KR100305983B1 - A method of hydrogenating a diolefin while isomerizing an outer olefin to an inner olefin - Google Patents

Abstract

The present invention relates to a method for isomerizing an external olefin contained in a charge containing diolefin into an internal olefin using a catalyst containing 0.05 wt% to 10 wt% sulfur and containing palladium as a main component. The catalyst is treated with at least one organic sulfur containing compound dissolved in a solvent prior to charging the reactor and then activated under a neutral or reducing atmosphere at a temperature of 20 ° C. to 300 ° C. before contacting the charge.

Description

[Name of invention]

Isomerization of the outer olefins to the inner olefins while hydrogenation of the diolefins

Detailed description of the invention

The present invention is directed to C ₄ , C ₅ and C ₆ classifications which contain diolefins mixed with olefins, which are obtained by selective hydrogenation of the diolefins and at the same time obtained by liquid hydrocarbon classifications such as catalytic cracking or steam cracking distillation. And to isomerize the external olefin into the internal olefin. In order to use such olefins, the diolefins must be selectively hydrogenated and removed. Also, if the internal olefins are typically used as the main reactant in downstream processes such as alkylation or etherification units, it is advantageous to isomerize the external olefins to the internal olefins.

This treatment (selective hydrogenation and isomerization) is carried out on a catalyst mainly composed of at least one group VIII metal attached on an amorphous or crystalline support. Typically palladium is used.

U.S. Patent No. 4,724,274 discloses 2-methyl-1 using catalysts based on Group VIII metals containing 2 to 50 ppm of sulfur-containing compounds in charges (H ₂ S, thiols, thiophenes ...). A process for preparing 2-methyl-2-butene (internal olefin) from a C ₅ charge comprising butene (outer olefin) and at least one n-pentene is described. This selectively hydrogenates the straight olefins and at the same time isomerizes 1-butene. The process is carried out at a temperature of 60 to 120 ° C. and a pressure of 5 to 100 bar.

However, palladium catalysts do not sufficiently isomerize external olefins even when used in the process described above. Although the charge to be treated contains a small amount of sulfur, the sulfur containing compound in the reactor must be introduced into the catalyst in situ before contacting the catalyst with the reactive charge to increase the activity of the metal.

However, due to the in situ sulfidation of the catalyst and / or the presence of sulfur in the charge, it is difficult to carry out such sulfidation, which must be evenly distributed throughout the catalyst bed in order to greatly increase the selectivity of the catalyst. Because. In addition, this method requires a long time, which increases the cost; Thus, production may be reduced or the operation may be dangerous depending on the sulfur containing compound used.

More specifically, it is an object of the present invention, in the presence of a palladium-based catalyst, in the presence of hydrogen, a temperature of 20 to 200 ° C., a pressure of 1 to 50 bar, a VVH of 0.5 to 10 o'clock ⁻¹ and H ₂ of 0.5 to 5 A method for isomerizing external olefins contained in a liquid charge comprising diolefins into internal olefins under isomerization conditions of a / diolefin molar ratio, wherein at least one sulfur-containing compound dissolved in a solvent prior to charging the catalyst into the isomerization reactor Treated, and the catalyst obtained above containing 0.05 to 10% by weight of sulfur is charged into the reactor and activated under neutral or reducing atmosphere at a temperature of 20 to 300 ° C., a pressure of 1 to 50 bar and a VVH of 50 to 600 hours ⁻¹ . To provide a method for contacting the activated catalyst and the charge under the isomerization conditions.

Applicants have found that introducing organic sulfur containing compounds prior to charging into the reactor can improve the isomerization activity of the catalyst despite the fact that it will handle intermediates in the air. It also eliminates the need to add sulfur containing compounds to the charge.

The present invention is not limited to such compounds, and the compounds used may be sulfur compounds, in particular organic sulfur compounds, which can be decomposed during catalytic activation treatment in the reactor. The activation is carried out at a temperature of 20 to 300 ° C., preferably 60 to 210 ° C., a pressure of 1 to 50 bar, preferably 3 to 20 bar, and a catalyst of 1 m ³ per hour at 50 to 600 hours ⁻¹ , preferably 100 to 200 hours ⁻¹ . The volume of sugar charges (1 m 3) (VVH) is carried out in a neutral or reducing atmosphere.

