TECHNICAL FIELD
[0001] The present disclosure relates generally to the field of zeolites. Particularly, the present disclosure provides a TON/MTT intergrowth zeolite with dominion of TON character. Aspects of the present disclosure also relates to a method of preparation of a TON/MTT intergrowth zeolite with dominion of TON character.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Zeolites are crystalline aluminosilicates, either of natural or synthetic origin with highly ordered structures. They consist of SiO4 and AlO4- tetrahedra, which are interlinked through shared oxygen atoms to give a three dimensional network. They consist of channels and in some cases cavities. The interior of these channels contain adsorbed water molecules and exchanged alkali metal ions, the latter can be exchanged with other metal cations. These cations compensate for the excess negative charge in the framework resulting from the substitution of aluminum in the lattice. The interior of the pore system, with its atomic-scale dimensions, is the active surface of the zeolites. The inner pore structure depends on the zeolite type, composition, and the cations. Zeolites are represented by the general formula:
My/n [(SiO2)x (AlO2)y].zH2O
wherein, M is the charge compensating cation with the valency n. M represents the exchangeable cation (e.g. alkali or alkaline earth metals or an organic cations). The ratio x/y can have the value 1 to 8. According to Lowenstein’s rule no two aluminum tetrahedras can exist adjacent to one another. The Si/Al molar ratio corresponds to the acid sites in the zeolites. z represents the number of water molecules, which can be reversibly adsorbed in the pores, while y represents the exchange capacity.
[0004] Zeolites are also popularly known as ‘molecular sieves’ due to their ability to differentiate between molecules of different shapes and size. Typically, zeolites exhibits properties like high surface area, molecular dimensions of the pores, high adsorption capacity, molecular shape selectivity for reactants/products, tunable acidity and the likes.
[0005] Such unique properties of zeolites have led to their applications in the field of adsorption and catalysis. Today, zeolites have found widespread application as adsorbents, ion exchange materials, detergent builders and catalysts, especially in petroleum refining as Fluidized Catalytic Cracking (FCC) and hydroprocessing catalysts and in the production of petrochemicals.
[0006] In the current scenario, due to stringent environmental norms and pressures on refiners to produce clean fuels, hydroprocessing of petroleum feedstocks has become important. Hydroprocessing includes processes that utilize hydrogen to convert petroleum feed stocks to clean and valuable products useful for wide range of applications from transportation fuels to base stocks for lubricating oils. Hydroisomerization is a hydroprocessing route to carry out conversion of n-paraffin to isoparaffin as it offers benefit in terms of product yield. It is routinely practiced for production of motor spirit with desired Research Octane Number (RON), winter grade diesel and Lube Oil Base Stock (LOBS) in oil refineries [Recent Advances and Future Aspects in the Selective Isomerization of High n-Alkanes, Catalysis Reviews: Science and Engineering, 49:1, 33-139 (2007)]. The mechanistic aspect of catalysis by hydroisomerization catalysts is discussed in detail in Fischer-Tropsch Waxes Upgrading via Hydrocracking and Selective Hydroisomerization Oil & Gas Science and Technology – Rev. IFP, Vol. 64, No. 1, 91-112 (2009).
[0007] Skeletal branching of n-alkanes can be achieved using bifunctional zeolite catalysts. According to the bifunctional reaction scheme, the n-alkane is dehydrogenated on the metal and the resulting alkene protonated on the acid site. The alkylcarbenium ion formed upon protonation undergoes skeletal rearrangements and, eventually, cracking through ß-scission. ß-scission becomes more and more favorable as the branching degree of the carbon chain increases. This explains why on a bifunctional catalyst, the yield of skeletal isomers obtained from an n-alkane when plotted against conversion always exhibits an optimum owing to the occurrence of hydrocracking consecutive to hydroisomerization. Minimization of the hydrocracking reaction is mandatory when high yields of skeletal isomers out of n-alkanes must be achieved. Hence, an ideal balance of metal and acid functions is desired to maximize hydroisomerization. Processes for isomerization of short chain n-paraffin (C6, C8) of gasoline range are performed by employing one of the catalyst systems consisting from group of catalysts such as Chlorinated Pt/Alumina, sulfated zirconia, and Pt/Zeolite and are intended for Research Octane Number (RON) boosting as described in US patent 4003849 and EP 1243332 A1. On the other hand, for long chain n-paraffins (C12 plus) isomerization, medium pore one-dimensional zeolites are found to be potential candidates. Typically, zeolites namely ZSM-23, ZSM-22, ZSM-48, ZSM-12 and SSZ-32 are found to offer ideal options for the targeted application with yield maximization as described in “Studies on Wax Isomerization for Lubes and Fuels, Stud. Surf. Sci. Catal. 84C, 2319-2326”. The literature reports mentioned hereinabove explains the important role of one-dimensional frameworks for isomerization, due to their unique pore geometry which favors the concept of pore-mouth/ key-lock catalysis, which is a phenomena occurring on external surface and hence, it is required for the aforementioned zeolites to have an submicron crystal size, optimum external surface area in order to obtain higher conversions and isomer selectivities in hydroisomerization reaction as described in Monomethyl-Branching of Long n-Alkanes in the range from Decane to Tetracosane on Pt/H-ZSM-22 Bifunctional Catalyst, J. Catal. 190, 1, 39-48.
