Mesoporous zeolites and their use in the dewaxing of hydrocarbon feedstocks

Abstract

The present invention relates to the field of dewaxing of hydrocarbon feedstocks. More specifically, the present invention relates to the use of a basic-treated mesoporous zeolite and a catalyst comprising such a basic-treated mesoporous zeolite for dewaxing of hydrocarbon feedstocks. It was found that the zeolite and catalyst of the present invention can significantly reduce cracking of the hydrocarbon feedstock and, thus, significantly reduce the loss of liquid hydrocarbon feedstock during processes such as dewaxing.

Description

Technical Field

[0001] This invention relates to the field of hydrocarbon feedstock dewaxing. More specifically, this invention relates to the use of mesoporous zeolites and catalysts comprising said mesoporous zeolites for hydrocarbon feedstock dewaxing. Background Technology

[0002] Many fuels (hydrocarbons) such as diesel have a tendency to solidify (i.e., to become waxy at low temperatures (e.g., -10°C to 0°C), which hinders their practical use in many parts of the world during winter. This tendency to become "waxy" can be determined by a variety of methods, such as the point at which diesel begins to form solid crystals, known as the cloud point (CP).

[0003] Catalytic dewaxing is one solution to this problem and a preferred refining option for lowering the CP temperature (through branching of the heaviest straight-chain alkanes) to approximately -35°C. However, a significant drawback of catalytic dewaxing is that it also involves significant cracking, resulting in the loss of valuable diesel fuel in a manner that favors the formation of lighter gases. There is a need for more selective dewaxing processes, not only because of the obvious benefit of higher diesel fuel retention, but also because the resulting lower gas formation has a positive impact on the overall capacity of the dewaxing unit.

[0004] It is well known that mesoporous zeolites increase isomerization and reduce cracking, as primarily observed with model compounds such as straight-chain alkanes. However, the value of mesoporous zeolites has never been clearly demonstrated for actual diesel feedstocks, which are far more complex than the simple straight-chain alkanes used as model compounds. Therefore, the object of this invention is to find a dewaxing solution with reduced cracking, applicable to actual industrial feedstocks such as diesel and lubricating oils.

[0005] Therefore, the present invention provides a specific mesoporous zeolite that has particular value in the field of dewaxing by significantly reducing the cracking of hydrocarbon feedstock and thus significantly reducing the loss of liquid hydrocarbon feedstock during dewaxing.

[0006] EP2554259 describes the synthesis and use of metal-modified zeolite-based hydrogenation isomerization catalysts, wherein the metal is selected from Na, K, Cs, Mg, Ca, and Ba. The teachings therein differ from the present invention in several respects, for example, based on the need for metal modification of organic-containing zeolites not exposed to temperatures exceeding 450°C. The present invention is highly effective for zeolites with organic templates, as well as for those zeolites for which the template has been removed and for zeolites heat-treated above 450°C. The mesoporosity aspect and the need for controlled pH, which are key aspects of the present invention, are not mentioned in EP2554259. Other significant differences are the method of performing metal modification, which in EP2554259 is ion exchange rather than precipitation as disclosed herein. Another difference concerns the type of suitable metal, particularly monovalent metals such as Na, Cs, and K. The latter are clearly outside the scope of the present invention. Furthermore, at any stage of metal modification, the metal / zeolite range is relatively low (resulting in a metal / Al molar ratio of approximately 0.05 in EP2554259), whereas the present invention features a much wider range of metal / alumina (or metal / zeolite) molar ratios, often resulting in metal / Al molar ratios exceeding 1. Additionally, in EP2554259, metal modification is the final step in a series of zeolite modifications, followed only by catalyst preparation and noble metal impregnation steps. This application employs a systematic approach to further zeolite modification steps, which may take the form of subsequent ion exchange and / or acid treatment. These differences prevent the teachings in EP2554259 from enhancing hydroisomerization performance by increasing diesel or lubricant retention with a fixed improvement in cloud point or pour point, as disclosed herein. Summary of the Invention

[0007] Therefore, in a first aspect, the present invention provides a method for dewaxing hydrocarbon feedstock, the method comprising the following steps:

[0008] -Provide hydrocarbon feedstock to the reactor,

[0009] -Provide the reactor with a catalyst, and

[0010] - To bring the hydrocarbon feedstock into contact with the catalyst;

[0011] The catalyst comprises at least 300 ppm of metal hydride and alkaline-treated mesoporous zeolite, wherein the alkaline-treated mesoporous zeolite contains 17 to 20 T / nm. 3 skeleton density (FD) Si The Si / Al molar ratio is 20 to 400 and the mesopore volume is 0.05 to 1.2 ml / g, wherein the alkaline-treated mesoporous zeolite is prepared by alkaline treatment comprising the following steps:

[0012] - Provide a parent zeolite to an aqueous solution having a pH of up to 8 and containing at least one salt, the salt containing an element selected from Mg, Ca, Ti, V, Cr, Ni, Co, Fe, Cu, Mn, La, Ce, W, Mo;

[0013] - Add an alkali to the reaction mixture, wherein the pH of the aqueous reaction mixture is increased to at least 10;

[0014] - Reacting an alkali with the parent zeolite to obtain the alkali-treated mesoporous zeolite; and

[0015] - Separate the alkaline-treated mesoporous zeolite.

[0016] It is worth noting that, in this application, the parent zeolite refers to zeolite before alkaline treatment. In other words, the parent zeolite is untreated zeolite and may be mesoporous parent zeolite.

[0017] Furthermore, it is worth noting that in this application, alkaline-treated mesoporous zeolite refers to zeolite that has already been treated with alkali. Therefore, in other words, alkaline-treated mesoporous zeolite is obtained by alkaline treatment of the (mesoporous) parent zeolite.

[0018] In one particular embodiment, the invention provides a method as defined herein, further comprising the following: the alkaline-treated mesoporous zeolite is characterized by a magnesium content in the range of 0.3 wt% to 10 wt%. Preferably, the magnesium content is at least 50%, as measured by oxalic acid chemisorption.

[0019] In one particular embodiment, the present invention provides a method as defined herein, the method further comprising having the mesoporous zeolite treated with alkali having a mesoporous volume of 0.05-0.4 ml / g.

[0020] In one particular embodiment, the present invention provides a method as defined herein, the method further comprising having the mesoporous zeolite treated with alkalinity having a mesoporous volume of 0.4-1.2 ml / g.

[0021] In one particular embodiment, the present invention provides a method as defined herein, wherein the alkaline treatment further comprises performing a subsequent acid treatment.

[0022] In one particular embodiment, the present invention provides a method as defined herein, wherein the hydrocarbon feedstock is selected from the group consisting of waxes, hydrogenated waxes, diesel fuels, lubricating oils, base oils, vegetable oils, Fisher-Tropsch derivatives, or any combination thereof.

[0023] In one particular embodiment, the present invention provides a method as defined herein, wherein the cloud point of the hydrocarbon feedstock is reduced by at least 10°C after the contact step, and wherein the hydrocarbon feedstock has a cloud point greater than -10°C and a pour point greater than -15°C before the contact step.

[0024] In one particular embodiment, the present invention provides a method as defined herein, wherein the method reduces diesel fuel loss to less than 0.2% improvement in cloud point per degree Celsius.

[0025] In one particular embodiment, the present invention provides a method as defined herein, wherein dewaxing conditions include temperatures in the range of 200°C to 450°C, preferably in the range of 250°C to 400°C. Preferably, the temperature can be in the range of 200°C to 350°C, or approximately 260°C, 270°C, 280°C, 290°C, 300°C, 310°C, 320°C, 330°C, or 340°C. It should be noted that the temperature may be the upper and / or lower limits of the disclosed range.

[0026] In one particular embodiment, the present invention provides a method as defined herein, wherein dewaxing conditions include a hydrogen partial pressure in the range of 15 bar to 350 bar, preferably in the range of 15 bar to 250 bar. Preferably, the hydrogen partial pressure can be in the range of 15 bar to 200 bar, more preferably in the range of 15 bar to 150 bar, even more preferably in the range of 15 bar and 100 bar, and most preferably in the range of 15 bar to 50 bar.

[0027] In one particular embodiment, the present invention provides a method as defined herein, wherein the dewaxing conditions include a hydrogen treatment gas rate in the range of 100 NI / L to 1000 NI / L, preferably in the range of 100 NI / L to 500 NI / L. Preferably, the hydrogen treatment gas rate can be in the range of 150 NI / L to 450 NI / L, more preferably in the range of 200 NI / L to 400 NI / L, and even more preferably in the range of 250 NI / L to 350 NI / L.

[0028] It should be noted that the hydrogen treatment gas rate can also be referred to as the gas / oil ratio.

[0029] In a preferred embodiment of the invention, the hydrogen treatment gas rate remains substantially constant.

[0030] In one particular embodiment, the present invention provides a method as defined herein, wherein the catalyst comprises at least 5 wt% of a metal oxide support, wherein the metal oxide support may be one or more selected from alumina, silica, silica-alumina, magnesium oxide, and titanium oxide, and comprises at least 300 ppm of a metal hydride. Preferably, the metal hydride may be one or more selected from Pt, Pd, Ni, Co, Mo, W, and Fe, particularly Pt, Pd, Ni, Co, and Fe.

[0031] In one particular embodiment, the present invention provides a method as defined herein, wherein the alkaline-treated zeolite has a framework topology of MTT, TON, AEL, MRE, MTW, MFI, FER, or MEL, particularly MTT, TON, AEL, MRE, MTW, MFI, or MEL, and more particularly MFI or FER.

[0032] In one particular embodiment, the present invention provides a method as defined herein, wherein the alkaline-treated zeolite has a unidirectional microporous structure and a 10-membered ring.

[0033] In one particular embodiment, the present invention provides a method as defined herein, wherein the mesopore volume in the parent zeolite and / or alkaline-treated mesoporous zeolite with a diameter in the range of 4 to 20 nm can be in the range of 0.05 to 0.3 ml / g, wherein the mesopore volume in the parent zeolite and / or alkaline-treated mesoporous zeolite with a diameter greater than 20 nm can be greater than 0.2 ml / g, and wherein the ratio of mesopores with a diameter in the range of 4 to 20 nm to mesopores with a diameter greater than 20 nm can be less than 1.0.

[0034] In one particular embodiment, the present invention provides a method as defined herein, wherein alkaline-treated mesoporous zeolites can be prepared using alkaline treatment with pH > 10.

[0035] In a particular preferred embodiment, the present invention provides a method as defined herein, wherein the alkaline treatment can be performed gradually.

[0036] In one particular embodiment, the present invention provides a method as defined herein, wherein alkaline treatment is performed by passing an alkaline solution through a fixed membrane containing a parent zeolite.

[0037] In one particular embodiment, the present invention provides a method as defined herein, wherein the preparation of alkaline-treated mesoporous zeolite using an alkaline treatment with pH > 10 comprises the following steps:

[0038] - Provide a suspension of the parent zeolite in an aqueous solution, wherein the aqueous solution has a pH of up to 8 and contains at least one salt, the salt containing an element selected from Mg, Ca, Ti, V, Cr, Ni, Co, Fe, Cu, Mn, La, Ce, W, Mo;

[0039] - Add an alkali to the suspension to form a reaction mixture, wherein the pH of the aqueous solution is increased to at least 10;

[0040] - Reacting the alkali and the parent zeolite in a suspension to obtain the alkali-treated mesoporous zeolite; and

[0041] - Separate the alkaline-treated mesoporous zeolite from the suspension.

[0042] In one particular embodiment, the present invention provides a method as defined herein, wherein the step of reacting the alkali and zeolite in the suspension can be carried out at a temperature of 25°C to 100°C. Preferably, the temperature can be in the range of 40°C to 80°C, and more preferably, the temperature can be in the range of 60°C to 80°C.

[0043] In one particular embodiment, the present invention provides a method as defined herein, wherein the step of reacting the alkali and zeolite in the suspension can be carried out over a time period of 1 minute to 6 hours. Preferably, the step of reacting the alkali and zeolite in the suspension can be carried out over a time period of 1 minute to 4 hours, more preferably over a time period of 1 minute to 3 hours.

