JP2019206714A - Method for producing reformed gasoline - Google Patents

Abstract

To provide a method for producing reformed gasoline capable of efficiently obtaining reformed gasoline.SOLUTION: There is provided a method for producing reformed gasoline which comprises: a first step of separating a raw material oil comprising a hydrocarbon having 6 to 10 carbon atoms and having a content concentration of an aromatic hydrocarbon of 1 to 30 mass% into a first composition and a second composition having a content concentration of an aromatic hydrocarbon larger than that of the first composition; and a second step of catalytically reforming raw material oil to be reformed containing the first composition to obtain a third composition having a content concentration of an aromatic hydrocarbon larger than that of the reforming raw material oil.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing reformed gasoline. Furthermore, the present invention relates to a gasoline base material and a method for producing aromatic hydrocarbons.

  The reformed gasoline is a gasoline base material having a high octane number obtained by catalytic reforming using a straight-run naphtha (SR) obtained from an atmospheric distillation apparatus (topper) as a raw material. In the catalytic reforming process, numerous reactions occur sequentially and concurrently to increase the octane number. It is known that the reaction is roughly classified into the following (1) to (6) (for example, Non-Patent Document 1). (1) 6-membered ring naphthene dehydrogenation, (2) 5-membered ring naphthene isomerization dehydrogenation, (3) Paraffin cyclization dehydrogenation, (4) Paraffin isomerization, (5) Hydrogen of various hydrocarbons (6) Other reactions (coke formation, desulfurization, etc.).

  Regarding the octane number, there are a research method octane number (RON) and a motor method octane number (MON). In Japan, the research method octane number (hereinafter referred to as RON) is widely used. The following relationship is generally known between the hydrocarbon structure and the octane number (for example, Non-Patent Document 2). (I) In paraffinic hydrocarbons and olefinic hydrocarbons, if the branch structure in the molecule is the same, the octane number is lower when the number of carbon atoms is the same. (Ii) Paraffinic hydrocarbons have no methyl side chains Paraffin (isoparaffin) with a side chain is higher in octane number than linear paraffin (normal paraffin), (iii) Olefin hydrocarbon has higher octane number than paraffin hydrocarbon having the same carbon number, (iv) Aroma Group hydrocarbons have the highest octane number and RON exceeds 100. That is, normal paraffin has the lowest octane number and aromatic hydrocarbons have the highest octane number. When a gasoline base material is mixed to make a gasoline product, additivity is not strictly established with respect to the octane number, but if a large number of base materials having a high octane number are mixed, the octane number of the gasoline product becomes high. Therefore, it can be said that an important reaction in the catalytic reforming process is a reaction for obtaining an aromatic hydrocarbon having a high octane number from paraffinic hydrocarbons or naphthenes having a low octane number.

The Petroleum Society, “Oil Refinery Process” Kodansha Scientific, May 20, 1998 Mitsubishi Nisseki “Oil Handbook 2000” Fuel and Oil Newspaper, published March 1, 2000

  Because reformed gasoline is rich in aromatic hydrocarbons such as benzene, toluene, and xylene (collectively referred to as BTX), the catalytic reforming process to obtain reformed gasoline is not only a gasoline base manufacturing process but also petrochemical. It also occupies an important position as an aromatic hydrocarbon production process.

  An object of this invention is to provide the manufacturing method of reformed gasoline which makes it possible to obtain reformate gasoline efficiently. A further object of the present invention is to provide a method for co-production of a gasoline base material and an aromatic hydrocarbon that makes it possible to separate and recover aromatic hydrocarbons and obtain a gasoline base material with higher efficiency.

  A part of the raw material of the catalytic reforming process contains aromatic hydrocarbon which is the target product of the reaction. The present inventors speculate that this aromatic hydrocarbon may reduce the contact efficiency between the paraffinic hydrocarbon or naphthenes and the catalyst, and may reduce the efficiency of the reaction to obtain the aromatic hydrocarbon. Based on the above. And the present inventors have confirmed that the reactivity in catalytic reforming is improved by separating the aromatic hydrocarbons from the feedstock to be subjected to the catalytic reforming process, and the conversion of the aromatic content to be produced is improved. The headline and the present invention were completed.

  In order to solve the above-mentioned problem, the present invention includes a first oil composition containing a hydrocarbon having 6 to 10 carbon atoms and a content concentration of aromatic hydrocarbon of 1 to 30% by mass, The first step of separating the first composition into a second composition having a higher aromatic hydrocarbon content concentration than the first composition, and the reformed feedstock containing the first composition are contact-reformed to improve And a second step of obtaining a third composition having a higher aromatic hydrocarbon content concentration than the raw material oil.

