JP5491912B2 - Method for producing kerosene oil base and alkylbenzenes - Google Patents

Description

  The present invention relates to a method for producing a kerosene base material and alkylbenzenes from a fraction containing a relatively large amount of non-aromatic hydrocarbons.

  Alkylbenzenes represented by benzene, toluene and xylene (BTX) have been conventionally produced by a catalytic reforming method in petroleum refining. The catalytic reforming reaction is basically a reaction in which the carbon number does not change, but on the other hand, there is a large number of carbons, that is, the study to convert heavy oil into light oil such as gasoline fraction has long been studied. Consideration is ongoing. At that time, it is known to use a solid acid as a catalyst in order to perform a reaction for reducing the number of carbon atoms.

  As a method for selectively producing a monocyclic aromatic hydrocarbon from a polycyclic aromatic hydrocarbon, a selective hydrocracking technique is known (Patent Document 1). However, the raw material that can be used is required to have a large amount of aromatic hydrocarbons, and cannot be applied to those having a large amount of non-aromatic hydrocarbons. That is, if a fraction containing a large amount of non-aromatic hydrocarbons is hydrocracked, the gasification reaction proceeds and the liquid yield is reduced.

  A method of extracting an aromatic hydrocarbon having 6 to 8 carbon atoms from a fraction containing a relatively large amount of non-aromatic hydrocarbons is also known (Patent Documents 2 and 3), but it is only a separation method and is originally used as a raw material. This was a method of merely concentrating the aromatic hydrocarbon having 6 to 8 carbon atoms contained therein, and was not intended to increase the amount.

  On the other hand, from the viewpoint of fuel oil production, hydrorefining treatment is necessary in the case of raw material oils containing hetero compounds such as sulfur compounds and nitrogen compounds in addition to aromatic hydrocarbons. However, in conventional hydrorefining for such feedstocks, hydrogen consumption increases due to the progress of hydrogenation of aromatic hydrocarbons at the same time as desulfurization and denitrification, and aromatic hydrocarbons, especially polycyclic aromatics. There is a problem that the reaction must be carried out at a high temperature due to adsorption and poisoning of the catalytic active sites by hydrocarbons. In particular, when a kerosene oil fraction is used as a raw material oil and converted to fuel oil, an oil type containing a relatively large amount of aromatic hydrocarbons is not suitable.

  In the case of converting a polycyclic aromatic hydrocarbon to an alkylbenzene while producing a low-sulfur fuel oil, in particular, a kerosene oil base material, using the raw material containing a large amount of non-aromatic hydrocarbons, the target alkylbenzenes No method has been established for selectively and efficiently obtaining a gas without excessive generation of gas.

International Publication No. 2007/135769 JP 2004-323544 A JP 2006-089659 A

  Under such circumstances, the present invention suppresses overdecomposition, efficiently produces high-value-added alkylbenzenes from polycyclic aromatic hydrocarbons, and saves the load required for desulfurization treatment while reducing the load of low-sulfur kerosene oil It is an object of the present invention to provide a method for manufacturing the same.

As a result of intensive studies, the inventors have obtained an alkylbenzene efficiently under relatively mild conditions by combining an appropriate separation operation with a desulfurization reaction and a decomposition reaction, and at the same time, a low-sulfur high-quality kerosene oil. The present inventors have found that a substrate can be obtained and have come up with the present invention.
That is, the present invention for solving the above-described problems is as follows.

(1) A non-aromatic raw material hydrocarbon oil containing less than 30% by volume of alkylbenzenes having 6 to 8 carbon atoms, 10% by volume or more of polycyclic aromatic hydrocarbons and 25% by volume or more of non-aromatic hydrocarbons. A first step of separating a fraction rich in hydrocarbons and a fraction rich in aromatic hydrocarbons, a second step of obtaining a kerosene oil base by desulfurizing a fraction rich in non-aromatic hydrocarbons, and A process for producing a kerosene oil base and alkylbenzenes comprising a third step in which a fraction containing a large amount of aromatic hydrocarbons is brought into contact with a hydrotreating catalyst in the presence of hydrogen and converted to alkylbenzenes having 6 to 8 carbon atoms. .

(2) The above-mentioned hydrocarbon oil containing at least one of kerosene fraction obtained from desulfurization apparatus or cracking apparatus of heavy oil, kerosene or diesel oil fraction obtained from atmospheric distillation apparatus, and desulfurized oil thereof ( A method for producing a kerosene oil base material and alkylbenzenes according to 1).
(3) The kerosene oil base material and alkylbenzene according to the above (1) or (2), wherein the separation in the first step uses one or more methods selected from extraction separation, membrane separation or adsorption separation Manufacturing method.
(4) The desulfurization treatment in the second step uses any one or more methods selected from hydrodesulfurization, extraction desulfurization, or adsorptive desulfurization, as described in any one of (1) to (3) above A method for producing kerosene oil base and alkylbenzenes.
(5) The lamp according to any one of (1) to (4), wherein the hydrotreating catalyst used in the third step contains at least one of Ni and Co and contains at least one of Mo or W. A method for producing a light oil base and alkylbenzenes.

  It is possible to obtain BTX from a fraction containing a relatively small amount of aromatic hydrocarbons and containing a large amount of non-aromatic hydrocarbons without complicated separation or reaction while suppressing an excessive decomposition reaction. At the same time, while reducing energy consumption, it is possible to produce low-sulfur, high-quality kerosene oil bases together with excellent total performance.

