JP6254882B2 - Method for producing xylene - Google Patents

Description

  The present invention relates to a method for producing xylene.

  Xylene is an important compound as a starting material for producing various important industrial chemicals such as phthalic acid (terephthalic acid, isophthalic acid, orthophthalic acid) which is a raw material for polyester.

As a method for producing xylene, there is usually a method of extracting and fractionating naphtha after reforming with a catalytic reformer, or a method of extracting and fractionating cracked gasoline by-produced by thermal decomposition of naphtha. Are known.
In addition, conventionally, a method for producing other aromatic hydrocarbons having different carbon numbers using an aromatic hydrocarbon as a raw material has been attempted (see, for example, Patent Document 1 (Japanese Patent Laid-Open No. 60-246330)), As a method for producing xylene, a production method using a transalkylation reaction or a disproportionation reaction of aromatic hydrocarbons in which aromatic hydrocarbons are reacted with each other to convert them into aromatic hydrocarbons having different carbon numbers can be considered.

JP-A-60-246330

The transalkylation reaction is a method in which a plurality of aromatic hydrocarbons having different carbon numbers are reacted to convert them into the target aromatic hydrocarbon, and the disproportionation reaction of aromatic hydrocarbons is the same for two molecules. This is a method in which an aromatic hydrocarbon reacts and is converted into a target aromatic hydrocarbon.
For example, as a method for producing xylene using a disproportionation reaction of an aromatic hydrocarbon, a method of producing benzene and xylene by a disproportionation reaction of toluene can be cited, and further, an aromatic having 9 or more carbon atoms as a raw material A method of increasing the yield of xylene by adding a group hydrocarbon to cause a transalkylation reaction is also conceivable.

  On the other hand, when xylene is industrially produced using a transalkylation reaction or disproportionation reaction, various petroleum fractions, which are a mixture of a large number of hydrocarbon compounds, will be used as the feedstock. Since the yield of xylene varies depending on the raw material oil to be produced, a method for producing xylene at a high yield while selecting an appropriate raw material oil is required.

  Under such circumstances, in the case of producing xylene by subjecting a feedstock comprising a petroleum fraction to a disproportionation reaction or a transalkylation reaction, xylene is produced in a high yield while selecting an appropriate feedstock. The object is to provide a method of manufacturing.

  In order to solve the above technical problems, the present inventors have conducted intensive studies, and as a result, a method for producing xylene by subjecting a feedstock based on petroleum fractions to a transalkylation reaction or a disproportionation reaction, , Xylene containing an alkylbenzene having 7 to 10 carbon atoms and having an average number of methyl groups directly bonded to each benzene ring of the alkylbenzene is 1.2 to 2.8. By manufacturing, it discovered that the said technical problem could be solved and came to complete this invention based on this knowledge.

That is, the present invention
(1) A method for producing xylene by performing a transalkylation reaction or a disproportionation reaction on a raw material oil based on a petroleum fraction using a Mo catalyst ,
As the feedstock comprises alkylbenzenes having 7 to 10 carbon atoms, the average value of the methyl groups directly bonded to each benzene ring of the alkylbenzenes is Ri der 1.2 to 2.8, aromatic 10 carbon atoms A method for producing xylene characterized by using a hydrocarbon containing 1.5 to 5.0% by mass of hydrocarbon ,
(2) The above-mentioned feed oil containing an alkylbenzene having 7 to 10 carbon atoms and having an average value of the number of methyl groups directly bonded to each benzene ring of the alkylbenzene is 1.5 to 2.5 The method for producing xylene according to (1),
(3) The method for producing xylene according to the above (1) or (2), wherein the raw material oil contains 43 to 96% by mass of an alkylbenzene having 9 carbon atoms,
Is to provide.

  According to the present invention, when xylene is produced by subjecting a feedstock based on petroleum fractions to a disproportionation reaction or a transalkylation reaction, xylene is produced in a high yield while selecting an appropriate feedstock. A method of manufacturing can be provided.

  A method for producing xylene according to the present invention is a method for producing xylene by subjecting a feedstock based on a petroleum fraction to a transalkylation reaction or a disproportionation reaction, wherein the feedstock has 7 carbon atoms. 10 to 10 alkylbenzenes, and the average number of methyl groups directly bonded to each benzene ring of the alkylbenzenes is 1.2 to 2.8.

In the method for producing xylene according to the present invention, a raw material oil based on a petroleum fraction is used as the raw material oil.
In the method for producing xylene according to the present invention, the raw material oil preferably has a boiling range of 90 to 240 ° C, more preferably 100 to 210 ° C, and still more preferably 110 to 180 ° C.
The petroleum fraction used as the base material for the above-mentioned feedstock includes catalytic reforming gasoline distilled from a catalytic reformer and fluid catalytic cracking gasoline (FCC) distilled from a fluid catalytic cracking (FCC) device. One or more types selected from gasoline).

