CN111826217B

CN111826217B - Low-carbon light-color sulfur-free chlorine-free ash-free polymerization inhibitor and application thereof

Info

Publication number: CN111826217B
Application number: CN202010797176.XA
Authority: CN
Inventors: 梁朝林; 程丽华; 黄克明; 范钦臻; 洪晓英; 陈宏�; 杨冲
Original assignee: Guangdong University of Petrochemical Technology
Current assignee: Guangdong University of Petrochemical Technology
Priority date: 2020-08-10
Filing date: 2020-08-10
Publication date: 2022-06-07
Anticipated expiration: 2040-08-10
Also published as: CN111826217A

Abstract

The invention relates to a medium material required in the petrochemical production process, in particular to a low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor and application thereof. According to the fact that the mixed oil (hereinafter referred to as light mixed oil) of gasoline and diesel oil is distilled and separated, a low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor is compounded, the use safety performance of the low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor is evaluated, technical guarantee is provided for long-period safe operation of a distillation device, and the method is applicable to distillation and separation of the light mixed oil under the conditions of normal pressure and the temperature of less than or equal to 250 ℃; the method can prevent olefin in oil products, olefin, oxygen and various oil product additives in the oil products in the distillation process, and condensation coking of iron ions, manganese ions and the like generated by equipment corrosion and/or separated by the additives in the distillation separation process by adding diphenylamine derivatives, p-phenylenediamine derivatives, alkyl succinimide and carbon nonaromatic hydrocarbon, and reduce scaling coke-forming substances.

Description

Low-carbon light-color sulfur-free chlorine-free ash-free polymerization inhibitor and application thereof

Technical Field

The invention relates to a medium material required in the petrochemical production process, in particular to a low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor and application thereof.

Background

Pipeline transportation technology has been widely adopted for remote transportation of finished products of gasoline and diesel oil for vehicles at home and abroad, but few reports on mixed oil treatment technology appear in the pipeline transportation technology, and five methods are summarized: direct back-doping method; distillation separation method; metal oxide treatment; an alkali treatment method; and (4) filtering. Of these, distillation separation methods are most effectively used. However, the distillation separation method also has the problems that the olefin in the oil product is easy to condense and scale with the olefin, various additives, iron ions, manganese ions and the like in the oil product during heating, and coke is formed during distillation, so that the oil product has large chroma, high colloid content, short start cycle and the like.

In order to reduce the condensation, scaling and coking of oil products during transportation, storage and use, a detergent dispersant, a polymerization inhibitor, an anti-thermal oxidation stabilizer and the like can be added. However, most of the additives are only suitable for the normal temperature process, can be safely used in the high-temperature heating process, and are very rare, and related reports are few.

According to the fact that the mixed oil (hereinafter referred to as light mixed oil) generated by conveying gasoline and diesel oil through pipelines needs to be separated by distillation to obtain gasoline and diesel oil again, a low-carbon light-color sulfur-free ashless polymerization inhibitor suitable for the distillation and separation process of the light mixed oil is compounded, and the polymerization inhibitor can prevent the olefin in the oil product, the olefin, oxygen and various oil product additives in the oil product, and the condensation coking of iron ions, manganese ions and the like generated by equipment corrosion and/or separated by the additives in the distillation and separation process, reduce scaling coke-forming substances, and prevent the quality influence problems of large chromaticity, high colloid content and the like of the oil product from being generated in the distillation process, thereby ensuring that a distillation device runs safely for a long period and the distilled oil product meets the national quality index requirements.

Disclosure of Invention

In order to solve the above problems, the first aspect of the present invention provides a low-carbon light-colored sulfur-free chlorine-free ashless polymerization inhibitor, which comprises carbon, hydrogen, oxygen and nitrogen.

As a preferable technical scheme of the invention, the preparation raw materials of the polymerization inhibitor comprise diphenylamine derivatives, p-phenylenediamine derivatives, succinimide and carbon nonaarene.

According to a preferable technical scheme, the polymerization inhibitor comprises, by weight, 5-25 parts of diphenylamine derivatives, 25-40 parts of p-phenylenediamine derivatives, 7-20 parts of succinimide and 20-35 parts of nona-carbon aromatic hydrocarbons.

As a preferable technical scheme of the invention, the substituent of the diphenylamine derivative is selected from one or more of hydroxyl, alkyl, alkoxy and amino.