[0008] Typically, synthesis of one dimensional zeolites namely ZSM-22 and ZSM-23 is reported in the presence of organic structure directing agent (template) under hydrothermal conditions. The selective templates reported for ZSM-22 synthesis are 1,8-Diaminooctane, Hexamethylenediamine and N-ethylpyridinium bromide, respectively. On the other hand, ZSM-23 is synthesized using pyrrolidine, Heptamethonium Bromide and Octamethonium Bromide. Recently, attempts have been made to prepare intergrowth of ZSM-22 and ZSM-23 using mixed template approaches. Attempts have also been made to prepare intergrowth zeolite based catalyst for hydroisomerization of long chain n-paraffins. The primary drivers for such attempts were to explore the possibility of unique pore structure with moderate acidity to improve isomer selectivity and yields.
[0009] J. Phys. Chem. B 1999, 103, 7175-7183 describes a study related to the role of small amines in synthesis of different zeolites like ZSM-22, ZSM-23, ZSM-5 and ZSM-48. In this article, the author reported the synthesis of ZSM-22/ZSM-23 intergrowth zeolite by employing ethylenediamine template at low concentration. The crystallization time for the synthesis was 65 hrs and the crystallization temperature was 1600C and needle-shaped ZSM-22 crystals of 2 micron length were obtained.
[0010] Materials Research Bulletin 44, 2258-2261 (2009), reported the novel dual-template strategy for the synthesis of ZSM-23/ZSM-22 intergrowth zeolite. In the above article, the author reported the synthesis of ZSM-23/ZSM-22 intergrowth zeolite with fixed proportion of 60%ZSM-23/40%ZSM-22 using dimethylamine and diethylamine as a dual template system. In this article, the author has reported that, a molar ratio of diethylamine to dimethylamine of 1:24 resulted in an ZSM-23/ZSM-22 intergrowth zeolite when aluminumsulfate was used as aluminum source, whereas, sodium meta-aluminate as aluminum source, resulted in ZSM-23/ZSM-22 intergrowth zeolite with a molar ratio of diethylamine to dimethylamine of 1:12. The crystallization time for the synthesis was 50hrs and the crystallization temperature was 1700C and needle-shaped ZSM-22 crystals of less than 1 micron length were obtained.
[0011] Similarly, US patent 6,676,923 B1 and Microporous and Mesoporous Materials 132 (2010) 54–5, reported two different approaches to prepare zeolites with intergrowths of the MTT and TON topologies. In one route the author employed single structure-directing agent (N-isopropylethylenediamine) in hydroxide mediated syntheses and in the second approach the author used a mixture of structure-directing agent (SDA) molecules to prepare the MTT/TON intergrowths. In this case, one molecule alone is selective for MTT-type zeolites and the other molecule alone is selective for TON-type zeolites. Here the inventor have employed KOH, Ludox AS-30 colloidal silica/Cabosil M5 fumed silica, Nalco 1056 colloidal silica particles coated With A12O3/Reheis F-200 dried aluminum hydroxide along with structure-directing agent (SDA) molecules for the synthesis of MTT/TON intergrowths. However, US’923 only discloses preparation of MTT/TON zeolites with dominion of MTT character. Further, crystallization time for the synthesis in single structure-directing agent approach was 9 days and the crystallization temperature was 1700C with 43 rpm tumbling. The crystallization time for the synthesis in dual structure-directing agent approach was 12–14 days and the crystallization temperature was 1500C with 43 rpm tumbling.
[0012] Pet. Sci., 10 (2013) 242-250, compared the hydroisomerization activity of Pt/ZSM-22 and Pt/ZSM-23 catalysts vis à vis Pt/ZSM-22/ZSM-23 intergrowth catalysts. In the above article, the author reported that the, intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23 with dominion of ZSM-23 character, and the catalyst prepared using the inter growth Pt/ZSM-22/ZSM-23 had similar pore structure but mild acidity as compared to Pt/ZSM-22 and Pt/ZSM-23 catalysts, due to which, the hydroisomerization selectivity was highest for Pt/ZSM-22/ZSM-23 as compared to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Furthermore, Pt/ZSM-22/ZSM-23 catalyst showed higher selectivity for mono-branched isomers during the hydroisomerization of long chain paraffins. The maximum yield of i-dodecane product obtained during hydroisomerization of n-dodecanewas 68.3% at around 88 % conversion over Pt/ZSM-22/ZSM-23 at 320 ºC. The author reported surface area of 183 m2/g for the Pt/ZSM-22/ZSM-23 catalysts.