Moreover, as a petroleum fraction used as the base material of the said raw material oil, what removed the specific component from catalytic reforming gasoline or fluid catalytic cracking gasoline may be sufficient.
For example, as the raw material oil, in order to improve the reaction efficiency of the transalkylation reaction or disproportionation reaction described later, a fraction obtained by removing toluene and xylene from the catalytic reformed gasoline (hereinafter referred to as “base material” as appropriate). A ”).
The base material A is rich in the content of C9-10 alkylbenzenes, and further mixed with a fraction containing toluene (hereinafter referred to as base material B as appropriate) By performing the disproportionation reaction, xylene can be produced in a high yield.

  The catalytic reformed gasoline distilled from the catalytic reformer is a reformed product obtained by contacting heavy straight-run naphtha, etc., with a catalyst under high temperature and pressure in a hydrogen stream using the catalytic reforming method. Examples thereof include those obtained by removing benzene from gasoline by distillation.

  The contact reforming method may be any method selected from a platform forming method, a magna forming method, an aromaizing method, a reforming method, a hood reforming method, an ultra forming method, a power forming method, and the like. As the catalytic reforming apparatus for performing the treatment by the reforming method, any of a fixed bed semi-regenerative apparatus, a cyclic apparatus, a continuous regenerative apparatus, and the like may be used.

Various catalysts can be used as the catalyst used in the catalytic reforming reaction. For example, a platinum / alumina catalyst in which platinum is supported on an alumina carrier is preferable, and rhenium, germanium, tin, iridium is further used as the second component. Examples thereof include one or more selected from the group consisting of rhodium and chlorine.
As said platinum / alumina-type catalyst, what contains 0.2-0.8 mass% of platinum is preferable.

When the catalytic reforming reaction is performed using a fixed bed semi-regenerative apparatus, the operating temperature of the catalytic reforming apparatus is preferably a reaction temperature of 470 to 540 ° C, more preferably 490 to 520 ° C, and a reaction pressure. However, it is preferably 1 to 3.5 MPa, more preferably 1.2 to 2.8 MPa, the hydrogen oil ratio is preferably 76 to 3000 NL / L, more preferably 150 to 250 NL / L, and the liquid space velocity (LHSV) is preferably ¹ to 4 h ⁻¹ , more preferably 2 to 3 h ⁻¹ .
By the reaction temperature at the time of the catalytic reforming treatment being 470 ° C. or higher, the content ratio of the aromatic hydrocarbon in the obtained catalytic reforming treatment oil can be easily improved, and by being 540 ° C. or lower, It can be easily suppressed that the hydrocracking proceeds and the liquid yield decreases, and that the catalytic activity decreases due to the formation of coke.
When the reaction pressure during the catalytic reforming treatment is 1 MPa or more, the production of coke can be easily suppressed, and when the reaction pressure is 3.5 MPa or less, the dehydrocyclization reaction is not suppressed. In addition, it is possible to obtain a catalytic reformed oil having a high aromatic hydrocarbon content.

When the catalytic reforming reaction is carried out using a continuous regeneration type apparatus, the operating temperature of the catalytic reforming apparatus is that the reaction temperature is preferably 510 to 530 ° C, more preferably 515 to 525 ° C, and the reaction pressure is Preferably, it is 0.35-1 MPa, more preferably 0.5-1.0 MPa, the hydrogen oil ratio is 140-530 NL / L, more preferably 250-500 NL / L, and the liquid space velocity (LHSV) is , Preferably ¹ to 4 h ⁻¹ , more preferably 2 to 3 h ⁻¹ .
When the reaction temperature at the time of the catalytic reforming treatment is 510 ° C. or higher, the content ratio of the aromatic hydrocarbon in the obtained catalytic reforming treatment oil can be easily improved, and by being 530 ° C. or lower, It can be easily suppressed that the hydrocracking proceeds and the liquid yield decreases, and that the catalytic activity decreases due to the formation of coke.
When the reaction pressure during the catalytic reforming treatment is 0.35 MPa or more, the production of coke can be easily suppressed, and when the reaction pressure is 1 MPa or less, the dehydrocyclization reaction is not suppressed. In addition, it is possible to obtain a catalytic reformed oil having a high aromatic hydrocarbon content.

  In the method for producing xylene according to the present invention, when a fraction obtained by removing toluene and xylene from catalytic reformed gasoline (base material A) is used as a raw material oil, as a fraction containing the toluene (base material B), The toluene removed from the contact reformed gasoline during the preparation of the substrate A can be mentioned, and a solvent toluene may be used separately.

In the method for producing xylene according to the present invention, when a mixture of the base material A and the base material B is used as the raw material oil, the mixture ratio of the base material A is 45.0 to 89.0 vol%. Some are preferable, more preferably 80.0 to 89.0% by volume, more preferably 11.0 to 55.0% by volume of the base material B, 11.0-20. What is 0 volume% is more preferable.
By controlling the blending ratio of the substrate A and the substrate B within the above range, xylene can be produced with a high yield.

  In the method for producing xylene according to the present invention, fluid catalytic cracking gasoline used as a feedstock is distilled from a fluid catalytic cracking apparatus.