Hereinafter, embodiments of the present invention will be described in detail.
In the present invention, alkylbenzenes mean those in which hydrogen of benzene is substituted with 0 to 6 saturated hydrocarbon groups, and those other than unsubstituted are scientifically called alkylbenzenes. Refers to alkylbenzenes (which may be referred to as “single-ring aromatic hydrocarbons”) in which unsubstituted benzene is included in this alkylbenzene. In particular, a mixture of benzene, toluene and xylene is referred to as BTX. In addition, many of the saturated hydrocarbon groups to be substituted are lower alkyl groups having 1 to 4 carbon atoms.
In addition, one aromatic ring and one saturated naphthene ring such as tetralin (1,2,3,4-tetrahydronaphthalene), indane (2,3-dihydroindene), and cyclohexylbenzene are contained in one molecule. The compound having 1.5 ring aromatic hydrocarbons includes those obtained by substituting hydrogen of the aromatic ring and naphthene ring with chain hydrocarbon groups. Furthermore, tetralin and alkyltetralin may be collectively referred to as tetralins, indane and alkylindan may be collectively referred to as indans, and cyclohexylbenzene and alkylcyclohexylbenzene may be collectively referred to as cyclohexylbenzenes.

Furthermore, the polycyclic aromatic hydrocarbon is a hydrocarbon having two or more aromatic rings (one having a plurality of condensed rings and single rings bonded), and a hydrocarbon having two aromatic rings is called a two-ring aromatic hydrocarbon. .
Non-aromatic hydrocarbons are hydrocarbons other than aromatic hydrocarbons, and are mainly composed of linear and branched paraffins, olefins, and naphthenes.
In the present invention, those having a boiling point up to 30 ° C. are gas components, those having a boiling point of 30 to 85 ° C. are light naphtha fractions, those having a boiling point of 85 to 190 ° C. are heavy naphtha fractions, and those having a boiling point of 190 to 380 ° C. This is called kerosene oil fraction.

Hereinafter, the details of the present invention will be described sequentially by dividing into raw material hydrocarbon oil, first step, second step, and third step.
[Raw material hydrocarbon oil]
The raw material hydrocarbon oil used in the present invention is one having an alkylbenzene having 6 to 8 carbon atoms of less than 30% by volume, a polycyclic aromatic hydrocarbon of 10% by volume or more, and a non-aromatic hydrocarbon of 25% by volume or more. is there. Alkylbenzenes having 6 to 8 carbon atoms are 30% by volume or more, polycyclic aromatic hydrocarbons are less than 10% by volume, non-aromatic hydrocarbons are less than 25% by volume, alkylbenzenes and high-quality kerosene oil base Cannot be obtained in high yield.

The smaller the alkylbenzene having 6 to 8 carbon atoms, the more preferable it is for increasing the yield of alkylbenzenes, preferably less than 20% by volume, more preferably less than 10% by volume, and 0% by volume, that is, it may not be contained.
The more polycyclic aromatic hydrocarbons are preferred for increasing the yield of alkylbenzenes, preferably 20% by volume or more, more preferably 30% by volume or more, but 70% by volume from the balance with the kerosene oil base yield. The following is preferred.
The non-aromatic hydrocarbon is preferably 30% by volume or more, and more preferably 40% by volume or more in order to obtain a high-quality kerosene oil base material in a high yield, but 70% by volume from the balance with the yield of alkylbenzenes. % Or less is preferable.
In order to increase the yield of alkylbenzenes, it is preferable that 0 to 65% by volume of 1.5-ring aromatic hydrocarbon is contained, and 5 to 60% by volume is more preferable.

  Specifically, as the raw material hydrocarbon oil of the present invention, a distillate obtained by atmospheric distillation of crude oil, a vacuum gas oil obtained by vacuum distillation of atmospheric residue, a process for lightening various heavy oils Distillates obtained from (catalytic cracking device, thermal cracking device, etc.), for example, catalytic cracking oil (particularly LCO) obtained from catalytic cracking device, pyrolysis oil obtained from thermal cracking device (coker, visbreaking, etc.) , Heavy residues of ethylene crackers obtained from ethylene crackers, contact reformed oils obtained from catalytic reformers, and aromatic rich contact reformed oils obtained by extraction, distillation or membrane separation of contact reformed oils, Those satisfying the above composition ratio from a fraction obtained from an aromatic extraction device for producing a lubricating base oil, an aromatic rich fraction obtained from a solvent dewaxing device, or a fraction obtained by hydrorefining these. Properly selected, it can be used in combination. Here, the term “aromatic rich” refers to a material having 10 or more carbon atoms and a content of aromatic compound exceeding 50% by volume obtained from a catalytic reformer. In addition, desulfurization method or hydroconversion method to purify atmospheric distillation residue, vacuum distillation residue, dewaxed oil, oil sand, oil shale, coal, biomass, etc. (for example, heavy oil decomposition such as H-Oil process, OCR process, etc.) A distillate generated from a process or a cracking process of heavy oil with a supercritical fluid) can be suitably used alone or in combination as long as it satisfies the above composition ratio.