[0044] In one particular embodiment, the present invention provides a method as defined herein, wherein the step of reacting the alkali and zeolite in the suspension can be carried out at a solid / liquid ratio of 5 g / L to 300 g / L, wherein the solid refers to the parent zeolite. Preferably, the solid / liquid ratio can be in the range of 5 g / L to 250 g / L, more preferably, the solid / liquid ratio can be 50 g / L to 250 g / L, and even more preferably, the solid / liquid ratio can be 100 g / L to 200 g / L.

[0045] In one particular embodiment, the present invention provides a method as defined herein, wherein the step of reacting the alkali in the suspension with the parent zeolite can be carried out at an alkali concentration of 0.5 mmol to 25 mmol alkali / g parent zeolite.

[0046] In one particular embodiment, the present invention provides a method as defined herein, wherein the alkaline treatment is carried out in the presence of 0.1 to 30 mmol salt / gram of parent zeolite, said salt comprising an element selected from Mg, Ca, Ti, V, Cr, Ni, Co, Fe, Cu, Mn, La, Ce, W, and Mo.

[0047] In one particular embodiment, the present invention provides a method as defined herein, the method further comprising the following steps:

[0048] - Perform subsequent acid treatment; and / or

[0049] - Perform ion exchange treatment; and / or

[0050] - Perform calcination treatment; and / or

[0051] - The alkaline-treated mesoporous zeolite is shaped into macroscopically formed catalyst particles.

[0052] Preferably, the macroscopically shaped catalyst particles are extruded materials.

[0053] In one particular embodiment, the present invention provides a method as defined herein, wherein the alkaline-treated mesoporous zeolite is in proton form.

[0054] Therefore, in a second aspect, the present invention provides a dewaxing catalyst comprising an alkaline-treated mesoporous zeolite having an MTT framework topology and at least 300 ppm of Pt or Pd, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.4-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area in the range of / g, and at least 50 μmol / g measured using pyridine. acidity.

[0055] In one particular embodiment, the present invention provides a dewaxing catalyst comprising alkaline-treated mesoporous zeolite having an MTT framework topology as defined herein, further comprising a magnesium content in the range of 0.3 wt% to 10 wt%.

[0056] In another aspect, the present invention provides an alkaline-treated mesoporous zeolite having an MTT framework topology, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.4-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area in the range of / g, and at least 50 μmol / g measured using pyridine. Acidity. Preferably, the alkaline-treated mesoporous zeolite contains at least 300 ppm of Pt or Pd.

[0057] In one particular embodiment, the present invention provides an alkaline-treated mesoporous zeolite having an MTT framework topology as defined herein, further comprising a magnesium content in the range of 0.3 wt% to 10 wt%.

[0058] In another aspect, the present invention provides a hydrocarbon feedstock comprising at least 90% of a fraction with a boiling point in the range of 150°C to 370°C, a cloud point of at most -25°C, a pour point of at most -28°C, and a thickness of at least 4.42 mm. 2 The kinematic viscosity at 30°C is 0.8300 g / ml. Preferably, the density is 0.830 g / ml, more preferably 0.8300 g / ml.

[0059] In another aspect, the present invention provides a dewaxing catalyst comprising an alkaline-treated mesoporous zeolite having an MFI framework topology and at least 300 ppm of Pt or Pd, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.15-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area is in the range of / g, and further includes a magnesium content in the range of 0.3wt% to 15wt%.

[0060] In one particular embodiment, the present invention provides a dewaxing catalyst comprising an alkaline-treated mesoporous zeolite having an MFI framework topology as defined herein, wherein magnesium exhibits a dispersion of at least 50% as determined by oxalic acid chemisorption.

[0061] In another aspect, the present invention provides a mesoporous zeolite with an MFI framework topology, having a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.15-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area is within the range of / g, and also includes magnesium content in the range of 0.3wt% to 15wt%.

[0062] In one particular embodiment, the present invention provides alkaline-treated mesoporous zeolites having an MFI framework topology as defined herein, wherein magnesium exhibits a dispersion of at least 50% as determined by oxalic acid chemisorption.

[0063] In another aspect, the present invention provides a method for dewaxing hydrocarbon feedstock, the method comprising the following steps:

[0064] - Provide hydrocarbon feedstock to the reactor;

[0065] -Provide the reactor with a catalyst; and

[0066] - Under dewaxing conditions, the hydrocarbon feedstock is brought into contact with the catalyst.

[0067] The catalyst comprises alkaline-treated mesoporous zeolite and metal hydride, wherein the alkaline-treated mesoporous zeolite contains 17 to 20 T / nm.3 skeleton density (FD) Si The hydrocarbon feedstock has a Si / Al molar ratio of 20 to 400, wherein the hydrocarbon feedstock has a cloud point of at least -5°C and a pour point of at least -10°C before the contact step, wherein the hydrocarbon feedstock has a cloud point in the range of -10°C to -45°C after the contact step, and wherein the percentage of diesel fuel loss improved per degree Celsius of cloud point is at most 0.1% / °C. Invention Details

[0069] The invention will now be described further. In the following paragraphs, different aspects of the invention are defined in more detail. Each aspect thus defined may be combined with any other aspect or pluralities unless expressly indicated otherwise. In particular, any feature indicated as preferred or advantageous may be combined with any other one or more features indicated as preferred or advantageous.

[0070] As described above, the present invention provides a method for dewaxing hydrocarbon feedstocks using a catalyst comprising a specific alkaline-treated mesoporous zeolite. It has been found that the alkaline-treated mesoporous zeolite and catalyst of the present invention can significantly reduce the cracking of hydrocarbon feedstocks and correspondingly significantly reduce the loss of liquid hydrocarbon feedstocks in processes such as dewaxing.

[0071] The method of the present invention dewaxes a hydrocarbon stream, such as hydrocracking bottom products, diesel fuel, and hydrogenated vacuum gas oil. The method according to the invention operates by contacting the hydrocarbon feed stream with an alkaline-treated mesoporous zeolite as defined herein, or a catalyst containing said alkaline-treated mesoporous zeolite. The catalyst of the present invention is highly effective in lowering the pour point and cloud point of the feedstock, selected from waxes, diesel fuel, base oils, hydrogenated waxes, lubricating oils, Fischer-Tropsch derivatives, biomass-derived oils such as vegetable oils and deoxygenic fatty acids, or any combination thereof. Feedstocks selected from carboxylic acids and / or their derivatives may also be suitably used in the method of the present invention, such as fatty acids, fatty acid esters, fatty alcohols, fatty aldehydes, fatty acid anhydrides, and metal salts of fatty acids of biological or synthetic origin, or combinations thereof. Therefore, the method according to the invention provides a way to efficiently and effectively obtain the desired hydrocarbons from the feedstock. Furthermore, due to this efficiency, a larger volume of the desired hydrocarbons can be obtained from the initial amount compared to conventional methods. A larger amount of the required hydrocarbons may come from the lower degree of cracking of lighter materials (e.g., C1-C4) or from the lower bulk density of the resulting feedstock.

[0072] Therefore, the method according to the invention can be used to dewax a variety of feedstocks, ranging from relatively light fractions to high-boiling-point materials, particularly those in which waxy components are undesirable. The method according to the invention is particularly suitable for waxy feedstocks used in the production of diesel fuel, gas oil, kerosene, jet fuel, lubricating oils, heating oils, and other fractions for which pour points and viscosities need to be maintained within specific specification limits. Lubricating oils typically have boiling points above 230°C (450°F), and more commonly above 315°C (600°F).

[0073] Hydrocracking feedstock can be used, or other fractions containing a large amount of waxy n-alkanes can be used, which are produced by removing polycyclic aromatic hydrocarbons. The feedstock of the method of the present invention is usually a C10+ feedstock, preferably a C16+ feedstock, containing alkanes, alkenes, cycloalkanes, aromatic compounds and heterocyclic compounds, with a considerable proportion of high molecular weight n-alkanes and slightly branched alkanes that contribute to the waxy properties of the feedstock.

[0074] Typical waxy feedstocks that can be appropriately dewaxed according to the present invention are waxes, waxy feedstocks, waxy raffinate, waxy distillate, loose wax, heavy hydrocracking products, and Fischer-Tropsch-derived waxy feedstocks.

[0075] The method of the present invention can also be used for advanced dewaxing of raw materials, said raw materials including unsaturated compounds, such as triglycerides, having a carbon number of C1-C2. 38 Carboxylic acids, C1-C 38 Carboxylic acids and C1-C 11 Esters of alcohols, C1-C 38 Carboxylic acids and C 12 -C 38 Esters of alcohols, natural waxes, and dicarboxylic acids. Such oxygenated hydrocarbons are preferably dewaxed in combination with ketation and / or hydrodeoxygenation steps.

[0076] Examples of suitable raw materials are biologically derived streams, such as vegetable fats, vegetable oils, vegetable waxes, animal fats, animal oils, animal waxes, fish fats, fish oils, fish waxes, starting materials derived from algae and insects, and fatty acids or free fatty acids obtained from vegetable fats, vegetable oils, vegetable waxes, animal fats, animal oils, animal waxes, fish fats, fish oils, fish waxes by hydrolysis, ester exchange or pyrolysis, and esters obtained from vegetable fats, vegetable oils, vegetable waxes, animal fats, animal oils, animal waxes, fish oils, fish waxes by ester exchange, and alkyl esters of fatty acids obtained by esterification of alcohols with fatty acids of plant, animal and fish origin, as well as food-grade fats and oils from waste and recycled sources, and fats, oils and waxes obtained through genetic engineering, and mixtures of said materials. Other preferred biological sources of raw materials include fats contained in rapeseed oil, canola oil, tallow oil, sunflower oil, soybean oil, hemp seed oil, olive oil, flaxseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, lard, tallow, whale oil, or milk.

[0077] It is also desirable to incorporate alkaline-treated mesoporous zeolites into the binder (or matrix) material. The binder material includes, but is not limited to, inorganic materials such as clay, silica, and / or metal oxides. The metal oxide can be a metal oxide binder material such as alumina (Al₂O₃), silica-alumina, silica-magnesium oxide, silica-zirconium oxide, silica-thorium oxide, silica-beryllium oxide, silica-titanium oxide, and ternary compositions such as silica-alumina-thorium oxide, silica-alumina-zirconium oxide, silica-alumina-magnesium oxide, and silica-magnesium oxide-zirconium oxide. Preferred binders are alumina-based, with γ-alumina being the most preferred. Another preferred binder is titanium oxide. The advantage of using titanium oxide as a binder is that it allows the production of catalyst compositions that are substantially free of non-zeolite silica and non-zeolite alumina. Preferred binders have a total surface area exceeding 100 m². 2 / g.

[0078] In a preferred embodiment of the invention, alkaline-treated mesoporous zeolite is incorporated into the binder, wherein the binder may be present in the range of 10wt%-80wt%, preferably in the range of 20wt%-70wt%, more preferably in the range of 20wt% to 50wt%.

[0079] Metal hydrides:The catalyst of the present invention requires alkaline-treated mesoporous zeolite and metal to function in the method of the present invention. At least one hydride metal is incorporated (i.e., deposited) onto the catalyst before or after (preferably after) the binder and / or support (e.g., a refractory metal oxide support) is incorporated with the molecular sieve. At least one hydride metal, such as Pd, Pt, Ni, Fe, or Co, can be deposited by any known effective method. In an alternative preferred embodiment, hydride metals Mo and / or W can be deposited by any known effective method. Preferably, hydride metals Mo and / or W are deposited in combination with any of the hydride metals Pd, Pt, Ni, Fe, and Co. In a preferred embodiment, hydride metals Mo and / or W are combined with Ni for deposition. Non-limiting examples of suitable incorporation methods include initial wet impregnation, ion exchange, mechanical mixing of the metal oxide precursor with the molecular sieve and binder, or combinations thereof, wherein initial wet impregnation is a preferred method.

