Amorphous silica alumina

Abstract

To provide an amorphous silica-alumina capable of controlling a hydrocracking reaction of a long-chain paraffin to primary cracking with high efficiency and exhibiting high catalytic activity when containing an active metal element, and to provide a method for producing the same.SOLUTION: The amorphous silica-alumina has a ratio of the pore volume of pores having a diameter of 0-2 nm to the pore volume of pores having a diameter of 0-10 nm of ≥60% and a specific surface area of ≥280m2 / g.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to amorphous silica-alumina. [Background technology]

[0002] In the hydrocracking of long-chain paraffins using a bifunctional catalyst, if the catalyst's hydrogenation ability is low and its acidity is too high, repeated cleavage of carbon bonds occurs, resulting in an increase in the production of hydrocarbons with one to four carbon atoms and a decrease in the production of hydrocarbons with five or more carbon atoms that can be used for liquid fuels (hereinafter referred to as "overcracking"). On the other hand, if the catalyst's acidity is insufficient, the reaction remains isomerization and the cracking reaction does not proceed. Because it is difficult to control the degree of overcracking, in order to improve the selectivity of hydrocarbons with specific carbon numbers, such as gasoline and middle distillates (kerosene + diesel), it is necessary to control the number of cracking reactions so that they occur only once, a process known as primary cracking.

[0003] Hydrocracking catalysts have been reported in which amorphous silica-alumina is used as a catalyst support and an active metal element from Groups 8 to 10 is supported on the support. Amorphous silica-alumina is generally produced by a sol-gel method, a coprecipitation method, or the like. For example, Patent Document 1 discloses a method in which an acidic silica sol is mixed with an acidic aluminum source to prepare a silica-alumina sol, which is then neutralized with basic ammonium water to precipitate a silica-alumina gel. Patent Document 2 also discloses a method in which a basic silica-alumina sol is prepared, which is then instantaneously mixed with sulfuric acid to acidify the solution, which is then neutralized with basic ammonium water. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-284520 [Patent Document 2] Japanese Patent Application Publication No. 2018-083723 [Non-patent literature]

[0005] [Non-Patent Document 1] Fuel,Volume 279, page 118487. Summary of the Invention [Problem to be solved by the invention]

[0006] The amorphous silica-alumina disclosed in Patent Documents 1 and 2 has large pores with an average pore diameter of 2 nm or more. Metal particles present in large pores are less spatially confined, which makes metal sintering more likely to occur, and the hydrogenation ability of the catalyst derived from the active metal element decreases. When the hydrogenation ability decreases, the cracking activity of the catalyst decreases, and the cracking reaction does not stop at primary cracking, but rather occurs over-cracking.

[0007] The present disclosure aims to provide at least one of an amorphous silica-alumina that, when carrying an active metal element, can control the hydrocracking reaction of long-chain paraffins to primary cracking with high efficiency and can also exhibit high catalytic activity, a method for producing the same, and a paraffin reforming catalyst containing the same. [Means for solving the problem]

[0008] The present inventors have investigated the pore structure of amorphous silica-alumina in order to control the hydrocracking reaction of long-chain paraffins. As a result, they have found that amorphous silica-alumina, which has a specific pore structure and a large specific surface area for nitrogen adsorption, is an excellent catalyst carrier that can control the hydrocracking reaction to primary decomposition with high efficiency when an active metal element is contained therein, and also exhibits high catalytic activity.

[0009] That is, the present invention is as described in the claims, and the gist of the present disclosure is as follows. [1] The ratio of the pore volume of pores with a diameter of 0 nm to 2 nm to the pore volume of pores with a diameter of 0 nm to 10 nm is 60% or more, and the specific surface area is 280 m 2 / g or more amorphous silica-alumina. [2] Total pore volume is 0.2 cm 3 / g or more. [3] The amorphous silica-alumina according to [1] or [2] above, wherein the molar ratio of silica to alumina is 10 or more and 100 or less. [4] The amorphous silica-alumina according to any one of [1] to [3] above, having an acid amount of 0.3 mmol / g or more. [5] The amorphous silica-alumina according to any one of the above [1] to [4], wherein the ratio of the area intensity of the peak having a peak top at a chemical shift of 40 ppm or more and 60 ppm or less to the area intensity of the peak having a peak top at a chemical shift of -10 ppm or more and 10 ppm or less is 0.40 or more and less than 0.80. [6] The amorphous silica-alumina according to any one of [1] to [5] above, which contains one or more elements selected from the group consisting of Groups 8, 9 and 10. [7] A method for producing amorphous silica-alumina according to any one of [1] to [6], comprising: a gelling step of mixing a solution containing an alumina source, an acid source, and water, and a solution containing a basic silica source and water, with an aqueous sulfate solution containing an alkali metal, to obtain an amorphous silica-alumina gel; an ion exchange step of ion-exchanging the amorphous silica-alumina gel; and a firing step of firing the amorphous silica-alumina gel after the ion exchange step. [8] The method according to [7] above, wherein the aqueous sulfate solution containing an alkali metal is an aqueous solution of one or more selected from the group consisting of lithium sulfate, sodium sulfate, and potassium sulfate. [9] A catalyst for reforming paraffins, comprising the amorphous silica-alumina according to any one of [1] to [6].

[10] A method for reforming paraffins, comprising a step of contacting the paraffin-containing hydrocarbon fluid with the paraffin reforming catalyst according to [9] above. [Effects of the Invention]

[0010] The present disclosure aims to provide at least one of an amorphous silica-alumina that, when containing an active metal element, can control the hydrocracking reaction of long-chain paraffins to primary cracking with high efficiency and can also exhibit high catalytic activity, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0011] The amorphous silica-alumina of the present disclosure will be described below with an example of embodiment.In the present disclosure, each configuration and parameter disclosed in this specification includes any combination, and the upper and lower limits of the values ​​disclosed in this specification include any combination.The terms in this embodiment are as follows:

[0012] "Amorphous silica-alumina" is an amorphous compound containing at least aluminum (Al), silicon (Si), and oxygen (O). The fact that the amorphous silica-alumina of this embodiment is an amorphous compound can be determined from its powder X-ray diffraction (hereinafter also referred to as "XRD") pattern. In an XRD pattern, a compound having a crystalline XRD peak is a "crystalline aluminosilicate," while a compound having no crystalline XRD peak is an "amorphous silica-alumina." Specifically, when the XRD pattern of the amorphous silica-alumina of this embodiment obtained under the following conditions does not have a diffraction peak with a full width at half maximum (FWHM) of less than 1.0 in the range of 2θ = 10° or more and 50° or less, the amorphous silica-alumina of this embodiment can be determined to be amorphous.

[0013] The XRD pattern can be measured using a general powder X-ray diffractometer (for example, Ultima IV Protectus, manufactured by Rigaku Corporation). The XRD pattern can be obtained by XRD measurement under the following conditions.

