Selective method for producing n-paraffin hydrolysis products from heavier n-paraffins

Abstract

A process for the selective production of hydrocracked n-paraffins from a hydrocarbon composition containing heavy n-paraffins is disclosed. The process generally involves the use of a hydrocracking catalyst comprising an unsulfided, low acidity, precious metal-containing zeolite. The invention is generally useful for upgrading hydrocarbon feedstocks for the production of fuels, solvents, lubricants, chemicals, and other hydrocarbon-based compositions, and more particularly for the production of lighter n-paraffin products for a variety of uses, including as feedstocks for the production of ethylene and linear alkylbenzenes, and as blending components for jet fuel and diesel fuel.

Description

[Technical Field]

[0001] Cross-reference of related applications This application relates to and claims priority of U.S. Provisional Application No. 63 / 005,938, filed on April 6, 2020, titled "SELECTIVE PRODUCTION OF N-PARAFFIN HYDROCRACKING PRODUCTS FROM HEAVIER N-PARAFFINS," which is incorporated herein by reference in its entirety.

[0002] Field of Invention The present invention relates to a method for selectively producing hydrocracking n-paraffins from hydrocarbon compositions containing heavy n-paraffins, more particularly to the method using a hydrocracking catalyst containing an unsulfurized, low-acidity precious metal-containing zeolite. The present invention broadly relates to improving the quality of hydrocarbon raw materials for producing fuels, solvents, lubricants, chemicals, and other hydrocarbon compositions, and more particularly to the production of lighter n-paraffin products for various applications, such as raw materials for the production of ethylene and linear alkylbenzenes, and as components of jet fuels and diesel fuels. [Background technology]

[0003] Background of the Invention Light n-paraffin products have a variety of applications, including as solvents, raw materials for ethylene production, components of jet and diesel fuels, and raw materials for linear alkylbenzene production. Hydrocracking of n-paraffins typically produces branched paraffins in yields comparable to those of n-paraffins. Recovery of n-paraffin degradation products for such applications usually requires a potentially costly separation step. Furthermore, the formation of branched paraffins can lead to a decrease in the yield of n-paraffins.

[0004] Previous studies have demonstrated the advantages associated with using low-acidity molecular sieves for the conversion of highly branched heavy hydrocarbons into high-octane gasoline (U.S. Patent No. 5,364,997) and for the selective hydrocracking of distillates to produce high-octane isoparaffins in the naphtha range (U.S. Patent No. 5,284,985). Platinum-supported borosilicate or aluminoborosilicate zeolites have also been reported to provide high selectivity for n-paraffins (U.S. Patent Application Publication 2007 / 0032692A1).

[0005] Despite advances made in the preparation of hydrogenation catalysts selective for producing specific paraffins, there remains a need for catalysts useful for producing n-paraffin compositions, and for improved and simplified methods for producing such compositions. [Overview of the project]

[0006] Summary of the Invention Broadly speaking, the present invention provides a novel approach for producing n-paraffin compositions having desirable properties and n-paraffin content by hydrocracking a heavier n-paraffin raw material. Hydrocracking of the heavier n-paraffin raw material is carried out using a hydrocracking catalyst that improves selectivity for lower n-paraffin products. The present invention broadly provides a method for selectively producing hydrocracking n-paraffins from heavy n-paraffins, comprising contacting a hydrocarbon raw material containing heavy n-paraffins with a hydrocracking catalyst containing an unsulfurized, low-acidity precious metal-containing zeolite under hydrocracking conditions to produce hydrocarbon products containing hydrocracking n-paraffins. In one embodiment, the hydrocracking catalyst may be an aluminosilicate having a silica / alumina ratio sufficient to selectively produce n-paraffin products, preferably n-paraffin products, rather than isoparaffin products.

[0007] One of the objectives of the present invention is to improve the yield of lower n-paraffin product compositions, which may also result in lower capital and operating costs for other hydrogenation applications. It is also desirable to provide a manufacturing method that utilizes milder process conditions and minimizes undesirable side reactions in specific applications. [Brief explanation of the drawing]

[0008] Simple description of the drawing The scope of the present invention should not be limited by any representative drawings attached to this disclosure, but rather should be understood to be defined by the claims of this application.

[0009] [Figure 1a] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=60 hydrocracking catalyst described in the examples. [Figure 1b] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=60 hydrocracking catalyst described in the examples. [Figure 1c] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=60 hydrocracking catalyst described in the examples. [Figure 1d] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=60 hydrocracking catalyst described in the examples. [Figure 1e] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=60 hydrocracking catalyst described in the examples.