[0080] A typical catalyst consists of 15-80% alkaline-treated mesoporous zeolite, at least 15% binder, noble metal (such as Pt or Pd, 300 ppm–0.2 wt%) or base metal (such as Ni, several wt%); wherein the amount of binder is used as filler to reach 100%.

[0081] Hydrogenation processing conditions The feedstock is contacted with the isomerization dewaxing catalyst in the presence of hydrogen under elevated temperature and pressure hydrotreating conditions. Conditions similar to those used in conventional isomerization dewaxing operations can be employed, including temperature, pressure, space velocity, hydrogen / feed ratio, and hydrogen partial pressure.

[0082] The feedstock is typically contacted with an isomerization dewaxing catalyst in a fixed-bed reactor. Here, the feedstock is passed through a fixed-bed reactor containing an isomerization catalyst bed, usually in the form of an extrudate.

[0083] Temperatures of the methods of the present invention, ranging from about 200°C to about 485°C, can be used, although temperatures above about 420°C are generally not used because the reactions and / or methods of the present invention become unfavorable at temperatures above that point. The total pressure is in the range of about 15 bar to about 350 bar, preferably about 15-250 bar. The heavy hourly space velocity or liquid hourly space velocity is from 0.1 to 10 h⁻¹. -1 Within the range, 0.2-5h is preferred. -1 The spacetime speed.

[0084] The dewaxing method of this invention, as defined herein and applied to hydrocarbon feedstocks, provides effective and efficient improvements in cloud point and pour point, while significantly reducing losses of middle fractions due to over-cracking. Therefore, higher diesel retention is achieved in diesel dewaxing, and greater lubricating oil retention is achieved in lubricating oil dewaxing.

[0085] Specifically, the cloud point of the hydrocarbon feedstock can be reduced by at least 10°C. For example, diesel dewaxing is performed on hydrocarbon feedstocks with a cloud point below -10°C and a pour point below -15°C. For lubricating oil dewaxing, the range may differ. For example, the pour point of lubricating oil dewaxing can be reduced from 50°C to below 0°C. Furthermore, the quality of the feedstock can be improved by increasing density and viscosity. In addition, the degree of aromatic compounds can be significantly reduced, thereby increasing viscosity and reducing the discoloration and toxicity of the product stream, which is particularly relevant to lubricating oil dewaxing. Furthermore, for diesel dewaxing, the diesel loss is less than 0.2% / °C of cloud point improvement. Preferably, the diesel loss is less than 0.15% / °C, and most preferably less than 0.1% / °C.

[0086] As used herein, the term "zeolite" can be defined as a crystalline material whose chemical composition essentially comprises aluminum, silicon, and oxygen, unless otherwise specified. Generally, zeolites are described as aluminosilicates with a three-dimensional framework and molecular-sized pores. Some zeolite materials are ordered, porous crystalline aluminosilicates with a defined crystal structure determined by X-ray diffraction, containing numerous small cavities interconnected by many even smaller channels or windows. Zeolites are typically composed of the formula H... x Al x Si 1-x O2 characterization, where H can be replaced by any other monovalent cation such as sodium or potassium, or (when x associated with H is divided by its valence) by a polyvalent cation such as magnesium or calcium. The term "zeolite" also refers to an open tetrahedral framework structure capable of ion exchange, and loosely held water molecules that allow for reversible dehydration. 4+ Or Al 3+ The prepared "zeolite-related materials" or "zeolite-like materials" include, for example, aluminophosphates (e.g., MeAPO, SAPO, ElAPO, MeAPSO, and ElAPSO), gallium phosphates, zinc phosphates, titania silicates, etc. Zeolites can be crystalline porous materials with any fully ordered or partially disordered framework topology provided in the zeolite framework type database of the International Zeolite Association (IZA) Structural Committee.

[0087] This invention is particularly suitable for framework densities higher than 17 T atoms per cubic nanometer (T / nm). 3Zeolites, particularly those with 10-membered rings, are preferred. The zeolites of this invention particularly possess framework topologies selected from the following: AEL, MRE, MFI, MEL, MTT, TON, FER, or MTW framework topologies. These framework topologies have been found to enable efficient and effective dewaxing. A three-letter framework code (such as "MRE") describes and defines a network sharing the angles of tetrahedral coordinated framework atoms. Tetrahedral coordinated framework atoms are referred to as "T atoms," most commonly Si and Al, but can also be other elements such as Ga, B, and P. Framework density can be expressed as the number of T atoms per cubic nanometer, also known as "T / nm". 3 The framework density will depend to some extent on the type of element present as a T atom. Therefore, the framework density used in this paper is based on the most common T atom, namely silicon, resulting in "FD". Si The term "member ring," "-membered ring," or "MR" refers to the minimum number of T atoms required to form the circumference of accessible microporous channels in a zeolite. Therefore, the member ring is related to the micropore size characteristic of the zeolite framework: 10-membered ring frameworks (MFI, MTT, MRE) typically have smaller micropore sizes compared to frameworks with 12-membered rings (BEA and FAU). Some zeolite frameworks have two types of member rings, such as FER. Within a given framework, different zeolite materials can be classified. For example, ZSM-5 and silicalite-1 materials both belong to the MFI framework, while ZSM-48 and EU-2 materials both belong to the MRE framework. The differences between different materials are generally related to the composition of T atoms. It is possible and hypothesized that, as long as the zeolite framework is intact (as routinely examined by powder X-ray diffraction), the bulk framework topology and density will not change significantly during mesoporization via alkaline treatment.

[0088] The alkaline-treated mesoporous zeolite according to the present invention is typically prepared by alkaline treatment, wherein the alkaline treatment comprises contacting the parent zeolite with an aqueous solution of pH > 10 in the presence of at least one salt comprising an element selected from Mg, Ca, Ti, V, Cr, Ni, Co, Fe, Cu, Mn, La, Ce, W and Mo.

[0089] Untreated zeolite materials, i.e., those prior to alkaline treatment, are generally referred to as “parent” zeolites. Parent zeolites may also exhibit varying degrees of mesoporosity, which typically arises from hydrothermal synthesis and is generally related to the average crystal size of the zeolite. Parent zeolites with smaller average crystal sizes generally have larger mesopore volumes and / or mesopore surface areas. Typically, alkaline treatment will result in an increase in the mesopore volume or mesopore surface area of ​​the parent zeolite. Nevertheless, in some cases, alkaline treatment can result in similar mesopore surface areas or mesopore volumes, or even a reduction. In such cases, the invention can remain effective based on the different properties of the resulting mesopore surface areas or volumes. In other words, the mesopore quality produced by the alkaline treatment of the present invention is specific for generating catalytic benefits during dewaxing.

[0090] alkaline treatment An important aspect of this invention relates to the alkaline treatment of zeolites. This can be achieved using several methods, such as direct alkaline treatment, progressive alkaline treatment, suspension-based treatment, and configurations where the zeolite is located in a fixed layer and is passed through by an alkaline medium.

[0091] As used herein, unless otherwise specified, the term "alkali treatment" (also known as "alkali leaching" or "alkaline treatment") refers to the contact of conventional (parent) zeolite with an alkaline aqueous solution, resulting in alkaline-treated mesoporous zeolite by removing some of the solids to make way for intracrystalline or intercrystalline mesopores. Alkali treatment can convert most conventional (parent) zeolites into excellent mesoporous analogues.

[0092] The preferred solvent for alkaline treatment is water. In some embodiments, other solvents, such as alcohols (methanol, ethanol, or isopropanol), are used. Typical solutions are in water with a pH ranging from at least 10 to at most 14, which relates to a NaOH concentration of 0.0001M to 1M. The solid / liquid ratio (the ratio of (parent) zeolite to alkaline liquid) can range from very low as 1 g / L. -1 Up to a very high 1000g L -1 Variations are possible. It should be understood that other solid / liquid ratios may also be suitable. The temperature range may be at least room temperature to a maximum of 100°C, preferably at least 50°C to a maximum of 90°C, and more preferably at least 50°C to a maximum of 70°C. The concentration of alkali is in the range of 0.5-25 mmol of alkali per gram of parent zeolite added.

[0093] The amount of alkali used in the alkaline treatment is preferably from about 0.1, 0.2, 0.3, 0.4, 0.5, 1, 2, 5, 10, 15 or 20 to about 40, 45, 50, 55, 60, 65, 70, 75 or 100 mmol alkali / g parent zeolite, more preferably from about 0.5, 1 or 1.5 or 2 to about 30, 35, 40, 45 or 50 mmol alkali / g parent zeolite, and most preferably from about 2.5, 3 or 3.5 to 18, 19, 20, 21 or 22 mmol alkali / g parent zeolite. Processing time can vary widely from about 1 minute to 24 hours, but is preferably from about 1, 1.5, 2, 2.5 or 3 minutes to about 120, 180, 200, 220, 240, 260, 280 or 300 minutes, more preferably from about 2, 3, 4, 5, 6, 7, 8, 9 or 10 minutes to about 100, 110, 120, 130 or 140 minutes, and most preferably from about 7, 8 or 9 minutes to about 57, 58, 59, 60, 61, 62 or 63 minutes.

[0094] In one specific embodiment, the base is an inorganic base selected from NaOH, KOH, CsOH, LiOH, and NH4OH. Any base can be used as long as it can increase the pH value to 8 or higher. Preferred bases for preparing alkaline solutions are inorganic hydroxides, such as NaOH, LiOH, KOH, RbOH, CsOH, NH4OH, and Mg(OH)2. In some embodiments, inorganic non-hydroxide alkaline sources can be used, such as (NH4)2CO3, Na2CO3, and sodium hydride (NaH). In other embodiments, organic bases can be used, such as tetrapropylammonium hydroxide, diethylamine, dipropylamine, tetrabutylammonium hydroxide, and tetraethylammonium hydroxide (TEAOH).

[0095] direct alkaline treatment In certain embodiments, mesoporous zeolites can be prepared using a direct alkaline treatment (or alkaline treatment) step. Therefore, in one specific embodiment, alkaline treatment is used to prepare alkaline-treated mesoporous zeolites at pH > 10.

[0096] Alkali leaching is a widely used method for creating mesopores in zeolites. Descriptions of how this treatment is performed can be found in published literature, such as Colloids and Surfaces A: Physicochemical and Engineering Aspects, 241, 2004, 53-58. Typical alkali treatment is carried out in a “direct” manner, meaning that the zeolite is brought into contact with an alkaline solution in a single step. The latter is usually achieved by adding zeolite powder to the alkaline solution. This method differs from progressive alkaline treatment, which exposes the zeolite to alkali through gradual or stepwise addition (see Process AC).

[0097] Gradual alkaline treatment Gradual alkaline treatment represents a method for preparing alkaline-treated mesoporous zeolites, wherein the method includes the following steps:

[0098] a) with m s The amount of zeolite provided is the parent zeolite;

[0099] b) Provide a total of m b,总量 The base; and

[0100] c) For a total of m b,总量 For the alkali, within a time range of Δt, the parent zeolite reacts with a certain amount of alkali m in the solution. b (t) Contact and reaction;

[0101] This yields alkaline-treated mesoporous zeolite;

[0102] Wherein any given time t in step c), and the parent zeolite m s Contact with alkali m b (t)

[0103] The maximum quantity m b,max Less than m b,总量 / m s .

[0104] The total amount of alkali can be provided in the form of solid alkali or alkaline solution, preferably alkaline solution.

[0105] In some implementations, the process involves stepwise contact of the solid with the alkali, thereby largely preventing fragmentation. As a result, particle and crystal pore sizes similar to those of the starting solid can be obtained.

[0106] ratio m b,max / m s It can be considered as the maximum amount of alkali that comes into contact with a solid at any given time.

[0107] In some preferred embodiments, at any given time t in step c), the base m b The maximum quantity m of (t) b,max At most 0.75*m b,总量 Preferred size is at most 0.50*m b,总量 Preferred size is at most 0.25*m b,总量 .

[0108] In some preferred embodiments, step a) includes:

[0109] a') Provides m suspended in solution, preferably in water. s Amount of parent zeolite.