  The fluid catalytic cracking apparatus is for producing fluid catalytic cracking gasoline from heavy hydrocarbons by fluid catalytic cracking process (FCC process), where the fluid catalytic cracking process is a fluidized catalyst and hydrocarbon oil. Is a process for obtaining gasoline, middle distillate, etc.

  Examples of fluid catalytic cracking processes include, for example, ABB Lummus Global Inc. ya, Kellogg Brown & Roots, Inc. And Shell Global Solutions International B. V. Also, Stone & Webster Inc. , A Shaw Group Co. / Institut Francais du Petrole. And UOP LLC. The process proposed by various process manufacturers can be listed.

  In order to obtain the above fluid catalytic cracking gasoline, a relatively heavy hydrocarbon oil (hydrocarbon mixture) boiling above the boiling point of gasoline is converted to a so-called solid acid such as zeolite, silica alumina, and alumina by a fluid catalytic cracking process. What is necessary is just to make it contact with the catalyst shown at high temperature.

  In a fluid catalytic cracking process on a commercial scale, a fluid catalytic cracking catalyst having a solid acidity is usually continuously added to a fluid catalytic cracking apparatus composed of two types of containers, a vertically installed cracking reactor and a catalyst regenerator. It can be done by circulating it.

That is, the fluid catalytic cracking catalyst deactivated by the coke deposited on the surface as a result of being subjected to the treatment of hydrocarbon oil (hydrocarbon mixture) in the cracking reactor is separated from the cracked products (various product oils), After stripping, transfer to the catalyst regenerator, mix the hot regenerated catalyst regenerated in the catalyst regenerator with the hydrocarbon oil to be cracked again, and circulate through the cracking reactor in the upward direction. The reaction can be carried out continuously and the resulting cracked product is distilled off into one or more fractions such as dry gas, LPG, gasoline fraction, LCO and HCO or slurry oil. Further, the decomposition reaction may be further advanced by recirculating part or all of the decomposition product into the cracking reactor.
In the method for producing xylene according to the present invention, a gasoline fraction is used as fluid catalytic cracking gasoline among the fractions separated from the cracked product.

The hydrocarbon oil (hydrocarbon mixture) used in the catalytic cracking reaction in the fluid catalytic cracking process is a relatively heavy hydrocarbon mixture that boils above the boiling range of gasoline, specifically, atmospheric distillation of crude oil. Or gas oil fraction obtained by vacuum distillation, atmospheric distillation residue oil and vacuum distillation residue oil, etc. can be mentioned, such as coker light oil, solvent desulfurization oil, solvent desulfurization asphalt, tar sand oil, shale oil oil, coal liquefaction Oil etc. may be sufficient.
Further, as the hydrocarbon oil (hydrocarbon mixture) to be used in the fluid catalytic cracking process, a hydrotreatment well known to those skilled in the art, that is, a Ni—Mo catalyst, a Co—Mo catalyst, a Ni—Co—Mo catalyst. In addition, hydrotreated oil hydrodesulfurized at high temperature and high pressure in the presence of a hydrotreating catalyst such as a Ni-W catalyst may also be mentioned.

The operating conditions of the cracking reactor for obtaining fluid catalytic cracking gasoline used in the present invention are preferably a reaction temperature of 400 to 600 ° C., more preferably 450 to 550 ° C., and a reaction pressure of preferably normal pressure to 5 kg / cm ^3, more preferably from normal pressure ~3kg / cm ^3, the mass ratio of preferably 2 to 20, "fluid catalytic cracking catalyst / feedstock to become hydrocarbon oil" represented by, more preferably 4 to 15 It is.

When the reaction temperature is within the above range, fluid catalytic cracking gasoline containing a predetermined amount of aromatic hydrocarbon can be efficiently obtained. When the said reaction temperature is less than 400 degreeC, progress of the decomposition reaction of hydrocarbon oil becomes slow, and since the amount of decomposition products falls, it becomes difficult to perform economical driving | operation. Moreover, when the said reaction temperature is over 600 degreeC, it will become easy to produce | generate a large amount of olefin components, and the content rate of the aromatic hydrocarbon in the fluid catalytic cracking gasoline obtained will fall easily.
Moreover, when the reaction pressure is within the above range, the decomposition reaction in which the number of moles can be increased, and when the reaction pressure exceeds 5 kg / cm ³ , the decomposition reaction is difficult to proceed. Become.
Furthermore, when the mass ratio represented by “fluid catalytic cracking catalyst / raw hydrocarbon oil as raw material” is within the above range, fluid catalytic cracking gasoline can be obtained efficiently. When the mass ratio is less than 2, the catalyst concentration in the cracking reactor becomes too low, and it becomes difficult for the hydrocarbon oil used as a raw material to decompose. Moreover, when the said mass ratio is more than 20, the decomposition effect by the raise of a catalyst concentration will be saturated, and it will become uneconomical.

In the method for producing xylene of the present invention, the feedstock based on petroleum fraction contains alkylbenzenes having 7 to 10 carbon atoms.
In the present application documents, alkylbenzenes having 7 to 10 carbon atoms are those having 7 to 10 carbon atoms and having one or more alkyl groups bonded to the benzene ring. Except that is bonded cyclically to the benzene ring.