Moreover, the distillate obtained by processing combining the said some refiner | purifier suitably can also be used as raw material hydrocarbon oil of this invention. Furthermore, these raw material hydrocarbon oils may be used alone or as a mixture of two or more thereof. The alkylbenzene having 6 to 8 carbon atoms is less than 30% by volume, and the polycyclic aromatic hydrocarbon is 10% by volume. As long as the non-aromatic hydrocarbon is adjusted to be 25% by volume or more, it can be used without any problem.
Among the above-mentioned raw material hydrocarbon oils, catalytic cracking oil, pyrolysis oil, vacuum gas oil, ethylene cracker heavy residue, catalytic reforming oil, supercritical fluid cracking oil, or hydrorefined oils thereof are particularly preferable. Hydrodesulfurization of pyrolysis gas oil fraction obtained from pyrolysis equipment (coker, visbreaking, etc.) having a boiling point of 190 to 380 ° C., desulfurized kerosene, desulfurized gas oil and straight-run kerosene obtained from heavy oil desulfurization equipment Desulfurized kerosene obtained, desulfurized gas oil obtained by hydrodesulfurizing straight-run gas oil, and catalytic cracked gas oil are preferred.

  The raw material hydrocarbon oil of the present invention has a distillation property such that a 10% distillation temperature is preferably 180 to 280 ° C, more preferably 200 to 250 ° C, and a 90% distillation temperature is preferably 250 to 450 ° C, more preferably. Is composed of 300 to 380 ° C.

In addition, when using the petroleum fraction mentioned above as raw material hydrocarbon oil, about 0.1 to 0.3 weight% of nitrogen content and about 0.1 to 3 weight% of sulfur content are contained. The main sulfur compounds are benzothiophenes, dibenzothiophenes, and sulfides, but there are many benzothiophenes and dibenzothiophenes in the boiling range of the raw material hydrocarbon oil used in the present invention. Dibenzothiophene is stable because it is electronically delocalized, and since it is difficult to remove even if it is contacted with a catalyst mainly in the presence of hydrogen in the third step, the raw material hydrocarbon oil used in the present invention It is preferable that the content is not so much.
The sulfur content in the raw material hydrocarbon oil is preferably 500 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 50 ppm by weight or less, and the nitrogen content is preferably 50 ppm by weight or less, more preferably 20 ppm by weight or less. Particularly preferably, the content is 10 ppm by weight or less.

[First step]
In the first step, the present invention separates the raw material hydrocarbon oil into a fraction rich in non-aromatic hydrocarbons and a fraction rich in aromatic hydrocarbons. Any method can be used as long as it can be separated into a fraction rich in aromatic hydrocarbons and a fraction rich in aromatic hydrocarbons, but the extraction separation method, membrane separation method or adsorption separation method, or these two methods Use in combination of two or more is preferable because it can be carried out efficiently.

For extraction separation, as the extraction solvent, furfural, sulfolane, alkyl sulfolane, pyrrolidone, alkylpyrrolidone, phenol, ethylene glycol, diethylene glycol, triethylene glycol, dimethyl sulfoxide, diglycolamine, N-formylmorpholine, methyl carbamate, acetonitrile, etc. A method of extracting an aromatic hydrocarbon using a polar solvent that dissolves the aromatic hydrocarbon is preferred.
For extraction separation, an extraction tower having a plurality of extraction layers (for example, 20 stages) in the vertical direction is used, and raw material hydrocarbon oil is continuously supplied from the lower part thereof, while the extraction solvent is supplied from the upper part of the extraction tower. The method of supplying is preferable. In this case, the extraction conditions are determined in consideration of the properties of the raw material hydrocarbon oil, the type of extraction solvent, the form of the extraction tower, etc., but when using furfural as the extraction solvent, the extraction temperature is from room temperature to 300 ° C., pressure However, the pressure is appropriately selected within the range of the normal pressure to 10 MPa and the raw material hydrocarbon oil / solvent ratio of 1/10 to 10/1 L / L.

Polar solvents such as furfural, sulfolane, N-methylpyrrolidone, and phenol have low solubility in non-aromatic hydrocarbons and high solubility in sulfur compounds and aromatic hydrocarbons. In each of the extraction layers, aromatic hydrocarbons contained in the raw material hydrocarbon oil are extracted together with sulfur compounds (for example, thiophenes, benzothiophenes, mercaptans, etc.) and transferred to the solvent. For this reason, these aromatic hydrocarbons and sulfur compounds are extracted and removed from the upper part of the extraction tower, a fraction containing a large amount of non-aromatic hydrocarbons such as paraffin and olefin is extracted, and a small amount of the accompanying solvent is washed with water. It is removed by etc. A fraction containing a large amount of non-aromatic hydrocarbons from which a small amount of entrained solvent has been removed can be used as a kerosene base material by removing remaining sulfur compounds and the like in the second step.
A small amount of the recovered solvent is separated in a separate water stripper or the like and recycled to the extraction tower.
Further, when the boiling point of the extraction raw material is close to the boiling point of the polar solvent, the polar solvent cannot be removed only by a simple distillation operation. Therefore, a back extraction method in which another extractant having a different boiling point is added again can be applied.

  On the other hand, the extract containing a large amount of aromatic hydrocarbons is extracted from the lower part of the extraction tower, sent to the solvent recovery tower, separated into the solvent and the aromatic hydrocarbon, and the solvent is returned to the extraction tower again. The separated fraction containing a large amount of aromatic hydrocarbons is hydrotreated in the third step and converted to alkylbenzenes.

  Membrane separation is a method of separating a fraction containing a large amount of aromatic hydrocarbons from a fraction containing reduced aromatic hydrocarbons using a separation membrane. In the case of membrane separation, for example, a method of permeating only a compound having a small molecular size, such as an MFI type zeolite membrane having a molecular sieve function, and a Y type zeolite membrane, a silica membrane, a polymer membrane, etc. Although there is a method of allowing more specific compounds to permeate depending on the adsorption characteristics and dissolution characteristics of the separation membrane material, in the present invention, the latter method using the difference in polar characteristics of the molecules is particularly preferable.