  In the present specification, “reformed feedstock” refers to feedstock supplied to the contact reformer.

  According to the method for producing reformed gasoline of the present invention, by separating the aromatic hydrocarbon from the feedstock, it becomes possible to increase the feedstock supply amount to the contact reformer or supply other feedstock, Can improve the reactivity of catalytic reforming by reducing the concentration of aromatic hydrocarbons in the reformed feedstock, and can efficiently obtain reformed gasoline. Furthermore, according to the method for producing a reformed gasoline of the present invention, aromatic hydrocarbons useful as chemical raw materials can be obtained from the second composition and / or the third composition, and thereby the gasoline. A base material and an aromatic hydrocarbon can be produced together.

  In the method for producing reformed gasoline of the present invention, a part of the above-mentioned feed oil, or another feed oil having a boiling point of 30 ° C. or more and 200 ° C. or less and an aromatic hydrocarbon content concentration of 1 to 30% by mass. , And can be contained in the modified feedstock. In addition, in this specification, the measuring method of a boiling point shall be the atmospheric pressure method (corresponding international standard: ISO 3405) of JIS K2254 petroleum product-distillation test method.

  In the first step, the first composition and the second composition may be obtained by one or more separation operations of distillation separation, extraction separation, membrane separation, and adsorption separation.

  In the first step, it is preferable to obtain the first composition and the second composition by membrane separation from the viewpoint of simplifying the process and saving energy.

  In the method for producing reformed gasoline of the present invention, the concentration of aromatic hydrocarbons in the first composition obtained in the first step is smaller than the concentration of aromatic hydrocarbons in the feedstock, It is preferable that the content concentration of the aromatic hydrocarbon in the third composition obtained in the second step is 50% by mass or more. In this case, since the octane number of the third composition is sufficiently high, the reformed gasoline obtained from the third composition can be used as an excellent gasoline base material.

  In the method for producing reformed gasoline of the present invention, a part of the third composition can be recycled into the feedstock. In this case, a part of the aromatic hydrocarbon generated by the reforming reaction can be separated and recovered in the second composition in the first step, and useful as a chemical raw material from the second composition. Aromatic hydrocarbons can also be co-produced.

  The method for producing reformed gasoline of the present invention comprises a mixture of the second composition and the third composition, a fourth composition, and an aromatic hydrocarbon content concentration higher than that of the fourth composition. A third step of separating into a fifth composition having a larger value can be further provided. In this case, the concentration of the aromatic hydrocarbon in the fifth composition can be further increased, and it can be recovered as an aromatic hydrocarbon useful as a chemical raw material. The fourth composition can also be a high octane gasoline base.

  In the third step, the fourth composition and the fifth composition may be obtained by one or more separation operations of distillation separation, extraction separation, membrane separation, and adsorption separation.

  The present invention can provide a method for producing reformed gasoline that makes it possible to efficiently obtain reformed gasoline. The reformed gasoline obtained by such a method can be used as a high-octane gasoline base and / or an aromatic hydrocarbon useful as a chemical raw material. The method for producing a reformed gasoline of the present invention includes a gasoline base material capable of separating and recovering aromatic hydrocarbons and obtaining a high octane number gasoline base material with high efficiency by improving the efficiency of the reforming reaction. It can be used as a method for co-producing aromatic hydrocarbons.

It is a mimetic diagram showing one embodiment of a manufacturing system with which a manufacturing method of reformed gasoline concerning this embodiment is implemented. It is a figure which shows the outline | summary of the membrane separator used in order to evaluate the separation power of a separation membrane.

  FIG. 1 shows an embodiment of a production system in which the method for producing reformed gasoline according to this embodiment is implemented. A manufacturing system 100 shown in FIG. 1 is connected to a line 1 that supplies crude oil, and is connected to an atmospheric distillation apparatus 2 that can distill the crude oil, and a line 3 that supplies raw oil from the atmospheric distillation apparatus 2. , A separation unit 10 for separating the raw material oil into the first composition and the second composition, and a reforming raw material oil containing the first composition obtained from the separation unit 10 for reforming treatment And a reforming unit 20. The separation unit 10 is connected to a line 5 for supplying the taken out first composition to the reforming unit and a line 4 for taking out the second composition. Further, in the manufacturing system 100, a processing unit that can perform a predetermined process on the second composition taken out from the separation unit 10 or the third composition obtained from the reforming unit 20 as necessary. 30 is provided.

  A method for producing a gasoline base material and aromatic hydrocarbons by the method for producing reformed gasoline of this embodiment using the production system 100 will be described.