In a preferred embodiment of the present invention, the total number of carbon elements in the diphenylamine derivative is not more than 14.

As a preferable technical scheme of the invention, the structural formula of the p-phenylenediamine derivative is shown as a formula (1):

R₁one or two selected from normal and/or isomeric alkane radicals; r₂One or two of normal and/or isomeric alkane radicals.

In a preferred embodiment of the present invention, the total number of carbon elements in the p-phenylenediamine derivative is 14 or less.

In a preferred embodiment of the present invention, the succinimide is an N-hydrocarbyl succinimide.

In a preferred embodiment of the present invention, the hydrocarbyl group in the N-hydrocarbyl succinimide is selected from one or more of methyl, ethyl, propyl, isobutyl, and N-butyl.

The second aspect of the invention provides application of the low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor in a high-temperature distillation separation process of light mixed oil.

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

(1) according to the fact that the mixed oil (hereinafter referred to as light mixed oil) of gasoline and diesel oil is actually distilled and separated, the invention compounds a low-carbon light-color sulfur-free ashless polymerization inhibitor, evaluates the use safety performance of the low-carbon light-color sulfur-free ashless polymerization inhibitor, provides technical guarantee for realizing long-period safe operation of a distillation device, and is suitable for distillation and separation of the light mixed oil under the conditions of normal pressure and the temperature of less than or equal to 250 ℃.

(2) By adding diphenylamine derivatives, p-phenylenediamine derivatives, succinimide and carbon nonaromatic hydrocarbon, olefin in oil products, olefin, oxygen and various oil product additives in the oil products in the distillation process, and iron ions, manganese ions and the like generated by equipment corrosion and/or separated by the additives in the distillation separation process can be prevented from being condensed and coked, and scaling and coke-forming substances are reduced.

(3) In addition, the diphenylamine derivative provided by the invention can prevent the quality influence problems such as large oil chromaticity, high colloid content and the like, so that the safe long-period operation of a distillation device is ensured, and the distilled oil meets the national quality index requirements.

(4) When the polymerization inhibitor provided by the invention is used for distillation separation, the unwashed colloid of the gasoline can be ensured to be no more than 30mg/100ml, the washed colloid is no more than 5mg/100ml, and the chroma is less than 1; the oxidation stability (based on total insoluble substance) of the diesel oil is no more than 2.5mg/100ml, the chroma is less than 3, and the indexes of the boiling range, the sulfur content and the like of gasoline and diesel oil products are not influenced.

(5) In addition, all the materials in the polymerization inhibitor provided by the invention have low toxicity, and the personal health and the safety in the production and use processes can be ensured by slightly protecting in the use process.

(6) The raw materials used in the invention are colorless or light yellow, and the mixture is a light yellow liquid mixture after being compounded, and the color of the mixture is lighter than that of gasoline and diesel oil, and the chromaticity of the gasoline and the diesel oil is not influenced.

Drawings

FIG. 1 is a device for carrying out distillation separation on light mixed oil in a laboratory.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted to include the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise specified, the range is intended to include the endpoints thereof, and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein throughout the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes portions that are literally received for modification without substantial change in the basic function to which the invention is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the present description and claims, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are intended to have no limitation on the number (i.e., number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the stated number clearly indicates that the singular form is intended.

The present invention is illustrated by the following specific embodiments, but is not limited to the specific examples given below.

The applicant controls the polymerization inhibitor to burn out ashless in the use process of gasoline or diesel oil by controlling the components of the polymerization inhibitor mainly to consist of carbon, oxygen, hydrogen and nitrogen, thereby avoiding environmental pollution. The invention provides a low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor, which comprises the components of carbon element, hydrogen element, oxygen element and nitrogen element; further, the polymerization inhibitor does not contain sulfur and chlorine. By controlling the polymerization inhibitor not to be added with preparation raw materials containing elements such as sulfur, chlorine and the like, the method can avoid the increase of sulfur and chlorine contents in gasoline and diesel oil obtained by distillation and simultaneously avoid the damage to devices such as gasoline engine parts in the using process.

In one embodiment, the polymerization inhibitor is prepared from diphenylamine derivatives, p-phenylenediamine derivatives, succinimide and nona-carbon aromatic hydrocarbons.