  As a separation membrane, a porous support represented by alumina or stainless steel is used as a substrate, and an inorganic membrane represented by zeolite membrane or silica alumina membrane or an organic membrane represented by polyimide resin membrane is used as a porous support. A separation membrane formed on the surface or inside the pores can be used. The porous support may be one in which needle-like holes are continuous in a direction perpendicular to the stainless steel surface, or one in which alumina or metal fine particles are bonded. In addition, the material must have high mechanical strength and be stable in material properties in hydrothermal treatment and subsequent heat treatment for forming a zeolite layer. For example, ceramics such as alumina, titania, mullite, stainless steel, etc. Metal such as titanium and glass, glass and the like can be used, and a porous support such as titania and alumina is preferable. The shape of the porous support and the separation membrane may be any shape as long as it is suitable for separating hydrocarbons, for example, a membrane shape, a plate shape, a cylindrical shape, a cylindrical shape, and a honeycomb shape. Etc.

  Membrane separation operations include vapor permeation in which both the supply and permeate sides are in the gas phase, pervaporation in which the supply side is in the liquid phase and the permeate side is in the gas phase, Any method of the liquid phase method in which the both sides are in a liquid phase may be adopted, but more efficiency can be achieved by adopting a separation operation method in consideration of the boiling point range of the raw material. The separation operation temperature is not particularly limited, but a suitable temperature is obtained from the permeation rate and the separation factor, and normal temperature to 300 ° C is preferable, and 100 to 200 ° C is more preferable. The pressure is preferably a low pressure in order to avoid damage to the separation membrane, and an absolute pressure of 0.5 kPa to 0.5 MPa is particularly preferable.

  Adsorption separation is a method in which a fraction containing a large amount of aromatic hydrocarbons is adsorbed using an adsorbent to separate a fraction with reduced aromatic hydrocarbons. As the adsorbent used for the adsorption separation, porous inorganic oxides are preferable. For example, various zeolites represented by A type zeolite, ZSM-5 type (MFI type) zeolite, Y type zeolite, X type zeolite, silica, alumina, Examples thereof include silica alumina, titania, magnesia, zirconia, white clay, diatomaceous earth, activated carbon, and synthetic resin. An adsorbent may be used only by 1 type of the said compound, and may be used in combination of 2 or more type. For example, in the case of X-type zeolite, aromatic hydrocarbons, sulfur compounds, and nitrogen compounds having a strong polarity are taken into the pores and adsorbed, and the adsorbed polar compounds are desorbed by a compound having a higher adsorption power. Thus, only polar compounds can be separated. At the time of solvent desorption, desorption can also be performed using a temperature difference or a pressure difference.

  In various zeolites, cations that contribute to adsorption separation performance include protons (H), alkali metals such as sodium (Na) and potassium (K), and alkaline earths such as magnesium (Mg) and calcium (Ca). A metal is preferred, but a transition metal may also be used. Specific examples of the transition metal include silver (Ag), platinum (Pt), ruthenium (Ru), rhodium (Rh), nickel (Ni), copper (Cu), and the like. Adsorbents other than zeolite, such as silica, alumina, silica alumina, titania, magnesia, zirconia, clay, diatomaceous earth, activated carbon, synthetic resin, etc. also contain these cations and have improved adsorption performance. It may be. The adsorbent is preferably in the form of powder, pellets, tablets, or beads.

In the adsorptive separation, the pressure is preferably a low pressure from the viewpoint of separation ability, and particularly preferably 0.1 to 0.5 MPa. Although the separation operation temperature is not particularly limited, it may be obtained by obtaining a suitable temperature from the adsorption rate and adsorption equilibrium, and is generally preferably 0 to 200 ° C, more preferably 20 to 100 ° C. Is done. If the liquid space velocity is excessively high, the separation ability is lowered. On the other hand, if the liquid space velocity is too low, the apparatus becomes too large. Specifically, LHSV is preferably 0.05~10h ^-1, 0.1~5h ^-1 is particularly preferred. Further, when the adsorbed polar compound is desorbed from the adsorbent, a gas such as hydrogen or nitrogen may coexist.

[Second step]
In the present invention, in the second step, the kerosene oil base material is obtained by desulfurizing the fraction containing a large amount of the non-aromatic hydrocarbons separated in the first step. For this desulfurization treatment, various desulfurization methods usually used in petroleum refining can be applied, but hydrodesulfurization, extraction desulfurization or adsorptive desulfurization is preferable because it is low in cost and can be efficiently desulfurized. . As described above, most of the sulfur compounds in the raw hydrocarbon oil are transferred to a fraction containing a large amount of aromatic hydrocarbons, and the amount of sulfur compounds in the non-aromatic hydrocarbons is small. Accordingly, the desulfurization treatment here is sufficient under relatively mild conditions as compared with a normal case.
In this step, the sulfur compound is preferably 10 ppm by weight or less, more preferably 8 ppm by weight or less, and particularly preferably 5 ppm by weight or less. When the concentration of the sulfur compound exceeds 10 ppm by weight, the blending amount is limited, and therefore it is not preferable as a kerosene oil base.