Examples of the alkylbenzene having 7 carbon atoms include toluene.
Examples of the alkylbenzene having 8 carbon atoms include one or more selected from xylene (o-xylene, m-xylene, p-xylene) and ethylbenzene.
Examples of the alkyl benzenes having 9 carbon atoms include one or more selected from isopropyl benzene, normal propyl benzene, methyl ethyl benzene and trimethyl benzene.
Examples of the alkylbenzene having 10 carbon atoms include one or more selected from isobutylbenzene, normal butylbenzene, methylpropylbenzene, diethylbenzene, dimethylethylbenzene and tetramethylbenzene.

On the other hand, for example, indane and indene, which are aromatic compounds having 9 carbon atoms, and methyl indane having 10 carbon atoms are formed by alkyl groups bonded to the benzene ring in a cyclic manner. Are excluded from the alkylbenzenes.
In addition, polycyclic aromatic compounds such as naphthalene do not correspond to alkylbenzenes, and thus do not correspond to alkylbenzenes having 7 to 10 carbon atoms.

  In the method for producing xylene of the present invention, a raw material oil having an average value of the number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 7 to 10 carbon atoms is 1.2 to 2.8 is used.

In this application document, the number of methyl groups directly bonded to each benzene ring of alkylbenzenes (the number of moles of methyl groups directly bonded to the benzene ring constituting the alkylbenzenes per mole of each alkylbenzene) is determined as follows. be able to.
For example, in the case of toluene, there is only one methyl group directly bonded to the benzene ring in one molecule of toluene (since 1 mol of methyl group directly bonded to the benzene ring per 1 mol of toluene), it is directly connected to the benzene ring. The number of methyl groups to be bonded is “1”.
Furthermore, for example, in the case of xylene and trimethylbenzene, there are two and three methyl groups that are directly bonded to the benzene ring in one molecule, respectively (for each mole of xylene and trimethylbenzene, methyl bonded directly to the benzene ring). Since the groups are 2 mol and 3 mol, respectively, the number of methyl groups directly bonded to the benzene ring is also “2” and “3”, respectively.
On the other hand, in the case of ethylbenzene, there is no methyl group directly bonded to the benzene ring in one molecule (since 1 mole of ethylbenzene directly bonds to the benzene ring per 1 mol of ethylbenzene), it directly bonds to the benzene ring. The number of methyl groups is “0”.

When the alkylbenzenes having 7 to 10 carbon atoms are classified according to the number of methyl groups directly bonded to the benzene ring, they can be exemplified as follows.
(1) The number of methyl groups directly bonded to the benzene ring is “0”. Ethylbenzene, isopropylbenzene, normal propylbenzene, isobutylbenzene, normal butylbenzene and diethylbenzene.
(2) The number of methyl groups directly bonded to the benzene ring is “1” Toluene, methylethylbenzene and methylpropylbenzene.
(3) The number of methyl groups directly bonded to the benzene ring is “2” Xylene and dimethylethylbenzene.
(4) The number of methyl groups directly bonded to the benzene ring is “3” Trimethylbenzene.
(5) The number of methyl groups directly bonded to the benzene ring is “4” Tetramethylbenzene.

In the method for producing xylene of the present invention, the average value of the number of methyl groups directly bonded to each benzene ring of the alkylbenzenes having 7 to 10 carbon atoms contained in the raw material oil is 1.2 to 2.8, The average value is preferably 1.5 to 2.5, and more preferably 1.8 to 2.2.
When the average value of the number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 7 to 10 carbon atoms is within the above range, the yield of xylene can be effectively improved.
When the average value is less than 1.2 or more than 2.8, the yield of xylene is greatly reduced.

  In the method for producing xylene of the present invention, the feedstock oil is one having an average value of the number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 7 to 10 carbon atoms within the above range. A large amount of components capable of producing xylene by the alkylation reaction or disproportionation reaction are contained in the feedstock oil, and it is considered that the yield of xylene can be greatly improved.

In the present application documents, the average number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 7 to 10 carbon atoms is the number of methyl groups directly bonded to the benzene ring of each alkylbenzene determined as described above. It means an average value calculated in consideration of the presence ratio (mol fraction) of alkylbenzenes.
In this application document, the average value of the number of methyl groups directly bonded to each benzene ring of an alkylbenzene having 7 to 10 carbon atoms is the ratio of the content of each alkylbenzene to the total content of the alkylbenzene having 7 to 10 carbon atoms ( (Mole fraction) was measured according to the Petroleum Institute method JPI-5S-33-90 (gas chromatograph method), and each benzene ring was compared with the content (mole fraction) of each alkylbenzene obtained. Can be calculated by the sum of the product of the number of methyl groups directly bonded to.
For example, the feedstock oil is alkylbenzenes having 7 to 10 carbon atoms such as toluene (the number of methyl groups directly bonded to the benzene ring is “1”), methylethylbenzene (the number of methyl groups directly bonded to the benzene ring is “1”), and trimethyl. Including benzene (the number of methyl groups directly bonded to the benzene ring is “3”), the content ratio of toluene to the total content of alkylbenzenes having 7 to 10 carbon atoms is 0.2 in terms of molar fraction and 7 to 10 carbon atoms. When the content ratio of methylethylbenzene to the total content of alkylbenzenes is 0.3 by mole fraction, and the content ratio of trimethylbenzene to the total content of alkylbenzenes having 7 to 10 carbon atoms is 0.5 by mole fraction The average number of methyl groups directly bonded to each benzene ring of the alkylbenzenes having 7 to 10 carbon atoms is 0.2 × 1 + 0.3 × 1 It is calculated as + 0.5 × 3 = 2.0.