[0010] [Figure 2a] This figure shows the selectivity profile of paraffin decomposition products using the Pt / USY, SAR=108 hydrocracking catalyst described in the examples. [Figure 2b]It is a diagram showing the selectivity profile of paraffin decomposition products using the hydrocracking catalyst of Pt / USY with SAR = 108 described in the examples. [Figure 2c] It is a diagram showing the selectivity profile of paraffin decomposition products using the hydrocracking catalyst of Pt / USY with SAR = 108 described in the examples. [Figure 2d] It is a diagram showing the selectivity profile of paraffin decomposition products using the hydrocracking catalyst of Pt / USY with SAR = 108 described in the examples. [Figure 2e] It is a diagram showing the selectivity profile of paraffin decomposition products using the hydrocracking catalyst of Pt / USY with SAR = 108 described in the examples.

[0011] [Figure 3a] It is a diagram showing the comparison of the selectivities for linear and branched paraffin decomposition products regarding C6 products between Pt / USY with SAR = 60 and Pt / USY with SAR = 108 described in the examples. [Figure 3b] It is a diagram showing the comparison of the selectivities for linear and branched paraffin decomposition products regarding C8 products between Pt / USY with SAR = 60 and Pt / USY with SAR = 108 described in the examples. [Figure 3c] It is a diagram showing the comparison of the selectivities for linear and branched paraffin decomposition products regarding C10 products between Pt / USY with SAR = 60 and Pt / USY with SAR = 108 described in the examples.

Modes for Carrying Out the Invention

[0012] Detailed description While exemplary embodiments of one or more aspects are provided herein, the manufacturing methods disclosed and the compositions formed therefrom can be carried out using any number of techniques. This disclosure is not limited to the exemplary or specific embodiments, drawings, and techniques illustrated herein, including any exemplary designs and embodiments illustrated and described herein, and may be modified within the scope of the appended claims, together with the entire scope of equivalents of the claims.

[0013] Unless otherwise indicated, the following terms, technical terms, and definitions apply to this disclosure. If a term is used in this disclosure but is not specifically defined herein, the definition in the IUPAC Compendium of Chemical Terminology, 2nd ed (1997) may be applied, provided that such definition does not conflict with any other disclosure or definition applicable herein, or that such definition does not obscure or invalidate any claim to which such definition applies. To the extent that any definition or usage provided in any document incorporated herein conflicts with the definition or usage provided herein, the definition or usage provided herein should be understood to apply.

[0014] The term "periodic table" refers to the IUPAC periodic table of elements as of June 22, 2007, and the group numbering scheme of the periodic table is as described in Chemical and Engineering News, 63(5), 27 (1985).

[0015] The terms "hydrocarbons," "hydrocarbons," and similar terms refer to compounds containing only carbon and hydrogen atoms. Other identifiers may be used to indicate the presence of specific groups (if any) in such hydrocarbons (for example, halogenated hydrocarbons indicate the presence of one or more halogen atoms that substitute for an equivalent number of hydrogen atoms in the hydrocarbon).

[0016] "Hydrogenation" or "hydrogen conversion" refers to a process in which hydrocarbon-based raw materials are brought into contact with hydrogen and a catalyst at high temperature and pressure for the purpose of removing undesirable impurities and / or converting the raw materials into desired products. Such processes include, but are not limited to, methanation, water-gas shift reactions, hydrogenation, hydrogenation purification, hydrogenation desulfurization, hydrogenation denitrification, hydrogenation demetallation, hydrogenation dearomatization, hydrogenation isomerization, hydrogenation dewaxing, and hydrogenation cracking, including selective hydrogenation. Depending on the type of hydrogenation and reaction conditions, the products of hydrogenation may exhibit improved physical properties such as viscosity, viscosity index, saturation content, low-temperature properties, volatility, and depolarization.

[0017] Hydrocracking refers to a process in which hydrogenation and dehydrogenation are involved in the breakdown / fragmentation of hydrocarbons, such as the conversion of heavier hydrocarbons to lighter hydrocarbons, or the conversion of aromatic and / or cycloparaffins to acyclic paraffins.

[0018] The term "binder," or more specifically "support" in the term "catalyst support," typically refers to a conventional material that is a high-surface-area solid to which a catalytic substance is added. The support material may be inert or participate in the catalytic reaction, and may be porous or non-porous. Common catalyst supports include various types of carbon, alumina, silica, and silica-alumina, such as amorphous silica aluminates, zeolites, alumina-boria, silica-alumina-magnesia, silica-alumina-titania, and materials obtained by adding other zeolites or other composite oxides to them.

[0019] A "molecular sieve" refers to a material that has pores of uniform molecular size within a framework structure, where, depending on the type of molecular sieve, only specific molecules can access the pore structure of the molecular sieve, while other molecules are excluded, for example, due to molecular size and / or reactivity. Zeolites, crystalline aluminophosphates, and crystalline silicoaluminophosphates are typical examples of molecular sieves.