  Hydrodesulfurization is performed by bringing a fraction rich in non-aromatic hydrocarbons into contact with a hydrorefining catalyst in the presence of hydrogen. As the hydrorefining catalyst, a commercially available catalyst can be used, and a catalyst in which at least one metal selected from Groups 6 and 8 of the periodic table is supported on a refractory oxide support is suitable. Can be used. As such a catalyst, specifically, a support containing at least one selected from alumina, silica, boria, and zeolite, molybdenum, tungsten, nickel, which are metals of Groups 6 and 8 of the periodic table. , Cobalt, platinum, palladium, iron, ruthenium, osmium, rhodium, iridium, and a catalyst on which at least one metal selected from the group is supported. The hydrorefining catalyst may be used after being subjected to treatments such as drying, reduction, and sulfidation before the hydrogenation reaction, if necessary.

This hydrodesulfurization reaction is not generally determined depending on the properties of the raw hydrocarbon oil, the catalyst, the form of the reaction apparatus, the desired desulfurization rate, etc., but generally the temperature is 150 to 400 ° C., more preferably 200 to 380. ° C., further preferably from 250 to 360 ° C., pressure 1 to 10 MPa, more preferably 2 to 8 MPa, liquid hourly space velocity (LHSV) 0.1~10.0h ^-1, more preferably 0.1～8.0H ^{- 1} , more preferably 0.2 to 5.0 h ⁻¹ , hydrogen / hydrocarbon ratio of 100 to 5000 NL / L, preferably 150 to 3000 NL / L.

Extraction desulfurization is a method in which a fraction containing a large amount of sulfur is extracted using a solvent and a fraction having a reduced sulfur content is separated. Solvents used include furfural, sulfolane, alkyl sulfolane, pyrrolidone, N-methylpyrrolidone, phenol, ethylene glycol, diethylene glycol, triethylene glycol, dimethyl sulfoxide, diglycolamine, N-formylmorpholine, methyl carbamate, acetonitrile, All of them have a large dissolving power for sulfur compounds.
The conditions for extraction desulfurization cannot be determined in general depending on the type of solvent used, the boiling point range of the oil used as a raw material, and the regeneration temperature of the solvent and the energy efficiency of the entire process. It is a pressure range of normal pressure to 10 MPa in a temperature range of ˜300 ° C.

  Adsorption desulfurization is a method in which a fraction containing a large amount of sulfur is adsorbed using an adsorbent, and a fraction having a reduced sulfur content is separated. As the adsorbent used for adsorptive desulfurization, porous inorganic oxides are preferable. For example, various zeolites represented by A-type zeolite, ZSM-5 type (MFI type) zeolite, Y-type zeolite, X-type zeolite, silica, alumina, Examples thereof include silica alumina, titania, magnesia, zirconia, white clay, diatomaceous earth, activated carbon, and synthetic resin. An adsorbent may be used only by 1 type of the said compound, and may be used in combination of 2 or more type. For example, in the case of A-type zeolite, only a highly polar sulfur compound is taken into the pores and adsorbed, and the adsorbed sulfur compound is desorbed by a compound having a higher adsorbing power to separate only the sulfur compound. can do. At the time of solvent desorption, desorption can also be performed using a temperature difference or a pressure difference. Further, not the solvent desorption but a method of burning and removing can be applied.

  In various zeolites, cations that contribute to adsorption separation performance include protons (H), alkali metals such as sodium (Na) and potassium (K), and alkaline earths such as magnesium (Mg) and calcium (Ca). A metal is preferred, but a transition metal may also be used. Specific examples of the transition metal include silver (Ag), platinum (Pt), ruthenium (Ru), rhodium (Rh), nickel (Ni), copper (Cu), and the like. Adsorbents other than zeolite, such as silica, alumina, silica alumina, titania, magnesia, zirconia, clay, diatomaceous earth, activated carbon, synthetic resin, etc. also contain these cations and have improved adsorption performance. It may be. The adsorbent is preferably in the form of powder, pellets, tablets, or beads.

In the adsorptive desulfurization, the pressure is preferably a low pressure from the viewpoint of separability, and particularly preferably 0.1 to 0.5 MPa. Although the separation operation temperature is not particularly limited, it may be obtained by obtaining a suitable temperature from the adsorption rate and adsorption equilibrium, and is generally preferably 0 to 200 ° C, more preferably 20 to 100 ° C. Is done. If the liquid space velocity is excessively high, the separation ability is lowered. On the other hand, if the liquid space velocity is too low, the apparatus becomes too large. Specifically, LHSV is preferably 0.05~10h ^-1, 0.1~5h ^-1 is particularly preferred. Further, when the adsorbed sulfur compound is desorbed from the adsorbent, a gas such as hydrogen or nitrogen may coexist.

The desulfurized product oil obtained by the above method is obtained by distillation separation, etc., so that the lighter part from the boiling point of about 0-30 ° C. is the LPG fraction, the higher boiling point to 150-215 ° C. is the gasoline fraction, A portion with a high boiling point up to about 215 to 260 ° C. can be used as a kerosene fraction, and a portion with a higher boiling point up to about 260 to 370 ° C. can be used as a light oil fraction. The desulfurized product oil obtained from the raw material hydrocarbon oil has a particularly large kerosene fraction and a light oil fraction, and these can be used as a kerosene base material.
Since this kerosene oil base material contains almost no aromatic hydrocarbon, the kerosene base material has a low smoke point, the light oil base material has a high cetane number, low sulfur, and a high quality base material.