[0110] By adding alkali to the suspension of the parent zeolite, for example in water (tmb >t ms The non-instantaneous mixing / dissolving of alkali implies an initial value m b,max / m s <m b,总量 / m s .

[0111] In some embodiments, the alkali is added in multiple discrete steps. The zeolite is not separated between these steps. In some preferred embodiments, the method includes multiple additions of alkali without separation by a solids separation step, and the amount of alkali added each time (m...) b,i The characteristic of (i = 1..x) is that x is not equal to 1, preferably x is at least 2, preferably at least 3, and preferably at least 4.

[0112] In some embodiments, the alkali is added gradually or continuously. During this gradual addition process, the alkali-treated mesoporous zeolite is not separated. In some preferred embodiments, the rate of change of the amount of alkali added over time is at most 3.0 mmol g. -1 min -1 Preferred dosage is up to 1.0 mmol g -1 min -1 Preferred dosage is up to 0.5 mmol g. -1 min -1 Unit: mmol / g - 1 min -1 In this article, it refers to the number of mmol of alkali per gram of parent zeolite in the alkaline treatment reaction per minute.

[0113] In some preferred embodiments, the alkali is continuously added to the parent zeolite over a time range Δt, wherein the total amount of alkali used for addition is m b,总量 The time range Δt is at least 15 s, preferably at least 30 s, for example at least 60 s, for example at least 2 minutes, for example at least 4 minutes, for example at least 8 minutes, for example at least 15 minutes, for example about 30 minutes. In some embodiments, Δt is at least 8 minutes and at most 6 hours, preferably at least 15 minutes and at most 60 minutes, for example about 30 minutes. Furthermore, the total amount m used to add alkali... b,总量 The Δt is at most 5 hours, preferably at most 4 hours, more preferably at most 3 hours, or any time range therein.

[0114] In some embodiments, the gradual alkalinity treatment can be carried out by passing an alkaline solution through a membrane containing the parent zeolite. This can be achieved using a filtration device, such as a Buchner filter (see zeolite 5) or a plate filter. Alternatively, the alkali can be contacted with the parent zeolite in a continuous stirred tank reactor, or in any other configuration that allows for gradual or stepwise contact between the solid and the alkali.

[0115] Suitable salts in alkaline treatment Another important embodiment relates to the presence of the salts of the present invention in an alkaline treatment. This can be achieved using a process comprising the following steps: a) contacting the parent zeolite with an aqueous solution of pH < 8, wherein at least one salt having > 95% 'acid solubility' and < 95% 'base solubility' is dissolved; b) adding a base to the solution or suspension of step a) to raise the pH > 8 and to react the alkaline solution with the parent zeolite to increase the mesoporousness of the zeolite; and c) separating the alkaline-treated mesoporous zeolite from the suspension of step b. This process can be supplemented by ion exchange in a subsequent acid treatment step.

[0116] In a preferred embodiment, the addition of alkali when performing alkaline treatment with the salt of the present invention is carried out in a manner similar to that defined herein for progressive alkaline treatment, i.e., dropwise.

[0117] Specifically, mesoporous materials (i.e., alkaline-treated mesoporous zeolites) can be prepared by suspending untreated (parent) zeolite in an aqueous solution of neutral or acidic pH, wherein at least one specific type of salt is dissolved (step a). The latter salt may be completely or almost completely soluble in acidic or neutral solutions, and its cations or anions may precipitate completely or partially when the aqueous solution is alkaline. The suspension of the parent zeolite from step a in the salt-containing aqueous solution can then be contacted with an alkali to increase the pH to 8 or higher, thereby initiating salt precipitation and mesoporous formation (step b). After the suspension has reacted in the alkaline medium for a specific time, the suspension can be separated (step c).

[0118] In the case of progressive alkalinity treatment in a fixed-bed / membrane structure, it is preferable to add the salt to the alkaline solution before the alkaline solution passes through the zeolite membrane.

[0119] In some embodiments, the resulting alkaline-treated mesoporous zeolite may be exposed to further post-synthetic steps, such as ion exchange treatment and calcination, to obtain the active (proton) form of the alkaline-treated mesoporous zeolite.

[0120] As used herein, unless otherwise specified, the term "salt" refers to a combination of cations and anions and does not imply anything else, such as whether it is dissolved or in an aggregated state, such as a solid or a liquid.

[0121] Suitable salts differ from other salts treated with zeolite in the prior art to form mesopores, such as TPABr, aluminum nitrate, gallium nitrate, and sodium chloride, all of which tend to dissolve completely at high pH values. That is, any salt that dissolves completely or nearly completely at pH values ​​above 8 is not within the scope of embodiments of the invention and is therefore not considered a suitable salt. Examples of such unsuitable salts are several salts containing elements of Group 1 of the periodic table, such as most basic salts like NaCl, KBr, and NaNO3. Other salts not within this range are Al(NO3)3 and Ga(NO3)3, and most tetraalkylammonium salts (e.g., TPABr or CTABr).

[0122] The amount of salt relative to the amount of zeolite to be treated (parent zeolite) (also referred to herein as “the preferred amount of suitable salt”) can vary significantly depending on the type of zeolite and the type of salt used.

[0123] The preferred amount of salt is preferably from about 0.01, 0.05, or 0.1 to about 5, 6, 7, 8, 9, or 10 mmol salt / g of parent zeolite, more preferably from about 0.25 or 0.3 to about 4.5 or 5 mmol g. -1 The most preferred values ​​are about 0.45 or 0.5 to about 1.7, 1.8, 1.9 or 2 mmol g. -1 .

[0124] The preferred amount of salt is also preferably from about 0.001, 0.005, 0.01, 0.02, 0.03, 0.04 or 0.05 to about 3, 4, 5, 6 or 7 g salt / g parent zeolite, more preferably from about 0.01 to 5 or 0.045 or 0.05 to 1.5, 2 or 2.5 g. -1 The most preferred values ​​are about 0.24, 0.25, or 0.26 to about 0.95, 1, or 1.05 g. -1 .

[0125] The preferred concentration of the suitable salt is preferably from about 0.001, 0.002, 0.005, 0.01, or 0.02 to about 0.5, 0.75, 1, 1.1, 1.25, or 1.5 M, more preferably from about 0.01 to 0.5 M, and most preferably from about 0.025, 0.03, or 0.035 to about 0.18, 0.19, 0.2, 0.21, or 0.22 M. Alternatively, the preferred concentration of the suitable salt is preferably from about 0.05 to 40 mmol g. -1 The range of the parent zeolite is more preferably about 0.1 to 30 mmol g. -1 The range of the parent zeolite.

[0126] Furthermore, as used herein, the salts used in the process of this invention may contain elements from Group II of the periodic table, selected from: magnesium, calcium, strontium, and barium, or alternatively: titanium, zirconium, vanadium, tin, chromium, manganese, iron, cobalt, nickel, copper, zinc, lanthanum, and cerium; particularly selected from titanium, zirconium, vanadium, tin, chromium, manganese, iron, cobalt, nickel, copper, and zinc. Therefore, in certain embodiments of this invention, the salts used herein include elements selected from Mg, Ca, Ti, V, Cr, Ni, Co, Fe, Cu, Mn, La, Ce, W, and Mo; exemplary salts are, for example: Fe(NO3)3, Mn(NO3)2, Co(NO3)2, Mg(NO3)2, and Ni(NO3)2.

[0127] In this specification and examples, the degree of salt hydration is not mentioned because the amount of salt mentioned is generally based on moles rather than weight, and it is assumed that the degree of salt hydration has a negligible effect because alkaline treatment is usually carried out in excess water.

[0128] Within a suitable salt group, several other criteria exist that make the salt more advantageous. These criteria can be based on the salt's efficiency in mesoporous formation, or on cost, toxicity, and potential role in catalytic reactions. Different suitable salts can also be mixed with other suitable salts or salts used in existing technologies to achieve improved efficiency. Among suitable salts, cations are of paramount importance because their hydroxides can be precipitated salts.

[0129] Suitable salt cations can include elements from Group 2 of the periodic table, such as beryllium, magnesium, calcium, strontium, and barium. Among these elements, magnesium and calcium are preferred.

[0130] Other suitable salt cations may include elements in period 4 of the periodic table with atomic numbers in the range of 22-30, such as titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc. Iron, zinc, nickel, cobalt, and copper are preferred elements.

[0131] Other suitable salt cations may include elements in the fifth period of the periodic table with atomic numbers in the range of 40 to 50. Zirconium, molybdenum, and tin are preferred elements.

[0132] Other suitable salt cations may include refractory metals such as chromium, molybdenum, and tungsten (or W).

[0133] Other suitable salt cations may include rare earth elements, such as scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, and samarium. Lanthanum and cerium are preferred elements.

[0134] In suitable salts, anions are generally considered less important than cations. The suitability of anions is based on availability, cost, and their effect on acid and base solubility. Suitable salt anions can be inorganic, such as NO3-. - PO43- SO4 2- Cl - and Br - It can also be a common organic class, such as alkoxides (as in titanium propoxide) or those based on carboxylic acids, such as acetate, citrate, and malate. Suitable salts can be one or more selected from magnesium nitrate, magnesium hydroxide, magnesium acetate, magnesium carbonate, calcium sulfate, ferric chloride, nickel nitrate, and nickel acetate.

[0135] The suspensions defined herein can be prepared in several ways, provided that the end result includes a suitable amount of salt in solution and the parent zeolite is suspended or otherwise contacted with an alkaline solution. This can be achieved by placing a cake of parent zeolite on a membrane. In some embodiments, the parent zeolite can be added to a stirred solution of dissolved salt, or the salt can be added to a stirred suspension of parent zeolite in water.

[0136] Some implementations involve impregnating the parent zeolite with a suitable amount of salt, and then introducing the resulting salt / parent zeolite complex into a stirred aqueous solution. The pH of the solution can be lowered, for example, by adding a small amount of inorganic acid to ensure sufficient salt dissolution. The interaction time between the parent zeolite and the dissolved salt is considered to have a relatively small effect.

[0137] In the next step, the pH of the suspension can be increased to pH ≥ 8 to neutralize the potentially acidic saline solution, thereby causing partial precipitation of the salt and creating alkaline conditions to induce mesopore formation, thus increasing the mesopore size of the zeolite. The required pH depends largely on the properties of the zeolite to be treated (parent material) and the salt used, and is preferably pH 9-14, more preferably pH 11-13.5, and most preferably pH 12-13.

[0138] Subsequently, the treated zeolite (alkaline-treated mesoporous zeolite) can be separated from the solution using established separation techniques such as Buchner filtration, plate filtration, or centrifugation. After the separation, the resulting solid can be washed with water to remove dissolved substances from the solid and finally dried in an oven to the desired humidity level.

[0139] Subsequent ion exchange and acid treatment Another important embodiment of the present invention relates to a method for producing a high-quality dewaxing catalyst by alkaline treatment of zeolite, further characterized by a supplementary acid treatment or ion exchange step after separating the zeolite from the alkaline solution.

[0140] Typically, the metal deposition achieved using this invention is quite different from existing deposition techniques (e.g., ion exchange and initial wetting). Metals deposited using this invention exhibit a much higher degree of dispersion. While typical existing methods produce a dispersion of about 10-15%, this invention produces a dispersion of 50-90%. Importantly, the metal stability during subsequent modification in aqueous media is significantly higher (see, for example, zeolite 3). Therefore, this invention enables subsequent ion exchange steps to be performed after alkali-induced metal deposition, which would otherwise result in complete metal removal.

[0141] In particular, the sequence of post-synthesis processing steps and the manner in which ion exchange and / or acid treatment are performed depend heavily on the target amount of residual metal on the solid. Generally, removal of all monovalent cations is preferred, while the presence of certain metals such as Mg, Ca, and Ni on the solid may be necessary to achieve optimal dewaxing performance. Therefore, different scenarios can be envisioned to adjust the amount of the metals of the invention remaining on the solid. For example:

[0142] 1) The metal is not targeted, and the subsequent acid step is carried out with a large excess of protons (and in the absence of undesirable cations). In this case, the acid removes >90% of the metal, while removing sodium, potassium, or lithium (usually from alkaline treatment), leaving the alkaline-treated mesoporous zeolite in proton form, thus rendering the subsequent IE ineffective.