[0013] US patent 5,182,248 discloses a novel, high porosity, high surface area catalyst to isomerize wax into lube oil base stocks with high viscosity index and low pour point. The inventors have also disclosed an example where in catalyst having surface area of 200m2/gm produces higher quality lube products (high viscosity index and low pour point) at higher yields than the catalysts having low surface area of 173 m2/ gm.
[0014] To the best of the knowledge of inventors of the present disclosure, no report exists that disclose or suggest TON/MTT intergrowth zeolite with dominion of TON character. Accordingly, there remains a need in the art of a TON/MTT intergrowth zeolite with dominion of TON character. Need is also felt of a catalyst including a TON/MTT intergrowth zeolite with dominion of TON character. Need is also felt for a method of preparation of a TON/MTT intergrowth zeolite with dominion of TON character. The present disclosure satisfies the existing needs, inter alia, others and provides a TON/MTT intergrowth zeolite with dominion of TON character, method of preparation thereof and a catalyst including such intergrowth zeolites.

OBJECTS OF THE INVENTION
[0015] An object of the present disclosure is to provide a TON/MTT intergrowth zeolite.
[0016] Another object of the present disclosure is to provide a ZSM-22/ZSM-23 intergrowth zeolite.
[0017] Another object of the present disclosure is to provide a catalyst containing TON/MTT intergrowth zeolite that exhibits desired crystal size, optimum acidity and high surface area.
[0018] Another object of the present disclosure is to provide a catalyst containing ZSM-22/ZSM-23 intergrowth zeolite that exhibits desired crystal size, optimum acidity and high surface area.
[0019] Another object of the present disclosure is to provide a catalyst containing ZSM-22/ZSM-23 intergrowth zeolite that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.
[0020] Another object of the present disclosure is to provide a catalyst containing TON/MTT intergrowth zeolite that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.
[0021] Another object of the present disclosure is to provide a method for preparation of a TON/MTT intergrowth zeolite.
[0022] Another object of the present disclosure is to provide a method for preparation of a ZSM-22/ZSM-23 intergrowth zeolite.
[0023] Another object of the present disclosure is to provide a method for preparation of a TON/MTT intergrowth zeolite that is cost effective.
[0024] Another object of the present disclosure is to provide a catalyst including a TON/MTT intergrowth zeolite.
[0025] Another object of the present disclosure is to provide a method for preparation of a TON/MTT intergrowth zeolite that finds utility in preparation of hydroisomerization catalysts.
[0026] Another object of the present disclosure is to provide a method for preparation of a catalyst containing TON/MTT intergrowth zeolite that exhibits desired crystal size, optimum acidity and high surface area.
[0027] Another object of the present disclosure is to provide a method for preparation of a catalyst containing TON/MTT intergrowth zeolite that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.

SUMMARY
[0028] The present disclosure relates generally to the field of zeolites. Particularly, the present disclosure provides a TON/MTT intergrowth zeolite with dominion of TON character. Aspects of the present disclosure also relates to a method of preparation of a TON/MTT intergrowth zeolite with dominion of TON character.
[0029] An aspect of the present disclosure provides a TON/MTT intergrowth zeolite, wherein the TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the TON/MTT intergrowth zeolite exhibits surface area ranging from about 70 m2/gm to about 300 m2/gm. In an embodiment, the TON/MTT intergrowth zeolite exhibits surface area more than 210 m2/gm. In an embodiment, the TON/MTT intergrowth zeolite exhibits crystal size of less than about 1 micron. In an embodiment, the TON/MTT intergrowth zeolite exhibits external surface area ranging from about 10 m2/gm to about 80 m2/gm.
[0030] Another aspect of the present disclosure provides a catalyst including: at least one TON/MTT intergrowth zeolite; and at least one noble metal supported thereon, wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the at least one noble metal is selected from a metal of Group-VIII. In an embodiment, the at least one noble metal includes any or a combination of platinum and palladium. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.05 wt% to about 3 wt%. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.1 wt% to about 1 wt%. In an embodiment, the catalyst exhibits dispersion/impregnation of the at least one noble metal over at least about 10% of its total surface area.