[Third step]
In the third step, the present invention, in the third step, the fraction containing a large amount of aromatic hydrocarbons separated in the first step is brought into contact with the hydrotreating catalyst in the presence of hydrogen to convert the polycyclic aromatic hydrocarbons to the number of carbon atoms. Convert to 6-8 alkyl benzenes.
In this case, a method of converting polycyclic aromatic hydrocarbons into alkylbenzenes having 6 to 8 carbon atoms in a single step using a hydrocracking catalyst, and a partial nuclear water of polycyclic aromatic hydrocarbons using a hydrotreating catalyst There is a method in which a 1.5-ring aromatic hydrocarbon composed of one aromatic ring and a naphthene ring is added, and the naphthene ring is cleaved to convert to an alkylbenzene, and any of them may be used.

  However, since the fraction containing a large amount of aromatic hydrocarbons separated in the first step contains a large amount of sulfur compounds as described above, first, hydrodesulfurization and partial nuclei using a hydrodesulfurization catalyst are used. It is preferable to perform hydrogenation and then to cause a ring-opening reaction with a hydrocracking catalyst having a relatively mild hydrocracking reaction and a relatively low acid strength because a large amount of alkylbenzenes can be obtained.

  Hydrodesulfurization and partial nuclear hydrogenation can be performed by the same method as the hydrodesulfurization method described in the second step. In this case, the sulfur content is preferably 500 ppm by weight or less, more preferably 100 ppm by weight or less, particularly preferably 50 ppm by weight or less, and the nitrogen content is preferably 100 ppm by weight or less, more preferably 20 ppm by weight or less, particularly preferably. Reduce to 10 ppm by weight or less. Along with the desulfurization and denitrogenation reactions, the hydrogenation of aromatic hydrocarbons partially proceeds, but it is not desirable to reduce the amount of alkylbenzenes. Accordingly, it is preferable to treat the reaction conditions so that the polycyclic aromatic hydrocarbon can be hydrogenated to a single ring or 1.5 ring aromatic hydrocarbon, and for this purpose, on a volume basis. It is preferable to control so that the total aromatic hydrocarbon amount after the reaction remains 0.50 or more before the reaction, and a more preferable remaining ratio is 0.60 or more, and further preferably 0.70 or more.

  On the other hand, in order to convert polycyclic aromatic hydrocarbons to alkylbenzenes, in the presence of hydrogen, a carrier composed of a composite oxide and a binder that binds it is supported on groups 6 and 8 of the periodic table. It can be carried out by using a hydrocracking catalyst carrying at least one metal component selected from the group. In particular, the metal component selected from Groups 6 and 8 of the periodic table is preferably at least one of Ni and Co and at least one of Mo or W.

  The composite oxide is selected from silica-alumina, silica-titania, silica-zirconia, silica-magnesia, silica-alumina-titania, silica-alumina-zirconia, tungsten oxide-zirconia, sulfated zirconia, alumina sulfate, and zeolite. One kind can be used alone, or two or more kinds can be used in combination. In particular, silica-alumina and zeolite are preferably used.

In addition, when hydrodesulfurization and partial nuclear hydrogenation are performed in advance, it is preferable to use a zeolite having a maximum acid strength of Bronsted acid of 110 kJ / mol to less than 140 kJ / mol as the composite oxide. When the maximum acid strength of Bronsted acid is less than 110 kJ / mol, a sufficient acid point is not imparted, so that the ring-opening reaction does not proceed easily. When the maximum acid strength is 140 kJ / mol or more, only the ring-opening reaction occurs. Since the hydrocracking such as dealkylation reaction or nuclear hydrogenation reaction proceeds excessively and the liquid yield decreases, it is not preferable, and the yield of alkylbenzenes decreases.
The maximum acid strength of this Bronsted acid is determined as the heat of adsorption of ammonia, and the measurement method is N. Katada, T. Tsubaki, M. Niwa, Appl. Cat. A: Gen., 340, (2008) 76 Page, or Naoto Katada, Miki Niwa, Zeolite, Vol. 21, (2004), p. 45, ammonia adsorption-temperature desorption method (NH ₃ -TPD method) and Fourier transform infrared spectroscopy (FT- (IR method). That is, the amount of acid is determined from the difference in absorption temperature at each temperature due to the bending vibration (1430 cm ⁻¹ ) of Bronsted acid. Assuming that the heat of adsorption of ammonia is constant, the maximum acid strength distribution is determined from the temperature dependence. In the obtained distribution, the strong acid side peak of Bronsted acid is read, and this is used as the maximum acid strength.

Reaction conditions such as reaction temperature, reaction pressure, hydrogen flow rate, and liquid space velocity for conversion of polycyclic aromatic hydrocarbons to alkylbenzenes are generally determined by the properties of the raw hydrocarbon oil, hydrotreating catalyst, equipment, etc. In general, in the presence of hydrogen, the reaction temperature is 200 to 450 ° C, more preferably 250 to 430 ° C, still more preferably 280 to 400 ° C, the reaction pressure is 2 to 10 MPa, more preferably 2 to 8 MPa, The liquid space velocity (LHSV) is 0.1 to 10.0 h ⁻¹ , more preferably 0.2 to 5.0 h ⁻¹ , still more preferably 0.3 to 3.0 h ⁻¹ , and the hydrogen / hydrocarbon ratio (volume) Ratio) 100 to 5,000 NL / L, preferably 150 to 3,000 NL / L.
By the above operation, the polycyclic aromatic hydrocarbon is partially decomposed and converted into desired monocyclic aromatic alkylbenzenes.