  The method for producing the reformed gasoline of the present embodiment includes a first oil composition containing a hydrocarbon having 6 to 10 carbon atoms and a content concentration of aromatic hydrocarbon of 1 to 30% by mass, A first step S1 for separating the first composition into a second composition having a higher aromatic hydrocarbon content concentration than the first composition, and catalytic reforming of the reformed feedstock containing the first composition; And a second step S2 for obtaining a third composition having a higher aromatic hydrocarbon content concentration than the reforming feedstock.

  Examples of the feed oil include catalytic cracking gasoline (CCG), straight-run naphtha (particularly heavy naphtha: HSR), and the like.

  As the heavy naphtha, as shown in FIG. 1, a fraction derived from straight-run naphtha obtained by applying crude oil to an atmospheric distillation apparatus 2 can be used. For example, a product obtained by desulfurizing a heavy component of straight-run naphtha or a product obtained by desulfurizing and fractionating a straight-run naphtha can be used. Moreover, what desulfurized the fraction corresponded to the heavy naphtha obtained by apply | coating crude oil to an atmospheric distillation apparatus can be used. Although the above desulfurization is not shown in FIG. 1, for example, a known desulfurization apparatus is provided after the atmospheric distillation apparatus 2 and can be performed on a straight-run naphtha fraction obtained by atmospheric distillation. . Examples of the desulfurization method include straight-run naphtha in the presence of hydrogen, a reaction temperature of 280 to 350 ° C., a hydrogen partial pressure of 0.5 to 10 MPaG, an LHSV of 1.0 to 8.0 h-1, and a hydrogen / oil ratio of The method of making it contact with a hydrorefining catalyst at 10-150 NL / L is mentioned.

  As the hydrorefining catalyst, a catalyst in which an element of Group 6 of the periodic table and an element of Group 9 or 10 is supported on an inorganic porous oxide carrier such as alumina, silica, silica-alumina, or the like can be used. . Molybdenum and tungsten can be used as an element of Group 6 of the periodic table. Cobalt can be used as the Group 9 element. Nickel can be used as the Group 10 element.

  In the present embodiment, it is preferable to use a desulfurized straight-run heavy naphtha having a 5% distillation temperature of 75 to 115 ° C and a 95% distillation temperature of 120 to 170 ° C, and a 5% distillation temperature of 85. It is more preferable to use a desulfurized straight-run heavy naphtha having a temperature of ˜110 ° C., particularly 95 to 105 ° C., and a 95% distillation temperature of 125 to 160 ° C., particularly 135 to 150 ° C. When the 5% distillation temperature is 75 ° C. or higher, a large amount of naphtha having 6 or more carbon atoms is contained, and the catalytic reforming can be performed efficiently in the catalytic reforming apparatus. When the 95% distillation temperature is 120 ° C. or higher, the proportion of naphthene contained in the raw material naphtha fraction increases, and catalytic reforming can be carried out efficiently in the catalytic reforming apparatus. On the other hand, when the 95% distillation temperature is 170 ° C. or lower, there is little risk of containing sulfur or nitrogen that adversely affects the reforming reaction catalyst.

  The catalytic cracking gasoline is not particularly limited with respect to the obtained process (catalytic cracking device, catalytic cracking feedstock, catalytic cracking catalyst, operating conditions, etc.), and catalytic cracking gasoline obtained in any known production process should be used. Can do. The catalytic cracking unit uses a catalyst such as amorphous silica alumina, zeolite, etc., in addition to petroleum fractions from light oil to vacuum gas oil, while being obtained from heavy oil indirect desulfurization equipment, it can be obtained directly from delight oil or heavy oil direct desulfurization equipment. It is a device that obtains a high octane gasoline base material by catalytic cracking of de-heavy oil, atmospheric residue oil, etc. For example, UOP catalytic cracking method described in Non-Patent Document 1, flexi cracking method, ultra-orthoflow method, fluid catalytic cracking method such as Texaco fluid catalytic cracking method, residual oil fluid catalytic cracking method such as RCC method and HOC method Such processes are known.

  In the production system 100 shown in FIG. 1, catalytic cracking gasoline obtained by the distillation column 12 and the fluid catalytic cracking device 14 connected to the atmospheric distillation device 2 can be supplied from the line 15 to the separation unit 10.

  As the catalytic cracking gasoline, a light catalytic cracking gasoline having a boiling range of about 30 to 100 ° C. or a heavy catalytic cracking gasoline having a boiling range of about 100 to 200 ° C. can be used.