[0020] Examples of "middle distillates" include jet fuel, diesel fuel, and kerosene, and they typically have the following cut points. [Table 1]

[0021] The SiO2 / Al2O3 ratio (SAR) is measured by inductively coupled plasma (ICP) elemental analysis. An infinite SAR means that there is no aluminum present in the zeolite, i.e., the molar ratio of silica to alumina is infinite.

[0022] In this disclosure, compositions and methods or methods of production are often described in terms of "including" various components or steps, but unless otherwise specified, such compositions and methods may "essentially consist of" or "consist of" various components or steps.

[0023] The terms “a,” “an,” and “the” are intended to include multiple options, e.g., at least one. For example, the disclosure of “a transition metal” or “an alkali metal” means, unless otherwise expressly stated, to include one transition metal or alkali metal, or a mixture or combination of more than one transition metal or alkali metal.

[0024] All numerical values ​​in the embodiments and claims for carrying out the inventions herein are modified by values ​​indicated as "approximately" or "roughly," taking into account experimental errors and variations that a person skilled in the art would expect.

[0025] The present invention provides a method for selectively producing hydrocracked n-paraffins from heavy n-paraffins by contacting a hydrocarbon raw material containing heavy n-paraffins with a hydrocrack catalyst selective for producing such n-paraffins. Generally, the hydrocrack catalyst contains an unsulfurized, low-acidity precious metal-containing zeolite, and the hydrocrack conditions are suitable for producing hydrocarbon products containing hydrocracked n-paraffins.

[0026] The above zeolite may typically be an aluminosilicate having low acidity, low alumina content, and / or a high silica / alumina ratio. While not particularly limited to specific low values ​​or ranges, the silica / alumina ratio of the zeolite is a value or range sufficient to selectively produce n-paraffin decomposition products, preferably n-paraffin products, rather than isoparaffin products. More detailed useful ranges include low-acidity zeolites with a silica / alumina ratio of at least about 70, or 80, or 90, or 100, or 110, or 120. The above zeolite may be boron-free, or not a borosilicate or aluminoborosilicate, or an aluminosilicate other than a borosilicate or aluminoborosilicate. Specific examples of suitable zeolites include hydrogenolytic catalysts selected from USY, Beta, ZSM-4, ZSM-12, ZSM-18, ZSM-20, Y, L, or combinations thereof. Useful zeolites referred to herein are described in detail in the patent documents, for example, U.S. Patents 5,284,985 and 5,364,997.

[0027] This manufacturing method can be used to produce a hydrolyzed n-paraffin composition from a heavier n-paraffin, where the heavier n-paraffin is, for example, C 12+ Contains n-paraffin or is primarily C 12+ n-paraffin, or C 12+The content is approximately 50% by weight, or 60%, 70%, 80%, 90%, 95%, or 98%, or approximately 100%. Suitable raw materials containing heavier n-paraffins are not necessarily limited and include wax-based raw materials such as high molecular weight Fischer-Tropsch wax, recirculated flow from hydrocracking units, diesel fuel, and paraffinic residues. Raw materials containing linear paraffins up to and exceeding approximately 30% by weight, as well as slightly branched paraffins having two or fewer alkyl substituents, can also be used.

[0028] The above-mentioned precious metal may generally contain any precious metal such as platinum and palladium together with other Group VIIIA metals such as iridium and rhodium. The above-mentioned precious metal preferably contains platinum or is platinum.

[0029] The above-mentioned precious metals can be incorporated into the catalyst by any and appropriate method, such as impregnation or replacement of the zeolite. The above-mentioned precious metals are Pt(NH3)4 2+ The noble metal can be incorporated in the form of cationic, anionic, or neutral complexes, and it will be understood that this type of cationic complex is convenient for replacing metals on the zeolite. The amount of noble metal is preferably about 0.01 to about 10 weight percent, and usually about 0.1 to about 2.0 weight percent. In a preferred method for synthesizing Pt / boron-containing zeolite beta, the platinum compound is tetraammineplatinum hydroxide. The noble metal is preferably introduced into the catalyst composition using a pH-neutral solution.

[0030] It is generally preferable that the precious metals are dispersed at a high level. For example, the dispersion of platinum is measured by hydrogen chemisorption and expressed as an H / Pt ratio. The higher the H / Pt ratio, the more dispersed the platinum. The resulting zeolite is preferably H / Pt ratio greater than approximately 0.8.

[0031] Binder materials such as silica, silica-alumina, silica-boria, silica-magnesia, silica-zirconia, silica-tria, silica-beryllia, silica-titania, and ternary compositions such as silica-alumina-boria, silica-alumina-tria, silica-alumina-zirconia, silica-alumina-magnesia, or silica-magnesia-zirconia can also be used with zeolites. When used, the ratio of binder to zeolite typically varies from about 9:1 to about 1:9, and more commonly from about 3:1 to about 1:3 (by weight).