[0031] Another aspect of the present disclosure relates to a method of preparation of a TON/MTT intergrowth zeolite, the method including the step of effecting hydrothermal crystallization of at least one silica precursor and at least one alumina precursor in presence of at least one alkali and a combination of structure directing agents, wherein at least one of said combination of structure directing agents imparts, at least in part, a MTT character to said TON/MTT intergrowth zeolite, and wherein the other structure directing agent of said combination of structure directing agents imparts, at least in part, a TON character to said TON/MTT intergrowth zeolite, characterized in that, the method affords preparation of a TON/MTT intergrowth zeolite with dominion of TON character. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character.
[0032] In an embodiment, the step of effecting hydrothermal crystallization is conducted at a temperature ranging from about 130°C to about 180°C. In an embodiment, the step of effecting hydrothermal crystallization is conducted for a time period ranging from about 10 hours to about 96 hours. In an embodiment, the step of effecting hydrothermal crystallization is conducted for a time period of about 24 hours. In an embodiment, the combination of structure directing agents comprises N,N-dimethyl formamide (DMF) and 1,6-diaminohexane (DAH). In an embodiment, the combination of structure directing agents comprises 1,6-diaminohexane (DAH) and N,N-dimethyl formamide (DMF) in a mole ratio ranging from about 1:57 to about 1:10. In an embodiment, the at least one silica precursor is selected from a group including silica sols, tetraalkylorthosilicates and silicon dioxides including fumed silicas and precipitated silicas. In an embodiment, the at least one alumina precursor is Al2(SO4)3.18H2O. In an embodiment, the at least one alkali is selected from any or a combination of sodium hydroxide and potassium hydroxide. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240.
[0033] Still further aspect of the present disclosure relates to a method for preparation of a catalyst including at least one TON/MTT intergrowth zeolite and at least one noble metal, the method including the steps of: effecting conversion of said at least one TON/MTT intergrowth zeolite to its acidic form; and contacting said acidic form of the at least one TON/MTT intergrowth zeolite with at least one precursor of the at least one noble metal to effect preparation of the catalyst. In an embodiment, the step of effecting conversion of said at least one TON/MTT intergrowth zeolite to its acidic form comprises effecting ion-exchange by contacting said at least one TON/MTT intergrowth zeolite with a precursor that releases ammonia. In an embodiment, said precursor is ammonium nitrate.
[0034] In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits surface area ranging from about 70 m2/gm to about 300 m2/gm. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits surface area more than 210 m2/gm. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits crystal size of less than about 1 micron. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits external surface area ranging from about 10 m2/gm to about 80 m2/gm. In an embodiment, the acidic form of the at least one TON/MTT intergrowth zeolite exhibits the titrable acidity ranging from about 50 µmol/gm to about 200 µmol/gm.
[0035] In an embodiment, the step of contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal comprises effecting ion-exchange by contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal. In an embodiment, the precursor of the at least one noble metal is tetra-ammonium platinum nitrate complex. In an embodiment, the method further includes the step of drying the catalyst. In an embodiment, the method further includes the steps of: effecting mixing of an appropriate amount of said catalyst with an appropriate amount of at least one binder to form a coherent mass; and effecting extrusion of said mixture. In an embodiment, the extruded mixture includes the catalyst in an amount ranging from about 30% to about 70% by weight of the extruded mizture. In an embodiment, the binder is selected from any or a combination of a clay, silica, alumina and a metal oxide. In an embodiment, the method further includes the step of effecting calcination of the said extruded mixture. In an embodiment, the calcinations is effected at a temperature ranging from about 250°C to about 400°C. In an embodiment, the calcinations is effected under constant air flow.
[0036] Still further aspect of the present disclosure provides a catalyst for effecting hydroisomerization of C12 to C40 n-paraffins, the catalyst comprising: at least one TON/MTT intergrowth zeolite; and at least one noble metal supported thereon, wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the at least one noble metal is selected from a metal of Group-VIII. In an embodiment, the at least one noble metal includes any or a combination of platinum and palladium. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.05 wt% to about 3 wt%. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.1 wt% to about 1 wt%. In an embodiment, the catalyst effects hydroisomerization of C12 to C40 n-paraffins to mid-branched isomers thereof in a yield ranging from about 10% to about 60% by weight of the C12 to C40 n-paraffins. In an embodiment, the catalyst effects hydroisomerization of C12 to C40 n-paraffins to mid-branched isomers thereof in a yield ranging from about 20% to about 40% by weight of the C12 to C40 n-paraffins. In an embodiment, the catalyst effects hydroisomerization of n-hexadecane (C16) to mid-branched isomers thereof in a yield ranging from about 10% to about 60% by weight of the n-hexadecane (C16).
[0037] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0039] FIG. 1 illustrates an exemplary snippet depicting x-ray diffraction pattern for ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character, in accordance with embodiments of the present disclosure.
[0040] FIG. 2 illustrates an exemplary snippet depicting x-ray diffraction patterns for ZSM-22, ZSM-23, ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character (indicated as intergrowth) and physical mixtures of ZSM-22 and ZSM-23 (indicated as PM-20, PM-40, PM-60 and PM-80), in accordance with embodiments of the present disclosure.