  In the present embodiment, it is preferable to use catalytic cracking gasoline having a 5% distillation temperature of 80 ° C or higher and a 95% distillation temperature of 180 ° C or lower, and a 5% distillation temperature of 90 ° C or higher, particularly 95 ° C. As described above, it is more preferable to use catalytic cracking gasoline having a 95% distillation temperature of 160 ° C. or lower, particularly 150 ° C. or lower. When the 5% distillation temperature is 80 ° C. or higher, a large amount of hydrocarbons having 6 or more carbon atoms is contained, and the catalytic reforming can be carried out efficiently in the catalytic reforming apparatus. On the other hand, when the 95% distillation temperature is 180 ° C. or lower, there is little fear of containing sulfur or nitrogen that adversely affects the reforming reaction catalyst.

  In the present embodiment, a purified naphtha fraction having a sulfur content of 1 ppm or less obtained by further hydrotreating catalytically cracked gasoline can be used. As the hydrotreating, a catalytic cracking gasoline fraction was subjected to a reaction temperature of 280 to 350 ° C., a hydrogen partial pressure of 0.5 to 10 MPaG, an LHSV of 1.0 to 8.0 h-1, a hydrogen / oil ratio in the presence of hydrogen. May be brought into contact with the hydrorefining catalyst at 10 to 150 NL / L. As the hydrorefining catalyst, a catalyst in which an element of Group 6 of the periodic table and an element of Group 9 or 10 is supported on an inorganic porous oxide carrier such as alumina, silica, silica-alumina, or the like can be used. . Molybdenum and tungsten can be used as an element of Group 6 of the periodic table. Cobalt can be used as the Group 9 element. Nickel can be used as the Group 10 element.

  The feed oil preferably has an aromatic hydrocarbon content concentration of 1 to 30% by mass, preferably 5 to 30% by mass, more preferably 10 to 25% by mass, and still more preferably 15 to 25% by mass.

  The feedstock oil preferably has a sulfur content of preferably 5 mass ppm or less, more preferably 1 mass ppm or less, and even more preferably 0.5 mass ppm or less. The sulfur content means the mass of sulfur of a compound containing a sulfur atom. In addition, in this specification, the measuring method of sulfur content shall be JIS K2541-2 crude oil and petroleum products-sulfur content test method Part 2: Microcoulometric titration oxidation method.

  As the separation unit 10, one capable of performing one or more separation operations among distillation separation, extraction separation, membrane separation, and adsorption separation can be used.

  In the present embodiment, it is preferable that the separation unit 10 is membrane separation from the viewpoint that the process can be simplified and energy is saved. In this case, it is preferable that the membrane separation does not require an operation for desorbing the adsorbate as in the case of adsorption separation.

  A membrane that can selectively permeate aromatic hydrocarbons is desirable as a membrane for performing membrane separation in the separation unit 10. This separation membrane selectively adsorbs molecules having a large adsorbing force and allows molecules having a large adsorbing force to permeate. Aromatic hydrocarbons can be selectively separated because of their large adsorptive power due to the π atom of the aromatic ring. As described above, the separation membrane that separates the molecules by the adsorption force between the separation membrane and the molecules performs separation according to chemical properties, and thus has a feature that even molecules having a large minimum molecular diameter such as aromatic hydrocarbons can permeate. A preferable separation membrane includes a zeolite membrane.

  As the inorganic film, a film in which a film material is formed on the surface of the porous support or inside the pores can be used. In addition, a porous support having a high mechanical strength can be appropriately selected according to the production environment such as the synthesis temperature of the membrane, the use temperature of the membrane, and other use situations. From the viewpoint of heat resistance and acid resistance, a ceramic porous support is preferable, an alumina porous support is more preferable, and an α-alumina porous support is more preferable.

  As a zeolite constituting the zeolite membrane, a currently known synthetic zeolite can be applied. For example, the zeolite described in Yoshio Ono and Kenaki Yajima "Zeolite Science and Engineering" Kodansha Scientific (issued July 10, 2000) can be applied. Specific examples include A type zeolite (LTA), faujasite type zeolite (FAU), mordenite type zeolite (MOR), and ZSM-5 type zeolite (MFI). Preferably, it is a faujasite type zeolite, and examples of the faujasite type zeolite include X type zeolite and Y type zeolite.

