JPH03229793A - Antifouling agent for petroleum refining and petrochemical plants - Google Patents

Abstract

PURPOSE:To provide an antifouling agent for use in petroleum refining and petrochemical plants which may demonstrate an antifouling effect even for a process fluid having large amounts of dissolved oxygen by compounding a specific diphenylguanidine derivative as the active principle therein. CONSTITUTION:An antifouling agent contains a diphenylguanidine derivative shown by the formula where R<1> and R<2> are H or lower alkyls the same or different from each other (e.g. 1,3-diphenylguanidine) as the active principle. It is added to oil to be treated (particularly naphtha, heavy gas oil, etc., containing at least several mg/l of dissolved oxygen) in petroleum refining and petrochemical plants, for example, a heat exchanger and a heating furnace in hydrorefining, FCC or alkylation equipment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is a novel antifouling agent for oil refining and petrochemical plants, and more particularly, it is a new antifouling agent for use in oil refining and petrochemical plants. The present invention relates to a drug that can effectively prevent stains generated in heating systems in which dissolved oxygen is present.

[Conventional technology] Conventionally, various processes such as atmospheric distillation, vacuum distillation, hydrodesulfurization, catalytic cracking, catalytic reforming, and isomerization have been adopted in the petroleum refining and petrochemical industries. Raw material oils are repeatedly subjected to processes such as heating, cooling, decomposition, and separation to produce various petroleum products. In addition, coal-based raw material oils such as carbonized coal oil are also mixed with single or petroleum-based raw material oils and subjected to similar treatment.

By the way, in these processes, when the process fluid is heated, for example, in a preheating heat exchanger, a heating furnace, etc., it undergoes thermal denaturation and sludge is generated, and this sludge forms on the heat transfer surface of the heat exchanger or heating furnace. Alternatively, it is inevitable that dirt will adhere to piping and the like, and such dirt is particularly severe when dissolved oxygen is present in the process fluid.

Therefore, in order to prevent such stains, conventionally,
In oil refining and petrochemical plants, antioxidants,
Antifouling agents such as metal deactivators, dispersants, or a combination of these are used. Examples of this antifouling agent include (1) polyalkenyl succinimide;
(2) Antifouling agent containing an alkyl- or alkenyl-substituted organic carboxylic acid, a polyalkylene polyamine copolymer, and a phosphite (Japanese Patent Publication No. 46-6503), (
3) Antifouling agent consisting of 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 No. 60-54327 N) 1(4) Styrene-maleic ester copolymer, succinic ester and N,
Antifouling agent comprising a composition containing N'-disalicylidene-1,2-propanediamine (Japanese Patent Application Laid-Open No. 62-207
No. 265) and the like are known.

However, these conventional antifouling agents do not exhibit sufficient antifouling effects in systems with dissolved oxygen; in other words, their antioxidative effects are weak, and some of them exhibit a certain degree of antioxidative effect under low temperature conditions; Under high-temperature conditions of .degree. C. or higher, it is inevitably deactivated due to decomposition, etc., and has drawbacks such as not being able to exhibit sufficient effects.

As described above, conventional antifouling agents are not always fully satisfactory, and there is a need to develop agents that can sufficiently prevent fouling even in process fluids with a large amount of dissolved oxygen or in process fluids under high temperature conditions. It was strongly desired.

[Problems to be Solved by the Invention] The present invention overcomes the drawbacks of conventional antifouling agents, and provides sufficient antifouling effects even for process fluids with a large amount of dissolved oxygen and process fluids under high temperature conditions. The purpose of this invention is to provide an antifouling agent for petroleum refining and petrochemical plants that can be used in a variety of applications.

[Means for Solving the Problems] As a result of intensive research to develop an antifouling agent for petroleum refining and petrochemical plants having the above-mentioned preferable properties, the present inventor has developed an antifouling agent containing specific diphenylguanidines. discovered a scale suitable for that purpose, and based on this knowledge, completed the present invention.

That is, the present invention provides a compound represented by the general formula (in which R1 and R2 are each a hydrogen atom or a lower alkyl group, and they may be the same or different) The purpose of this invention is to provide an antifouling agent for petroleum refining and petrochemical plants, which contains at least one selected from among the following as an active ingredient.