[0014] Acceleration current / voltage: 10mA / 30kV Radiation source: CuKα radiation (λ=1.54178Å) Measurement mode: Continuous scan Scan condition: 2° / min Measurement range: 2θ=10~70° Scattering slit: 1 / 3° Divergence slit: 1 / 3° Receiving slit: 0.3 mm Filter: Ni filter The "specific surface area" can be determined by measurement in accordance with JIS Z 8830: 2013. That is, the specific surface area of ​​amorphous silica-alumina can be measured by the single-point method using the nitrogen adsorption method described above.

[0015] "Decane" refers to at least one of straight-chain decane (n-decane) and branched-chain decane (iso-decane).

[0016] "Cracking" refers to the decomposition of decane into hydrocarbons with 1 to 9 carbon atoms (hereinafter referred to as "Cn" (where n is the number of carbon atoms in the hydrocarbon)).

[0017] The "n-decane conversion rate" is the proportion of the total amount of n-decane reacted in the hydrocracking reaction, and can be calculated using the following formula.

[0018] n-Decane Conversion Rate [%] = ([n-decane] in) - ([n-decane] out) / ([n-decane] in) × 100 (1) [n-decane]in is the concentration of n-decane at the inlet of the atmospheric pressure fixed-bed flow reactor, and [n-decane]out is the concentration of n-decane at the outlet of the atmospheric pressure fixed-bed flow reactor.

[0019] "Iso-decane" refers to isomerized n-decane.

[0020] "Iso-decane selectivity" is the proportion of iso-decane in the product, and can be calculated using the following formula.

[0021] iso-decane selectivity [C%] = (amount of iso-decane produced) / (total amount of products) × 100 (2) "Cracking selectivity" is the ratio of the total amount of hydrocarbons produced with 1 to 9 carbon atoms to the total amount of products, and can be calculated using the following formula.

[0022] Cracking selectivity [C%] = (C1 + C2 + ... + C9) / (total amount of products) x 100 (3) The "cracking yield" is the ratio of the total amount of hydrocarbons with 1 to 9 carbon atoms produced to the total amount of n-decane reacted in the hydrocracking reaction, and can be calculated using the following formula:

[0023] Cracking yield [C%] = n-Decane conversion rate × cracking selectivity / 100 (4) The "C3 / C7 ratio" refers to the ratio of the amount (mol) of three-carbon hydrocarbons (hereinafter also referred to as "C3") to the amount (mol) of seven-carbon hydrocarbons (hereinafter also referred to as "C7"). In the hydrocracking reaction of decane, for example, if the reaction is completely controlled by primary cracking, equal molar numbers of C3 and C7 are produced, resulting in a C3 / C7 ratio of 1. On the other hand, if overcracking occurs, the C7 produced in primary cracking is cleaved, resulting in C3 and four-carbon hydrocarbons (hereinafter also referred to as "C4"), resulting in a C3 / C7 ratio greater than 1. The "C3 / C7 ratio" can be used as an indicator of the number of cracking reactions occurring. In other words, a C3 / C7 ratio of 1 indicates that one hydrocracking reaction of decane has occurred, whereas a C3 / C7 ratio greater than 1 indicates that more than one hydrocracking reaction of decane has occurred.

[0024] The amorphous silica-alumina of this embodiment will be described below.

[0025] The amorphous silica-alumina of this embodiment has a pore volume of pores having a diameter of 0 nm or more and 2 nm or less (hereinafter also referred to as "0-2 nm pore volume") relative to the pore volume of pores having a diameter of 0 nm or more and 10 nm or less (hereinafter also referred to as "0-10 nm pore volume") (hereinafter also referred to as "micropore volume ratio") of 60% or more, and a specific surface area of ​​280 m 2 / g or more.

[0026] The micropore volume ratio can be measured using a nitrogen adsorption method. Specifically, the amorphous silica-alumina of this embodiment is measured using the nitrogen adsorption method to obtain an adsorption isotherm. In the adsorption isotherm, the nitrogen adsorption amount [cm 3 (STP) / g](hereinafter referred to as “PV (0-0.8) The nitrogen adsorption amount [cm 3 (STP) / g](hereinafter referred to as “PV (0-0.2) ") can be taken as the micropore volume ratio.

[0027] PV (0-0.8) and PV (0-0.2) can be obtained by a constant volume method using a common nitrogen adsorption apparatus (e.g., BELSORP-miniII, manufactured by Microtrac-Bel).

[0028] Measurement temperature: -196℃ Pretreatment: 350℃, vacuum drying for 2 hours The micropore volume ratio of the amorphous silica-alumina of this embodiment is 60% or more. If the micropore volume ratio is less than 60%, the C3 / C7 ratio tends to be large, making it difficult to control the hydrocracking reaction by primary cracking. The micropore volume ratio is preferably 65% ​​or more, more preferably 75% or more. The upper limit of the micropore volume ratio is 100% or less, and from the viewpoint of n-decane conversion, examples of the upper limit and lower limit of the micropore volume ratio include 60% or more and 100% or less, 60% or more and 100% or less, 65% or more and 95% or less, and 75% or more and 85% or less.

[0029] PV (0-0.2) corresponds to the amount of nitrogen adsorbed by pores with a diameter of 2 nm or less, and PV (0-0.8)is considered to correspond to the amount of adsorption by pores with a diameter of 10 nm or less (for example, JIS Z 8831-2:2010). The fact that the amorphous silica-alumina of this embodiment has a micropore volume ratio of 60% or more is considered to suggest that it has many pores with a diameter of 2 nm or less. By having a micropore volume ratio of 60% or more, the amorphous silica-alumina of this embodiment can easily disperse and support active metal elements, thereby exhibiting high catalytic activity.

[0030] The amorphous silica alumina of this embodiment has a specific surface area of ​​280 m 2 / g or more. The specific surface area is 280m 2 If the specific surface area is less than 290 m / g, the cracking yield is likely to decrease. 2 / g, and 300m 2 / g, and more preferably 350m 2 In this embodiment, the upper limit of the specific surface area is 800 m / g or more. 2 / g or less is preferable, and 2 / g, and more preferably 600m 2 / g. A specific combination of the upper and lower limits of the specific surface area is 280 m 2 / g or more 800m 2 / g or less, 290m 2 / g or more 700m 2 / g or less, 300m 2 / g or more 700m 2 / g or less, or 350m 2 / g or more 650m 2 For example, it can be exemplified as being / g or less.

[0031] The amorphous silica-alumina of this embodiment has a total pore volume of 0.2 cm 3 / g or more. The total pore volume is the volume of pores per unit mass of amorphous silica-alumina. The pore volume of the amorphous silica-alumina of this embodiment is determined by the nitrogen adsorption amount V [cm] in the relative pressure range of 0 to 0.99 from the nitrogen adsorption / desorption isotherm of the amorphous silica-alumina. 3 ] can be calculated using the following formula:

[0032] Total pore volume [cm 3 / g]=V×1.547×10 -3 (5) The nitrogen adsorption / desorption isotherm for determining the nitrogen adsorption amount V in the above formula (5) can be obtained by the above-mentioned constant volume method.