[0032] This manufacturing method is carried out under hydrocracking conditions suitable for the specific catalyst used, which typically include a temperature of approximately 270°C to 330°C, a pressure in the range of approximately 200 psig to 2000 psig, and a LHSV of approximately 0.4 to 2.0 hr. -1 This includes spatial velocities in the range of [this].

[0033] This manufacturing method is generally carried out using low-sulfur raw materials with a sulfur content of less than approximately 500 ppm and a nitrogen content of less than approximately 50 ppm. Preferably, the sulfur content of the raw materials used in this manufacturing method is less than approximately 50 ppm. A raw material with a sulfur content of less than approximately 500 ppm that has not undergone pre-hydrogenation purification before contact with the unsulfurized catalyst composition of the present invention is preferred.

[0034] A hydrogenation purification step using a conventional hydrogenation purification catalyst may be performed to remove nitrogen and sulfur and saturate the aromatics to naphthenes without substantially altering the boiling point range. Suitable hydrogenation purification catalysts generally contain a metallic hydrogenation component, usually a group VIA or VIIIA metal. Hydrogenation purification usually improves catalyst performance, allowing the use of lower temperatures, higher space velocities, lower pressures, or a combination of these conditions.

[0035] The production method of the present invention offers many advantages compared to hydrocracking catalysts that do not utilize low-acidity zeolites, including an improvement in the ratio yield of the hydrocracking n-paraffin product relative to the resulting isoparaffin, as supported by the following examples. For example, when comparing the hydrocracking performance for n-paraffin production with a similar zeolite that differs from the low-acidity zeolite only in terms of silica / alumina ratio (SAR), a significant improvement in the content of the resulting n-paraffin can be achieved. Such an improvement in the ratio yield can be at least about 10 mol% greater than the corresponding ratio yield obtained using a different hydrocracking catalyst, for example, one that differs only in that the silica / alumina ratio of the zeolite is about 60 or less. In some embodiments, the yield improvement expressed in such ratios is even greater, and can be at least about 20 mol%, or 30 mol%, or 40 mol%, or 50 mol%, or 60 mol%, or 70 mol%, or 80 mol%, or 90 mol%, or 100 mol%, compared to the yield expressed in the corresponding ratio obtained using different hydrocracking catalysts, for example, only in that the silica / alumina ratio of the zeolite is about 60 or less.

[0036] Examples Example 1 Preparation of Pt / USY zeolite with a silica-to-alumina ratio (SAR) = 60 The USY zeolite CBV-760 used was obtained from Zeolyst. Platinum was added as follows.

[0037] One gram of CBV-760 (FAU zeolite manufactured by Zeolyst) was added to a vial along with 5 g of 0.148 M NH4OH solution and 6 mL of deionized water. A platinum-containing solution was prepared by dissolving 350 mg of Pt(NH3)4(NO3)2 in 5 g of 0.148 M NH4OH solution and 32 mL of H2O. One mL of the latter platinum solution was added to the vial containing CVV-760, 0.148 M NH4OH solution, and water.

[0038] This solution was left to stand at room temperature for 2-3 days, and then filtered. The platinum-containing zeolite powder was dried in an oven at 90°C for 2-4 hours, then placed in a shallow glass dish as a fine powder and dried for 20-40 ft. 3 The product was fired in an airflow of 1°C / min at temperatures up to 300°C. A stepwise heating program was used: a) heat up to 120°C at 1°C / min, b) hold for 2 hours, c) heat up to 300°C at 1°C / min, d) hold for 3 hours, e) stop heating and allow to cool to room temperature.

[0039] The catalyst described above was compressed into pellets, crushed, and then sieved to obtain solids with a mesh size of 20 to 40.

[0040] The characteristics of the low-SAR Pt / USY catalyst described above are shown below. Pt content, weight%: 0.43 Pt's variance, strong, %: 52.20 Pt's variance, total, %: 128.20 Al content, weight%: 1.22 Si content, wt%: 44.5 SiO2 / Al2O3 molar ratio (SAR): 58.5

[0041] Example 2 Selectivity profile when using Pt / USY (SAR=60) prepared as described in Example 1. 0.7 g of the catalyst described in Example 1 was diluted with inert alundum and packed into a reactor consisting of a tube with an outer diameter of 0.25 inches and a wall thickness of 0.035 inches, which was placed inside the furnace.

[0042] 50cm above the catalyst floor 3 The catalyst was dried by flowing N2 / min at 250°F for at least 2 hours. This catalyst was then dried at atmospheric pressure for 50 cm. 3 The reaction was reduced by heating the mixture to 600°F in H2 flowing at a rate of 1 / min and maintaining that temperature for at least 1 hour. The reactor was then cooled to 518°F and pressurized to 1200 psig with hydrogen, after which the reactant n-hexadecane was pumped into the reactor.