[0143] 2) If all metals are to be removed (removal >90%), but unwanted cations were not completely removed during acid treatment, then acid treatment is performed, followed by IE with a common ammonium salt such as ammonium nitrate or ammonium sulfate, see Synthetic Zeolites 2.

[0144] 3) If efforts are made to contain some metals after (removing 20-90%), the acid step is not performed, and a weakly acidic IE is performed, see Synthetic Zeolite 3.

[0145] 4) If efforts are made to contain some metals after (removing 20-90%), the acid step is not performed, and a mild alkaline IE is performed, see Synthetic Zeolite A2.

[0146] Another embodiment of the invention relates to activating the alkali-treated material by ion exchange treatment in an aqueous solution primarily containing ammonium cations. This treatment, common in the prior art and often combined with heat treatment, maximizes the acidity of the solid by removing unwanted cations such as sodium, potassium, lithium, and cesium, which is typically desired in catalytic applications.

[0147] Therefore, in one specific embodiment, the present invention provides a method as defined herein, wherein a supplementary ion exchange (IE) treatment is performed after mesoporization by alkaline treatment, or, where applicable, after a supplementary acid step.

[0148] Ion exchange treatment can be carried out under similar process conditions to the acid treatment methods described herein, except that the pH of the ion exchange is not necessarily acidic and depends primarily on the properties of the ammonium salt used. However, similar contact methods, temperatures, solid / liquid ratios, and times can be used for ion exchange treatment. Furthermore, to maximize the effectiveness of ion exchange, multiple consecutive ion exchange treatments are typically performed.

[0149] In some implementations, ammonium nitrate, ammonium sulfate, ammonium chloride, ammonium hydroxide, ammonium carbonate, monoammonium phosphate, diammonium phosphate, and ammonium acetate are used for ion exchange.

[0150] Another embodiment of the invention relates to a method for increasing the mesoporosity of a parent zeolite, further characterized by a supplementary acid treatment step following the separation of alkaline-treated mesoporous zeolite.

[0151] Following separation after alkaline treatment, the resulting solids can be acid-treated. This can be done on any form of solid after separation. For example, acid treatment can be performed after the solids have been separated, washed, and dried, but it can also be performed on unwashed wet solids and any form in between. Acid treatment can be carried out in any desired manner to make the solids contactable with acid. For example, it can be carried out in a batch reactor, but it can also be done by positioning the parent zeolite on a membrane and then allowing an acid solution to flow through the membrane covered by the solids. The latter can be performed directly after, for example, the recovery of the solids using a plate filter.

[0152] In one specific embodiment, a supplementary acid treatment step is performed using one or more organic acids selected from oxalic acid, malic acid, citric acid, monosodium, disodium and trisodium citrate, acetic acid, benzoic acid, formic acid, ethylenediaminetetraacetic acid (H4EDTA), and disodium ethylenediaminetetraacetate (Na2H2EDTA). Preferred acids for preparing the acidic solution are mineral acids selected from HCl, HNO3, H2SO4, H3PO4, and H3BO3.

[0153] In some embodiments, sulfonic acid organic acids, such as methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid, can be used. In some embodiments, carboxylic acid organic acids, such as acetic acid, citric acid, malic acid, formic acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid, can be used. In some embodiments, aminopolycarboxylic acid organic acids, such as ethylenediaminetetraacetic acid (EDTA), iminodiacetic acid (IDA), and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), can be used. In some embodiments, only a portion of the carboxyl group in the organic acid can be in a protonated (acidic) form, such as monosodium citrate, disodium citrate, trisodium citrate, and Na₂H₂EDTA.

[0154] In one specific embodiment, the supplemental acid treatment step is carried out at a temperature of 25°C to 100°C for a period of 5 minutes to 24 hours, preferably 15 minutes to 24 hours, more preferably 15 minutes to 6 hours, wherein the solid / liquid ratio of the aqueous solution is 10 to 300 g / L, and the concentration of the acid is in the range of 0.25 to 50 mmol / g of the alkaline-treated mesoporous zeolite obtained.

[0155] In a preferred embodiment, the solvent used for acid treatment may be water. The typical total pH of the solution used for acid treatment is from about pH 0, 1, or 2 to about pH 7, 8, 9, or 10, preferably from about pH 0.1, 0.2, 0.3, 0.4, or 0.5 to about pH 4.5, 5, or 5.5, and most preferably from about pH 0.3, 0.4, 0.5, or 0.6 to about pH 3.4, 4, or 4.5. The solid / liquid ratio (the ratio of the amount of solid to the volume of liquid) can preferably be about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, or 50 g / L. -1 Approximately 100, 110, 120, 125, 150, 200, 250, 300, or 400 g / L -1 More preferably, it is from about 15, 20 or 25 to about 125, 150 or 175 or 250 g / L, and most preferably from about 150 to about 250 g / L.

[0156] The temperature is preferably about 10, 15, 20, 25 or 30 to about 80, 85, 90, 95 or 100°C, more preferably about 30, 35, 40, 45 or 50°C to about 80, 85, 90, 95 or 100°C, and most preferably about 48, 49, 50, 51 or 52°C to 80, 85, 90, 95 and 100°C. The acid treatment time is preferably about 0.05, 0.08, 0.09, 0.1, 0.2, 0.3, 0.5, 1, 5 or 10 to about 50, 60, 65, 70, 76 or 80 hours, more preferably about 0.4, 0.5 or 0.6 to about 20, 21, 22, 23, 24, 25 or 26 hours, even more preferably from about 0.9, 0.95, 1, 1.05 or 1.1 to about 4, 5, 6, 7 or 8 hours, and most preferably about 0.25 to about 1 hour. The concentration of acid is preferably 0.8, 0.9, 1.0, 1.1 or 1.2 to about 90, 95, 100, 105 or 110 mmol / g of the solid to be treated, more preferably about 0.90, 0.95, 1.0, 1.05 or 1.1 to about 48, 49, 50, 51 or 52 mmol / g, and most preferably about 0.98, 0.99, 1.0, 1.01 or 1.02 to 9.90, 9.95, 10.0, 10.05 or 10.1 mmol / g.

[0157] Suitable properties of mesoporous zeolites

[0158] As described above, the method of the present invention is particularly suitable for mesoporous zeolites, and more particularly for unidirectional mesoporous zeolites with high framework density. The method of the present invention is most suitable for mesoporous zeolites having a framework topology selected from MTT, TON, AEL, MRE, MTW, or MEL. These zeolites have similar functions in dewaxing and exhibit high isomerization activity. Furthermore, zeolites with unidirectional framework topologies (which typically exhibit the highest framework density) also behave in a similar manner during post-synthetic mesoporization treatment (see, for example, CrystEngComm, 2011, 13, 3408-3416). Therefore, this makes the desired positive effects of the present invention applicable to all these zeolites.

[0159] Details of the suitable zeolite framework topology, framework dimensions, framework density, and framework micropore size in terms of rings can also be found in Table I.

[0160] Table I: Framework topology, framework dimensions, framework density, and framework micropore size of different zeolites

[0161] It is worth noting that FD SiIt relates to the framework topological density, where all T atoms (referred to as 'T') are silicon. The framework density can be found in "Atlas of Zeolite Framework Types", Ch. Baerlocher, LB McCusker and D. Holson, Atlas of Zeolite Framework Types, 6th revision, Elsevier, Amsterdam, 2007.

[0162] Zeolites with 2D and 3D microporous channels (and the desired high framework density), such as ZSM-5 (MFI) and magnesium alkali zeolite (FER), can also produce positive catalytic effects in the dewaxing process of this invention. In these cases, the positive effects on catalytic selectivity in dewaxing are generally similar in absolute terms (increased retention of diesel or lubricating oil at a fixed cloud point improvement), but are generally smaller in relative terms because 2D and 3D zeolites are generally slightly less selective for middle fractions than unidirectional zeolites.

[0163] Suitable mesoporous zeolites preferably exhibit a framework density of about 16.0, 16.5, 17.0, 17.3, 17.6, 18.0 to about 19.0, 19.3, 19.6, 20.0, 20.5, 21 T / nm. 3 More preferably, it is about 17, 17.2, 17.4, 17.6, 18.0 to about 19.0, 19.3, 19.6, 20.0 T / nm. 3 The most preferred values ​​are approximately 17.6, 17.8, 18.0 to approximately 18.5, 18.7, 19.0 or 19.8 T / nm. 3 Here, 'T' refers to the T atom.

[0164] Suitable mesoporous zeolites preferably exhibit microporous channels with 8-12-membered rings, more preferably 8-10-membered rings, and most preferably 10-membered rings.

[0165] Zeolites β and USY, exhibiting much lower framework densities, typically behave quite differently under dewaxing conditions (with much lower selectivity for isomerization) and require very different conditions to be properly mesoporous using post-synthetic modifications such as alkali and acid leaching. Therefore, these zeolites (and their associated frameworks) are not part of this invention. In one particular embodiment, the mesoporous zeolites used herein comprise 17 to 20 T / nm. 3 skeleton density (FD) Si ), Si / Al molar ratios of 20 to 400 and mesopore volumes of 0.4 to 1.2 ml / g.

[0166] In another specific embodiment, the alkaline-treated mesoporous zeolite used herein is characterized in that the mesopore volume in the alkaline-treated mesoporous zeolite with a diameter in the range of 4 to 20 nm is in the range of 0.05 to 0.3 ml / g, wherein the mesopore volume in the alkaline-treated mesoporous zeolite with a diameter greater than 20 nm is greater than 0.2 ml / g, and wherein the ratio of mesopores with a diameter in the range of 4 to 20 nm to mesopores with a diameter greater than 20 nm is less than 1.0. Further details herein can also be found in Table 2 of the Examples section.

[0167] Alkaline-treated mesoporous zeolites exhibit mesopore volumes ranging from 0.05 ml / g to 1.20 ml / g, preferably from 0.10 ml / g to 0.80 ml / g, and more preferably from 0.20 ml / g to 0.8 ml / g. Examples include 0.06 ml / g, 0.07 ml / g, 0.08 ml / g, 0.09 ml / g, 0.10 ml / g, 0.15 ml / g, 0.20 ml / g, 0.25 ml / g, 0.30 ml / g, 0.40 ml / g, 0.50 ml / g, 0.60 ml / g, 0.70 ml / g, 0.80 ml / g, 0.90 ml / g, or 1.20 ml / g.

[0168] Alkali-treated mesoporous zeolite showed a mesoporous surface area of ​​30 m². 2 / g to 500m 2 / g, preferably 60m 2 / g to 300m 2 / g, more preferably 80m 2 / g to 250m 2 Within the range of / g. For example, 30m 2 / g、40m 2 / g, 50m 2 / g、60m 2 / g、70m 2 / g、80m 2 / g、90m 2 / g, 100m 2 / g, 150m 2 / g、200m 2 / g、250m 2 / g、300m 2 / g, 350m 2 / g、400m 2 / g、450m 2 / g or 500m 2 / g.

[0169] Alkali-treated mesoporous zeolite shows a total surface area (S) BET ) at 60m 2 / g to 650m2 Within the range of / g, 120m is preferred. 2 / g to 500m 2 / g, more preferably 160m 2 / g to 450m 2 / g. For example, 60m 2 / g、80m 2 / g, 100m 2 / g、120m 2 / g, 140m 2 / g、160m 2 / g、180m 2 / g、200m 2 / g、300m 2 / g, 350m 2 / g、400m 2 / g、450m 2 / g、500m 2 / g、550m 2 / g、600m 2 / g or 650m 2 / g.

[0170] Alkaline-treated mesoporous zeolites exhibit micropore volumes in the range of 0.01 ml / g to 0.15 ml / g, preferably 0.01 ml / g to 0.12 ml / g, and more preferably 0.02 ml / g to 0.09 ml / g. Examples include 0.03 ml / g, 0.04 ml / g, 0.05 ml / g, 0.06 ml / g, 0.07 ml / g, 0.08 ml / g, 0.09 ml / g, 0.10 ml / g, 0.11 ml / g, 0.12 ml / g, 0.13 ml / g, 0.14 ml / g, and 0.15 ml / g.