  The zeolite membrane may be a FAU-type zeolite membrane because it has a large adsorptive power with aromatic hydrocarbons and a large micropore diameter of zeolite. The FAU type zeolite membrane is a separation membrane composed of FAU type zeolite. Examples of the FAU type zeolite include X type zeolite (Si / Al ratio is 1.0 to 1.5) and Y type zeolite (Si / Al ratio is 1.5 or more). The upper limit of the Si / Al ratio of the Y-type zeolite is not limited, but is preferably 11 or less, more preferably 6 or less, and particularly preferably 3 or less. Further, the FAU-type zeolite may contain a metal element other than Si and Al. Examples of the metal element include Li, Na, K, Ca, Mg, Ba, Ni, Ag, Cu, and Pd. Among these, alkali metals (Li, Na, and K) are preferable.

  Hydrothermal synthesis can be mainly used for the synthesis of the zeolite membrane. In the hydrothermal synthesis, various starting materials and blending amounts thereof are selected, and further, hydrothermal conditions are selected, whereby various zeolites are synthesized. Prior to the synthesis of the zeolite membrane on the surface of the porous support, it is preferable to support the zeolite particles on the surface including the pores on the surface of the porous support. In order to support zeolite particles in this manner, the surface of the porous support is polished by dry using zeolite particles, the immersion method in which the zeolite particles are dispersed in a dispersion medium, and the dip coating method. And a method in which a suspension in which zeolite particles are dispersed in a dispersion medium is brush-coated on the surface of the support. Examples of the zeolite particles to be supported include those having X-type zeolite and / or Y-type zeolite as a main component.

  When the zeolite membrane is hydrothermally synthesized with the zeolite particles supported on the surface of the porous support in this manner, the zeolite particles that become seed crystals for the synthesis of the polycrystalline zeolite membrane are densely packed into the porous group. It can be present on the surface of the material. As a result, the synthesized polycrystal is also densely synthesized on the base material according to the presence state of these seed crystals. For this reason, pinholes and crystal gaps are hardly formed, and a state in which the surface of the porous support is covered with a continuous polycrystalline film is formed.

  The shape of the separation membrane is not particularly limited, and may be, for example, a flat membrane shape, a cylindrical shape, a cylindrical shape, a hollow fiber shape, a monolith shape, a honeycomb shape, a spiral shape, or the like. The thickness of the film is not particularly limited, but the film thickness can be set in the range of about 1 to 100 μm in order to improve the permeability.

  The inorganic membrane preferably has an aromatic hydrocarbon separation factor of 2 or more, more preferably 10 or more, and still more preferably 100 or more, with respect to non-aromatic hydrocarbons.

In this specification, the separation coefficient of component A of inorganic membrane with respect to component B is the permeation-side component A (the ratio of the supply-side component A (mol%) and the component B (mol%) defined by the following formula: Mol%) and the value of the ratio of component B (mol%).
Separation coefficient of component A with respect to component B = (Pa / Pb) / (Fa / Fb)
Pa: mol concentration of component A on the transmission side, Pb: mol concentration of component B on the transmission side, Fa: mol concentration of component A on the supply side, Fb: mol concentration of component B on the supply side

  As a means for membrane separation, a known membrane separator can be used. For example, in the case of a membrane separator in which a separation membrane is formed on the outer periphery of a tubular support, feed oil is introduced from one end on the outside of the membrane separator, a non-permeate component is taken out from the other end, and permeated from the inside of the support. Ingredients can be removed.

  Membrane separation operations include vapor permeation, which is in the gas phase on both the supply and permeation sides, pervaporation, where the supply side is in the liquid phase and the permeation side is in the gas phase, and on the supply and permeation sides. Any method of a liquid phase method in which both sides are in a liquid phase may be adopted. In this embodiment, since the permeation flow rate of the substance is proportional to the partial pressure difference between the substance on the supply side and the permeation side, the vapor permeation method is preferable from the viewpoint of easily increasing the partial pressure on the supply side.

  Although the separation operation temperature is not particularly limited, a suitable temperature can be set from the permeation rate and the separation factor, and 70 to 500 ° C. is preferable. In order to perform membrane separation, it is necessary that the partial pressure of the permeation substance on the non-permeation side (raw material side) is higher than the partial pressure of the permeation substance on the permeation side. For this reason, by a known method, (a) the pressure on the non-permeation side is increased from the atmospheric pressure, (b) the pressure on the permeation side is decreased from the atmospheric pressure, and (c) a sweep gas (also referred to as carrier gas) on the permeation side. ) To lower the partial pressure of the permeate on the permeate side, whereby membrane separation can be performed. Two or more kinds of the operations (a) to (c) may be used in combination. The pressure on each of the non-permeation side and the permeation side is not particularly limited, but a suitable range can be set from the permeation speed and the separation factor. For example, the absolute pressure on the non-transmission side is 101 to 2100 kPa, The absolute pressure on the transmission side can be set to less than 101 kPa.

