reaction product of a polyamine and a succinic acid compound, a phenolic compound and N, N'-disalicylidene-1,2-propanediamine (JP-A-60-54327). , (4) Styrene-
An antifouling agent comprising a composition containing a maleic acid ester copolymer, a succinic acid ester and N, N'-disalicylidene-1,2-propanediamine (JP-A-62-20)
No. 7265), (5) an antifouling agent comprising a combination of aniline and t-butylcatechol (Japanese Patent Publication No. 59-24).
138), (6) nitrosophenol-based stain inhibitor (JP-A-3-350147), (7) nitroso-based stain inhibitor (JP-B-4-26639),
(8) Amine-based stain inhibitors (Japanese Patent Laid-Open No. 64-13041) and the like are known. However, in these conventional antifouling agents, the antifouling effect is insufficient for the process fluid mixed with dissolved oxygen or the process fluid under high temperature conditions, or the antifouling agent is added directly to the process, so In addition to causing coloring, there are drawbacks such as generation of unfavorable by-products and difficulty in handling.

[0003]

DISCLOSURE OF THE INVENTION The present invention overcomes the disadvantages of the conventional antifouling agents and prevents the contamination of the process fluid mixed with dissolved oxygen and the process fluid under high temperature conditions. Can be fully exerted and is easy to handle, and has no adverse effect on the process.
The purpose of the present invention is to provide an antifouling agent for petroleum refining or petrochemical processes such as for petroleum refining processes and petrochemical processes.

[0004]

DISCLOSURE OF THE INVENTION The inventors of the present invention have conducted diligent research to develop an antifouling agent for petroleum refining or a petrochemical process having the above-described preferable properties, and as a result, have obtained polyoxythio having an antioxidant function. It has been found that an antifouling agent in which a phosphonate ester and a dispersant are combined can meet the purpose, and the present invention has been completed based on this finding. That is, the present invention provides (A) general formula

[0005]

[Chemical 2]

(In the formula, R ¹ is an alkyl or alkenyl group having 3 to 30 carbon atoms, and R ² and R ³ are each 2 to 5 carbon atoms.
Is an alkylene group or alkenylene group, which may be the same or different from each other, and n and m are each an integer of 1 to 5), and ( B) A stain preventive agent for petroleum refining or petrochemical processes, which comprises a dispersant. In the antifouling agent of the present invention,
As the component (A), a general formula

[0007]

[Chemical 3]

A polyoxythiophosphonate represented by the following formula is used. In the general formula [1], R ¹ is an alkyl group or an alkenyl group having 3 to 30 carbon atoms,
It may be linear, branched, or cyclic. On the other hand, R ² and R ³ are each an alkylene group having 2 to 5 carbon atoms or an alkenylene group, and may be linear or branched, and R ² and R ³ are each It may be the same or different. n and m are each an integer of 1 to 5, and they may be the same or different from each other. The polyoxythiophosphonate ester as the component (A) has an antioxidant function, especially at high temperature (10
It has an excellent antioxidant function at 0 ° C or higher). The polyoxythiophosphonate may be used alone or in combination of two or more. In the antifouling agent of the present invention, as the dispersant used as the component (B), organic sludge or inorganic sludge can be dispersed in the process fluid to prevent deposits from adhering to the heat transfer surface or the pipe. There is no particular limitation as long as it is available. Examples of such a dispersant include, for example, (1) the general formula

[0009]

[Chemical 4]

(R ⁴ and R ⁵ in the formula each have 12 carbon atoms.
~ 18 alkyl groups, which may be the same or different from each other, and p and q have a molecular weight of 10,000.
~ 1,000,000, the ratio is 1: 9
Styrene-maleic acid ester copolymer represented by the formula (2), and (2) a polyalkyl (meth) acrylate having a molecular weight of about 1,000 to 10,000 and a general formula

[0011]

[Chemical 5]

(Wherein R ⁶ is a hydrocarbon group having 10 to 15 carbon atoms, a is 1 to 5, preferably 1 to 3 and b is 1 to
Polymerization ratio with polyethylene polyamine naphthenic acid amide represented by
Mixture with 10 to 10:90, (3) general formula

[0013]

[Chemical 6]

(In the formula, R ⁷ is a polybutene group having a molecular weight of 400 to 3000, and R ⁸ is a carbon number of 1 to 5, preferably 1 to 3.
Is an alkylene group, R ⁹ and R ¹⁰ are each a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably 1 to 3 carbon atoms, and k is 1
A polyalkenyl succinimide derivative represented by (an integer of 10), (4) a polyalkenyl succinic acid ester derivative, and the like. Examples of the polyalkyl (meth) acrylate (2) include, for example, a homopolymer of an alkyl (meth) acrylate having an alkyl group having 5 to 18 carbon atoms, or a copolymer obtained by copolymerizing two or more kinds, Further, the alkyl (meth) acrylate 1
Obtained by copolymerizing one or more species with one or more unsaturated monomers having an ethylenic double bond such as N-vinyl-2-pyrrolidone, ethylene glycol, di (meth) acrylate, and diethylaminoethyl methacrylate. And copolymers. The dispersant for these components (B) is 1
One kind may be used, or two or more kinds may be used in combination. In the antifouling agent of the present invention, the compounding ratio of the polyoxythiophosphonic acid ester as the component (A) and the dispersant as the component (B) is usually 25: 100 to 10 by weight.
It is selected in the range of 0:25.