[0033] In the amorphous silica-alumina of this embodiment, the upper limit of the pore volume is 1 cm 3 / g or less is sufficient, but from the viewpoint of further increasing the cracking yield, it is 3 / g or less, and 3 / g or less. From the viewpoint of further increasing the cracking yield, the pore volume of the amorphous silica-alumina of this embodiment is preferably 0.2 cm 3 / g or more 0.7cm 3 / g or less, and 3 / g or more 0.5cm 3 It is more preferable that the saturation coefficient is 1 / g or less.

[0034] The amorphous silica-alumina of this embodiment contains Si and Al as constituent elements. Furthermore, the amorphous silica-alumina of this embodiment preferably has a molar ratio of silica to alumina (the molar ratio of silicon in SiO2 equivalent to aluminum in Al2O3 equivalent; hereinafter also referred to as the "SiO2 / Al2O3 ratio") of 10 or more and 100 or less. Since this tends to have acidity suitable for a cracking catalyst, the amorphous silica-alumina of this embodiment preferably has a SiO2 / Al2O3 ratio of 50 or less or 25 or less. Since this tends to suppress overcracking in the hydrocracking of long-chain paraffins, the amorphous silica-alumina of this embodiment preferably has a SiO2 / Al2O3 ratio of 10 or more or 13 or more. That is, the SiO2 / Al2O3 ratio of the amorphous silica-alumina of this embodiment can be, for example, 10 or more and 30 or 13 or more and 25 or less.

[0035] The amorphous silica-alumina of this embodiment contains Si and Al, which can be determined by performing elemental analysis using inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a general high-frequency inductively coupled plasma device (for example, OPTIMA5300DV, manufactured by PerkinElmer). Specifically, if Si and Al are detected at values ​​above the lower limit of quantification in the elemental analysis, it can be determined that the silica-alumina of this embodiment contains Si and Al. In this embodiment, the SiO2 / Al2O3 ratio can be determined by the ICP-AES measurement described above, as the molar ratio of silicon converted into SiO2 to aluminum converted into Al2O3, based on the aluminum (Al) and silicon (Si) contents in the amorphous silica-alumina of this embodiment.

[0036] The amorphous silica-alumina of this embodiment preferably has an acid amount of 0.3 mmol / g or more or 0.4 mmol / g or more, and preferably 0.8 mmol / g or less, 0.6 mmol / g or less, or 0.5 mmol / g or less. The acid amount of the above value makes it easier to improve the cracking yield. Specific examples of the combination of the upper and lower limits of the acid amount include 0.3 mmol / g or more and 0.8 mmol / g or less, 0.4 mmol / g or more and 0.6 mmol / g or less, or 0.4 mmol / g or more and 0.5 mmol / g or less.

[0037] The acid amount of the amorphous silica-alumina of this embodiment may be measured by a method conforming to the ammonia-TPD method (for example, Measurement of Solid Acidity by Ammonia Temperature Programmed Desorption Method, Catalysts, Vol. 42, p. 218 (2000)). A typical catalyst analyzer (for example, BELCAT II, ​​manufactured by Microtrac) can be used for measurement by the ammonia-TPD method. Specifically, 0.05 g of amorphous silica-alumina is placed in the sample tube of the apparatus, heated to 500 ° C and maintained for 2 hours for pretreatment, and then cooled to 100 ° C., after which ammonia is saturated and adsorbed onto the amorphous silica-alumina. Subsequently, the ammonia remaining in the measurement atmosphere is removed at 100 ° C., and the total acid amount can be determined from the ammonia desorption peak measured during the temperature increase process up to 800 ° C. at a temperature increase rate of 10 ° C. / min. Helium may be used as the atmospheric gas for measurement. The flow rate of helium gas may be 50 ml / min.

[0038] When the amorphous silica-alumina of this embodiment is used as a catalyst for hydrocracking reaction, it preferably contains one or more elements selected from the group consisting of Groups 8, 9 and 10 (hereinafter also referred to as "active metal elements").

[0039] The amorphous silica-alumina of this embodiment has an integrated intensity of a peak having a peak top at a chemical shift of 40 ppm or more and 60 ppm or less (hereinafter referred to as "Al iv ") and the area intensity of the peaks with peak tops between -10 ppm and 10 ppm (hereinafter referred to as "Al viThe area intensity (Al iv ) ratio (hereinafter referred to as "Al iv / (Al iv +Al vi From the viewpoint of easily controlling the hydrocracking reaction of long-chain paraffins to primary cracking with higher efficiency, the Al content of the amorphous silica-alumina of this embodiment is preferably 0.40 or more and less than 0.80. iv / (Al iv +Al vi ) is preferably 0.45 or more and 0.75 or less, and more preferably 0.50 or more and 0.73 or less.

[0040] Here, 27Al-MAS-NMR is known as a means for analyzing the local structure around aluminum atoms in the zeolite framework structure. In the NMR spectrum measured by 27Al-MAS-NMR, it is known that, among the aluminum (Al) contained in zeolite, tetracoordinated aluminum (hereinafter referred to as "tetracoordinated Al") is assigned to a peak having a peak top at a chemical shift of 40 ppm to 60 ppm, and hexacoordinated aluminum (hereinafter referred to as "hexacoordinated Al") is assigned to a peak having a peak top at a chemical shift of -10 ppm to 10 ppm (for example, International Publication No. 2017 / 090751). Therefore, Al iv / (Al iv +Al vi ) functions as an index showing the ratio of tetrahedral Al to the sum of tetrahedral and hexahedral Al contained in the zeolite.

[0041] The 27Al-MAS-NMR measurement of the amorphous silica-alumina of this embodiment can be performed using a general nuclear magnetic resonance spectrometer (for example, AVANCE NEO 700, manufactured by Bruker). The measurement sample can be amorphous silica-alumina that has been calcined in air at 500°C for 1 hour and then maintained in a vacuum atmosphere in the presence of a saturated ammonium chloride aqueous solution at a relative humidity of 60% for 24 hours. The following conditions can be used for the 27Al-MAS-NMR measurement.