[0041] FIG. 3A to 3C illustrates exemplary Powder X-ray Diffraction patterns of ZSM-22, ZSM-23 and ZSM-22/ZSM-23 intergrowth zeolites, in accordance with embodiments of the present disclosure.
[0042] FIG. 4 illustrates exemplary Scanning Electron Microscope images of ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0043] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0044] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the “invention” may in some cases refer to certain specific embodiments only. In other cases it will be recognized that references to the “invention” will refer to subject matter recited in one or more, but not necessarily all, of the claims.
[0045] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0046] All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0047] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0048] The present disclosure relates generally to the field of zeolites. Particularly, the present disclosure provides a TON/MTT intergrowth zeolite with dominion of TON character. Aspects of the present disclosure also relates to a method of preparation of a TON/MTT intergrowth zeolite with dominion of TON character.
[0049] An aspect of the present disclosure provides a TON/MTT intergrowth zeolite, wherein the TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the TON/MTT intergrowth zeolite exhibits surface area ranging from about 70 m2/gm to about 300 m2/gm. In an embodiment, the TON/MTT intergrowth zeolite exhibits surface area more than 210 m2/gm. In an embodiment, the TON/MTT intergrowth zeolite exhibits crystal size of less than about 1 micron. In an embodiment, the TON/MTT intergrowth zeolite exhibits external surface area ranging from about 10 m2/gm to about 80 m2/gm.
[0050] FIG. 1 illustrates an exemplary snippet depicting x-ray diffraction pattern for ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character, in accordance with embodiments of the present disclosure. The ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character, as realized in accordance with embodiments of the present disclosure, exhibits characteristic peaks (2 theta degree) at 8.175, 20.375, 24.215, 24.675, 25.865 and 35.645, as depicted in FIG. 1.
[0051] The ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character, as realized in accordance with an embodiment of the present disclosure, exhibits peak intensity (c/s) to be 486 c/s for peak at 8.175 (2 theta degree), 369 c/s for peak at 20.375 (2 theta degree), 479 c/s for peak at 24.215 (2 theta degree), 510 c/s for peak at 24.675 (2 theta degree), 221 c/s for peak at 25.865 (2 theta degree) and 216 c/s for peak at 35.645 (2 theta degree).
[0052] Further, amount of TON character in the TON/MTT intergrowth zeolite, as realized in accordance with embodiments of the present disclosure, is assessed by preparing different sets of physically mixed zeolites (ZSM-22 and ZSM-23) and subjecting them to XRD to measure characteristic x-ray diffraction patterns thereof vis-à-vis the TON/MTT intergrowth zeolite. FIG. 2 illustrates an exemplary snippet depicting x-ray diffraction patterns for ZSM-22, ZSM-23, ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character (indicated as intergrowth) and physical mixtures of ZSM-22 and ZSM-23 (indicated as PM-20, PM-40, PM-60 and PM-80).
[0053] Another aspect of the present disclosure provides a catalyst including: at least one TON/MTT intergrowth zeolite; and at least one noble metal supported thereon, wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the at least one noble metal is selected from a metal of Group-VIII. In an embodiment, the at least one noble metal includes any or a combination of platinum and palladium. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.05 wt% to about 3 wt%. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.1 wt% to about 1 wt%. In an embodiment, the catalyst exhibits dispersion/impregnation of the at least one noble metal over at least about 10% of its total surface area.
[0054] Another aspect of the present disclosure relates to a method of preparation of a TON/MTT intergrowth zeolite, the method including the step of effecting hydrothermal crystallization of at least one silica precursor and at least one alumina precursor in presence of at least one alkali and a combination of structure directing agents, wherein at least one of said combination of structure directing agents imparts, at least in part, a MTT character to said TON/MTT intergrowth zeolite, and wherein the other structure directing agent of said combination of structure directing agents imparts, at least in part, a TON character to said TON/MTT intergrowth zeolite, characterized in that, the method affords preparation of a TON/MTT intergrowth zeolite with dominion of TON character. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character.
[0055] In an embodiment, the step of effecting hydrothermal crystallization includes: preparing solutions/dispersions of precursor of silica, precursor of alumina, alkali and structure directing agent (SDA) in a suitable solvent; effecting mixing of solutions/dispersions of precursor of alumina, alkali and SDA with a solution of precursor of silica; effecting aging of the resultant mixture at a pre-defined temperature for a pre-defined time period; and heating the resultant aged mixture (alternatively termed as gel) at a suitable temperature for a desired time period to effect crystallization of the intergrowth zeolite. In an embodiment, the solvent is distilled water. However, any other solvent or a combination of solvents, as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention. In an embodiment, the step of effecting hydrothermal crystallization is conducted at a temperature ranging from about 130°C to about 180°C. In an embodiment, the step of effecting hydrothermal crystallization is conducted for a time period ranging from about 10 hours to about 96 hours. In an embodiment, the step of effecting hydrothermal crystallization is conducted for a time period of about 24 hours.