The present invention will be explained in detail below.

The antifouling agent of the present invention uses diphenylguanidines represented by the above-mentioned formula (I).

R1 and R2 in the formula (I) each represent a hydrogen atom or a lower alkyl group, and they may be the same or different. Examples of the lower alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, 5ec-butyl group, tert-butyl group, and isobutyl group.

In addition, regarding the bonding positions of R1 and R2, with respect to the nitrogen atom bonded to the benzene ring,
It may be either m-position or p-position. Further, the bonding positions of R1 and R2 may be the same or different.

Specific examples of diphenylguanidines in the above-format (I) include 1,3-diphenylguanidine, 1, 3
-ditolylguanidine, 1,3-di(ethylphenyl)
Guanidine, 1,3-di(n-propylphenyl)guanidine, 1,3-di(isopro-ruphenyl)guanidine, 1,3-di(n-butylphenyl)guanidine, 1
．． 3-di(butylphenyl)guanidine, 1,3-
Di(sec-butylphenyl)guanidine, 1.3-'
(tert-7'tylphenyl)guanidine, 1-phenyl-3-tolylguanidine, 1-phenyl-3-(ethylphenyl)guanidine, l-phenyl-3-(n-j ropylphenyl)guanidine, 1- Phenyl-3-(isopropylphenyl)guanidine, l-
7enyl-3-(n-butylphenyl)guanidine, 1
-7enyl-3-(inbutylphenyl)guanidine,
l-phenyl-3-(se<n7'tylphenyl)guanidine, 1-phenyl-3-(tert-butylphenyl)guanidine, l-tolyl-3-(ethylphenyl)guanidine, 1-tolyl-3 -(n-propylphenyl)guanidine, 1-tolyl-3-(isopropylphenyl)guanidine, l-)liru-3-(n-butylphenyl)guanidine, l-tolyl-3-(imbutylphenyl)guanidine, l-tolyl -3-(sec-butylphenyl)guanidine, l-tolyl-3-(ter
t-Butylphenyl)guanidine, 1-(ethylphenyl)-3-(n-propylphenyl)guanidine, 1-
(ethyl7enyl)-3-(impropylphenyl)guanidine, l-(ethylphenyl)-3-(n-butylphenyl)guanidine, l-(ethylphenyl)-3-
(imbutylphenyl)guanidine, l-(ethylphenyl)-3-(sec-butylphenyl)guanidine,
1-(ethylphenyl)-3-(tert-7'tylphenyl)guanidine, 1-(n-j ropylphenyl)-
3-(isopropylphenyl)guanidine, 1-(n-
propylphenyl)-3-(n-butylphenyl)guanidine, 1-(n-propylphenyl)-3-(isobutylphenyl)guanidine, 1-(n-7'-butylphenyl)-3-(sec-butylphenyl) ) Guanidine, 1-(n-propylphenyl)-3-(ter
t-7'tylphenyl)guanidine, 1-(isopropylphenyl)-3-(n-butylphenyl)guanidine, l-(isopropylphenyl)-3-(imbutylphenyl)guanidine, 1-(isopropylphenyl)-
3-(sec-butylphenyl)guanidine, 1-(isopropylphenyl)-3-(tertbutylphenyl)guanidine, 1-(n-7'tylphenyl)-3-(
Inbutylphenyl)guanidine, 1-(n-butylphenyl)-3-(sec-butylphenyl)guanidine, 1-(n-butylphenyl)-3-(tert-butylphenyl)guanidine, 1-(inbutylphenyl) )
-3-(see-butylphenyl)guanidine, 1-(
inbutylphenyl)-3(tert-butylphenyl)guanidine, 1(sec-butylphenyl)-3-(
tert-butylphenyl) guanidine and the like.

The antifouling agent of the present invention may use one type of diphenylguanidine, or may use two or more types in combination, and may include other components as desired, as long as the object of the present invention is not impaired. For example, it may be used in combination with known antifouling agents and adjuvants.

There are no particular restrictions on the process fluid that can be treated with the antifouling agent of the present invention, and the antifouling agent of the present invention can be applied to all treated oils that generate fouling when processed in oil refineries and petrochemical plants. Although it can be applied, it is particularly preferable to apply it to oil to be treated in a preheating heat exchanger or heating furnace in a hydrorefining unit, FCC unit, or alkylation unit.