  Examples of the extraction separation include a solvent extraction process and an extractive distillation process, but the apparatus and conditions are not particularly limited, and any known process can be employed. The solvent extraction process is a process in which a solvent is mixed with a mixed liquid composed of a large number of components and separated using the difference in solubility with respect to the solvent. As the solvent to be used, for example, sulfolane, dimethyl sulfoxide, N-methyl-2-pyrrolidone and the like can be used. As typical processes, there are, for example, the Sulfolane process and the Arosolvan process described in Non-cited Document 1. In the extractive distillation process, the raw material and the solvent come into contact with each other in the extractive distillation column, and aromatic hydrocarbons are extracted into the solvent to form a bottom fraction, and at the same time, non-aromatics are separated as a top fraction by distillation. As the solvent to be used, the same solvent as the above solvent extraction process can be used, and typical processes include, for example, the Distapex process and the Morphylane process described in Non-cited Document 1.

  For adsorption separation, the apparatus and conditions are not particularly limited, and any known process can be employed. The adsorption separation process is a process in which a mixture composed of a large number of components is introduced into an adsorption layer and separated using the difference in affinity for the adsorbent. As the adsorbent to be used, molecular sieve or the like can be used, and typical processes include, for example, Parex process and Aromax process described in Non-cited Document 1.

  In the present embodiment, the aromatic hydrocarbon content concentration in the first composition obtained in the first step should be lower than the aromatic hydrocarbon content concentration in the feedstock, From the viewpoint of further improving the reaction efficiency in the second step, it is preferable to separate the raw oil so that the amount is preferably 10% by mass or less, more preferably 5% by mass or less. In particular, when the aromatic hydrocarbon content concentration in the raw material oil exceeds 10% by mass, the raw material oil is preferably separated so that the aromatic hydrocarbon content concentration in the first composition falls within the above range.

  Further, the content concentration of the aromatic hydrocarbon in the second composition obtained in the first step is preferably 70% by mass or more, and more preferably 90% by mass or more.

  In the present embodiment, a part of the third composition can be recycled into the raw material oil via the line 18. In this case, a part of the aromatic hydrocarbon generated by the reforming reaction can also be separated and recovered in the first step (separation unit 10). In the present embodiment, the second composition can be recovered via the line 4.

  In the reforming unit 20, contact reforming of the reforming raw material oil containing the first composition is performed. There are no particular limitations on the catalytic reforming apparatus and operating conditions for performing catalytic reforming, and any known manufacturing apparatus and operating conditions can be employed. Examples of the catalytic reforming apparatus include a platinum alumina catalyst and a bimetallic alumina catalyst obtained by adding a second metal such as rhenium, germanium, tin, or iridium to platinum. As such an apparatus, for example, a desulfurized desulfurization straight-run heavy naphtha having a boiling point range of about 80 to 180 ° C. is processed to reformate which is a high octane gasoline base material, or aromatic carbonization such as benzene, toluene and xylene. An apparatus widely used for obtaining hydrogen can be used. For example, there are UOP platforming process, reniforming process, ERE power forming process, and magna forming process described in Non-Patent Document 1.

  The reaction temperature is preferably 400 to 600 ° C, more preferably 450 to 550 ° C. LHSV (liquid hourly space velocity) is preferably 0.5 to 5h-1, more preferably 1 to 2h-1. The reaction pressure is preferably 0.1 to 2 MPa, more preferably 0.2 to 1.5 MPa. The hydrogen / oil ratio (molar ratio) is preferably 0.5 to 10, more preferably 1 to 5.

  In the present embodiment, from the viewpoint that the obtained reformed gasoline can be applied as an excellent gasoline base material, the aromatic hydrocarbon content concentration in the third composition obtained in the second step is 50% by mass. Preferably, it becomes 70% by mass or more, more preferably 80% by mass or more.

  In the present embodiment, a part of the raw material oil, or another raw material oil having a boiling point of 30 ° C. or higher and 200 ° C. or lower and an aromatic hydrocarbon content concentration of 1 to 30% by mass is used as the reforming raw material. It can be contained in oil. For example, in the manufacturing system 100 shown in FIG. 1, a part of the raw material oil can be included in the reformed raw material oil via the line 17. Further, when other raw material oil is contained, the above-mentioned catalytic cracking gasoline can be contained in the reformed raw material oil via the line 16.