[0056] In an embodiment, the combination of structure directing agents comprises N,N-dimethyl formamide (DMF) and 1,6-diaminohexane (DAH). In an embodiment, the combination of structure directing agents comprises 1,6-diaminohexane (DAH) and N,N-dimethyl formamide (DMF) in a mole ratio ranging from about 1:57 to about 1:10. In an embodiment, the at least one silica precursor is selected from a group including silica sols, tetraalkylorthosilicates and silicon dioxides including fumed silicas and precipitated silicas. However, any other silica precursor(s), as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention. In an embodiment, the at least one alumina precursor is Al2(SO4)3.18H2O. However, any other alumina precursor(s), as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention. In an embodiment, the at least one alkali is selected from any or a combination of sodium hydroxide and potassium hydroxide. However, any other alkali(s), as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240.
[0057] Still further aspect of the present disclosure relates to a method for preparation of a catalyst including at least one TON/MTT intergrowth zeolite and at least one noble metal, the method including the steps of: effecting conversion of said at least one TON/MTT intergrowth zeolite to its acidic form; and contacting said acidic form of the at least one TON/MTT intergrowth zeolite with at least one precursor of the at least one noble metal to effect preparation of the catalyst. In an embodiment, the step of effecting conversion of said at least one TON/MTT intergrowth zeolite to its acidic form comprises effecting ion-exchange by contacting said at least one TON/MTT intergrowth zeolite with a precursor that releases ammonia. In an embodiment, said precursor is ammonium nitrate.
[0058] In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits surface area ranging from about 70 m2/gm to about 300 m2/gm. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits surface area more than 210 m2/gm. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits crystal size of less than about 1 micron. In an embodiment, said acidic form of the at least one TON/MTT intergrowth zeolite exhibits external surface area ranging from about 10 m2/gm to about 80 m2/gm. In an embodiment, the acidic form of the at least one TON/MTT intergrowth zeolite exhibits the titrable acidity ranging from about 50 µmol/gm to about 200 µmol/gm.
[0059] In an embodiment, the step of contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal comprises effecting ion-exchange by contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal. In an embodiment, the precursor of the at least one noble metal is tetra-ammonium platinum nitrate complex. However, any other noble metal precursor(s), as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention.
[0060] In an embodiment, the method further includes the step of drying the catalyst. In an embodiment, the method further includes the steps of: effecting mixing of an appropriate amount of said catalyst with an appropriate amount of at least one binder to form a coherent mass; and effecting extrusion of said mixture. In an embodiment, the extruded mixture includes the catalyst in an amount ranging from about 30% to about 70% by weight of the extruded mixture. In an embodiment, the binder is selected from any or a combination of a clay, silica, alumina and a metal oxide. However, any other binder(s), as known to or appreciated by a person skilled in the art, can be utilized to serve its intended purpose, as laid down in embodiments of the present disclosure, without departing from the scope and spirit of the present invention.
[0061] In an embodiment, the method further includes the step of effecting calcination of the said extruded mixture. In an embodiment, the calcinations is effected at a temperature ranging from about 250°C to about 400°C. In an embodiment, the calcinations is effected under constant air flow.
[0062] Still further aspect of the present disclosure provides a catalyst for effecting hydroisomerization of C12 to C40 n-paraffins, the catalyst comprising: at least one TON/MTT intergrowth zeolite; and at least one noble metal supported thereon, wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character. In an embodiment, the at least one noble metal is selected from a metal of Group-VIII. In an embodiment, the at least one noble metal includes any or a combination of platinum and palladium. In an embodiment, the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio of less than 300. In an embodiment, the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from about 60 to about 240. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.05 wt% to about 3 wt%. In an embodiment, the catalyst includes the at least one noble metal in an amount ranging from about 0.1 wt% to about 1 wt%. In an embodiment, the catalyst effects hydroisomerization of C12 to C40 n-paraffins to mid-branched isomers thereof in a yield ranging from about 10% to about 60% by weight of the C12 to C40 n-paraffins. In an embodiment, the catalyst effects hydroisomerization of C12 to C40 n-paraffins to mid-branched isomers thereof in a yield ranging from about 20% to about 40% by weight of the C12 to C40 n-paraffins. In an embodiment, the catalyst effects hydroisomerization of n-hexadecane (C16) to mid-branched isomers thereof in a yield ranging from about 10% to about 60% by weight of the n-hexadecane (C16).