[0042] Observation kernel: 27 Al (182.4MHz) Rotation frequency: 24kHz Pulse width: 2.1 μsec Wait time: 2 seconds Accumulation count: 2600 times Al iv / (Al iv +Al vi ) is a peak having a chemical shift between -10 ppm and 10 ppm in the NMR spectrum measured by 27Al-MAS-NMR (hereinafter referred to as "P -10~10ppm ") and peaks with a chemical shift between 40 ppm and 60 ppm (hereinafter referred to as "P 40~60ppm ") and P 40~60ppm Area intensity (Al iv ) to P 40~60ppm Area intensity (Al iv ) and P 0ppm Area intensity (Al vi ) can be calculated by dividing by the sum of

[0043] From the NMR spectrum measured by 27Al-MAS-NMR, P -10~10ppm and P 40~60ppm To separate P, a conventionally known waveform separation method (peak fitting) can be used. Specifically, P is extracted from the NMR spectrum measured by 27Al-MAS-NMR (hereinafter also referred to as the "measured NMR spectrum"). -10~10ppm and P 40~60ppm To separate the peaks, the least squares method can be used, using a Gaussian function as the peak representation function. -10~10ppm and P 40~60ppm The separation of one P -10~10ppm and two Ps 40~60ppm The measured NMR spectrum contains one P0 and two P 55 It is preferable to assume that P -10~10ppm and P 40~60ppmThe separation of P is preferably carried out so that the NMR spectrum obtained by recombining the separated peaks (hereinafter also referred to as the "calculated NMR spectrum") has a relative error of less than 5% at any point (ppm) compared to the actually measured NMR spectrum. -10~10ppm and P 40~60ppm The area intensities of -10~10ppm and P 40~60ppm The integrated intensity of P -10~10ppm Two or more peaks are separated as P 40~60ppm When two or more peaks are separated as a result of the analysis, the total integrated intensity of the two or more separated peaks can be used as the area intensity. Furthermore, for baseline correction, a line can be drawn between -50 ppm and 150 ppm in the measured NMR spectrum, and the line can be corrected to 0.

[0044] The active metal element is preferably one or more selected from the group consisting of platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (Ru), nickel (Ni), and cobalt (Co), more preferably one or more selected from at least either platinum or palladium, and particularly preferably platinum.

[0045] The state of the active metal element in the amorphous silica-alumina of this embodiment is not particularly limited, but can be exemplified as, for example, a compound (e.g., oxide), a metal, an ion, an alloy, or two or more of these states.

[0046] The content of the active metal element contained in the amorphous silica-alumina of this embodiment is not particularly limited as long as it is within a range that achieves the effects of this embodiment. From the viewpoint of obtaining a higher cracking yield, the content is preferably 0.05% by mass or more, more preferably 0.20% by mass or more, and particularly preferably 0.30% by mass or more, relative to 100% by mass of the solid content of the amorphous silica-alumina. Furthermore, from the viewpoint of obtaining a higher cracking yield, the upper limit of the content of the active metal element is preferably 10.0% by mass or less, more preferably 5.0% by mass or less, and particularly preferably 1.0% by mass or less. The upper and lower limits of the content of the active metal element may be any combination of the above upper and lower limits, but the specific range of the content of the active metal element is preferably 0.05% by mass or more and 10.0% by mass or less, more preferably 0.20% by mass or more and 5.0% by mass or less, and particularly preferably 0.30% by mass or more and 1.0% by mass or less.

[0047] Incidentally, "containing an active metal element" means that the amorphous silica-alumina contains an active metal element, and as long as the amorphous silica-alumina contains the active metal element, it does not matter in what state or at what position the active metal element is contained. On the other hand, "supporting an active metal element" means that the amorphous silica-alumina contains the active metal element as an atom other than that constituting the amorphous silica-alumina. In other words, "supporting an active metal element" means that the active metal element is contained in the amorphous silica-alumina in a state where the active metal element is not present as an atom constituting the amorphous silica-alumina. A preferred form of "supporting an active metal element" can be a state where the active metal element is not present as an atom constituting the amorphous silica-alumina, and is contained at least on the surface or in the pores of the amorphous silica-alumina.

[0048] When used as a catalyst for hydrocracking reaction, amorphous silica-alumina containing one or more elements selected from the group consisting of Groups 8, 9 and 10 (hereinafter also referred to as "active metal elements") can be used as a paraffin reforming catalyst containing the same (hereinafter also referred to as "catalyst of the present embodiment").

[0049] The catalyst of this embodiment can be used in a hydrocracking reaction to reform C10 or higher linear paraffins through highly efficient primary cracking, and exhibits an excellent cracking yield and C3 / C7 ratio. The C10 or higher linear paraffins to be reformed may be linear paraffins having a carbon number of 10 or more, but are preferably linear paraffins having a carbon number of 10 to 100, more preferably linear paraffins having a carbon number of 10 to 30, and particularly preferably n-decane.

[0050] The method for reforming C10 or higher linear paraffins using the catalyst of this embodiment can be achieved by a method including a step of contacting the catalyst of this embodiment with a fluid containing C10 or higher linear paraffins and hydrogen (hereinafter also referred to as a "paraffin-containing fluid") (hereinafter also referred to as a "contact step"). A specific example of a method for contacting the catalyst of this embodiment with the paraffin-containing fluid is a method in which the amorphous silica-alumina of this embodiment is packed into a stationary-phase flow-type reactor tube to form a catalyst-packed layer, and the paraffin-containing fluid is passed through this catalyst-packed layer.

[0051] The reforming of C10 or higher linear paraffins using the catalyst of this embodiment proceeds by contacting the catalyst of this embodiment with a paraffin-containing fluid, and the contact conditions are not particularly limited. Preferred contact conditions include, for example, the following conditions.

[0052] The contact temperature between the catalyst of this embodiment and the paraffin-containing fluid is preferably 200°C or higher and 350°C or lower, more preferably 230°C or higher and 320°C or lower, from the viewpoint of obtaining a higher cracking yield.

[0053] The pressure (gauge pressure) at which the catalyst of this embodiment is brought into contact with the paraffin-containing fluid is preferably 0.05 MPa or more and 10 MPa or less, and more preferably 0.1 MPa or more and 5 MPa or less, from the viewpoint of obtaining a higher cracking yield. The gauge pressure is a pressure obtained by setting atmospheric pressure at 0 MPa.

[0054] From the viewpoint of obtaining a higher cracking yield, the flow rate of hydrogen in the paraffin-containing fluid brought into contact with the catalyst of this embodiment is preferably such that the ratio of the volumetric flow rate of hydrogen to the volumetric flow rate of normal paraffins is 300 or more and 1,500 or less, and more preferably 500 or more and 1,000 or less.

[0055] The weight hourly space velocity (WHSV) of C10 or higher normal paraffins in the paraffin-containing fluid that is brought into contact with the catalyst of this embodiment is 0.5 h from the viewpoint of obtaining a higher cracking yield. -1 More than 10h -1 Preferably less than 1h -1 More than 3 hours -1 It is preferable that the WHSV is equal to or less than 1000 kJ / h. The WHSV is a parameter representing the amount of C10 or more linear paraffin supplied per unit mass of amorphous silica-alumina per hour ([g (amorphous silica-alumina)] / [g (C10 or more linear paraffin) / h] (=[h -1 ])).

[0056] The contact time between the catalyst of this embodiment and the paraffin-containing fluid can be set appropriately depending on the amount of Cn hydrocarbons that is desired to be obtained.

[0057] The paraffin-containing fluid to be brought into contact with the catalyst of this embodiment may be a liquid, a gas, or a mixed fluid of a liquid and a gas. From the viewpoint of obtaining a higher cracking yield, the paraffin-containing fluid is preferably a gas. Furthermore, the paraffin-containing fluid may be composed only of C10 or higher normal paraffins and hydrogen, but may also contain fluids other than these.