In one embodiment, the polymerization inhibitor is prepared from, by weight, 5-25 parts of diphenylamine derivative, 25-40 parts of p-phenylenediamine derivative, 7-20 parts of succinimide and 20-35 parts of aromatic hydrocarbon.

Diphenylamine derivatives

In one embodiment, the substituents of the diphenylamine derivative of the invention are selected from one or more of hydroxyl, alkyl, alkoxy and amino.

Examples of diphenylamine derivatives whose substituent(s) is (are) a hydroxyl group include, but are not limited to, 4,4' -dihydroxydiphenylamine and 4-hydroxydiphenylamine.

Examples of diphenylamine derivatives having hydroxyl and alkyl as the substituent include, but are not limited to, 4-methyl-3 ' -hydroxydiphenylamine, 2, 6-dimethyl-3 ' -hydroxydiphenylamine, 2-methyl-3 ' -hydroxydiphenylamine.

Examples of diphenylamine derivatives in which the substituent is an alkyl group include, but are not limited to, 4,4' -dimethyldiphenylamine, 4-methyldiphenylamine.

Examples of diphenylamine derivatives whose substituent(s) are alkoxy groups include, but are not limited to, 4-methoxydiphenylamine, 4-ethoxydiphenylamine, 4' -dimethoxydiphenylamine.

Examples of diphenylamine derivatives in which the substituent is amino include, but are not limited to, 4,4' -diaminodiphenylamine.

The applicant finds that when the polymerization inhibitor obtained by using the diphenylamine derivative containing the amine functional group is used in a high-temperature distillation process, free radicals can be captured, the progress of chain reaction and gelling process can be interrupted, the color deepening can be prevented, the induction period of an oil product can be prolonged, and the like. Preferably, the substituents of the diphenylamine derivatives of the present invention include hydroxyl; further, the total number of carbon elements of the diphenylamine derivative is less than or equal to 14; further, the substituent of the diphenylamine derivative is hydroxyl. The applicant finds that the diphenylamine combined by phenol and amine has better oxidation resistance and higher thermal stability.

P-phenylenediamine derivative

The applicant finds that the addition of the p-phenylenediamine derivative and the diphenylamine derivative can further promote the termination of the free radical chain reaction, thereby reducing the free radical chain reaction of unstable components (such as olefin and the like) in gasoline under the initiation and catalysis of oxygen and metal, particularly reducing the generation of the chain reaction when an oxidation promoter is added into diesel oil (for improving the cetane number), obviously reducing the generation of colloid, and the addition of the p-phenylenediamine derivative and the diphenylamine derivative in the polymerization inhibitor also has the catalysis of passivated metal on the oxidation of the gasoline and the diesel oil. In one embodiment, the p-phenylenediamine derivative of the present invention has a structural formula as shown in formula (1):

Examples of alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl.

The applicant found that by using an aromatic secondary amine such as a phenylenediamine derivative, it is more effective than aniline, probably because the phenylenediamine derivative is oxidized to form a quinoid structure, and the conjugated chain of the quinoid structure has a strong radical trapping ability and can trap a larger number of molecules of radicals. Preferably, R₁Is alkyl, R₂Is an alkyl group; further, the total number of carbon elements of the p-phenylenediamine derivative is 14 or less; further, the total number of carbon elements of the p-phenylenediamine derivative is less than or equal to 12; further, R₁、R₂Are all n-butyl and/or isobutyl. In addition, by controlling R₁And R₂The total carbon number is controlled, so that the side chain of the aromatic ring structure is controlled to be short and not easy to break, thermal cracking is avoided at the boiling point range of 159-288 ℃, no colloid is formed, the carbon number of each raw material of the carbon residue polymerization inhibitor of the distillation residue is not increased, and the boiling point is just in the distillation range of gasoline and diesel oil by controlling the total carbon number, so that the p-phenylenediamine derivative and the diphenylamine derivative are all introduced into gasoline and diesel oil products in the distillation process, and no waste is generated.

Succinimides

In one embodiment, the succinimide of the present invention is an N-hydrocarbyl succinimide.

Preferably, the alkyl group in the N-alkyl succinimide is selected from one or more of methyl, ethyl, propyl, isobutyl and N-butyl; further, the hydrocarbon group in the N-hydrocarbon-based succinimide of the present invention is a methyl group.