  In the xylene production method of the present invention, among the alkylbenzenes having 7 to 10 carbon atoms constituting the feedstock, the alkylbenzene having 9 carbon atoms has an average value of the number of methyl groups directly bonded to each benzene ring is 1.5. Is preferably -2.5, more preferably 1.7-2.3, and even more preferably 1.8-2.2.

When the average value of the number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 9 carbon atoms is within the above range, the yield of xylene can be effectively improved.
When the average value is less than 1.5 or more than 2.5, the yield of xylene is greatly reduced.

  In the present application documents, the average value of the number of methyl groups directly bonded to each benzene ring of alkylbenzenes having 9 carbon atoms is the content ratio (mol fraction) of each alkylbenzene having 9 carbon atoms, JPI-5S-33 -Measured according to -90 (gas chromatographic method) and calculated by the sum of the content (mol fraction) of each alkylbenzene multiplied by the number of methyl groups directly bonded to each benzene ring. Can do.

  In the method for producing xylene of the present invention, among the alkylbenzenes having 7 to 10 carbon atoms constituting the raw oil, the alkylbenzene having 10 carbon atoms has an average value of the number of methyl groups directly bonded to each benzene ring is 1.5. Is preferably -2.5, more preferably 1.7-2.3, and even more preferably 1.8-2.2.

  In this application document, the average value of the number of methyl groups directly bonded to each benzene ring of an alkylbenzene having 10 carbon atoms is the content ratio (mol fraction) of each alkylbenzene having 10 carbon atoms. JPI-5S-33 -Measured according to -90 (gas chromatographic method) and calculated by the sum of the content (mol fraction) of each alkylbenzene multiplied by the number of methyl groups directly bonded to each benzene ring. Can do.