[0058] According to the reforming method including the contacting step described above, the catalyst of this embodiment can reform C10 or higher linear paraffins through highly efficient primary cracking. An example of the hydrocarbons primarily obtained by reforming is a hydrocarbon having half the carbon number of the hydrocarbons contacted with the catalyst of this embodiment. A more specific example is C10 when at least one of a linear paraffin having a carbon number of 20 (hereinafter also referred to as a "C20 linear paraffin") and a branched paraffin having a carbon number of 20 (hereinafter also referred to as a "C20 branched paraffin") is contacted with the catalyst of this embodiment.

[0059] The catalyst of this embodiment may have any shape, but is preferably a molded body in consideration of packing into a reaction tube.

[0060] When the catalyst of the present embodiment is a molded body, it can be molded into any shape by any molding method, such as at least one selected from the group consisting of rolling granulation molding, press molding, extrusion molding, injection molding, slip casting, and sheet molding. Examples of the shape of the molded body include at least one selected from the group consisting of spherical, approximately spherical, elliptical, disk-like, cylindrical, polyhedral, irregular, and petal-like.

[0061] When the catalyst of the present embodiment is a molded body, the molded body may contain a binder, such as at least one selected from the group consisting of silica, alumina, kaolin, attapulgite, montmorillonite, bentonite, and sepiolite, and alumina is preferred.

[0062] The method for producing amorphous silica-alumina according to this embodiment will be described below.

[0063] The method for producing amorphous silica-alumina of the present embodiment is a production method (hereinafter also referred to as "production method of the present embodiment") that includes a gelling step of mixing a solution containing an alumina source, an acid source, and water (hereinafter also referred to as "solution A") and a solution containing a basic silica source and water (hereinafter also referred to as "solution B") with an aqueous sulfate solution containing an alkali metal (hereinafter also referred to as "solution C") to obtain amorphous silica-alumina gel, an ion exchange step of ion-exchanging the amorphous silica-alumina gel, and a firing step of firing the amorphous silica-alumina gel after the ion exchange step.

[0064] Solution A is a solution containing an acid source, an alumina source, and water.

[0065] The alumina source is a compound containing aluminum (Al), and examples thereof include one or more selected from the group consisting of aluminum nitrate, aluminum sulfate, and aluminum chloride, with aluminum sulfate being preferred.

[0066] The acid source may be one or more inorganic acids selected from the group consisting of sulfuric acid, hydrochloric acid, and nitric acid. In this embodiment, from the viewpoint of production, the acid source is preferably sulfuric acid. Furthermore, the acid source may contain an organic acid in addition to the inorganic acid. Examples of the organic acid include one or more selected from the group consisting of acetic acid, malic acid, tartaric acid, and citric acid.

[0067] The acid source preferably has a ratio of the number of moles of alkali metal contained in the silica source of Solution B (described later) calculated as oxide to the total number of moles of anions contained in the acid source and the alumina source (hereinafter also referred to as the "MO / anion molar ratio") of 0.5 to 2.0, more preferably 0.8 to 1.3, in order to facilitate control of the pH during the gelation process and the SiO / AlO molar ratio of the resulting amorphous silica-alumina. When the alkali metal is sodium (Na) and the anion is sulfate, the MO / anion molar ratio may be the NaO / sulfate molar ratio. When the alkali metal is sodium and potassium (K), the MO / anion molar ratio may be the (NaO + KO) / sulfate molar ratio.

[0068] The water may be at least one selected from the group consisting of distilled water, deionized water, and pure water. When the alumina source and the acid source contain water such as hydrates, structural water, or solvents, they can be considered as water contained in solution A.

[0069] The content of water in solution A is preferably such that the molar amount of water (hereinafter also referred to as "H2O / Al2O3 molar ratio") is 50 or more and 500 or less, in order to easily improve the specific surface area and acid amount of the obtained amorphous silica-alumina.

[0070] Solution A preferably has the following molar composition:

[0071] MO / anion molar ratio: 0.5 or more, or 0.8 or more, and 2.0 or less, or 1.3 or less H2O / Al2O3 molar ratio: 50 or more, 60 or more, or 70 or more, and 500 or less, 300 or less, 200 or less Here, M refers to the alkali metal contained in solution B.

[0072] The liquid temperature of solution A is preferably 45°C or lower, more preferably 35°C or lower.

[0073] Solution B is a solution containing a basic silica source and water.

[0074] The basic silica source is a basic compound containing silicon (Si), and examples thereof include one or more selected from the group consisting of sodium silicate, potassium silicate, and lithium silicate. At least one of sodium silicate and potassium silicate is preferred, and sodium silicate is more preferred.

[0075] The water is the same as that in solution A, and therefore a description thereof will be omitted.

[0076] In solution B, the molar amount of water relative to the molar amount of Si contained in solution B converted into SiO2 (hereinafter also referred to as "H2O / SiO2 molar ratio") is preferably 8 or more and 100 or less.

[0077] Solution B preferably has the following molar composition:

[0078] H2O / SiO2 molar ratio: 8 or more, 10 or more, or 15 or more, and 100 or less, 50 or less, 30 or less The liquid temperature of solution B is preferably 40°C or lower, more preferably 35°C or lower.

[0079] Furthermore, the ratio of the molar amount of Si contained in solution B, calculated as SiO2, to the molar amount of Al contained in solution A, calculated as Al2O3 (hereinafter also referred to as the "SiO2 / Al2O3 raw material molar ratio") is preferably 10 or more and 100 or less, more preferably 10 or more and 30 or less, and even more preferably 13 or more and 30 or less, in order to easily control the SiO2 / Al2O3 molar ratio of amorphous silica-alumina.

[0080] Solution C is an aqueous sulfate solution containing an alkali metal.

[0081] The alkali metal may be one or more selected from the group consisting of potassium, sodium, and lithium, and is preferably at least one of potassium and sodium, and more preferably sodium.

[0082] The content of the alkali metal in solution C is preferably 1% by mass or more and 5% by mass or less, since this makes it easier to obtain amorphous silica-alumina with a high specific surface area.

[0083] The content of sulfuric acid in solution C is preferably 2% by mass or more and 30% by mass or less, since this makes it easier to obtain amorphous silica-alumina with a high specific surface area.

[0084] Solution C is preferably an aqueous solution of one or more selected from the group consisting of lithium sulfate, sodium sulfate and potassium sulfate, and more preferably sodium sulfate, in view of ease of industrial handling.

[0085] The temperature of solution C is preferably 35°C or higher and 60°C or lower.

[0086] In the gelation step, solution A and solution B are simultaneously mixed with solution C to obtain an amorphous silica-alumina gel.

[0087] In the gelation step, it is preferable to maintain the pH of solution C, which is a mixture of solutions A and B, at 6.0 or more and 8.0 or less. This allows the alumina source of solution A and the basic silica source of solution B to undergo dehydration condensation, facilitating the formation of an amorphous silica-alumina gel having the micropore volume ratio and specific surface area of ​​this embodiment. It is more preferable to maintain the pH of solution C at 6.5 or more and 7.0 or less, since this facilitates the formation of the amorphous silica-alumina gel in a shorter time.