EXAMPLES Hereinafter, although this invention is demonstrated concretely using an Example and a comparative example, this invention is not limited to this.
In addition, the analysis method of the raw material oil and produced | generated oil property in an Example and a comparative example, and the measuring apparatus and method used in the catalyst physical property measurement are as follows.

[Property analysis]
The density was measured by the vibration type density test method of JIS K2249, and the distillation property was measured by the atmospheric pressure distillation test method of JIS K2254.
The composition of alkylbenzenes (benzene, toluene, xylenes) and 1.5-ring aromatic hydrocarbons (tetralins, etc.) was measured using a hydrocarbon total component analyzer manufactured by Shimadzu Corporation and measured according to JIS K2536. did.
For the type analysis (ring analysis) of aromatic compounds, a high-performance liquid chromatograph is used in accordance with the Petroleum Institute method JPI-5S-49-97, normal hexane is used for the mobile phase, and RI is used for the detector. Measured.
The sulfur content was measured by the fluorescent X-ray method in the high concentration region and the microcoulometric titration method in the low concentration region according to the sulfur content test method of JIS K2541.
The nitrogen content was measured by a chemiluminescence method according to the nitrogen content test method of JIS K2609.

[Maximum acid strength of Bronsted acid]
About 10 mg of sample was compression-molded into a disk shape with a diameter of 10 mm, set in an in-situ infrared cell, heated in oxygen 40 kPa (300 Torr), kept at 500 ° C. for 1 hour, and kept at 500 ° C. 15 After vacuum degassing for minutes, the temperature was lowered to 100 ° C. while maintaining the vacuum, and then 82 μmol / s (120 cm ³ / min in the standard state volume) of He was circulated to keep the system at 3.33 kPa (25 Torr). The temperature was raised to 500 ° C at a rate of ° C / min, and the IR spectrum was measured once at 10 ° C during the temperature rise. Subsequently, 133 kPa of ammonia was introduced at 100 ° C. and maintained for 30 minutes. After degassing for 30 minutes, He was circulated under the same conditions as before adsorption, the temperature was increased, and IR spectrum and MS spectrum were measured. After the measurement, a known amount of ammonia was sent to the mass spectrometer to correct the MS spectrum. The amounts of Bronsted acid (1430 cm ^-1 ) and Lewis acid (1330 cm ^-1 ) are quantified by the bending vibration of ammonia, and the respective acid strength distributions are obtained from the temperature dependence of ammonia desorbed from both acid points. In the obtained distribution, the strong acid side peak of Bronsted acid was read out and taken as the maximum acid strength.

[Measurement method of pore characteristics]
For measurement of pore characteristics (specific surface area, pore volume occupied by pores having a pore diameter of 2 nm to less than 60 nm, central pore diameter) by a nitrogen gas adsorption method, an ASAP2400 type measuring instrument manufactured by Micromeritics was used.

Example 1
Extraction operation was performed using a pyrolysis gas oil fraction having the properties shown in Table 1 as a raw material hydrocarbon oil and using furfural as a solvent. 50% raw material hydrocarbon and 50% furfural are extracted by mixing and stirring vigorously at room temperature and normal pressure, and the operation of removing the furfural layer by decantation is repeated three times, followed by washing and dewatering the raffinate. Was purified by passing 2 L through a column packed with 500 g of silica gel activated at 140 ° C. for 5 hours. The extract was obtained by distilling off furfural. As a result of the extraction operation, 50% by volume of raffinate and 50% by volume of extract were obtained.

The sulfur and nitrogen contained in the raffinate are 6,596 ppm by weight and 25 ppm by weight, respectively, and the hydrocarbon composition is 0.5% by volume of aromatic hydrocarbons, 58.5% by volume of saturated hydrocarbons, The olefin was 41.0% by volume.
The sulfur and nitrogen contained in the extract were 4.2% by weight and 1,257% by weight, respectively, and the hydrocarbon composition was 66.8% by volume of aromatic hydrocarbons and 16% of saturated hydrocarbons. It was 0.2% by volume and olefin was 17.0% by volume.

Subsequently, using the obtained raffinate as a raw material oil, a commercially available NiMoP-supported desulfurization catalyst A (composition: Mo12.3) under the conditions of a reaction pressure of 8.0 MPa, LHSV 0.9 h ⁻¹ , and a hydrogen / raw oil ratio of 300 NL / L. Wt%, Ni 3.5 wt%, P 2.0 wt%, Al 43.3 wt%, specific surface area: 185 m ² / g, pore volume in the range of pore diameter 2-60 nm: 0.415 mL / g, Hydrodesulfurization treatment was performed using a median pore diameter: 7.9 nm).
As a result, the reaction temperature necessary to obtain a light oil base material having a sulfur content of 8 ppm by weight was 316 ° C., and the cetane number at that time was 80.