[0063] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
EXAMPLES
[0064] EXAMPLE 1: PREPARATION OF ZSM-22 ZEOLITE
[0065] ZSM-22 (bulk molar ratio of Si/Al = 60) was synthesized using 1,6-diaminohexane (DAH) as a structure directing agent. Crystallization of ZSM-22 was performed using gel molar composition of 27DAH/12K2O/Al2O3/120SiO2/3670H2O. Firstly, solutions (or dispersions) of precursor of Silica, precursor of Alumina, alkali and structure directing agent (SDA) were prepared in distilled water. Then solutions of Alumina, alkali and SDA were introduced to a solution of Silica, one by one and aged for 2 hrs under stirring condition at room temperature. The resultant aged mixture is termed as gel. The gel was heated to 160 °C under stirring condition (500 rpm) in an Amar autoclave batch reactor for 24 hours.
[0066] EXAMPLE 2: PREPARATION OF ZSM-23 ZEOLITE
[0067] ZSM-23 (bulk molar ratio of Si/Al = 60) was synthesized using N, N-dimethylformamide (DMF) as a structure directing agent. The crystallization of ZSM-23 was performed using gel molar composition of 57DMF/47Na2O/Al2O3/120SiO2/3670H2O. The hydrothermal crystallization of the gel so prepared was carried out at 160°C under stirred conditions for 48 hr, utilizing the method as described in Example 1. The crystallized samples were filtered, washed several times with deionized water, dried at 110°C for 24 hr, and finally calcined at 550°C for 12 hr in the presence of air.
[0068] EXAMPLE 3: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0069] ZSM-22/23 (bulk molar ratio of Si/Al = 60) was synthesized utilizing 1,6-diaminohexane (DAH) and N,N di-methylformamide (DMF) as templates (structure directing agents). The crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/1DAH/47Na2O/Al2O3/120SiO2/3670H2O. The hydrothermal crystallization of the gel so prepared was carried out at 160°C under stirred conditions for 24 hr, utilizing the method as described in Example 1.
[0070] EXAMPLE 4: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0071] ZSM-22/23 (bulk molar ratio of Si/Al = 60) was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/3DAH/47Na2O/Al2O3/120SiO2/3670H2O.
[0072] EXAMPLE 5: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0073] ZSM-22/23 (bulk molar ratio of Si/Al = 60) was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/4DAH/47Na2O/Al2O3/120SiO2/3670H2O.
[0074] EXAMPLE 6: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0075] ZSM-22/23 (bulk molar ratio of Si/Al = 60) was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/6DAH/47Na2O/Al2O3/120SiO2/3670H2O.
[0076] EXAMPLE 7: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0077] ZSM-22/23 was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/6DAH/47Na2O/Al2O3/60SiO2/3670H2O. In this example the bulk molar ratio of Si/Al = 30. No Intergrowth of ZSM-22/23 was observed in this case.
[0078] EXAMPLE 8: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0079] ZSM-22/23 was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/6DAH/47Na2O/Al2O3/180SiO2/3670H2O. In this example the bulk molar ratio of Si/Al = 90.
[0080] EXAMPLE 9: PREPARATION OF ZSM-22/ZSM-23 INTERGROWTH ZEOLITE
[0081] ZSM-22/23 was synthesized utilizing 1,6-diaminohexane and N,N di-methylformamide as templates (structure directing agents). The hydrothermal crystallization of ZSM-22/23 was performed using gel molar composition of 57DMF/6DAH/47Na2O/Al2O3/240SiO2/3670H2O. In this example the bulk molar ratio of Si/Al = 120.
[0082] ASSESSMENT OF AMOUNT OF TON CHARACTER IN TON/MTT INTERGROWTH ZEOLITES
[0083] Assessment of amount of TON (ZSM-22) character in the ZSM-22/ZSM-23 intergrowth zeolite was done by preparing different sets of physically mixed zeolites (ZSM-22 and ZSM-23) and subjecting them to XRD to measure characteristic x-ray diffraction patterns thereof vis-à-vis the ZSM-22/ZSM-23 intergrowth zeolite. FIG. 2 illustrates an exemplary snippet depicting x-ray diffraction patterns for ZSM-22, ZSM-23, ZSM-22/23 intergrowth zeolite with dominion of ZSM-22 character (indicated as intergrowth) and physical mixtures of ZSM-22 and ZSM-23 (indicated as PM-20, PM-40, PM-60 and PM-80). Area under the characteristic peak of ZSM-22, 2? ~ 20.36 was calculated for all physical mixture samples by Originpro 8.5 software and compared with the area of the characteristic peak of ZSM-22, 2? ~ 20.36 in the intergrowth samples. The intensity of characteristic peak of ZSM-22, 2? ~ 20.36 [0 2 1] increases with increasing amount of ZSM-22 on the physically mixed samples and the same trend was observed in synthesized intergrowth samples (ZSM-22/ZSM-23 intergrowth zeolites) with increasing amount of DAH. Interestingly and surprisingly, the DAH exhibited the template dominating effect, amongst the pair of structure directing agents (SDAs) - DAH and DMF, on the intergrowth samples. With utilization of increasing amount of DAH, the broader peak in the XRD slowly became narrow and with pattern similar to that of the ZSM-22. However, intergrowth zeolites prepared utilizing low concentration of DAH (2.5 mole percent) exhibited noisy XRD pattern evidencing poorly crystallized intergrowth zeolite. Accordingly, judicious selection of the amount/concentration of DAH and DMF is imperative to form desired crystallized intergrowth zeolites.