[0088] In order to make it easier to control the pH of solution C to the above value in a shorter time, it is preferable that the ratio of the flow rate [ml / min] of solution A to the flow rate [ml / min] of solution B (hereinafter also referred to as the "A:B flow rate ratio") be a value that satisfies the following formula:

[0089] A:B flow ratio = 279 × (H2O / Al2O3 molar ratio) (-0.85) (6) In the gelation step, it is preferable to mix solution A and solution B into solution C while stirring solution C. This allows solution A and solution B to be uniformly dispersed, which facilitates the formation of an amorphous silica-alumina gel network and makes it easier to control the micropore volume ratio of the resulting amorphous silica-alumina. The stirring power required per unit volume (hereinafter also referred to as "P / V") is 250 W / m 3 More than 450W / m 3 It is preferable that the power consumption is less than 300W / m 3 More than 350W / m 3 More preferably, it is:

[0090] The liquid temperature of solution C in the gelation step is preferably 35°C or higher and 60°C or lower. By keeping the liquid temperature within the above range, the formation of large pores in the resulting amorphous silica-alumina is suppressed, making it easier to obtain amorphous silica-alumina having the above-mentioned micropore volume ratio. The liquid temperature of solution C in the gelation step is more preferably 40°C or higher and 50°C or lower.

[0091] In the ion exchange step, the alkali metal contained in the amorphous silica-alumina gel obtained in the gelling step is removed by ion exchange.

[0092] The ion exchange method may be any known method that can remove alkali metals while suppressing the detachment of aluminum contained in the amorphous silica-alumina gel. One example of such a method is a method of contacting the amorphous silica-alumina gel with an aqueous solution containing ammonium ions (hereinafter referred to as "aqueous ammonium solution") (hereinafter referred to as "ammonium ion exchange method").

[0093] The ammonium ion exchange method may be carried out by either a batch method or a flow method, but the batch method is preferred in that the alkali metal contained in the amorphous silica-alumina gel can be efficiently removed.

[0094] When the ammonium ion exchange method is carried out in a batch system, the ammonium ion concentration of the ammonium aqueous solution can be adjusted appropriately by adjusting the amount of amorphous silica-alumina gel so that the alkali metal can be sufficiently removed, and the ammonium ion concentration can be, for example, 3% by mass or more and 10% by mass or less. In addition, the liquid volume of the ammonium aqueous solution can be, for example, such that the mass ratio of the ammonium aqueous solution to the solid content contained in the amorphous silica-alumina gel is 2% by mass or more and 50% by mass or less.

[0095] When the ammonium ion exchange method is carried out in a batch system, the time for contacting the amorphous silica-alumina gel with the ammonium aqueous solution is preferably 15 minutes to 10 hours, and the temperature for contacting the amorphous silica-alumina gel with the ammonium aqueous solution is 30°C to 100°C, preferably 50°C to 80°C.

[0096] When the ammonium ion exchange method is performed in a flow-through manner, the ion exchange step can be performed under conditions such that an ammonium ion solution having an ammonium ion concentration of 3% by mass to 10% by mass is passed through the amorphous silica-alumina gel for 1 minute to 30 minutes. The amount of the ammonium aqueous solution can be such that the mass ratio of the ammonium aqueous solution to the solid content in the amorphous silica-alumina gel is 2 to 50.

[0097] The production method of this embodiment may include, prior to the ion exchange step, a washing step of removing other components contained in the amorphous silica-alumina gel obtained in the gelling step.

[0098] In the washing step, a method for removing other components contained in the amorphous silica-alumina gel includes contacting the amorphous silica-alumina gel with water, which may be one or more selected from the group consisting of distilled water, deionized water, and pure water.

[0099] In the washing step, the amorphous silica-alumina gel is preferably brought into contact with water in an amount 5 to 100 times by mass relative to the mass of the amorphous silica-alumina gel at 30°C to 100°C.

[0100] In the calcination step, the amorphous silica-alumina gel after the ion exchange step is calcined, thereby removing ammonium ions contained in the amorphous silica-alumina gel and obtaining amorphous silica-alumina.

[0101] The firing temperature in the firing step is preferably 300°C or higher and 600°C or lower, and more preferably 400°C or higher and 550°C or lower.

[0102] The firing time in the firing step is preferably from 10 minutes to 20 hours, more preferably from 1 hour to 3 hours.

[0103] The firing step may be carried out in an air atmosphere. [Example]

[0104] The present disclosure will be explained in more detail below by way of examples, but the present disclosure is not limited to the following examples in any way. (composition analysis) A sample solution was prepared by dissolving the measurement sample in a mixed aqueous solution of hydrofluoric acid and nitric acid. The sample solution was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a common ICP device (device name: OPTIMA5300DV, manufactured by PerkinElmer). From the obtained measured values ​​of aluminum (Al), silicon (Si), the specified element, and other elements, the SiO2 / Al2O3 ratio of the measurement sample, the mass ratio (content) of the specified element relative to the measurement sample, and the mass ratio (content) of other elements relative to the measurement sample were calculated. (pore characterization) A common nitrogen adsorption apparatus (BELSORP-mini II, manufactured by Microtrack-Bell) was used to obtain nitrogen adsorption and desorption isotherms for the measurement sample. The constant volume method was used for nitrogen gas adsorption. The measurement conditions are as follows:

[0105] Sample amount: approx. 0.02g Pretreatment: 350℃, vacuum drying for 2 hours Measurement temperature: -196℃ Relative pressure (P / P0) range: 0 to 0.995 From the adsorption isotherm obtained by nitrogen adsorption measurement, the adsorption amount PV in the range of relative pressure 0 to 0.8 (the nitrogen adsorption range of pores with a diameter of 10 nm or less) (0-0.8) [cm 3 (STP) / g] was calculated. In addition, the adsorption amount PV in the range of relative pressure 0 to 0.2 (the nitrogen adsorption range corresponding to pores with a diameter of 2 nm or less) (0-0.2) [cm 3(STP) / g] was calculated. (0-0.8) Adsorption amount PV (0-0.2) The ratio was calculated and used as the micropore volume ratio of the measurement sample.

[0106] The specific surface area of ​​the measurement sample was determined by measurement in accordance with JIS Z 8830: 2013. That is, using the nitrogen adsorption method described above, the specific surface area of ​​the amorphous silica-alumina was measured by the single-point method from the adsorption isotherm obtained by the nitrogen adsorption measurement.