Organic sulfur compounds that can be used in the present invention include organic alkyl sulfides, organic aryl sulfides, organic alkylaryl sulfides, organic arylalkyl sulfides, and the like. Examples of this compound include butyl ethyl sulfide, diallyl sulfide, dibutyl sulfide, dipropyl sulfide, thiophene, dimethylthiophene and ethylthiophene.

In general, thiols (thioalcohols, mercaptans, thiophenols) of the general formula R ₁ -SH, wherein R ₁ is an organic radical, and R ₁ -SR ₂ , wherein R ₁ and R ₂ are identical to each other Or different) thioethers, organic disulfides of the general formula R ₁ -SSR ₂ and disulfides of the HO-R ₁ -SSR ₂ -OH type can be used separately or in combination.

In addition, the organic sulfur containing compound may be selected from the group consisting of thiodiazole, organic thio acid, thioamide, thioester and thiophenol. Examples include thiobenzoic acid, thicresol, 3,3-thiodipropionic acid, 2,3,6-trimethylthiophenol, methylthioglycolate, naphthalene 2-thiol, phenyl isothiocyanate, 2-phenyl thiophenol, timo Acetamide, thiobenzamide, 2,6-dimethylthiophenol, 3,5-dimethylthiophenol, 2,2'-dinitrodiphenyldisulfide, 2,5-dithiobiurea, ethyl thioglycolate, 2- Methoxy thiophenol and 3-methoxy thiophenol.

In addition, the process of the invention can be carried out in the presence of other types of sulfur containing additives. Therefore, the mercapto alcohol of the following general formula is mentioned.

Wherein n and m are integers, R ₁ , R ₂ , R ₃ and R ₄ are the same or different from each other and are a hydrogen atom, C ₁ -C ₂₀ , preferably C ₁ -C ₆ alkyl, aryl, aromatic Organic radicals, such as alkyl, preferably n is 1-10 (eg 1-2) and m is 1-10 (eg 1).

In addition, monothioglycols such as monothioethylene glycol, dithioglycols such as dithiopropylene glycol, dithiobenzenes such as dithioresorcin, heterocyclic compounds substituted with mercapto groups such as mercaptopyridine, mercaptopyrimi Dihydroxyalkyl sulfides such as dean, such as thiodiethylene glycol [S (CH ₂ CH ₂ OH) ₂ ], thiodipropylene glycol, and the like, diaryl sulfides such as diphenyl sulfide, dialkyl sulfides such as Dibenzyl sulfide, cyclic thioether and substituted derivatives (ethylene sulfide, thiophene, thiazole, thiopyrone, thioxanthone, thioxanthrol, 1,4-thioxane, etc.), mercaptans S alkyl ethers of the heterocyclic compounds, such as 2-methylthio 4,6-diaminopyrimidine and the like, may be mentioned.

Among these compounds, in particular dimethylsulfoxide, ethylthiol ethanol, thioglycolic acid, dithioglycol and organic disulfides, in particular the general formula HO-R ₁ -SSR ₂ -OH, wherein R ₁ and R ₂ are as described above. ) or _{HO- (CH 2) x -S- (} CH 2) x '-S- (CH 2) x "-OH ( wherein, x, x' and x" is an integer which may be the same or different from each other) of The compound can be mentioned.

In particular, diethanol disulfides of the general formula HO-C ₂ H ₄ -SSC ₂ H ₄ -OH or 2,2-dithio bis-ethanol (DEODS) soluble in water, glycols and polyhydric glycols are exemplified. .

It is also possible to use polysulfides of the general formula RS _n -R ', where n is the number of atoms of 3 to 20, preferably 4 to 8, in particular 5 to 7 (integer), R and R' Which may be the same or different and each represents an organic radical comprising C ₁ -C ₁₅₀ , preferably C ₁₀ -C ₆₀ or C ₅ -C ₄₀ , in particular C ₇ -C ₁₆ per molecule, said radicals being saturated or It is selected from the group consisting of unsaturated, linear or branched, or naphthenic alkyl radicals, aryl radicals, alkylaryl radicals and arylalkyl radicals. Such various radicals include one or more heteroatoms. R 'may also be a hydrogen atom.