[0043] After approaching a steady state under a specific set of conditions (temperature, pressure, weight hourly space velocity [WHSV]), the period for obtaining the target product was carried out. The conversion rate was varied by changing the WHSV.

[0044] The yields of iso- and normal C4-C paraffin products as a function of conversion rate at 1200 psig and 518 °F are shown in Figures 1a - 1e. 13 The yields of paraffin products are shown in Figures 1a - 1e.

[0045] As shown in Figures 1a - 1e, at conversion rates below 60%, iso- and normal cracking products are formed in similar yields. At higher conversion rates, the yield of isoparaffin cracking products becomes dominant. The yield at 50% n-hexadecane conversion is shown in Table A. The ratio of the yields of normal paraffin cracking products to isoparaffin cracking products for each carbon number is generally less than 1. Such a catalyst would not be suitable for the selective production of light n-paraffins.

Table A

[0046] Generally, using the catalyst of this example, the yields of isoparaffin and n-paraffin cracking products are similar at conversion rates below 60%, but the isoparaffin yield becomes dominant at higher conversion rates.

[0047] Example 3 : Preparation of Pt / USY Zeolite with SAR = 108 Add 3 g of high-silica FAU zeolite (Tosoh product 385HUA, SAR = 100 (nominal)) to a vial together with 18 cc of water and 15 g of 0.148 M NH4OH. Then add 3 g of tetraammineplatinum dinitrate solution [prepared by dissolving 0.286 g of tetraammineplatinum dinitrate (Aesar, Pt 49 wt%) in 24.5 g of water and 4.1 g of 0.148 M NH4OH solution], and let this reaction mixture stand at room temperature for 3 days.

[0048] Next, the solid material is filtered and collected, then washed in three separate washes with 50cc of water. After drying in a vacuum, the solid material is transferred to an oven and dried at 90°C for 2 hours. Then, the solid material is spread thinly on a Pyrex dish and baked according to the program described in Example 1.

[0049] The catalyst was compressed into pellets, crushed, and then sieved to obtain solids with a mesh size of 20-40.

[0050] The characteristics of the above-mentioned high SAR Pt / USY catalyst are shown below. Pt content, weight%: 0.472 Pt's variance, strong, %: 70.2 Pt's variance, total, %: 117.4 Al content, weight%: 0.739 Si content, wt%: 41.6 SiO2 / Al2O3 molar ratio (SAR): 10⁸

[0051] Example 4 Selectivity profile when using Pt / USY (SAR=108) prepared as described in Example 3. 0.7 g of the catalyst described in Example 3 was diluted with inert alundum and packed into a reactor consisting of a tube with an outer diameter of 0.25 inches and a wall thickness of 0.035 inches, which was placed inside the furnace. This catalyst was dried and reduced as shown in Example 1. The experiment was carried out at 1200 psig, and the conversion rate was varied by changing the WHSV. However, because the activity of this catalyst was lower, a higher temperature (626°F compared to 518°F) was required to obtain a conversion rate range similar to that shown in Example 2.

[0052] C4~C of iso and normal as a function of conversion rate at 1200 psig and 626°F 13 The yields of the paraffin product are shown in Figures 2a to 2e.

[0053] As shown in Figures 2a-2e, n-paraffins were produced in significantly higher yields than the corresponding isoparaffins at all conversion rates, in stark contrast to the selectivity obtained with Pt / USY, SAR=60, indicating the selective formation of n-paraffin degradation products. The yields at an n-hexadecane conversion rate of 50% are shown in Table B, where the n:i ratio is greater than 1 for any number of carbon atoms. Thus, the advantage of Pt / USY, SAR=108 for the selective production of n-paraffins is demonstrated. [Table B]

[0054] In general, when using the catalyst in this example, i.e., a Pt-containing catalyst on a low-acidity (i.e., high-SAR) USY zeolite, n-paraffin decomposition products are dominant, and it is important to note the selective formation of the latter.

[0055] The selectivity for linear and branched decomposition products can also be compared between the two catalysts by plotting the yields of the linear and branched decomposition products derived from each catalyst on the same graph with respect to a given number of carbon atoms. Figures 3a-3c show C6, C8, and C 10 Representative results for each species show that the yield of linear paraffin degradation products is significantly higher at a given conversion rate (indicating higher selectivity), with Pt / USY and SAR=10⁸. However, the yield and selectivity of branched paraffin degradation products are similar for the two catalysts mentioned above.

[0056] Example 5 Preparation of Pt / SiO2 catalyst 1.22 g of tetraammineplatinum disnitrate solution was added to 1.22 g of Cabosil M5 fumed silica (impurity < 5 ppm) (the latter solution was prepared by adding 0.286 g of tetraammineplatinum disnitrate (Aesar; Pt 49 wt%) to 24.5 g of water and 4.1 g of 0.148 M NH4OH solution). A further 4.2 g of water was added (gradually while gently mixing) to achieve initial wetting.