[0171] The alkaline-treated mesoporous zeolite exhibits a Si / Al molar ratio in the range of 15 to 800, preferably 20 to 200, and more preferably 30 to 90. For example, 25, 35, 40, 50, 60, 80, 100, 125, 150, 175, 250, 300, 350, 400, 500, 600, and 800.

[0172] When Mg is present in the alkaline-treated mesoporous zeolite at an amount greater than or equal to 0.05 wt%, the Mg content is in the range of 0.05 wt% to 13.5 wt%, preferably 0.1 wt% to 10 wt%, more preferably 1.0 wt% to 7.0 wt%. Examples include 0.1 wt%, 0.3 wt%, 0.6 wt%, 1.5 wt%, 2.0 wt%, 2.5 wt%, 4.0 wt%, 5.0 wt%, 6.0 wt%, 8.0 wt%, 9.0 wt%, 10.5 wt%, 11.0 wt%, 11.5 wt%, 12.0 wt%, 12.5 wt%, and 13.0 wt%.

[0173] As evaluated by oxalic acid chemisorption on a solid having at least 1.0 wt% Mg, the Mg dispersion is in the range of 20%-95%, preferably 30%-85%, more preferably 40%-80%. For example, 25%, 35%, 70%, 75%, 90%.

[0174] Furthermore, the alkaline-treated mesoporous zeolite according to the present invention may have any of the following characteristics and combinations thereof:

[0175] · The acidity range is 50-500 μmol / g; in particular, it is at least 50 μmol / g.

[0176] • The presence of additives left over from the synthesis process: for example, metals: Fe, Co, Ni, Mg, especially Mg and Ni, which can be present in the range of 0.1 wt% to 15 wt%;

[0177] Micropore volume (V) micro In approximately 0.02 ml g -1 Up to 0.10 ml g -1 Within the range; especially approximately 0.02 ml g -1 Up to 0.06 ml g -1 ;

[0178] Mesopore volume (V) meso In approximately 0.05 ml g -1 Up to 1.2 ml g -1 Within the range; preferably within about 0.4 ml g -1 Up to 1.2 ml g -1 Within the range; especially about 0.4 ml g -1 Up to 0.8ml -1 ;

[0179] • The alkaline-treated mesoporous zeolite may further be cationic (e.g., proton). In a particular embodiment, the alkaline-treated mesoporous zeolite may be 10-99% acidic, for example, 10-30%; however, a higher percentage is preferred to achieve maximum activity, for example, 70-99%, 80-99%, 90-99%.

[0180] • High SAR, for example, framework atom Si / Al > approximately 75;

[0181] ·17-20T / nm 3 Skeletal density.

[0182] According to the present invention, particularly suitable alkaline-treated mesoporous zeolites are those having an MTT framework topology and containing at least 300 ppm of Pt or Pd, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.4-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area in the range of / g, and at least 50 μmol / g measured using pyridine. acidity.

[0183] Another particularly suitable class of alkaline-treated mesoporous zeolites are those with an MFI framework topology, a Si / Al molar ratio of at least 20, a mesopore volume of 0.15-1.2 ml / g, and / or an external surface area of ​​100-350 m² / g. 2 / g. The latter material preferably contains magnesium in the range of 0.3 wt% to 15 wt%. When containing more than 0.3 wt% Mg, the Mg dispersion is preferably at least 50%, as determined using oxalate chemisorption. Based on the higher dispersion of magnesium and the greater relative stability of magnesium in subsequent post-synthetic modifications (such as ion exchange and acid treatment), this magnesium-containing mesoporous MFI material is significantly different from other magnesium-containing mesoporous MFI materials.

[0184] When used as a dewaxing catalyst, the zeolite as defined above can be combined with (noble) metals or metal oxides such as Ni, Pd or Pt, preferably in the range of 300 ppm to 2 wt%. Attached Figure Description

[0185] Figure 1 BJH mesopore size distribution of reference (parent) zeolite, comparative zeolite 1, and zeolite 2 and zeolite 3 according to the present invention;

[0186] Figure 2: Diesel yield loss (DYL) and cloud point (CP) improvement of the reference (parent) catalyst, comparative catalyst 1, and catalysts 2 and 3 according to the present invention. Figure 2A ) or pour point (PP) improvement ( Figure 2B The relationship between )

[0187] Figure 3 The relationship between the C1-C8 fraction distribution and carbon number and molecular type (straight-chain alkanes, branched alkanes, aromatics, cycloalkanes and alkenes) of the reference (parent) catalyst, comparative catalyst 1 and catalysts 2 and 3 according to the present invention, under the condition of fixed cloud point improvement.

[0188] Figure 4 The relationship between the C1-C8 fraction distribution of the reference (parent) catalyst, comparative catalyst 1, and catalysts 2 and 3 according to the present invention and the number of carbon atoms and molecular type (straight-chain alkanes, branched alkanes, aromatics, cycloalkanes, and alkenes) under the condition of fixed diesel loss.

[0189] Figure 5 The relationship between the total aromatic content of the dewaxed product stream and the reaction temperature after using a reference (parent) catalyst, comparative catalyst 1, and catalysts 2 and 3 according to the present invention;

[0190] Figure 6 The relationship between the total aromatic content and density of the dewaxing product streams after dewaxing using a reference (parent) catalyst, comparative catalyst 1, and catalysts 2 and 3 according to the present invention; and

[0191] Figure 7 The relationship between the total aromatic content and cloud point improvement of the product stream after dewaxing using a reference (parent) catalyst, comparative catalyst 1, and catalysts 2 and 3 according to the present invention. Detailed Implementation

[0192] Example

[0193] method

[0194] N2 adsorption technology

[0195] The properties of zeolites (catalysts) can be evaluated using nitrogen adsorption at 77 K, as this is a well-established technique for quantifying the inherent properties of zeolites (associated with crystalline microporous solids) as well as the secondary (mesoporous) porosity in the solid. The descriptor derived from the nitrogen isotherm is the total surface area (S). BET This is because it provides an indication of the total porosity (micropores and mesopores) of the solid. The inherent properties of zeolites can be expressed using micropore volume (V0). micro To examine this, the micropore volume originates from the adsorption branch of the isotherm when the t-plot is applied. The t-plot method also yields the external surface area (referred to as "S"). meso The outer surface area is used as an indicator of secondary porosity. Total pore volume (V) pore (V) is used as an indicator of total porosity. Mesopore volume is also an indicator of the amount of secondary porosity produced.meso ) is defined as V meso =V pore -V micro Ideally, the highest micropore porosity (V) is generally considered to be obtained. micro ) and mesoporous porosity (S meso V meso The solid, thus producing a high total porosity (S) BET V pore ).

[0196] The pore volumes for the diameter ranges D1 (3-4 nm), D2 (4-20 nm), and D3 (>20 nm) (as shown in Table 2) were calculated using the integral of the BJH adsorption dV / dD pore volume curve over the specified pore size range (see Table 2). Figure 1 These ranges were used to further quantify the mesoporosity formed in the zeolite. BJH adsorption dV / dD pore volume curves were derived from the N2 isotherm using the Harkins and Jura method and corrected for Faas.

[0197] acidity

[0198] Acidity measurement is important because it allows monitoring the number and type of acidic sites present in zeolites. Acidity assessment using pyridine probe infrared spectroscopy can be performed as previously reported in WO2017148852 using a desorption temperature and time of 150 °C and 20 minutes, thereby producing… The concentrations of site (B) and Lewis site (L), both expressed in μmol / g, can be combined to obtain the total acidity (B+L) and the relative Lewis acidity L / (B+L).

[0199] More specifically, pyridine FTIR measurements were performed using a Nicolet 6700 spectrometer equipped with a DTGS detector. The sample was pressed into a self-supporting wafer and degassed under vacuum at 400°C for 1 hour prior to measurement. Analysis was performed using a pyridine probe. And Lewis acid sites. After evacuation, the sample was subjected to 4-5 pulses of at least 25 mbar pyridine for 1 minute at 50 °C (until saturation), followed by heating the system to 150 °C after 20 minutes, and then acquiring the spectrum at the same temperature. 1550 and 1450 cm⁻¹ -1 The absorption at each point corresponds to The amount of Lewis acid sites and the extinction coefficient were determined by Emies, J. Catal, 1993, 141, 347-354.

[0200] Metal Dispersion

[0201] The dispersion of non-precious metals (e.g., Mg and / or Ni) can be appropriately assessed using the chemisorption of oxalic acid. Oxalic acid exhibits unique interactions with many metals, and the metal dispersion can be determined by relating the amount of metal complexes (formed upon contact with oxalic acid) to the total amount of metal on the solid. In this paper, the deposition of oxalic acid on the solid was carried out in the vapor phase. For this purpose, 0.5 g of solid was prepared into a sieve fraction and mixed with 0.5 g of oxalic acid. The mixture was placed in a metal cup, connected to a heating torch, heated to 200 °C, and held at this temperature for 30 minutes. During this period, the heating of the metal component caused the oxalic acid to evaporate and form metal oxalate material. Simultaneously, the gas flow provided by the heating torch ensured that excess oxalic acid (i.e., that which does not exist as metal-oxalate complexes) was removed from the solid. The amount of metal oxalate on the solid was then determined using thermogravimetric analysis (TGA). For this purpose, approximately 5–10 mg of sample was placed in a crucible and placed in a TGA apparatus. Next, analysis was initiated under a nitrogen atmosphere (10 ml / min) and a heating rate of 20 °C / min, within a temperature range from room temperature to 900 °C. The weight loss within the range of 275 °C to 800 °C was then quantified, and the amount of the metal oxalate complex was obtained by comparing the weight loss with that of pure metal oxalate compounds measured using the same protocol within the same range.

[0202] Preparation of mesoporous zeolite MTT

[0203] The examples describe the synthesis of zeolite treatments for comparison and the present invention, which can generally be categorized as follows:

[0204] Method A: Alkaline treatment followed by acid and ion exchange in the absence of a suitable salt. This is a comparative method based on the absence of a suitable salt in the alkaline treatment.

[0205] Method B: Alkaline treatment is performed in the presence of a suitable salt, followed by acid and ion exchange treatment. This is an inventive method based on the presence of a suitable salt during the alkaline treatment.

[0206] Method C: Alkaline treatment is performed in the presence of a suitable salt, followed by ion exchange treatment. This is an inventive method based on the presence of a suitable salt during alkaline treatment.

[0207] A) Reference (parent) zeolite

[0208] The parent zeolite with an MTT framework and a Si / Al molar ratio of 43 (therefore, a molar SAR or Si / Al2 of 86) is not in the active proton form and requires ion exchange (to the NH4 form) and calcination (to remove NH3) to produce the active proton form.

[0209] Therefore, in step 0, 10g is introduced at once into a round-bottom flask containing 1000ml of stirred 0.05M (NH4)2SO4 solution (10mmol NH4). + / gram of zeolite). The resulting suspension was stirred at 25°C and maintained for 8 hours. Then, the suspension was transferred to a single-stage deep-bed cylindrical filter (filter media: SK100 d=14cm, separation limit 7.0-18μm) to separate the solids from the suspension. The resulting wet zeolite was then dried overnight in an oven at 100°C. This procedure was repeated twice.

[0210] The dried solid obtained after the third IE (ion exchange) was calcined in air at 550°C for 15 hours, with an initial heating isotropic rate of 1.5°C / min.

[0211] B) Zeolite 1 (Comparison, Method A)

[0212] Zeolite 1 was mesoporized by alkaline-acid treatment in the absence of the salt of the present invention, and was used as a comparative example.

[0213] Add 33g of parent MTT zeolite to 900ml of water, stir in a round-bottom flask and keep at 85°C (to form the suspension of step 1A).