On the other hand, the extract obtained by the extraction operation was converted into a monocyclic aromatic hydrocarbon such as BTX by selective hydrogenolysis.
In the selective hydrocracking, 100 ml of the same commercially available NiMoP-supported desulfurization catalyst A as described above is charged in the first column, and 22 ml of hydrocracking catalyst B is charged in the second column, and the reaction pressure is 7.0 MPa, LHSV0. The hydrocracking reaction was carried out under the conditions of .11 h ⁻¹ , hydrogen / raw oil ratio 1,400 NL / L, reaction temperature 340 ° C. in the first column, and reaction temperature 360 ° C. in the second column.
Hydrocracking catalyst B is composed of H-β type zeolite (Lot-081106H manufactured by N.E. Chemcat) having an SiO ₂ / Al ₂ O ₃ ratio of 31.3 (molar ratio) and a specific surface area of 706 m ² / g, and alumina. (Alumina Versal 250 manufactured by UOP Co., Ltd.) A carrier obtained so that the dry weight (at 130 ° C.) was 50% by weight and 50% by weight, respectively, was spray impregnated with an aqueous ammonium molybdate solution and an aqueous nickel nitrate solution. And dried at 130 ° C. for 6 hours. Subsequently, it was obtained by firing at 500 ° C. for 30 minutes under an air stream. Mo and Ni contained in the catalyst B were 7.2% by weight and 2.7% by weight, respectively, and the highest acid strength of Bronsted acid of the used zeolite was 125 kJ / mol.

  As a result, a gas content of 12.8% by volume, a light naphtha content of 9.9% by volume, a heavy naphtha content of 30.7% by volume, and a kerosene oil content of 8.3% by volume were obtained as products on the basis of raw pyrolysis gas oil. . Of these, 12.8% by volume was obtained as alkylbenzenes, and BTX contained 6.1% by volume as the inner number.

(Comparative Example 1)
Using the same raw material hydrocarbon oil as in Example 1, conventional hydrodesulfurization treatment was performed without extracting and separating aromatic hydrocarbons. As the desulfurization catalyst, the same commercially available NiMoP-supported desulfurization catalyst A as in the examples was used, and hydrogenation was performed under the conditions of a reaction pressure of 8.0 MPa, LHSV of 0.9 h ⁻¹ , a hydrogen / feed oil ratio of 300 NL / L, and a reaction temperature of 316 ° C. Desulfurization treatment was performed.
As a result, the reaction temperature required to obtain a light oil base material having a sulfur content of 8 ppm by weight was 336 ° C., and the cetane number at that time was 59. The total aromatic hydrocarbon content in the product oil was 14.3% by volume, and BTX was 0.1% by volume or less.

(Comparative Example 2)
Using the same raw material hydrocarbon oil as in Example 1, the conventional selective hydrocracking treatment was performed without extracting and separating aromatic hydrocarbons. The same catalyst and reaction conditions as in the examples were applied.
As a result, a gas content of 55.3% by volume, a light naphtha content of 8.9% by volume, a heavy naphtha content of 27.6% by volume, and a kerosene oil content of 52.9% by volume were obtained as products. Of these, 11.5% by volume was obtained as alkylbenzenes, and BTX was 5.4% by volume. Moreover, the cetane number of the obtained kerosene oil was 30.

  In Example 1, 50% by volume and 12.8% by volume of an alkylbenzene containing a low sulfur gas oil base material having a cetane number of 80 and BTX could be simultaneously produced. In particular, BTX contained 6.1% by volume. On the other hand, in Comparative Example 1, BTXs are not obtained at all, and a high reaction temperature is required to make the sulfur content 8 ppm by weight, so even if a great amount of energy is consumed during hydrodesulfurization, Only a light oil base having a cetane number of 59 can be obtained. Further, in Comparative Example 2, only the selective hydrocracking reaction accompanied with a great amount of gas generation proceeds, the produced light oil base material has a low cetane number, and only 11.5% by volume of alkylbenzenes can be obtained. BTX was 5.4% by volume.

  Using a base material having a relatively low concentration of aromatic hydrocarbon as a raw material, it is possible to obtain BTX without complicated separation and reaction while suppressing an excessive decomposition reaction. At the same time, high-quality fuel base materials can be manufactured together, and the total performance is excellent. The energy consumption required for the production of fuel base materials and alkylbenzenes such as BTX can be comprehensively reduced because the energy input required for desulfurization treatment can be reduced and excessive gas generation can be suppressed without requiring complicated separation operations. Can be suppressed.

Claims (4)

Extraction separation, membrane separation, or raw material hydrocarbon oil having less than 30% by volume of alkylbenzenes having 6 to 8 carbon atoms, 10% by volume or more of polycyclic aromatic hydrocarbons and 25% by volume or more of non-aromatic hydrocarbons A first step of separating a non-aromatic hydrocarbon-rich fraction and an aromatic hydrocarbon-rich fraction using one or more methods selected from adsorptive separation, and containing a large amount of non-aromatic hydrocarbons In the second step of obtaining a kerosene oil base by desulfurizing the fraction, and in the presence of hydrogen, the fraction containing a large amount of aromatic hydrocarbons in a carrier composed of a composite oxide and a binder that binds it. A polycyclic aromatic hydrocarbon is converted into an alkylbenzene having 6 to 8 carbon atoms by contacting with a hydrocracking catalyst supporting at least one metal component selected from Groups 6 and 8 of the periodic table. Kerosene oil base characterized by including a third step Manufacturing method of the alkylbenzenes.   The feed hydrocarbon oil contains at least one of kerosene fraction obtained from a desulfurizer or cracker of heavy oil, kerosene or diesel fraction obtained from an atmospheric distillation unit, and desulfurized oil thereof. Of kerosene oil base and alkylbenzenes. The production of kerosene oil base material and alkylbenzene according to claim 1 or 2 , wherein the desulfurization treatment in the second step uses one or more methods selected from hydrodesulfurization, extraction desulfurization or adsorptive desulfurization. Method. The kerosene base material according to any one of claims 1 to 3 , wherein the hydrocracking catalyst used in the third step contains at least one of Ni and Co and carries at least one of Mo or W. And production method of alkylbenzenes.