[0107] From the nitrogen adsorption / desorption isotherm, the nitrogen adsorption amount V [cm 3 The total pore volume of the measurement sample was calculated using the obtained adsorption amount V and the above formula (5). (Acid amount analysis) The acid amount was measured by a method based on the ammonia-TPD method (see Measurement of Solid Acidity by Ammonia Temperature Programmed Desorption Method, Catalysts, Vol. 42, p. 218 (2000)). Specifically, ammonia was saturated and adsorbed onto the measurement sample at room temperature, and the sample was heated to 100°C to remove any ammonia remaining in the measurement atmosphere. The total acid amount was then calculated from the ammonia desorption peak measured during the temperature increase process up to 700°C at a rate of 10°C / min. (27Al-MAS-NMR measurement) 27Al-MAS-NMR measurement was performed to determine the Al iv / (Al iv +Al vi ) was determined. A common nuclear magnetic resonance spectrometer (product name: AVANCE NEO 700, manufactured by Bruker) was used for the measurement. As a pretreatment, the sample was baked in air at 500°C for 1 hour, and then held in a vacuum atmosphere in the presence of a saturated ammonium chloride aqueous solution at a relative humidity of 60% for 24 hours, and this was used as the measurement sample. 27Al-MAS-NMR measurement was performed under the following conditions.

[0108] Observation kernel: 27 Al (182.4MHz) Rotation frequency: 24kHz Pulse width: 2.1 μsec Wait time: 2 seconds Accumulation count: 2600 times From the NMR spectrum obtained by 27Al-MAS-NMR measurement (actual NMR spectrum), P 40~60ppm and P -10~10ppm The waveform is separated and P 40~60ppm Area intensity Al iv And, P -10~10ppm Area intensity Al vi I asked for Al. iv and Al vi From the above, the Al of the measurement sample iv / (Al iv +Al vi ) was sought.

[0109] In addition, Al iv and Al vi Detection and calculation of area intensity were performed using analytical software (GRAMS / AI ver. 8.0, manufactured by Thermo Fisher Scientific). 40~60ppm and P -10~10ppm The waveform separation was performed using the least squares method with a Gaussian function as the peak function. Baseline correction was performed by connecting the points at -50 ppm and 150 ppm in the measured NMR spectrum with a straight line, and correcting the result to 0. (Pt particle size) The Pt-containing amorphous silica-alumina was pressure-molded into a disk shape with a diameter of 4 cm at 500 KPa, and then the resulting molded body was crushed and passed through a sieve with a mesh size of 500 μm. The granules deposited on a sieve with a mesh size of 850 μm were collected. The resulting granules were treated in the order of steps 1 to 6 shown in the table below to prepare a measurement sample.

[0110] [Table 1]

[0111] The Pt particle size of Pt-containing amorphous silica-alumina was measured using a method based on the carbon monoxide pulse method ( Journal of the Chemical Society of Japan, No. 12, p. 218 (1989)). Specifically, using a general measuring device (product name: BEL-METAL-3SP, manufactured by Microtrac-Bell) at 50°C under a helium gas flow, carbon monoxide was repeatedly injected until the carbon monoxide emission reached a constant level. The amount of carbon monoxide adsorption was calculated from the difference between the total amount of carbon monoxide introduced and the total amount of carbon monoxide emitted.

[0112] The Pt surface area was calculated from the carbon monoxide adsorption amount using the following formula.

[0113] Pt surface area [m 2 / g]= K×6.02×10 23 ×(0.08×10 -18 ) (7) (where K refers to the number of moles of CO adsorbed per 1 g of the measurement sample [mol / g].) K can be calculated using the following formula:

[0114] K[mol / g]= CO adsorption amount [cm 3 (STP) / g] / (22.4×10 -3 x10 6 ) (8) The Pt particle size was calculated using the following formula.

[0115] Pt particle diameter [nm]= 60×metal content [mass%] / (Pt surface area [m 2 / g]×21.45 (9) Example 1 0.366 kg of an aluminum sulfate aqueous solution (containing 8.05 mass% Al calculated as Al2O3), 0.14 kg of pure water, and 0.015 kg of 97 mass% sulfuric acid (manufactured by Kishida Chemical Co., Ltd.) were mixed to obtain 0.52 kg of solution A of this example. The HO / Al2O3 molar ratio in solution A of this example was 21.

[0116] 0.88 kg of a sodium silicate aqueous solution (containing 14.5 mass% Si calculated as SiO and 4.5 mass% Na calculated as NaO) and 1.07 kg of pure water were mixed to obtain 1.94 kg of solution B of this example. The HO / SiO molar ratio in solution B of this example was 75.

[0117] The molar composition relationship between solutions A and B was as follows:

[0118] Na2O / sulfate ion molar ratio: 1.3 SiO2 / Al2O3 raw material molar ratio: 14.5 A 4 L heated stirring tank was charged with 1 L of pure water, and while heating and stirring at 45°C and 346 rpm, 250 g of sodium sulfate (Kishida Chemical, anhydrous) was added. Solution A was added dropwise at a flow rate of 26 mL / min, and solution B was added dropwise at a flow rate of 103±10 mL / min so that the pH of the solution in the stirring tank was 6.5 to 7.0, thereby obtaining solution C of this example.

[0119] Solution C of this example was subjected to solid-liquid separation to obtain approximately 0.3 kg of amorphous silica-alumina gel. The amorphous silica-alumina gel was then washed with 3 kg of pure water, then subjected to ion exchange treatment with a 20% by mass aqueous solution of ammonium chloride, and then washed with 3 kg of pure water.

[0120] The washed amorphous silica-alumina gel was dried in an air atmosphere at 150°C for 12 hours, and then calcined in an air atmosphere at 550°C for 1 hour to obtain the amorphous silica-alumina of this example. The evaluation results of the obtained amorphous silica-alumina are shown in the table below.

[0121] Example 2 0.240 kg of an aluminum sulfate aqueous solution (containing 8.05% by mass of Al2O3), 0.23 kg of pure water, and 0.064 kg of 97% by mass sulfuric acid (manufactured by Kishida Chemical Co., Ltd.) were added to a 3 L beaker to obtain 0.54 kg of Solution A of this example. The HO / Al2O3 molar ratio in Solution A of this example was 21.

[0122] 0.93 kg of a sodium silicate aqueous solution (containing 14.5 mass % Si calculated as SiO and 4.5 mass % Na calculated as NaO) and 1.14 kg of pure water were mixed to obtain 2.07 kg of solution B of this example. The HO / SiO molar ratio in solution B of this example was 117.

[0123] The molar composition relationship between solutions A and B was as follows:

[0124] Na2O / sulfate ion molar ratio: 1.1 SiO2 / Al2O3 raw material molar ratio: 23.5 Solution C of this example was obtained in the same manner as in Example 1, except that solutions A and B of this example were used.

[0125] Solution C of this example was subjected to solid-liquid separation to obtain approximately 0.3 kg (absolute dry mass) of amorphous silica-alumina gel. Subsequently, this amorphous silica-alumina gel was washed, ion-exchanged, washed, dried, and calcined in the same manner as in Example 1 to obtain the amorphous silica-alumina of this example. The evaluation results of the obtained amorphous silica-alumina are shown in the table below.

[0126] Comparative Example 1 The amorphous silica-alumina of this comparative example was obtained in the same manner as in Example 1, except that solution C was obtained without adding sodium sulfate. The evaluation results of the obtained amorphous silica-alumina are shown in the table below.