[0214] Then, in step 1B, 100 ml of 4M NaOH solution is added dropwise to the suspension from step 1A over a period of 120 minutes. Then, in step 1C, the suspension is filtered and dried as described in step 0.

[0215] • In step 1D, the dried solid obtained after step 1C is exposed to subsequent acid treatment. For this purpose, 20 g of the dried solid obtained after step 1C is introduced at once into a round-bottom flask containing 2000 ml of stirred 0.1 M HCl solution (10 mmol HCl / g alkaline-treated mesoporous zeolite). The resulting suspension is stirred and maintained at 65°C for 6 hours. The solid is then separated using the above-described filtration method and dried overnight in an oven at 100°C.

[0216] Then, the zeolite sample was subjected to ion exchange and calcination according to the procedure for the reference material described above.

[0217] C) Zeolite 2 (In this invention, Method B)

[0218] • Add 50 mmol of magnesium nitrate (salt) to 900 ml of water in one go, stir in a round-bottom flask and maintain at 85°C. Next, over a few minutes, add 33 g of parent MTT zeolite to the solution, stir, and maintain at 85°C for about 5 minutes (to form the suspension of step 2A).

[0219] Then, in step 2B, 100 ml of 4 M NaOH solution is added dropwise to the suspension from step 2A over 60 minutes. Then, in step 2C, the suspension is filtered and dried as described in step 0. In the obtained alkaline-treated solid, the molar ratio of metal (Mg) to aluminum is 2.3 mol / mol. Then, further acid treatment is performed as described in step 1D.

[0220] The zeolite sample was then subjected to ion exchange and calcined according to the procedure described above for the reference material.

[0221] D) Zeolite 3 (In this invention, method C)

[0222] The preparation of zeolite 3 is similar to that of zeolite 2, except that no subsequent acid treatment is performed after the alkali contact in step 2B. The resulting material contains a large amount of magnesium. This is unique to this invention because metals deposited using other metal deposition techniques (such as IWI or ion exchange) are completely washed away during the three-step ion exchange process.

[0223] E) Zeolite 4 (Invention, Method B)

[0224] • The preparation of zeolite 4 is similar to that of zeolite 2, except that 2.5 mmol HCl / g alkaline-treated mesoporous zeolite is used instead of 10 mmol HCl / g alkaline-treated mesoporous zeolite.

[0225] F) Zeolite 5 (Invention, Method B)

[0226] The preparation of zeolite 5 was similar to that of zeolite 2, except that the alkaline treatment was carried out in a fixed-bed structure, while the parent MTT zeolite existed in the form of a filter cake / membrane, with an alkaline solution added through the cake / membrane. To this end, firstly, the zeolite was formed into a cake membrane by slurrying 33g of parent ZSM-23 in 1L of demineralized water and filtering the suspension on a Buchner filter apparatus with cylindrical filter cups approximately 300ml in volume and 12cm in diameter, resulting in an average (wet) filter cake thickness of approximately 10-20mm. Subsequently, 1L of a preheated and stirred suspension of 50mmol Mg(NO3)2 in 400mmol NaOH was gradually dripped onto the filter cake over 75 minutes. After the alkaline treatment, the solid was washed and dried as described for zeolite 2. Like zeolite 2, the resulting material showed increased mesoporosity compared to the parent zeolite and contained no significant amount of Mg.

[0227] Mesoporous zeolite MTT performance

[0228] Tables 1 and 2 provide the properties of the reference (parent) zeolites and zeolites 1-5, as well as details of the mesoporization process used.

[0229] Table 1

[0230]

[0231] a: Molar ratio of silicon dioxide to aluminum oxide measured by elemental analysis: ICP (Inductively Coupled Plasma)

[0232] b: BET (total) surface area measured by N2 physisorption using the BET model.

[0233] c: Mesoporous surface area measured by N2 physisorption using a t-plot model.

[0234] d: Micropore volume measured by N2 physisorption using a t-plot model

[0235] e:V pore -V micro

[0236] Table 2

[0237]

[0238]

[0239] N2 physical adsorption was used to determine the isotherms, adsorption, and desorption properties of the zeolite used in this paper. (Data) Figure 1 The results show that the mesoporous types of the three mesoporous samples are largely similar, while differences in mesoporous size distributions are observed among the different mesoporous zeolites. These size distributions can be used to define the mesoporous volume of a specific type. Table 2 demonstrates that the porosity of each of D1, D2, and D3 in the zeolite of this invention is significantly increased compared to the reference zeolite, while the D2 / D3 ratio does not change significantly. The similarity in porosity and composition between zeolite 1 and zeolite 2 is highlighted.

[0240] Like the parent reference zeolite, the treated zeolites 1-5 all contain an MTT framework, which can be identified using powder X-ray diffraction.

[0241] Preparation of MTT catalysts 1-4 (metal-containing sieve fractions)

[0242] The catalyst was then prepared using the mesoporous zeolite as defined in this paper, according to the method defined below:

[0243] Step 1: Compress zeolite into tablets at 28 tons to produce 40mm pellets.

[0244] Step 2: Sieve the pellets into 315-500μm sieve grades.

[0245] Step 3: Dry the sieve fractions in air at 450℃ for 1-3 hours.

[0246] Step 4: Impregnate the dried sieve fractions dropwise at 90% of the impregnation volume over 60-120 minutes at room temperature with stirring, aiming for 1 wt% Pt.

[0247] Step 5: Dry the impregnated sieve fractions at 80°C for 15 hours.

[0248] - Step 6: Calcine the dried sieve fractions from Step 5 at 190°C under airflow (equal change rate 5°C / min, hold for 1 hour).

[0249] - Step 7: Calcine the fraction from step 6 at 300°C under an air stream (isotropic rate 5-10°C / min, hold for 5 hours).

[0250] - Step 8: Cool the fraction from step 8 to room temperature.

[0251] More specifically, step 4 of the above method is performed using the following:

[0252] • The impregnation solution consists of x mmol tetraammineplatin(II) nitrate dissolved in a pH 10 buffer solution containing 0.1M ammonia and 0.02M ammonium nitrate.

[0253] The x mmol amount of tetraammineplatin(II) nitrate depends on the target Pt amount and the water absorption volume of the sieve fraction.

[0254] Preparation of MTT catalysts 5-7 (metal-containing sieve fractions)

[0255] Catalyst 5 was prepared according to the same procedure as catalysts 1-4, except that in step 4, the target amount of 0.3 wt% Pt was used instead of 1 wt% Pt.

[0256] Catalysts 6 and 7 were prepared according to the same procedure as catalysts 1-4, except that tetraamminepalladium(II) nitrate was used instead of tetraammineplatinum(II).

[0257] Preparation of MTT catalysts 8 and 9 (containing metal extrudates)

[0258] Catalysts 8 and 9 were prepared according to the same procedure as catalysts 1-4, except that zeolite powder was first extruded with alumina binder (Catapal B) at a 50 / 50 weight ratio to form a cylindrical extrudate (0.9 mm in diameter and 3-4 mm in length), steps 1 and 2 were omitted, and step 3 was carried out at 550 °C instead of 450 °C.

[0259] MTT catalyst performance

[0260] Table 3 provides the properties of several catalysts used in this paper. The reference catalysts are derived from reference (parent) zeolites, while catalysts 1, 2, 3, and 4 are derived from zeolites 1, 2, 3, and 4, respectively. Reference catalysts 6 and 8 are made from reference (parent) zeolites, while catalysts 5, 7, and 9 are made from zeolite 3.

[0261] Table 3

[0262]

[0263]

[0264] h: Magnesium content measured by ICP

[0265] j: Pt content measured by ICP

[0266] k: Total acidity measured using pyridine probe FTIR (Fourier Transform Infrared Spectroscopy).

[0267] l: Pd replaces Pt as a metal hydride.

[0268] As can be clearly seen from Table 3, the catalyst of the present invention contains sufficient Pt (or Pd), which ensures that the metal functionality for hydrogenation is unrestricted. Compared with other catalysts, catalyst 3 contains a large amount of Mg, as well as limited (accessible) micropores and low acidity.

[0269] Hydrocarbon feedstock for catalytic testing

[0270] Table 4 provides the properties of the hydrocarbon feedstock used in the following experiments:

[0271] Table 4

[0272]

[0273]

[0274] SimDist refers to simulated distillation, an industry-standard method for characterizing raw materials during the refining process.

[0275] Catalytic test of MTT zeolite

[0276] The conditions used in the catalytic experiments in this paper are as follows:

[0277] • LHSV (Liquid Time Silica Voltage, Spacetime): 0.9 and 1.8 h -1

[0278] Temperature: 270-315℃

[0279] • Pressure: 30 bar (total pressure)

[0280] • Hydrogen treatment gas rate: 300 N / L

[0281] Catalytic test of MTT zeolite

[0282] As can be clearly seen from Figure 2, the cloud point (CP) and pour point (PP) of the catalyst of this invention are improved by at least 4 times compared with the reference catalyst, indicating that mesoporization has a significant impact on these parameters. Furthermore, the best performing catalysts are in the order of: catalyst 3 > catalyst 2 > catalyst 1; indicating that the mesoporization sequence in the presence of salt (method B / catalyst 2 and method C / catalyst 3) achieves far superior dewaxing compared to the mesoporization sequence in the absence of salt (method A / catalyst 1). Since acid-base mesoporization sequences have long been carried out only under salt-free conditions (e.g., method A / catalyst 1) in the prior art (Catalysis Today, Vol. 218-219, December 2013, pp. 135-142), the salt-containing mesoporization methods B and C achieve significantly improved dewaxing performance superior to the prior art. Moreover, the superior performance of catalyst 2 compared to catalyst 1 is surprising, as the properties of the catalyst and the associated alkaline-treated mesoporous zeolite are largely similar.

[0283] Next, since catalyst 3 is superior to catalyst 2, it demonstrates that the presence of salt (Mg in this case) on alkaline-treated mesoporous zeolite is of great value for achieving optimal dewaxing performance.

[0284] These catalysts in Improvement of fixed 30℃ cloud point Further experimental details below (the vertical line in Figure 2) can be found in Table 5.

[0285] Table 5

[0286]

[0287] • Alkane content (C4-C8) is the percentage of alkanes (straight-chain alkanes) relative to the total amount of hydrocarbons in the C4-C8 range.

[0288] As shown in Table 5, under the condition of fixed cloud point improvement (30°C), the catalyst of the present invention exhibits lower diesel yield loss (which is ideal) and lower liquid density (i.e., higher API gravity).

[0289] Figure 3 Table 5 shows that in Similar improvement in cloud point A comparison of the C1 to C8 fractions of different catalysts under different conditions. Compared with the reference catalyst, the catalysts of the present invention produce fewer small carbon numbers. In particular, the catalysts of the present invention (catalyst 2 and catalyst 3) produce higher average carbon numbers and lower levels of alkane content (and therefore, more branching).

[0290] These catalysts in Similar diesel production rates Further experimental details below (the horizontal line in Figure 2) can be found in Tables 6 and 7.

[0291] Table 6

[0292]

[0293]

[0294] Table 7

[0295]

[0296]

[0297] These data demonstrate that, with a fixed diesel yield loss (the horizontal line in Figure 2), the catalyst of this invention achieves significantly better product specifications, higher cloud point and pour point improvements, and lower density. This density can be related to the degree of aromatics in both the feed stream and the product stream. Figure 5 and Figure 6 According to ASTM D6591, the aromatic content of liquid samples is measured by high performance liquid chromatography with refractive index detection. Figure 5 and 6 The results show that using catalysts 2 and 3 of the present invention, much lower aromatic levels can be obtained. Furthermore, the aromatic content (and therefore density) is much less sensitive to temperature, thus enabling the production of the desired density / aromatic level under any cloud point improvement conditions. Figure 7 It has significant commercial value.

[0298] Figure 4 Table 8 shows the effects of different catalysts on... Similar to diesel production loss A comparison of the C1-C8 composition. Compared to the reference catalyst, the catalyst of the present invention produces fewer small carbon numbers. In particular, the catalyst of the present invention produces a higher average carbon number and a lower degree of alkane content.