The antifouling agent of the present invention includes, as long as the object of the present invention is not impaired, antioxidants and polymerizations conventionally used as antifouling agents for petroleum refining processes and petrochemical processes, as desired. Inhibitors, metal deactivators and the like can be added. There is no particular limitation on the process fluid to which the antifouling agent of the present invention is applied, and the antifouling agent of the present invention is applied to all oils to be treated that generate fouling when processed in a petroleum refining process or a petrochemical process. It can be applied, but especially in the petroleum refining process, topper, vacuum, hydrodesulfurization equipment, etc., in the petrochemical process, it is treated with raw material preheat heat exchanger in naphtha cracking or ethylene plant, reboiler of distillation column, etc. The application to the process fluids mentioned is preferred. Next, one example of a preferred method of using the stainproofing agent of the present invention will be described. First, a polyoxythiophosphonate, a dispersant, and other stainproofing agents or auxiliary agents that are optionally used in combination are appropriately used. After dissolving it in various organic solvents, continuously inject this solution into equipment that is contaminated in the petroleum refining process or petrochemical process, such as heat exchangers, reboilers, pipes, etc. inject. At this time, the concentration of the antifouling agent of the present invention to be used is usually selected in the range of 0.1 to 50,000 mg / kg treated oil. The antifouling agent of the present invention is particularly excellent in the antifouling effect at high temperatures and brings about an improvement of the antifouling rate of about 50% as compared with the conventional product. For example, in FCC (fluid catalytic cracking device), Contamination of the preheat heat exchanger made continuous operation impossible for one year, but it becomes possible by using the antifouling agent of the present invention. Further, in the vacuum bottom line heat exchanger, the U value (overall heat transfer coefficient), which is an index of dirt conventionally, was remarkably decreased due to adhesion of dirt, but by using the dirt preventive agent of the present invention, The decrease in U value can be suppressed, and the amount of heavy oil used in the heating furnace can be decreased.

[0016]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention thereto. The evaluation of the stain prevention effect was performed using the heating block test device shown in FIG. That is, the test tubes 3 and 4 were respectively set in the first heater block 1 and the second heater block 2 which can control the outlet fluid temperature (with TIC), and were sealed with nitrogen gas or nitrogen gas containing oxygen of a predetermined concentration. From the sample tank 5 with a capacity of 4 liters through the pump 6 to 1.2 liters / hr of sample
The sample flowing out of the tube 4 is returned to the sample tank 5 through the cooler 7 and the pressure-holding valve 8 at a speed of 1. The temperature of the tube 3 outlet fluid is 200 ° C,
Tube 4 outlet fluid temperature 300 ℃, system pressure 10
Hold at kg / cm ² -G, run continuously for 20 hours,
The thermocouples 9 and 10 set on the surfaces of the tubes 3 and 4 on the side of the second heater block 1 and 2 respectively continuously measure the surface temperature (the surface temperature rises when dirt adheres) and the tube after the test. The stain prevention effect was evaluated by measuring the weight of the stain adhered to the inner wall. Example 1 A heavy gas oil containing 15 mg / liter of dissolved oxygen was used as a raw material oil, and a stain inhibitor of the type and amount shown in Table 1 was added to the sample to prepare a sample. C. (first heater block) and 300.degree. C. (second heater block), the amount of dirt attached to the tubes of the first heater block and the tubes of the second heater block in a 20-hour test is calculated, and the dirt prevention rate is calculated. The stain prevention effect was evaluated. The results are shown in Table 1. The following stain inhibitors were used. Styrene-maleic acid ester copolymer: average molecular weight 3
0000-Polyoxythiophosphonate: R ¹ = butenyl group, R ² = R ³ = butenylene group, average molecular weight 1350

[0017]

[Table 1]

As can be seen from the table, the polyoxythiophosphonic acid ester has an excellent antifouling effect in the first heater block (200 ° C.), while the styrene maleic acid ester copolymer has the excellent effect in the second heater block (300 ° C.). Is excellent in the antifouling effect, and therefore, by mixing the both, the antifouling effect at 200 ° C. and 300 ° C. becomes remarkable.

[0019]

INDUSTRIAL APPLICABILITY The inhibitor for petroleum refining or petrochemical process of the present invention contains a polyoxythiophosphonic acid ester and a known dispersant, and is particularly excellent in antifouling effect at high temperature, It is possible to effectively prevent contamination of process fluids in plants and petrochemical plants.

[Brief description of drawings]

FIG. 1 is a schematic view of a heating block test apparatus used to evaluate a stain prevention effect.

[Explanation of symbols]

 1 1st heater block 2 2nd heater block 3 Test tube 4 Test tube 5 Sample tank 6 Pump 7 Cooler 8 Pressure-holding valve 9 Thermocouple 10 Thermocouple

Claims (1)

[Claims] 1. A general formula (A): (In the formula, R ¹ is an alkyl group or alkenyl group having 3 to 30 carbon atoms, R ² and R ³ are alkylene groups or alkenylene groups having 2 to 5 carbon atoms, and they may be the same or different. N and m are each 1 to
A fouling preventive agent for petroleum refining or petrochemical processes, which comprises a polyoxythiophosphonic acid ester represented by the formula (5 is an integer of 5) and (B) a dispersant.