[0057] The catalyst described above was prepared on a thin Pyrex dish so that it could be directly dried and calcined, as described for the other two catalysts (see Examples 1 and 3).

[0058] The properties of the above Pt / SiO2 catalyst are shown below. Pt content, weight%: 0.480 Pt's variance, strong, %: 37.2 Pt's variance, total, %: 62.3

[0059] Example 6 Reactivity of n-hexadecane in the presence of the catalyst prepared in Example 5 0.7 g of the catalyst described in Example 5 was diluted with inert alundum and packed into a reactor consisting of a tube with an outer diameter of 0.25 inches and a wall thickness of 0.035 inches, which was placed inside the furnace. This catalyst was dried and reduced as shown in Example 3.

[0060] The experiment was carried out at 1200 psig, WHSV = 0.97, and at two temperatures, 518°F and 536°F. In all cases, the n-hexadecane conversion rate was less than 2%, indicating that the Pt / SiO2 catalyst is less active than the catalysts described in Examples 3 and 4.

[0061] In subsequent experiments, when tetralin was supplied to the reactor at 1200 psig, 518°F, and WHSV=10 (i.e., significantly milder conditions than those used in experiments with n-hexadecane), complete hydrogenation of tetralin occurred, yielding cis- and trans-decalin, demonstrating the high hydrogenation activity of the Pt / SiO2 catalyst.

[0062] This example shows that Pt / SiO2 exhibits very low activity for n-hexadecane conversion under conditions comparable to those used in Examples 2 and 4. Therefore, the selective formation of n-paraffin degradation products requires platinum supported on a low-acidity (high-SAR) zeolite. Despite its high hydrogenation activity, Pt / SiO2 does not catalyze selective n-paraffin formation, indicating that a catalyst containing platinum supported on a low-acidity zeolite is necessary to catalyze the selective formation of n-paraffin degradation products.

[0063] Example 7 Preparation of Pt / ZSM-12 catalyst Two grams of a ZSM-12 structure, ZEO217, available from Zeolyst, was calcined to remove the organic template and added to a vial containing 12 grams of water and 20 grams of 0.148 M NH4OH solution. Two grams of tetraammineplatinum disnitrate solution were added to this vial. The tetraammineplatinum disnitrate solution was prepared by dissolving 0.286 grams of tetraammineplatinum disnitrate (Aesar; Pt 49 wt%) in 24.5 grams of water and 4.1 grams of 0.148 M NH4OH solution for buffering. If all the Pt ultimately remained on the zeolite, a catalyst with a loading of 0.5 wt% was obtained from 1 gram of this solution.

[0064] The contents described above were left to stand at room temperature for 2 days. The solid was then filtered and collected, and washed in three separate washes with 50cc of water. After drying in a vacuum, the solid was transferred to a 90°C oven and dried for 2 hours. The solid was then spread thinly on a Pyrex dish and baked according to the following program: heating to 120°C at 1°C / min in a positive pressure airflow; holding at this temperature for 2 hours; then heating to 300°C at the same rate; and holding for 3 hours.

[0065] The characteristics of the above Pt / ZSM-12 catalyst are shown below. Pt content, weight%: 0.447 Pt's variance is strong, %: 29.5 Pt's variance, total, %: 70.0 Al content, weight%: 0.701 Si content, wt%: 44.8 SiO2 / Al2O3 molar ratio (SAR): 115

[0066] Example 8 Reactivity of n-hexadecane in the presence of the catalyst prepared in Example 7 0.7 g of the catalyst described in Example 7 was diluted with inert alundum and packed into a reactor consisting of a tube with an outer diameter of 0.25 inches and a wall thickness of 0.035 inches, which was placed inside the furnace. This catalyst was dried and reduced as shown in Example 3.

[0067] The experiment was conducted at 1200 psig, WHSV = 1.0, and a temperature of °F 518. The conversion rate of n-hexadecane was 76%, which was significantly higher than that of the previously mentioned Pt / SiO2 and Pt / USY catalysts. Therefore, the Pt / ZSM-12 catalyst is significantly more active and selective for n-paraffin degradation products than the Pt / SiO2 and Pt / USY catalysts.

[0068] This example shows that Pt / ZSM-12 exhibits high activity for n-hexadecane conversion under conditions comparable to those used in Examples 2 and 4. Therefore, it appears that platinum supported on a low-acidity (high SAR) zeolite is necessary to form selective n-paraffin degradation products. As described above, despite its high hydrogenation activity, the Pt / SiO2 catalyst does not catalyze selective n-paraffin formation. This indicates that a catalyst containing platinum supported on a low-acidity zeolite, such as the Pt / ZSM-12 catalyst, is necessary to catalyze the selective formation of n-paraffin degradation products.