In the method for producing xylene of the present invention, the feedstock oil preferably contains 90 to 100% by mass of aromatic hydrocarbons, more preferably 93 to 99% by mass, more preferably 96 to 98% by mass. More preferably, it is included.
In addition, in this application document, the content rate of an aromatic hydrocarbon means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene of the present invention, the feedstock oil preferably contains 0 to 1% by mass, more preferably 0 to 0.5% by mass of an aromatic hydrocarbon having 6 carbon atoms, More preferably, the content is 0.1% by mass.
In the method for producing xylene of the present invention, the feedstock oil preferably contains 0 to 46 mass%, more preferably 0 to 20 mass%, and more preferably 0 to 15 mass% of an aromatic hydrocarbon having 7 carbon atoms. % Content is more preferable.
In the method for producing xylene of the present invention, the feedstock oil preferably contains 43 to 96% by mass, more preferably 80 to 95% by mass, and more preferably 92 to 94.5% of an aromatic hydrocarbon having 9 carbon atoms. More preferably, it is contained by mass%.
In the method for producing xylene of the present invention, the feedstock oil preferably contains 1.5 to 5.0% by mass of C10 aromatic hydrocarbon, and preferably contains 2.0 to 4.5% by mass. More preferably, it is more preferable to contain 2.5-4.0 mass%.
When the content ratio of each aromatic hydrocarbon is within the above range, xylene can be produced efficiently.
In addition, in this application document, the content rate of each said aromatic hydrocarbon means the value measured based on the Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the raw material oil preferably contains 25 to 60% by mass of trimethylbenzene, more preferably 35 to 60% by mass, and 45 to 55% by mass. Further preferred.
Here, trimethylbenzene is a generic name including various isomers such as 1,2,3-trimethylbenzene and 1,2,4-trimethylbenzene.
If the content of trimethylbenzene having a large number of methyl groups bonded to the benzene ring in the aromatic hydrocarbon having 9 carbon atoms is within the above range, it is advantageous in the disproportionation reaction and transalkylation reaction described later. Can be converted to xylene efficiently.
In addition, in this application document, the content rate of a trimethylbenzene means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the raw material oil preferably contains tetramethylbenzene in an amount of 0.5 to 1.5 mass%, more preferably 0.7 to 1.2 mass%, It is more preferable to contain 0.9-1.1 mass%.
Here, tetramethylbenzene is a generic name including various isomers such as 1,2,3,4-tetramethylbenzene and 1,2,3,5-tetramethylbenzene.
If the content of tetramethylbenzene having a large number of methyl groups bonded to the benzene ring in the aromatic hydrocarbon having 10 carbon atoms is within the above range, in the disproportionation reaction and transalkylation reaction described later. It works favorably and can be efficiently converted to xylene.
In addition, in this application document, the content rate of tetramethylbenzene means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the content ratio of the propylbenzene in the raw material oil is preferably 2.0 to 4.5 mass%, more preferably 2.0 to 3.0 mass%. Preferably, it is 2.0 to 2.5 mass%.
Here, propylbenzene is a general term including isopropylbenzene in addition to normal propylbenzene.
If the content ratio of propylbenzene is within the above range, the influence of inhibiting the conversion to xylene can be suppressed in the disproportionation reaction and the transalkylation reaction described later.
In addition, in this application document, the content rate of propylbenzene means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the content ratio of the butylbenzene in the raw oil is preferably 0.05 to 0.25% by mass, more preferably 0.05 to 0.15% by mass. Preferably, it is 0.05-0.10 mass%.
Here, butylbenzene is a generic name including various isomers such as isobutylbenzene.
If the content ratio of butylbenzene is within the above range, the influence of inhibiting the conversion to xylene can be easily suppressed in the disproportionation reaction and transalkylation reaction described later.
In addition, in this application document, the content rate of butylbenzene means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the feed oil preferably has an unsaturated hydrocarbon (olefin) content of 0 to 0.3% by mass, and preferably 0 to 0.2% by mass. More preferably, what is 0-0.1 mass% is further more preferable.
When the content ratio of the unsaturated hydrocarbon is within the above range, poisoning of the catalyst can be easily suppressed in the disproportionation reaction and the transalkylation reaction described later.
In addition, in this application document, the content rate of unsaturated hydrocarbon means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the feed oil preferably has a saturated hydrocarbon (paraffin) content of 0 to 7% by mass, more preferably 0 to 3% by mass, What is 0.1 mass% is still more preferable.
When the content ratio of the saturated hydrocarbon is within the above range, in the disproportionation reaction and transalkylation reaction described later, the influence of inhibiting the conversion to xylene can be easily suppressed.
In addition, in this application document, the content rate of saturated hydrocarbon means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the feed oil preferably has a cyclic saturated hydrocarbon (naphthene) content of 0 to 0.5% by mass, and 0 to 0.3% by mass. More preferably, what is 0-0.1 mass% is further more preferable.
When the content ratio of the cyclic saturated hydrocarbon is within the above range, the influence of inhibiting the conversion to xylene can be easily suppressed in the disproportionation reaction and the transalkyl reaction described later.
In addition, in this application document, the content rate of cyclic saturated hydrocarbon means the value measured based on the Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

In the method for producing xylene according to the present invention, the raw oil preferably has a sulfur content of 6 mass ppm or less, more preferably 4 mass ppm or less, and more preferably 2 mass ppm or less. Further preferred. In addition, the content rate of the sulfur content in raw material oil is 1 mass ppm or more normally.
In addition, in this application document, the content rate of a sulfur content means the value measured based on JISK2541.

In the method for producing xylene according to the present invention, the feed oil preferably has a nitrogen content of 6 mass ppm or less, more preferably 4 mass ppm or less, and 2 mass ppm or less. Further preferred. In addition, the content rate of the nitrogen content in raw material oil is 1 mass ppm or more normally.
In addition, in this application document, the content rate of a nitrogen content means the value measured based on JISK2609.

  According to the present invention, in the case of producing xylene by subjecting a feedstock based on petroleum fractions to a disproportionation reaction or a transalkylation reaction, a high yield can be obtained by selecting the specific feedstock described above. Xylene can be produced at a rate.

  In the method for producing xylene of the present invention, a transalkylation reaction or a disproportionation reaction is performed on the above-described feedstock based on the petroleum fraction.

The reaction conditions for the disproportionation reaction or alkylation reaction are not particularly limited as long as xylene can be obtained.
In the disproportionation reaction or transalkylation reaction, the liquid oil has a liquid space velocity (LHSV) of preferably 0.01 h ⁻¹ or more, more preferably 0.1 h ⁻¹ or more, and preferably 10 h ^{−. 1} or less, more preferably supplied in 5h ^-1 or less, it is preferable to carried out by contacting the catalyst.

In the disproportionation reaction or transalkylation reaction, the reaction temperature is preferably 200 ° C. or higher, more preferably 230 ° C. or higher, further preferably 260 ° C. or higher, preferably 550 ° C. or lower, more preferably 530 ° C. or lower. Particularly preferably, it is 510 ° C. or lower.
When the reaction temperature is less than 200 ° C., the activation of aromatic hydrocarbons is insufficient, and the active sites are poisoned by water generated by the reaction. The conversion rate tends to be low. On the other hand, when the reaction temperature exceeds 550 ° C., in addition to consuming a lot of energy, the catalyst life tends to be shortened.