N-methyl succinimide can be purchased directly. The non-polymeric ashless dispersant has excellent low-temperature dispersibility and good high-temperature stability, and can effectively prevent the deposition of oil sludge, paint films and carbon deposits formed on the filler and/or the tray of the separation element by olefin and the like in oil products. As an example of N-methyl succinimide, there is included, but not limited to, N-methyl succinimide from Conmanlin chemical industry Co., Ltd.

Carbon nonaarene

The applicants have found that by addingCarbon nonaromatic hydrocarbonBecause the structure of the benzene ring in the aromatic hydrocarbon is favorable for promoting the dissolution of other components of the polymerization inhibitor and the even dispersion in gasoline, diesel oil and the like, the carbon nine is a polymerization mixture and is a fraction of the aromatic hydrocarbon containing nine carbon atoms in a byproduct of the light fraction of petroleum after catalytic reforming, the invention does not specifically limit the carbon nine aromatic hydrocarbon, and can list that the aromatic hydrocarbons such as mesitylene, hemimellitene, 1, 2-dimethyl-3-ethyl benzene, propyl benzene and the like can all enter the gasoline component in the distillation separation process (the content of the gasoline aromatic hydrocarbon produced in China is still large and cannot exceed the standard), thereby improving the octane number of the gasoline. The invention is not rightPurchase factories of carbon nonaaromaticsIn one embodiment, the aromatic hydrocarbons are obtained by separation in a catalytic reforming unit of an oil refineryCarbon nonaromatic hydrocarbonThe component can be listed as carbon nonaarene obtained by a second set of catalytic reforming device in the oil refining subsection of the Nongchen petrochemical company.

Among the various hydrocarbons, normal paraffins have a much lower octane number than isoparaffins, and naphthenes have a lower octane number than aromatics, if the number of carbon atoms is the same. The main components of the straight-run gasoline are normal paraffin, isoparaffin and cycloparaffin, one of the purposes of the catalytic reforming is to convert atoms in the normal paraffin, isoparaffin and cycloparaffin into isoparaffin and aromatic hydrocarbon with similar or equal molecular weight through the structural rearrangement under the action of a catalyst under the conditions of certain temperature, pressure and hydrogen-oil ratio, thereby obtaining the gasoline with high octane number and various aromatic hydrocarbons.

The applicant has found that when a hydroxyl group-containing diphenylamine derivative and a p-phenylenediamine derivative having a certain total number of carbon atoms are used, it is advantageous to improve the thermal stability of both substances and promote the action during the high-temperature distillation, but in the case of the diphenylamine derivative and the p-phenylenediamine derivative containing a benzene ring, there is a significant volatilization phenomenon before the boiling point, so that the ability of both substances to inhibit the radical reaction cannot be sufficiently exerted. The applicant finds that the traditional polyolefin butadiene amide has good clean dispersibility when being applied to high-boiling-point lubricating oil due to large molecular weight and high boiling point, but increases colloid and carbon residue when being applied to light fuel oil; the N-methyl succinimide has small molecular weight and short hydrocarbyl chain, and the methyl of the N-methyl succinimide is not easy to be decomposed or broken by heat except for better oil cleaning and dispersing effects, thereby promoting the stability of each preparation raw material in the polymerization inhibitor and reducing the generation of decomposition and the like; but also has good effects of improving the oxidation stability of oil products, reducing crude rubber and raw coke and improving the chromaticity.

The preparation method of the polymerization inhibitor is not particularly limited, and the polymerization inhibitor can be prepared by adopting a mixing method.

The second aspect of the invention provides an application of the low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor, which is used for the high-temperature distillation separation process of light mixed oil.

The light mixed oil is a mixture of gasoline and diesel oil. The high-temperature distillation is the distillation separation of the light mixed oil under the conditions of normal pressure and the temperature of less than or equal to 250 ℃.

Examples

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

Example 1

The preparation raw materials of the polymerization inhibitor comprise, by weight, 15 parts of diphenylamine derivatives, 30 parts of p-phenylenediamine derivatives, 15 parts of succinimide and 30 parts of nonaromatic hydrocarbon; the diphenylamine derivative is 4-hydroxy diphenylamine, and the succinimide is N-methyl succinimide;

the structural formula of the p-phenylenediamine derivative is shown as a formula (1):

R₁、R₂are all sec-butyl.

The N-methyl succinimide is purchased from Nanjing Kanmarin chemical industry Co.