[0299] Table 8

[0300]

[0301] • Alkane content (C4-C8) is the percentage of alkanes (straight-chain alkanes) relative to the total amount of hydrocarbons in the C4-C8 range.

[0302] Tables A, B, and C show that the catalysts of the present invention maintain excellent performance (i.e., much lower diesel yield loss with fixed cloud point improvement) when the Mg content (catalyst 4), or the amount of hydride metal (catalyst 5), or the type of hydride metal (catalyst 6 and catalyst 7) ​​varies, or when alkaline-treated mesoporous zeolite is present in the extrudate (catalyst 8 and catalyst 9).

[0303] Table A

[0304]

[0305] Table B

[0306]

[0307] Table C

[0308]

[0309] Preparation of mesoporous zeolite MFI

[0310] To demonstrate that the invention is also effective for the MFI framework, reference zeolite A and two derived mesoporous variants, zeolite A1 and zeolite A2, were prepared using parent ZSM-5 zeolite with a Si / Al molar ratio of 40 (therefore, the SAR or Si / Al2 molar ratio is 80).

[0311] Reference zeolite A (parent material)

[0312] The parent zeolite is not in the active proton form and needs to be calcined according to the above procedure for the reference (MTT) zeolite.

[0313] Zeolite A1 (Comparison, Method A)

[0314] Mesoporous ZSM-5 zeolite A1 was prepared according to method A in the same manner as zeolite 1, except that:

[0315] Using ZSM-5 parent zeolite instead of MTT parent zeolite, during the alkaline treatment, 67 g of zeolite instead of 33 g was added to 900 ml of water, stirred in a round-bottom flask and maintained at 65°C, then 100 mL of 5 M NaOH solution was added dropwise to the suspension over 30 minutes. All other parameters and / or procedures were the same as described in the preparation of zeolite A1. Zeolite A1 is a comparative example.

[0316] Zeolite A2 (This invention, Method C)

[0317] Mesoporous ZSM-5 zeolite A2 is prepared according to method C as follows:

[0318] • Add 200 mmol of magnesium nitrate (salt) to 900 ml of water in one go, stir in a round-bottom flask and keep at 65°C. Next, over several minutes, add 67 g of zeolite to the solution, stir, and keep at 65°C for about 5 minutes (to form suspension A).

[0319] Then, add 100 ml of 6 M NaOH solution dropwise to suspension A over 30 minutes.

[0320] The suspension is then filtered and dried as described in zeolite 3.

[0321] Then, the obtained solid was subjected to ion exchange and calcination according to the procedure described above for the reference zeolite, except that the first IE step used 2.5 mmol (NH4)2CO3 / g zeolite, the second IE step used 5 mmol (NH4)2CO3 / g zeolite, the third IE step used 5 mmol (NH4)2SO4 / g zeolite, and the reaction time for each IE step was 1 h.

[0322] Mesoporous zeolite MFI performance

[0323] The properties of the parent (reference zeolite A) and mesoporous ZSM-5 (zeolite A1 and zeolite A2) zeolites are summarized in Table D, showing the increased mesoporous surface area and volume, while the spacing between the micropores largely preserves the micropore volume and total surface area.

[0324] As assessed using oxalic acid chemisorption, the magnesium dispersion on zeolite A2 was 73%. In contrast, when zeolite A1 was supplemented with 3.9 wt% Mg, only a 14% dispersion was obtained with initial wetting using Mg(NO3)2 solution, highlighting the advantages of alkali-induced metal deposition over established metal deposition methods.

[0325] Table D

[0326]

[0327] Catalytic test of MFI zeolite

[0328] The feedstocks and catalytic conditions used in the testing of the MFI, TON, MRE, and MEL frameworks described below are similar to those described for MTT zeolite.

[0329] All ZSM-5 samples were processed into catalysts using the same procedure as catalysts 1-4, yielding the following properties (Table E), showing successful incorporation of Pt and the presence of approximately 4 wt% Mg in catalyst A2.

[0330] The catalyst results (Table F) show that, in the absence of additives during the alkali treatment step, mesoporization method A, consistent with published work (Catal. Sci. Technol., 2016, 6, 6177-6186), only resulted in a slight reduction in diesel yield loss with a fixed cloud point improvement. Surprisingly, using method C of the present invention and the resulting catalyst, a similar cloud point improvement was achieved with both a significant reduction in diesel yield loss and a significant reduction in temperature.

[0331] Table E

[0332]

[0333]

[0334] Table F

[0335]

[0336] Catalytic experiments with TON, MRE and MEL zeolites

[0337] The effectiveness of the invention is further demonstrated by applying the synthesis methods of zeolite 3 or zeolite A2 to different parent zeolites having frameworks of TON (reference zeolite B and zeolite B1), MRE (reference zeolite C and zeolite C1), and MEL (reference zeolite D and zeolite D1, Tables G and H). The amounts of NaOH and Mg(NO3)2 used were adjusted. In all cases, the parent zeolite was in proton form, and the catalyst preparation was carried out as described for catalysts 1-5.

[0338] For clarity, the catalytic results shown in range demonstrate that, for different zeolite frameworks, the superior catalytic performance of the present invention is achieved on the same order of magnitude (i.e., a reduction in DYL / CPI greater than 0.1) over a wide range of Si / Al ratios, mesopore volumes, and Mg contents (with significantly lower diesel yield loss (DYL) relative to cloud point improvement (CPI), i.e., 'DYL / CPI' at approximately 30°C CPI).

[0339] Table G

[0340]

[0341]

[0342] Table H

[0343]

Claims

1. A method for dewaxing hydrocarbon feedstock under dewaxing conditions, comprising the following steps: -Provide hydrocarbon feedstock to the reactor, -Provide the reactor with a catalyst, and - To bring the hydrocarbon feedstock into contact with the catalyst; The catalyst comprises at least 300 ppm platinum or at least 300 ppm palladium and alkaline-treated mesoporous zeolite, wherein the alkaline-treated mesoporous zeolite has a magnesium content of 0.3%-10% by weight and a density of 17-20 T / nm. 3 skeleton density (FD) Si The skeletal topology of MTT, TON, MRE, MFI, or MEL, the Si / Al molar ratio of 20-400, and the mesoporous volume of 0.4 to 1.2 ml / g, wherein the alkaline-treated mesoporous zeolite is prepared by alkaline treatment comprising the following steps: - Provide the parent zeolite to the aqueous solution, wherein the aqueous solution has a pH of up to 8 and contains at least one magnesium salt; - Add a base to the reaction mixture, wherein the pH of the reaction mixture is increased to at least 10; - Reacting an alkali with the parent zeolite to obtain the alkali-treated mesoporous zeolite; and - Separate mesoporous zeolites treated with alkali.

2. The method according to claim 1, further comprising that the magnesium content of the alkaline-treated mesoporous zeolite is in the range of 0.3 wt% to 5 wt%.

3. The method according to claim 2, wherein the magnesium dispersion determined by oxalic acid chemisorption is at least 50%.

4. The method according to claim 1, wherein the alkaline treatment comprises the steps of claim 1 and further performing a subsequent acid treatment or a subsequent ion exchange treatment or a subsequent acid treatment followed by an ion exchange treatment.

5. The method according to claim 1, wherein the hydrocarbon feedstock is selected from wax, diesel oil, lubricating oil, base oil, vegetable oil, Fischer-Tropsch derivative oil, or any combination thereof.

6. The method according to any one of claims 1-5, wherein the cloud point of the hydrocarbon feedstock after contact is reduced by at least 10°C, and wherein the hydrocarbon feedstock before the contact step has a cloud point of more than -10°C and a pour point of more than -15°C.

7. The method according to claim 5, wherein the method reduces diesel and / or lubricating oil loss to less than 0.2% per degree Celsius cloud point improvement.

8. The method according to claim 1, wherein the dewaxing conditions include a temperature in the range of 200°C to 450°C.

9. The method according to claim 1, wherein the dewaxing conditions include a temperature in the range of 250°C to 400°C.

10. The method of claim 1, wherein the dewaxing conditions comprise a hydrogen partial pressure in the range of 15 bar to 350 bar.

11. The method of claim 1, wherein the dewaxing conditions comprise a hydrogen partial pressure in the range of 15 bar to 250 bar.

12. The method of claim 1, wherein the dewaxing conditions include a hydrogen treatment gas rate in the range of 100 NI / I to 1000 NI / I.

13. The method of claim 1, wherein the dewaxing conditions include a hydrogen treatment gas rate in the range of 100 NI / L to 500 NI / L.

14. The method of claim 1, wherein the catalyst comprises 10-80% by weight of a binder, alkaline-treated mesoporous zeolite, and 300 ppm to 2% by weight of platinum or palladium, wherein the binder is selected from one or more of alumina, silica, silica-alumina, magnesium oxide, and titanium oxide.

15. The method according to any one of claims 1-5, wherein the alkaline-treated mesoporous zeolite has an MTT framework topology.

16. The method according to any one of claims 1 to 5, wherein the alkaline-treated mesoporous zeolite has a unidirectional microporous structure and a 10-membered ring.

17. The method of claim 1, wherein the alkaline treatment is performed gradually.

18. The method of claim 1, wherein the alkaline treatment is performed by passing an alkaline solution through a fixed membrane containing the parent zeolite.

19. The method of claim 1, wherein preparing the alkaline-treated mesoporous zeolite using an alkaline treatment with pH > 10 comprises the following steps: - Provide a suspension of the parent zeolite in an aqueous solution, wherein the aqueous solution has a pH of up to 8 and contains at least one magnesium salt; - Add an alkali to the suspension to form a reaction mixture, wherein the pH of the aqueous solution is increased to at least 10; - The alkaline-treated mesoporous zeolite is obtained by reacting the alkali and the parent zeolite in a suspension. and - Separation of alkaline-treated mesoporous zeolites from suspension.

20. The method according to any one of claims 1-5, wherein the alkaline treatment is performed at a temperature in the range of 25°C to 100°C.

21. The method according to any one of claims 1-5, wherein the alkaline treatment is performed over a period of 1 minute to 6 hours.

22. The method according to any one of claims 1-5, wherein the alkaline treatment is carried out at a solid / liquid ratio of 5 g / L to 300 g / L, wherein the solid refers to the parent zeolite.

23. The method according to any one of claims 1-5, wherein the step of reacting the alkali with the parent zeolite is carried out at an alkali concentration of 0.5-25 mmol alkali / g parent zeolite.

24. The method according to any one of claims 1-5, wherein the alkaline treatment is carried out in the presence of 0.1-30 mmol magnesium salt / g parent zeolite.

25. The method according to claim 1, wherein the preparation of the catalyst further comprises the following step: - Ion exchange treatment of alkaline-treated mesoporous zeolite; and / or - Calcining of alkaline-treated mesoporous zeolite; and / or - The alkaline-treated mesoporous zeolite is shaped into macroscopically formed catalyst particles.

26. The method according to any one of claims 1-5, wherein the alkaline-treated mesoporous zeolite is in proton form.

27. The method of claim 5, wherein the wax is a hydrogenated wax.

28. The method of claim 14, wherein the adhesive is silicon oxide and / or silicon oxide-alumina.

29. A dewaxing catalyst comprising an alkaline-treated mesoporous zeolite having an MTT framework topology and at least 300 ppm Pt or at least 300 ppm Pd, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume of 0.4-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area per g, a Brønsted acidity of at least 50 μmol / g measured using pyridine, and a magnesium content in the range of 0.3 wt% to 10 wt%.

30. A dewaxing catalyst comprising an alkaline-treated mesoporous zeolite having an MFI framework topology and at least 300 ppm Pt or at least 300 ppm Pd, wherein the alkaline-treated mesoporous zeolite further comprises a Si / Al molar ratio of at least 20, a mesopore volume in the range of 0.15-1.2 ml / g, and / or 100-350 m³ / g. 2 The external surface area in the range of / g, which further includes a magnesium content in the range of 0.3wt% to 15wt%, and wherein said magnesium exhibits a dispersion of at least 50% as determined by oxalic acid chemisorption.

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