[0069] To avoid any ambiguity, this application covers the subject matter described in the following numbered clauses. 1. A selective method for producing hydroculated n-paraffins from heavy n-paraffins, comprising contacting a hydrocarbon raw material containing heavy n-paraffins with a hydroculation catalyst containing an unsulfurized, low-acidity precious metal-containing zeolite under hydroculation conditions to produce a hydrocarbon product containing hydroculated n-paraffins. 2. The manufacturing method described in paragraph 1, wherein the zeolite is an aluminosilicate. 3. The method for producing the product according to paragraph 1, wherein the zeolite is an aluminosilicate with a low alumina content and / or a high silica / alumina ratio. 4. The manufacturing method according to paragraph 2 or 3, wherein the silica / alumina ratio of the zeolite is a value or range sufficient to selectively produce n-paraffin decomposition products, preferably n-paraffin products, rather than isoparaffin products. 5. The manufacturing method according to paragraph 2 or 3, wherein the silica / alumina ratio of the zeolite is at least about 70, or 80, or 90, or 100, or 110, or 120. 6. The manufacturing method according to paragraphs 1 to 5, wherein the zeolite described above does not contain boron, is not a borosilicate or aluminoborosilicate, or is an aluminosilicate other than a borosilicate or aluminoborosilicate. 7. The manufacturing method according to paragraphs 1 to 6, wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY, Beta, ZSM-4, ZSM-12, ZSM-18, ZSM-20, Y, L, or combinations thereof. 8. The manufacturing method according to paragraph 7, wherein the zeolite is selected from USY and ZSM-12, or a combination thereof. 9. The above heavy n-paraffin is C 12+ Contains n-paraffin or is primarily C 12+ n-paraffin, or C 12+ The manufacturing method according to paragraphs 1 to 8, wherein the content is greater than approximately 50% by weight, or 60%, or 70%, or 80%, or 90%, or 95%, or 98%, or approximately 100%. 10. The manufacturing method described in paragraphs 1 to 9, wherein the above-mentioned precious metal includes platinum. 11. The above hydrocracking conditions are a temperature of approximately 270°C to approximately 330°C, a pressure in the range of approximately 200 psig to approximately 2000 psig, and approximately 0.4 to approximately 2.0 LHSV hr -1 The manufacturing method described in paragraphs 1 to 10, including spatial velocities in the range of . 12. The production method according to paragraphs 1 to 11, wherein the yield expressed as a ratio of hydrocracking n-paraffin products is at least about 10 mol% greater than the yield expressed as a corresponding ratio obtained using a different hydrocracking catalyst, except that the silica / alumina ratio of the zeolite is about 60 or less. 13. The method for producing the above-mentioned hydrocracked n-paraffin product, wherein the yield expressed as a ratio is at least about 20, 30, 40, 50, 60, 70, 80, 90, or 100 mol% greater. 14. Use of unsulfurized, low-acidity precious metal-containing zeolite for selective production of hydrolyzed n-paraffins from heavy n-paraffins according to the manufacturing methods described in paragraphs 1 to 13. 15. Use of an unsulfurized, low-acidity precious metal-containing zeolite as described in paragraph 14, wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY, Beta, ZSM-4, ZSM-12, ZSM-18, ZSM-20, Y, L, or a combination thereof. 16. Use of an unsulfurized, low-acidity precious metal-containing zeolite as described in paragraph 14, wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY and ZSM-12, or a combination thereof. 17. Hydroculated n-paraffin composition prepared according to the manufacturing methods described in paragraphs 1 to 13.

[0070] Further details regarding the present invention and the scope of this disclosure can be determined from the appended claims.

[0071] The foregoing description of one or more embodiments of the present invention is primarily illustrative, and it is recognized that variations may be used that still encompass the essence of the present invention. For determining the scope of the present invention, please refer to the following claims. In connection with the present invention, the following is further disclosed. [1] A selective method for producing hydroculated n-paraffins from heavy n-paraffins, comprising contacting a hydrocarbon raw material containing heavy n-paraffins with a hydroculation catalyst containing an unsulfurized, low-acidity precious metal-containing zeolite under hydroculation conditions to produce a hydrocarbon product containing hydroculated n-paraffins. [2] The method for producing the product according to [1], wherein the zeolite is an aluminosilicate. [3] The method for producing the product according to [1], wherein the zeolite is an aluminosilicate with a low alumina content and / or a high silica / alumina ratio. [4] The manufacturing method according to [2], wherein the silica / alumina ratio of the zeolite is a value or range sufficient to selectively produce n-paraffin decomposition products, preferably n-paraffin products, rather than isoparaffin products. [5] The manufacturing method according to [2], wherein the silica / alumina ratio of the zeolite is at least about 70, or 80, or 90, or 100, or 110, or 120. [6] The method for producing the product according to [1], wherein the zeolite is boron-free, or not a borosilicate or aluminoborosilicate, or an aluminosilicate other than a borosilicate or aluminoborosilicate. [7] The method for producing an aluminosilicate zeolite hydrocracking catalyst selected from USY, beta, ZSM-4, ZSM-12, ZSM-18, ZSM-20, Y, L, or combinations thereof, as described in [1]. [8] The manufacturing method according to [7], wherein the zeolite is selected from USY and ZSM-12, or a combination thereof. [9] The aforementioned heavy n-paraffin is C 12+ Contains n-paraffin or is primarily C 12+ n-paraffin, or C 12+ The manufacturing method according to [1], wherein the content is greater than approximately 50% by weight, or 60%, or 70%, or 80%, or 90%, or 95%, or 98%, or approximately 100%.