[0127] Comparative Example 2 A commercially available silica-alumina catalyst carrier (Sigma-Aldrich, Grade 135) was calcined at 550 ° C for 1 hour in an air atmosphere to obtain the amorphous silica-alumina of this comparative example. The evaluation results of the obtained amorphous silica-alumina are shown in the table below.

[0128] [Table 2]

[0129] [Table 3]

[0130] As can be understood from the specific surface area and total pore volume of Example 1 and Comparative Example 2 shown in Table 2, according to the production method of the present embodiment, amorphous silica alumina with a higher specific surface area and acid amount could be obtained.

[0131] Also, as shown in Table 3, it was found that the obtained amorphous silica alumina contains specific 4-coordinate Al and 6-coordinate Al.

[0132] Also, the micropore volume ratios of Example 1, Example 2, and Comparative Example 3 were 60% or more, and it was found that the nitrogen adsorption amount at a low relative pressure was large compared to the commercially available silica alumina of Comparative Example 1.

[0133] Measurement Example [[ID=十七]] <Pt supported> The amorphous silica alumina of the examples and comparative examples was impregnated with an aqueous H2PtCl6 solution so that the Pt content became 0.5% by mass, dried in an air atmosphere at 110 °C for 5 hours, and then calcined in an air atmosphere at 450 °C for 4 hours to obtain Pt-containing amorphous silica alumina powder. The Pt content, Pt surface area, and Pt particle diameter of the obtained Pt-containing amorphous silica alumina are shown in the following table.

[0134] [[ID=2 five]]

Table 4

[0135] ]END]]As can be understood from the Pt particle diameters of Example 1, 2, and Comparative Example 1 shown in Table 2, it was inferred that as the number of pores with a diameter of 2 nm or less increased, the particle diameter of the Pt particles on the carrier was small and they existed in a higher dispersion state. On the other hand, in the amorphous silica alumina of Comparative Example 1, there were many pores with a diameter exceeding 2 nm. It was inferred that the Pt particles existing in such large pores had weak spatial restrictions and grew into relatively large Pt particles. <Hydrocracking of n-decane> 1.1 g of Pt-containing amorphous silica-alumina of each of the examples and comparative examples was packed into a fixed-bed flow reactor using a stainless steel reaction tube (inner diameter 8 mm, length 650 mm), and hydrogen (gas) was passed through the reaction tube at a flow rate of 50 mL / min, a temperature of 350 °C, and 0.2 MPa (gauge pressure) for 3 hours as a pretreatment. After the pretreatment, hydrogen (gas) was supplied to the reaction tube at a volumetric flow rate of 20 mL / min and n-decane (liquid) at a volumetric flow rate of 0.025 mL / min so that the ratio of the volumetric flow rate of hydrogen to the volumetric flow rate of n-decane was 800, and the mixture was further heated at 280 °C, 0.2 MPa (gauge pressure), and a space velocity of n-decane of 1.0 Hr. -1 The hydrogenolysis reaction of n-decane was carried out so that the density of n-decane was 730 kg / cm. 3 It was decided. Ten hours after the start of n-decane flow, the outlet gas of the fixed-bed flow reactor was sampled using an autosampler (product name: GHS-343A, manufactured by J-Science Co., Ltd.), and the components in the outlet gas were analyzed using gas chromatography (product name: GC-7100, manufactured by J-Science Co., Ltd.). During this time, the temperature between the outlet of the fixed-bed flow reactor and the autosampler was maintained at 220°C. A capillary column (product name: Supelco® SPB-Octy, manufactured by Sigma-Aldrich) was used as the gas chromatography separation column.

[0136] The n-decane conversion, iso-decane selectivity, cracking selectivity (selectivity for cracked products with 1 to 9 carbon atoms), cracking yield, and C3 / C7 ratio (molar ratio of hydrocarbons with 3 to 7 carbon atoms) are shown in the table below.

[0137] [Table 5]

[0138] The hydrocracking reaction of n-decane is a sequential reaction in which straight-chain hydrocarbons are converted to shorter-carbon-chain hydrocarbons via branched hydrocarbons. If the support is not acidic enough, a relatively large amount of isomerized products (iso-decane) is produced, resulting in low decane conversion. Conversely, if the support is too acidic, the cracking reaction proceeds, but overcracking occurs, resulting in the production of large amounts of C3 and C4, and a high C3 / C7 ratio. On the other hand, if the hydrocracking reaction of long-chain paraffins can be controlled to complete first-order cracking, overcracking is suppressed, and the molar ratio of C3 to C7 is theoretically 1.

[0139] From the results of Table 5, it can be seen that the catalyst using amorphous silica-alumina as a carrier in the example has a higher cracking yield in the hydrogenation reaction of n-decane compared to the comparative example.In addition, it can be seen that the catalyst using amorphous silica-alumina as a carrier in the example has a C3 / C7 ratio of about 1, and can be controlled to primary cracking with high efficiency.

[0140] From the above results, it was understood that the catalyst of this embodiment has high catalytic activity and is suitable as a paraffin reforming catalyst capable of primary cracking of 10 or more straight-chain paraffins with high efficiency.

Claims

1. The ratio of the pore volume of pores having a diameter of 0 nm to 2 nm to the pore volume of pores having a diameter of 0 nm to 10 nm is 60% to 95% and the specific surface area is 280 m ２ / g or more.

2. Total pore volume is 0.2 cm ３ The amorphous silica-alumina according to claim 1, wherein the SiO 2 content is 1 / g or more.

3. 3. The amorphous silica-alumina according to claim 1 or 2, wherein the molar ratio of silica to alumina is 10 or more and 100 or less.

4. 3. The amorphous silica-alumina according to claim 1 or 2, wherein the acid amount is 0.3 mmol / g or more.

5. The amorphous silica-alumina according to claim 1 or 2, wherein the ratio of the area intensity of the peak that has a peak top at a chemical shift of 40 ppm or more and 60 ppm or less to the area intensity of the peak that has a peak top at a chemical shift of -10 ppm or more and 10 ppm or less is 0.40 or more and less than 0.

80.

6. 3. The amorphous silica-alumina according to claim 1 or 2, which contains one or more elements selected from the group consisting of Groups 8, 9 and 10.

7. 3. The method for producing amorphous silica-alumina according to claim 1 or 2, comprising: a gelling step of mixing a solution containing an alumina source, an acid source and water, and a solution containing a basic silica source and water with an aqueous sulfate solution containing an alkali metal to obtain an amorphous silica-alumina gel; an ion exchange step of ion-exchanging the amorphous silica-alumina gel; and a calcination step of calcining the amorphous silica-alumina gel after the ion exchange step.

8. 8. The method according to claim 7, wherein the aqueous sulfate solution containing an alkali metal is an aqueous solution of one or more selected from the group consisting of lithium sulfate, sodium sulfate, and potassium sulfate.

9. A catalyst for reforming paraffins, comprising the amorphous silica-alumina according to claim 1 or 2.

10. A method for reforming paraffins, comprising the step of contacting a paraffin-containing hydrocarbon fluid with the paraffin reforming catalyst according to claim 9.

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