  In the disproportionation reaction or transalkylation reaction, the reaction pressure is preferably at least atmospheric pressure, more preferably at least 0.1 MPaG, even more preferably at least 0.5 MPaG, preferably at most 10 MPaG, more preferably at most 5 MPaG. .

  Further, when performing the disproportionation reaction or transalkylation reaction, an inert gas such as nitrogen gas or helium gas or hydrogen gas for suppressing coking may be circulated or pressurized in the reaction system. .

The reaction catalyst used in the above disproportionation reaction or transalkylation reaction is not particularly limited as long as it is an aromatic conversion catalyst and causes disproportionation reaction or transalkylation.
The reaction catalyst is preferably one that selectively dealkylates an ethyl group or a propyl group while retaining a methyl group and simultaneously has a transalkylation ability.
Specifically, a shape-selective metallosilicate catalyst is preferable, crystalline aluminosilicate is more preferable, and zeolite is more preferable.
As zeolite, any zeolite selected from mordenite, Y-type zeolite, X-type zeolite, beta-type zeolite, ZSM-5 and the like can be used, but mordenite is preferred.

  When the disproportionation reaction or transalkylation reaction is performed, the reaction time is not particularly limited, but is preferably 0.5 to 4.0 hours, more preferably 1.0 to 3.0 hours, and 1.5 to 2.0 hours is more preferred.

In the method for producing xylene according to the present invention, two molecules of the same aromatic hydrocarbon are converted by a disproportionation reaction, so that one molecule of lower molecular weight aromatic hydrocarbon and one molecule of higher molecular weight aromatic hydrocarbon are converted. One molecule can be obtained. Specifically, for example, two molecules of toluene can be converted to obtain one molecule of benzene and one molecule of xylene.
The xylene production method of the present invention can convert two aromatic hydrocarbon molecules having different carbon numbers by transalkylation reaction to obtain two molecules of xylene, specifically, for example, one molecule of toluene. And 1 molecule of trimethylbenzene can be converted to obtain 2 molecules of xylene.

In the method for producing xylene according to the present invention, xylene can be selectively produced by subjecting a specific feedstock based on petroleum fractions to a disproportionation reaction or a transalkylation reaction. .
In the production method of the xylene production method of the present invention, the product oil obtained by performing a disproportionation reaction or a transalkylation reaction preferably has a xylene content of 30 to 38% by mass. What is mass% is more preferable, and what is 32-36 mass% is still more preferable.
In addition, in this application document, the content rate of xylene means the value measured based on Petroleum Institute method JPI-5S-33-90 (gas chromatograph method).

  According to the present invention, when xylene is produced by subjecting a feedstock based on petroleum fractions to a disproportionation reaction or a transalkylation reaction, xylene is produced in a high yield while selecting an appropriate feedstock. A method of manufacturing can be provided.

  EXAMPLES Hereinafter, although an Example demonstrates this invention, these are illustrations, Comprising: This invention is not restrict | limited at all by these Examples.

Example 1
As feedstock, 80.5% by volume (83.3% by mass) of a fraction obtained by removing toluene and xylene from catalytic reformed gasoline, and 19.5% by volume (16.7%) of toluene extracted from the catalytic reformed gasoline. (Mass%) A feedstock 1 containing 7 to 10 carbon alkylbenzenes and having an average value of 1.9 methyl groups directly bonded to each benzene ring of the alkylbenzene was used. The composition of the raw material oil 1 is shown in Table 1.
The above raw material oil 1 is supplied into a reaction vessel at a liquid space velocity of 3.0 h ⁻¹ , a Mo catalyst is used as a catalyst, a disproportionation reaction is performed under the conditions of a reaction temperature of 345 ° C., a reaction pressure of 2 MPa, and a reaction time of 2 hours. By performing a transalkylation reaction, a product oil 1 containing 36.6% by mass of xylene was obtained.
The composition of the resulting product oil 1 is shown in Table 1.

(Example 2)
The feedstock oil is obtained by removing toluene and xylene from catalytically reformed gasoline, contains alkylbenzenes having 7 to 10 carbon atoms, and the average number of methyl groups directly bonded to each benzene ring of the alkylbenzenes is 2.1. A feedstock 2 was used. The composition of the feedstock 2 is shown in Table 1.
The raw material oil 2 is supplied into the reaction vessel at a liquid space velocity of 3.0 h ⁻¹ , a Mo catalyst is used as a catalyst, a disproportionation reaction is performed under the conditions of a reaction temperature of 345 ° C., a reaction pressure of 2 MPa, and a reaction time of 2 hours. By performing a transalkylation reaction, a product oil 2 containing 35.5% by mass of xylene was obtained.
The composition of the resulting product oil 2 is shown in Table 1.