This example also provides a method for preparing the polymerization inhibitor described above, comprising the steps of: and mixing the preparation raw materials of the polymerization inhibitor to obtain the polymerization inhibitor.

Example 2

The preparation raw materials of the polymerization inhibitor comprise, by weight, 25 parts of diphenylamine derivatives, 40 parts of p-phenylenediamine derivatives, 20 parts of succinimide and 35 parts of nonaromatic carbon; the diphenylamine derivative is 4-hydroxy diphenylamine, and the succinimide is N-ethyl succinimide;

the structural formula of the p-phenylenediamine derivative is shown as the formula (1):

R₁、R₂are all sec-butyl.

The N-ethylsuccinimide is purchased from Nanjing Kanmarin chemical industry Co., Ltd.

Example 3

The polymerization inhibitor comprises, by weight, 5 parts of diphenylamine derivative, 25 parts of p-phenylenediamine derivative, 7 parts of succinimide and 20 parts of polymerization inhibitorCarbon nonaromatic hydrocarbon(ii) a The diphenylamine derivative is 4-hydroxy diphenylamine, and the succinimide is N-methyl succinimide;

R₁、R₂are all sec-butyl.

Example 4

The preparation raw materials of the polymerization inhibitor comprise, by weight, 15 parts of diphenylamine derivatives, 30 parts of p-phenylenediamine derivatives, 15 parts of succinimide and 30 parts of nonaromatic hydrocarbon; the diphenylamine derivative is 4-isopropoxydiphenylamine, and the succinimide is N-methyl succinimide;

R₁、R₂are all sec-butyl.

The N-methyl succinimide is purchased from Nanjing Kanmulin chemical industry Co., Ltd.

Example 5

R₁、R₂are all heptyl.

Example 6

R₁、R₂are all methyl.

Example 7

The embodiment provides a polymerization inhibitor, and the polymerization inhibitor comprises the following raw materials, by weight, 15 parts of diphenylamine derivative, 30 parts of p-phenylenediamine derivative, 15 parts of succinimide and 30 parts of C-nonaarene; the diphenylamine derivative is 4-hydroxy diphenylamine, and the succinimide is N-methyl succinimide;

R₁、R₂are all phenyl groups.

Example 8

The preparation raw materials of the polymerization inhibitor comprise, by weight, 15 parts of diphenylamine derivatives, 30 parts of p-phenylenediamine derivatives, 15 parts of succinimide and 30 parts of nonaromatic hydrocarbon; the diphenylamine derivative is 4-hydroxy diphenylamine, and the succinimide is polyisobutylene succinimide;

R₁、R₂are all sec-butyl.

The polyisobutylene succinimide was purchased from T154 of shenyang polycin chemical industries, ltd.

Evaluation of Performance

The following experiments were performed as experimental groups provided in the examples.

1. Laboratory inhibition test: referring to FIG. 1, firstly, a rapid distillation apparatus similar to the principle of an industrial distillation apparatus was used to perform tests on light mixed oil when the addition amount of polymerization inhibitor was 0ppm, 100ppm and 200ppm respectively relative to gasoline and diesel oil (atmospheric distillation, distillation still temperature 240 ℃ C. and distillation still top temperature 185 ℃ C. and 195 ℃ C., batch operation, heating distillation time 120 ℃ C. and 135 minutes), and the quality of gasoline and diesel oil obtained by distillation was evaluated using the polymerization inhibitor provided in example 1, and the test data are shown in Table 1 and Table 2.

TABLE 1 gasoline oil analysis project

TABLE 2 Diesel oil analysis project

The data in tables 1 and 2 show that the oxidation stability (calculated by total insoluble substances), the carbon residue of 10% of the distillation residue, the unwashed colloid content, the solvent washed colloid content, the color number and the like corresponding to the diesel oil and the gasoline obtained by adding the additive are all better than those of the diesel oil and the gasoline obtained by adding no inhibitor, so that the addition of the inhibitor for preventing green rubber from coking is one of simple, convenient and effective methods.

2. Industrialized polymerization inhibition test: 200ppm of polymerization inhibitor is added from the feed inlet of an industrial distillation tower or the reflux inlet at the top of the industrial distillation tower, and the light mixed oil is subjected to tests of different addition amounts of the polymerization inhibitor (atmospheric distillation, the top pressure of the distillation tower is 0.02MPa, the feed temperature of the distillation tower is 98-125 ℃, the bottom temperature of the distillation tower is 240-245 ℃, the top temperature of the distillation tower is 165-172 ℃, and continuous distillation operation), wherein the polymerization inhibitor provided in example 1 is used, the quality condition of gasoline and diesel oil obtained by distillation is evaluated, and the test data are shown in tables 3 and 4.