[10] The manufacturing method according to [1], wherein the aforementioned precious metal includes platinum.

[11] The aforementioned hydrocracking conditions are a temperature of approximately 270°C to approximately 330°C, a pressure in the range of approximately 200 psig to approximately 2000 psig, and approximately 0.4 to approximately 2.0 LHSV hr. -1 The manufacturing method according to [1], including a spatial velocity in the range of .

[12] The method for producing hydrocracking n-paraffin products according to [1], wherein the yield expressed as a ratio of hydrocracking n-paraffin products is at least about 10 mol% greater than the yield expressed as a corresponding ratio obtained using a different hydrocracking catalyst, except that the silica / alumina ratio of the zeolite is about 60 or less.

[13] The method for producing the product according to

[12] , wherein the yield, expressed as a ratio of the hydrolyzed n-paraffin product, is at least about 20, 30, 40, 50, 60, 70, 80, 90, or 100 mol% greater.

[14] Use of unsulfurized, low-acidity precious metal-containing zeolite for selective production of hydrolyzed n-paraffins from heavy n-paraffins according to the manufacturing method described in [1].

[15] The use of an unsulfurized, low-acidity precious metal-containing zeolite as described in

[14] , wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY, beta, ZSM-4, ZSM-12, ZSM-18, ZSM-20, Y, L, or a combination thereof.

[16] The use of an unsulfurized, low-acidity precious metal-containing zeolite as described in

[14] , wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY and ZSM-12, or a combination thereof.

[17] A hydroculated n-paraffin composition prepared according to the manufacturing method described in [1].

[0072] For the purposes of U.S. patent practice and in any other patent office where permitted, all patents and publications referenced in the foregoing description of the present invention and in any other part of this application are incorporated herein by reference, insofar as any information contained herein is consistent with and / or supplements the foregoing disclosure.

Claims

1. A selective method for producing hydroculated n-paraffins from heavy n-paraffins, comprising contacting a hydrocarbon raw material containing heavy n-paraffins with a hydroculation catalyst containing an unsulfurized precious metal-containing zeolite having a silica / alumina ratio of at least 70 under hydroculation conditions to produce a hydrocarbon product containing hydroculated n-paraffins, The zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY and ZSM-12, or a combination thereof. The aforementioned precious metal includes platinum, The manufacturing method wherein the hydrocracking conditions include a temperature of 270°C to 330°C, a pressure in the range of 200 psig to 2000 psig (1.48 MPa to 13.88 MPa), and a space velocity in the range of 0.4 to 2.0 LHSV hr⁻¹.

2. The manufacturing method according to claim 1, wherein the silica / alumina ratio of the zeolite is at least 80, or 90, or 100, or 110, or 120.

3. The manufacturing method according to claim 1, wherein the zeolite is boron-free, or not a borosilicate or aluminoborosilicate, or is an aluminosilicate other than a borosilicate or aluminoborosilicate.

4. The heavy n-paraffin is C １２＋ Contains n-paraffin or is primarily C １２＋ n-paraffin, or C １２＋ The manufacturing method according to claim 1, wherein the content is greater than 50% by weight, or 60%, or 70%, or 80%, or 90%, or 95%, or 98%, or 100%.

5. The production method according to claim 1, wherein the yield expressed as the ratio of hydrocracking n-paraffin products is at least 10 mol% greater than the yield expressed as the corresponding ratio obtained using a different hydrocracking catalyst, except that the silica / alumina ratio of the zeolite is 60 or less.

6. The production method according to claim 5, wherein the yield expressed as a ratio of the hydrolyzed n-paraffin products is at least 20, 30, 40, 50, 60, 70, 80, 90, or 100 mol% greater.

7. The use of an unsulfurized noble metal-containing zeolite having a silica / alumina ratio of at least 70 for selectively producing hydrolyzed n-paraffins from heavy n-paraffins according to the manufacturing method described in claim 1, The use wherein the zeolite is an aluminosilicate zeolite hydrocracking catalyst selected from USY and ZSM-12, or a combination thereof.

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