(Example 3)
As a feedstock, 46.8% by volume (54.3% by mass) of a fraction obtained by removing toluene and xylene from catalytically reformed gasoline, and 53.2% by volume (45.7%) of toluene extracted from the catalytically reformed gasoline. (Mass%) The feedstock 3 was used which was mixed and contained alkylbenzenes having 7 to 10 carbon atoms, and the average number of methyl groups directly bonded to each benzene ring of the alkylbenzenes was 1.5. The composition of the feedstock 3 is shown in Table 1.
The above raw material oil 3 is supplied into a reaction vessel at a liquid space velocity of 3.0 h ⁻¹ , a Mo catalyst is used as a catalyst, a disproportionation reaction is performed under conditions of a reaction temperature of 345 ° C., a reaction pressure of 2 MPa, and a reaction time of 2 hours. By performing a transalkylation reaction, a product oil 3 containing 33.1% by mass of xylene was obtained.
The composition of the resulting product oil 3 is shown in Table 1.

(Comparative Example 1)
Raw material oil consisting of commercially available toluene (purity 99.9% by mass) as a raw material oil, containing an alkylbenzene having 7 carbon atoms, and having an average value of 1.0 for the number of methyl groups directly bonded to the benzene ring of the alkylbenzene 4 was used. The composition of the raw material oil 4 is shown in Table 2.
The above raw material oil 4 is supplied into a reaction vessel at a liquid space velocity of 3.0 h ⁻¹ , a Mo catalyst is used as a catalyst, a disproportionation reaction is performed under conditions of a reaction temperature of 345 ° C., a reaction pressure of 2 MPa, and a reaction time of 2 hours. By performing a transalkylation reaction, a product oil 4 containing 23.9% by mass of xylene was obtained.
The composition of the resulting product oil 4 is shown in Table 2.

(Comparative Example 2)
Methyl which consists of commercially available pseudocumene (1,2,4-trimethylbenzene, purity 99.3 mass%) as a raw material oil, contains alkylbenzenes having 9 to 10 carbon atoms, and is directly bonded to each benzene ring of the alkylbenzenes. Feedstock 5 having an average number of bases of 3.0 was used. The composition of the raw material oil 5 is shown in Table 2.
The above raw material oil 5 is supplied into a reaction vessel at a liquid space velocity of 3.0 h ⁻¹ , a Mo catalyst is used as a catalyst, a disproportionation reaction is performed under conditions of a reaction temperature of 345 ° C., a reaction pressure of 2 MPa, and a reaction time of 2 hours. By performing a transalkylation reaction, a product oil 5 containing 20.5% by mass of xylene was obtained.
The composition of the resulting product oil 5 is shown in Table 2.

In addition, in each raw material oil and production | generation oil shown in Table 1 and Table 2 shown below, the content rate of a sulfur content means the value measured based on JISK2541, and the content rate of nitrogen content is JISK2609. The content ratio of components other than the sulfur content and the nitrogen content means a value measured according to the Petroleum Institute method JPI-5S-33-90 (gas chromatographic method).
In Tables 1 and 2, “Me / Ph” means the average value of the number of methyl groups directly bonded to the benzene ring of each alkylbenzene in C7-10 alkylbenzenes, and “C9-Me / Ph”. Means an average value of the number of methyl groups directly bonded to the benzene ring of each alkyl benzene in an alkyl benzene having 9 carbon atoms, and “C10-Me / Ph” is the value of each alkyl benzene in an alkyl benzene having 10 carbon atoms. Means the average number of methyl groups directly bonded to the benzene ring.

  From Table 1, in Examples 1 to 3, the raw material oil contains an alkylbenzene having 7 to 10 carbon atoms, and the average number of methyl groups directly bonded to each benzene ring of the alkylbenzene is 1.2 to While selecting what is 2.8, the disproportionation reaction or the transalkylation reaction is given to this, It turns out that the product oil excellent in the yield of xylene is obtained.

  On the other hand, from Table 2, Comparative Examples 1 to 2 include alkylbenzenes having 7 to 10 carbon atoms as the raw material oil, but the average value of the number of methyl groups directly bonded to each benzene ring of the alkylbenzenes is 1 It is understood that only a product oil inferior in the yield of xylene can be obtained because a disproportionation reaction or a transalkylation reaction is performed on a product outside the range of 2 to 2.8. .

  According to the present invention, when xylene is produced by subjecting a feedstock based on petroleum fractions to a disproportionation reaction or a transalkylation reaction, xylene is produced in a high yield while selecting an appropriate feedstock. A method of manufacturing can be provided.

Claims (3)

A method for producing xylene by performing a transalkylation reaction or a disproportionation reaction on a feedstock based on a petroleum fraction using a Mo catalyst ,
As the feedstock comprises alkylbenzenes having 7 to 10 carbon atoms, the average value of the methyl groups directly bonded to each benzene ring of the alkylbenzenes is Ri der 1.2 to 2.8, aromatic 10 carbon atoms A method for producing xylene characterized by using a hydrocarbon containing 1.5 to 5.0% by mass .   The raw material oil containing an alkylbenzene having 7 to 10 carbon atoms and having an average value of the number of methyl groups directly bonded to each benzene ring of the alkylbenzene is 1.5 to 2.5. The manufacturing method of xylene of description.   The method for producing xylene according to claim 1 or 2, wherein the raw material oil contains 43 to 96 mass% of an aromatic hydrocarbon having 9 carbon atoms.