TABLE 3 Performance index of diesel oil before and after the injection of polymerization inhibitor

TABLE 4 Performance index of gasoline before and after the injection of polymerization inhibitor

As can be seen from the data in tables 3 and 4, the addition of the polymerization inhibitor provided by the invention can obviously improve the performances of chroma, washed colloid content, oxidation stability, residual steam fog carbon residue and the like after high-temperature rectification.

3. And (3) researching the stability of the polymerization inhibitor: the 200ppm polymerization inhibitor provided in the examples was tested for 10% residue carbon c1 of diesel fuel in a light blend at 200 ℃ according to the laboratory polymerization inhibition test and compared with the residue carbon c0 of example 1, and the residue carbon increase rate of (c1-c0)/c0 × 100% compared with example 1 was calculated and counted, wherein the residue carbon increase rate of grade 1 was 5% or less, the residue carbon increase rate of grade 2 was more than 5% and 10% or less, the residue carbon increase rate of grade 3 was more than 10% and 20% or less, the residue carbon increase rate of grade 4 was more than 20% and 30% or less, and the residue carbon increase rate of grade 5 was more than 30%, and the results are shown in table 5.

Table 5 characterization test of properties

Examples	Rate of increase of residual carbon
		2	Level 1
3	Level 1
		4	4 stage
5	Grade 5
		6	Grade 3
7	Grade 5
		8	Grade 5

4. Physical and chemical properties: some of the physical and chemical properties of the inhibitor provided in example 1 were tested and the results are shown in Table 6.

TABLE 6 physicochemical Properties

The technical scheme of the invention is scientific and reasonable, can be safely applied to an industrial distillation device, effectively reduces olefin, oxygen and various oil additives in oil products, and condensation coking of iron ions, manganese ions and the like generated by equipment corrosion and/or separated by the additives in the distillation separation process, reduces scaling coke-forming substances, and ensures that the oil product quality index meets the national standard. In addition, the low-carbon-number substance is used as a raw material, so that the thermal cracking at the boiling point range of 159-. The invention of the polymerization inhibitor and the dependence on the mature distillation process technology can solve the quality problem and long-period operation problem caused by oil product condensation and coking in the distillation and separation process of light mixed oil, thereby obtaining good economic and social benefits.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Where the claims recite a range of values, such ranges are intended to include all sub-ranges subsumed therein, and variations within the ranges are intended to be encompassed by the claims as appended hereto where possible.

Claims

1. The application of the low-carbon light-color sulfur-free chlorine-free ashless polymerization inhibitor is characterized in that the polymerization inhibitor is used in the high-temperature distillation separation process of light mixed oil, and the components of the polymerization inhibitor comprise a carbon element, a hydrogen element, an oxygen element and a nitrogen element;

the polymerization inhibitor comprises the following raw materials, by weight, 5-25 parts of diphenylamine derivatives, 25-40 parts of p-phenylenediamine derivatives, 7-20 parts of succinimide and 20-35 parts of aromatic hydrocarbon;

the substituents of the diphenylamine derivative are selected from hydroxyl; the total number of carbon elements of the diphenylamine derivative is less than or equal to 14;

the succinimide is an N-hydrocarbyl succinimide.

2. The use of the low-carbon light-colored sulfur-free chlorine-free ashless polymerization inhibitor according to claim 1, wherein the p-phenylenediamine derivative has a structural formula represented by the formula (1):

（1）

R₁one or two of normal or isomeric alkane radicals; r₂Is selected from one or two of normal or isomeric alkane radicals.

3. The use of the low-carbon light-colored sulfur-free chlorine-free ashless polymerization inhibitor according to claim 2, wherein the total carbon element number of the p-phenylenediamine derivative is 14 or less.

4. The use of the low-carbon light-colored sulfur-free chlorine-free ashless polymerization inhibitor according to claim 1, wherein the hydrocarbon group in the N-hydrocarbyl succinimide is selected from one or more of methyl, ethyl, propyl, isobutyl, and N-butyl.