Examples of such oils to be treated include crude oil, naphtha fractions, gasoline fractions, kerosene, gas oil, and heavy gas oil fractions, but in particular, oils containing several mg/1 or more of dissolved oxygen are used. It is effective for distillate oils ranging from heavy gas oil to heavy gas oil. Examples of distillate oils containing several mg/1 or more of dissolved oxygen include distillate oils such as imported naphtha and imported diesel oil that are imported and refined domestically, or distillate oils that are crudely refined at one refinery and then refined at another refinery. Distillate oil is transported to an oil refinery by ship or other means in contact with air and refined there, or even within the same refinery after being crudely refined and stored in contact with air. Examples include distillate oil that is re-refined.

Next, to explain one example of a preferred method of using the antifouling agent of the present invention, first, the compound represented by the above-mentioned formula (I) and other antifouling agents and adjuvants used in combination as necessary. After dissolving it in a suitable organic solvent, this solution is continuously injected into equipment where fouling occurs in oil refining or petrochemical plants, such as heat exchangers, heating furnaces, piping, etc., or into raw oil tanks. Inject all at once.

At this time, the concentration of the antifouling agent of the present invention is usually 1 to 5.
Selected within the range of 0.000my/Q treated oil.

The antifouling agent of the present invention has an excellent antioxidation effect, and can exhibit a sufficient antifouling effect even in systems with high dissolved oxygen or high temperature systems. In general, in hydrodesulfurization equipment for naphtha or kerosene that contains dissolved oxygen of several rag/1 or more, if no antifouling agent is added, the equipment can often only be operated for several months due to fouling. The use of conventional antifouling agents had little effect on such systems, but the use of the antifouling agent of the present invention allows for more than twice the operating period compared to conventional ones, resulting in energy savings and savings. In addition to reducing maintenance costs, it can be expected to ensure long-term stable operation of the plant and avoid dangers associated with emergency shutdowns.

[Examples] Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.

In addition, as an evaluation of the stain prevention effect, the oxidation prevention effect of the sample oil was determined by the induction period method.

The induction period method is based on JISK-2287 and is performed at a temperature of 2.
00' C1 Oxygen pressure 3 kg/cm2・G (dissolved oxygen amount 150 ppm) using a constant temperature oil bath.
I.

Example 1 Using 1,3-diphenylguanidine as the antifouling agent and heavy gas oil as the sample oil, the induction period (minutes) at each addition amount of 1,3-diphenylguanidine was determined by the induction period method. The antioxidant effect was evaluated. The results are shown in Table 1.

The longer the induction period, the better the antioxidant effect.

Example 2 The same procedure as in Example 1 was carried out except that 1,3-di-o-tolylguanidine was used instead of 1,3-diphenylguanidine. The results are shown in Table 1.

Comparative Examples 1 to 4 Without using antifouling agent (Comparative Example 1), 51! Instead of 1,3-diphenylguanidine in Example 1, alkenylsuccinimide (Comparative Example 2), styrene-
Maleic acid ester copolymer, succinic acid ester and N,
It was carried out in the same manner as in Example 1 using a mixture of N'-disalicylidene and 1,2-propanediamine (Comparative Example 3) and guanidine carbonate (Comparative Example 4). The result is the first
Shown in the table.

(Hereinafter, blank spaces) Table 1 shows that the antifouling agent of the present invention exhibits an excellent antioxidant effect even when added in a small amount.

[Effect of the invention] The antifouling agent for petroleum refining and petrochemical plants of the present invention contains specific diphenylguanidines as an active ingredient, and is effective against fouling of process fluids in petroleum refining and petrochemical plants, especially dissolved oxygen. It can effectively prevent contamination of process fluids with a high content of Brings reduced maintenance costs.

Claims (1)

[Claims] 1 General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^1 and R^2 are each a hydrogen atom or a lower alkyl group, and they may be the same death,
An antifouling agent for petroleum refining and petrochemical plants, which contains as an active ingredient at least one compound selected from the compounds represented by (which may be different).