  The reformed gasoline can be obtained through the reforming unit 20, but in the present embodiment, the second composition and the third composition are used from the viewpoint of co-production of the gasoline base material and the aromatic hydrocarbon. It is possible to further comprise a third step of separating the mixture of products into a fourth composition and a fifth composition having a higher concentration of aromatic hydrocarbons than the fourth composition. In this case, the processing unit 30 shown in FIG. 1 can be used as a separation unit for performing the above steps, and the fourth composition and the fifth composition can be taken out from the lines 7 and 8, respectively. The fourth composition can be obtained as a gasoline base material, and the fifth composition can be obtained as an aromatic hydrocarbon useful as a raw material for chemical products. The second composition can be mixed with the third composition via line 4 (dashed line).

  The separation unit can have the same configuration as the separation unit 10 described above, but may be separation by distillation.

  In the present embodiment, the aromatic hydrocarbon content in the fifth composition is preferably 90% by mass or more, and more preferably 95% by mass or more.

  The gasoline base material obtained by the method according to this embodiment has a sulfur content of 5 ppm by mass or less, preferably 1 ppm by mass or less, more preferably 0.5 ppm by mass or less, and particularly preferably 0.1 ppm by mass or less. It is preferable that When the sulfur content is 5 mass ppm or less, it is easy to maintain flexibility when producing a gasoline composition by mixing with other gasoline base materials. Further, the nitrogen content of the gasoline base is preferably 1 ppm by mass or less, and more preferably 0.5 ppm by mass or less. The RON of the gasoline base material is preferably 100 or more, more preferably 102 or more, and still more preferably 104 or more. When RON is 100 or more, it becomes easy to maintain the flexibility when producing a gasoline composition by mixing with other gasoline base materials.

  The aromatic hydrocarbon obtained by the method according to this embodiment preferably has a nitrogen content of 1 mass ppm or less, and more preferably 0.5 mass ppm or less. When the nitrogen content is 1 mass ppm or less, the possibility of adverse effects in the process of obtaining higher-value-added aromatic hydrocarbons is reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example.

[Evaluation of separation performance of separation membrane]
(Membrane separator)
The membrane separation apparatus shown in FIG. 2 was prepared, and the separation ability of the separation membrane was evaluated using this device. The apparatus shown in FIG. 2 includes a membrane separation cell 54 that can accommodate a separation membrane 55, a feed tank 50a that feeds the feed through a feed line 53 having a preheater to the membrane separation cell 54, and a pump 50b. 51, a supply cylinder 52 connected to the membrane separation cell 54 for supplying a permeated component sweep gas, a heater 56 for heating the membrane separation cell 54, and a non-permeate component for taking out from the membrane separation cell 54 A non-permeate gas line 57 and a permeate gas line 58 for extracting a permeate component from the membrane separation cell 54 are provided.

  In this apparatus, the raw material can be supplied to the membrane separation cell 54 while being vaporized by a supply line 53 having a preheater. The components obtained from the non-permeating gas line 57 and the permeating gas line 58 can be collected in a recovery tank cooled with liquid nitrogen, and analyzed by a gas chromatograph.

(Separation membrane)
Zeolite particles are supported by dip coating on the outer surface of a tubular support (30 mm × 10 mmφ, thickness 1 mm) made of porous alumina, and this support is loaded with water glass, sodium aluminate, and deionized water. A NaY-type zeolite membrane element having a membrane area of 0.00094 m 2 was prepared by immersing in the solution contained therein and performing hydrothermal treatment at 60 ° C. for 24 hours while stirring. This NaY type zeolite membrane element was installed in the apparatus of FIG. 2 as a separation membrane, and an evaluation test was conducted. The effective membrane area after installation was 0.00063 m2.

A hydrocarbon composition having the composition shown in Table 1 as a feedstock was placed in a feed tank 50a and fed at 0.3 g / min into a membrane separation cell 54 maintained at atmospheric pressure while being vaporized by a feed line 53. The temperature of the separation membrane was set to 150 ° C. by the heater 56, helium gas was flowed at a rate of 300 mL / min as a carrier gas, and the permeate gas was collected in a recovery tank cooled with liquid nitrogen, and this was analyzed by a gas chromatograph. . The pressure on the non-permeate side at this time was atmospheric pressure (101 kPa), and the partial pressure of the hydrocarbon on the permeate side was 0.2 kPa. Further, Table 2 shows the transmittance (mol · m−2 · s−1 · Pa−1) of the components of each compound at this time. In addition, Table 3 shows the separation factor of the predetermined compound (component A) for the predetermined compound (component B) at this time. The separation factor of component A with respect to component B is the component A (mol%) in the permeate gas with respect to the ratio of component A (mol%) and component B (mol%) in the feedstock defined by the following formula: It calculated from the value of ratio with component B (mol%).
Separation coefficient of component A with respect to component B = (Pa / Pb) / (Fa / Fb)
Pa: mol concentration of component A in permeate gas Pb: mol concentration of component B in permeate gas Fa: mol concentration of component A in feedstock Fb: mol concentration of component B in feedstock