Preferred examples of polysulfides include di-t-dodecylpolysulfides (n = 5), wherein R and R 'are t-dodecyl radicals, respectively.

This material contains, in particular, 32% by weight of sulfur and is sold under the trade name TPS 32 by Elf Archiche. Di-t-nonylpolysulfides (n = 5), wherein R and R 'are t-nonyl radicals, respectively.

Depending on the nature of the sulfiding agent, the pretreatment is dissolved in an appropriate solvent. The solvent selected can be used alone or in admixture as follows.

For example, gasoline having a boiling point of 60 to 95 ° C,

Hexane type gasoline whose boiling point is 63-68 degreeC,

An F-type gasoline having a boiling point of about 100 to 160 ° C. and generally comprising 10 to 20% by volume of aromatic hydrocarbons, for example 15% by volume,

A “refined petroleum” type gasoline having a boiling point of 150 to 250 ° C. and generally comprising 14 to 22% by volume of aromatic hydrocarbons, for example 17% by volume, or

Any hydrocarbon classification or other classification corresponding to the gasoline mentioned above.

The formulations can be used in solvents such as alcohols (methanol, ethanol, propanol, etc.), aldehydes, ketones, ethers, esters, polyhydric alcohols, acids, polyhydric acids or glycols. The compound also acts as a reducing agent. As another solvent, water can be used.

After immersion of the catalyst, it is generally advantageous to heat treatment at 100 to 200 ° C.

According to the invention, it is advantageous to incorporate 0.05 to 10% by weight, preferably 0.2 to 1% by weight of sulfur, based on the weight of the catalyst.

Generally, the catalyst contains from 0.02 to 2% by weight, preferably from 0.05 to 1% by weight and advantageously from 0.05 to 0.5% by weight.

Thus, the presulfurization catalyst obtained before introducing the charge is activated in the reactor. The isomerization reaction is carried out at a pressure of 1 to 50 bar, preferably 5 to 30 bar, a temperature of 20 to 200 ° C., preferably 50 to 150 ° C., 0.5 to 10 o'clock ⁻¹ , preferably 1 to 6 o'clock ⁻¹ , It is carried out in a molar ratio of H ₂ / olefin of 0.5 to 5, preferably 1 to 3.

The following examples illustrate the invention without limiting its scope.

Example 1 (Comparative)

100 cm 3 of catalyst LD 265 (hereinafter referred to as catalyst A), commercially available from Societe Procatalize, containing 0.3% by weight of palladium supported on alumina, is placed in a steel tube 3 cm in diameter. This catalyst is commonly used for the selective hydrogenation of steam cracking distillation fractions or FCC fractions, which activate the catalysts according to the following operating methods.

Treatment of a gas mixture of H ₂ / H ₂ S (H ₂ S 1% by volume) at 150 ° C. for 6 hours at a flow rate of 30 L / h is subjected to sulfidation in the reactor.

Reduced under hydrogen at 200 ° C. for 5 hours at a flow rate of 30 L / hr.

The catalyst is then cooled under hydrogen flow and the apparatus is cleaned with nitrogen.

Hydrocarbon loading and isomerization activity of the catalyst were measured using a hydrocarbon charge having the weight composition shown in Table 1 below.

TABLE 1

The charge is passed using hydrogen as an ascending flow type in the catalyst bed under conditions of a pressure of 25 bar, a temperature of 80 ° C., a flow rate of a C ₄ fraction of 1,000 cm 3 / hour and a H ₂ / 1,3-butadiene mol of 2.2. .

The effluent in the reactor was analyzed by vapor phase chromatography using an alumina column 50 m long. The results obtained are shown in Table 2 below.

TABLE 2

Under the above conditions, it can be seen that catalyst A has a conversion ratio of 1,3-butadiene to 100% and an isomerization ratio of 1-butene to 56.6%. The yield of olefins is 99.4%.

Example 2 (Invention)

100 cm 3 of the catalyst LD 265 of Societe procatalide comprising 0.3 wt% of palladium supported on alumina was dried and impregnated with an aqueous solution of 2.2 mol of formic acid per liter and 0.15 mol of diethoxydisulfide per liter. . The impregnated catalyst was dried at 120 ° C. for 6 hours. This catalyst is called catalyst B. It is placed in a steel tube 3 cm in diameter and activated according to the following operation method.