[Manufacture of reformed gasoline]

Example 1
Based on the separation results (permeability and separation coefficient) obtained with the separation membrane, a simulation for supplying the raw material naphtha A (Table 4) having the same composition as the heavy naphtha fraction obtained from the atmospheric distillation apparatus to the separation membrane is performed. went. At this time, naphtha B after separation in which an amount corresponding to 90% by mass of the aromatic fraction contained in raw material naphtha A was separated was obtained. The obtained post-separation naphtha B was used as a reforming raw material oil, and a simulation was performed on the reaction to obtain the reformed product C by the following catalytic reforming.
Supply amount of reforming raw material oil: 117.6 ton / h
Reaction temperature: 490 ° C
Reaction pressure: 0.42 MPaG
LHSV: 1.7h-1
Hydrogen / hydrocarbon molar ratio: 1.7

  Table 4 shows the compositions of the separated naphtha B and the modified product C obtained by calculation. In addition, a simulation was performed for a reaction in which the raw material naphtha A was used as a reformed raw material oil and the reformed product D was obtained under the same conditions as described above. Table 4 shows the calculation results.

  The amount of increase in aromatic content when the naphtha B is modified after separation (aromatic content in the reformed product−aromatic content in the reformed raw material) is 67.3 ton / h. It increased by 9.6 ton / h compared with 57.7 ton / h in the case of modification. In addition, when the naphtha B is reformed after separation, the conversion rate from non-aromatic component to aromatic component and the conversion rate from linear hydrocarbon to aromatic component are 58.3% and 84.3%, respectively. It was higher than 57.6% and 83.2% when the raw material naphtha A was modified.

  These results indicate that separation of aromatic hydrocarbons from the reformed feedstock improved the reactivity in catalytic reforming, leading to an increase in the aromatic content produced.

  1, 3, 4, 5, 6, 7, 8, 11, 13, 15, 16, 17, 18 ... line, 2 ... atmospheric distillation apparatus, 10 ... separation unit, 12 ... distillation column, 14 ... fluid catalytic cracking Apparatus, 20 ... reforming unit, 30 ... processing unit, 50a ... supply tank, 50b ... pump, 51 ... raw material supply unit, 52 ... supply cylinder, 53 ... supply line, 54 ... membrane separation cell, 55 ... separation membrane, 56 ... heater, 57 ... non-permeate gas line, 58 ... permeate gas line, 100 ... production system.

Claims (6)

A feedstock containing a hydrocarbon having 6 to 10 carbon atoms and having an aromatic hydrocarbon content concentration of 1 to 30% by mass is composed of a first composition and an aromatic hydrocarbon more than the first composition. A first step of separating into a second composition having a high content concentration;
A second step in which a reformed feedstock containing the first composition is contact-reformed to obtain a third composition having a higher aromatic hydrocarbon content concentration than the reformed feedstock;
With
A method for producing reformed gasoline, wherein the reformed feedstock contains catalytic cracked gasoline.   A part of the raw material oil, or another raw material oil having a boiling point of 30 ° C. or higher and 200 ° C. or lower and an aromatic hydrocarbon content concentration of 1 to 30% by mass is contained in the reformed raw material oil. Item 2. A method for producing the reformed gasoline according to Item 1. A feedstock containing a hydrocarbon having 6 to 10 carbon atoms and having an aromatic hydrocarbon content concentration of 1 to 30% by mass is composed of a first composition and an aromatic hydrocarbon more than the first composition. A first step of separating into a second composition having a high content concentration;
A second step in which a reformed feedstock containing the first composition is contact-reformed to obtain a third composition having a higher aromatic hydrocarbon content concentration than the reformed feedstock;
With
A method for producing reformed gasoline, wherein the reformed feedstock contains a part of the feedstock.   4. The method according to claim 1, wherein in the first step, the first composition and the second composition are obtained by one or more separation operations of distillation separation, extraction separation, membrane separation, and adsorption separation. A method for producing the reformed gasoline according to claim 1.   The method for producing reformed gasoline according to any one of claims 1 to 4, wherein in the first step, the first composition and the second composition are obtained by membrane separation. The aromatic hydrocarbon content concentration in the first composition obtained in the first step is smaller than the aromatic hydrocarbon content concentration in the feedstock,
The method for producing a reformed gasoline according to any one of claims 1 to 5, wherein the content concentration of the aromatic hydrocarbon in the third composition obtained in the second step is 50% by mass or more.

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