Reduced under hydrogen at 200 ° C. for 5 hours at a flow rate of 30 l / hr.

The catalyst is then cooled under hydrogen flow and the apparatus is cleaned with nitrogen.

The hydrogenation activity and the isomerization activity of the catalyst were measured using the charge having the composition shown in Table 1 of Example 1.

The charge was passed using hydrogen in the ascending flow type on the catalyst bed under the operating conditions described in Example 1.

The reactor effluent was analyzed by vapor phase chromatography using a 50 m long alumina column. The results obtained are shown in Table 3 below.

TABLE 3

Under these conditions, catalyst B outperformed that shown in Example 1 using catalyst A. The conversion of 1,3-butadiene is 100% and the isomerization ratio of butene-1 is 59.6%. The yield of olefins is 99.4%.

Claims (14)

In the presence of a palladium-based catalyst and hydrogen, the diolefin is subjected to isomerization reaction conditions at a temperature of 20 to 200 ° C, a pressure of 1 to 50 bar, a VVH of 0.5 to 10 o'clock ^-1 and a molar ratio of H ₂ / diolefin of 0.5 to 5 A method of isomerizing an external olefin contained in a containing liquid charge into an internal olefin, wherein the catalyst is treated with at least one sulfur-containing compound dissolved in a solvent prior to charging the catalyst in an isomerization reactor, and 0.05 to 10 wt. The treated catalyst containing% sulfur is charged to the reactor and then activated under neutral or reducing atmosphere at a temperature of 20 to 300 ° C., a pressure of 1 to 50 bar and a VVH of 50 to 600 hours ⁻¹ and the isomerization. A process for isomerizing an external olefin to an internal olefin, characterized by contacting said activated catalyst with said charge under conditions. The method of claim 1, wherein the charge is selected from the group consisting of C ₄ steam cracking distillation, C ₅₊ steam cracking distillation, C ₄ catalytic cracking distillation and C ₅₊ catalytic cracking distillation. A method for isomerizing an external olefin to an internal olefin. 3. Process according to claim 1 or 2, characterized in that the catalyst consists of palladium attached on alumina. The method of claim 1 or 2, wherein the sulfur-containing compound is an organic alkyl sulfide, an organic aryl sulfide, an organic alkylaryl sulfide, an organic arylalkyl sulfide, thiol, thiodiazole, organic thio acid, thioamide, A method for isomerizing external olefins to internal olefins, characterized in that it is selected from the group consisting of thioesters, thiophenols, mercaptoalcohols and monothioglycols. The process for isomerizing external olefins to internal olefins according to claim 1 or 2, wherein the solvent is selected from the group consisting of gasoline and hydrocarbon classification. The isomerization of an external olefin to an internal olefin according to claim 1 or 2, wherein the solvent is selected from the group consisting of alcohols, aldehydes, ketones, ethers, esters, polyhydric alcohols, acids, polyhydric acids and glycols. Way. The method for isomerizing an external olefin to an internal olefin according to claim 1 or 2, wherein the solvent is water. The isomerization of external olefins to internal olefins according to claim 1 or 2, characterized in that the activation reaction is carried out at a temperature of 60 to 210 ° C, a pressure of 3 to 20 bar and a VVH of 100 to 200 hours ^-1 . Way. The process of claim 1 or 2, wherein the isomerization reaction is carried out at a temperature of 50 to 150 ° C, a pressure of 5 to 30 bar, a VVH of 1 to 6 o'clock ^-1 and a H ₂ / diolefin molar ratio of 1 to 3. A method for isomerizing an external olefin to an internal olefin. 3. Process according to claim 1 or 2, characterized in that the catalyst is treated with diethoxy disulfide prior to charging the catalyst into the reactor. 3. Process according to claim 1 or 2, characterized in that the catalyst comprises from 0.2 to 1% by weight of sulfur. 3. The process of claim 1, wherein the catalyst comprises from 0.02 to 0.2 weight percent of palladium. 4. 3. Process according to claim 1 or 2, characterized in that the catalyst comprises from 0.05 to 1% by weight of palladium. 3. The process of claim 1, wherein the catalyst comprises from 0.05 to 0.5 weight percent of palladium.