[0084] FIG. 3A through FIG. 3C illustrate Powder X-ray Diffraction patterns of ZSM-22 zeolite (Example 1), ZSM-23 (Example 2) and ZSM-22/ZSM-23 intergrowth zeolites (Example 3 through Example 9). FIG. 4 illustrates exemplary Scanning Electron Microscope images of ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character.

[0085] EXAMPLE 10: PREPARATION OF ACIDIC FORM OF ZEOLITE
[0086] All the crystallized samples were filtered, washed several times with de-ionized water, dried overnight at 110 °C. The sample was calcined in air at 550°C for 12 h. The proton (acidic) form of the sample was obtained by exchanging the sample three times with ammonium nitrate under reflux at 90 °C for 3-4 h followed by calcination at 550 °C for 4 h. The zeolite samples prepared in Example 1, Example 2, Example 3, and Example 4 and so on are labelled as Z1, Z2, Z3, Z4 and so on respectively.
[0087] EXAMPLE 11: CHARACTERISATION OF ZEOLITE AND ITS CATALYSTS SAMPLE
[0088] All the zeolites were characterized by several physiochemical techniques. The values are given in Table 1 below:
Table 1: Textural properties of the all the zeolites samples
Example
No. Si/Al
Ratio 1,6-DAH
(mole%) BET
(m2/g) SAmeso
(m2/g) Pvtotal
(cm3/g) Acidity
(µmol/g) % ZSM-22 phase
1 60 100 216 53 0.162 232 100
2 60 0 226 34 0.151 184 0
3 60 2.5 86 59 0.116 78 30
4 60 5 225 51 0.159 115 60
5 60 7.5 215 60 0.164 122 70
6 60 10 235 49 0.164 118 90
7 30 5 48 48 0.066 ** 0
8 90 5 204 50 0.146 75 60
9 120 5 204 46 0.144 50 60
** No measurable acidity due to amorphous phase
[0089] EXAMPLE 12: Pt loading, binding and extruding the ZSM-22 zeolite catalyst
[0090] The proton/acidic form of the above samples (example 1 through example 9) were used to make extruded Pt-loaded catalyst. 0.05 g of tetra-ammonium platinum nitrate complex was dissolved in 50 ml of distilled water. This solution was taken into a flask and 3.5 g of H-ZSM-22 was added on to it. The pH of the solution was adjusted to be maintained in the range of 9 to 10 using tetra butyl ammonium hydroxide. The product was filtered and dried at 100°C. 50 parts of Pt/H-ZSM-22 crystal were mixed with 50 parts of pseudoboehmite alumina binder in a muller. Sufficient amount of 5% acetic acid was added to produce an extrudable dough type mass on a 1'' diameter extruder. This dough was extruded into 1/16'' diameter cylindrical extrudates and then dried in an oven at 130°C overnight. The dried extrudate was calcined in oxygen at 400°C. Four catalyst samples were prepared and coded as CAT-1 (prepared using zeolite Z1), CAT-2 (prepared using zeolite Z2), CAT-3 (prepared using zeolite Z3) and CAT-4 (prepared using zeolite Z4) and so on. The final catalyst composition is shown below:
Component Weight %
Zeolite 49.85%
Binder 49.85%
Platinum 0.3%
[0091] EXAMPLE 13: MEASUREMENT OF ACTIVITY AND SELECTIVITY FOR THE PREPARED CATALYSTS
[0092] All the catalyst recipes were tested for hydroisomerization selectivity using n-hexadecane as the model feed. 5 g of calcined catalyst extrudate diluted with inert material (quartz) was packed in a stainless steel fixed bed reactor. The catalyst was then dried overnight at 130°C under nitrogen flow and reduced at 320°C under a constant H2 flow of 100 ml/min at 60 bar pressure for 5 h. After reduction of the metal, the catalyst was used for hexadecane isomerization reaction. The reaction was carried out at a temperature range of 280-320°C, WHSV of 0.8-1.2 h-1, with H2/ HC ratio of 600 at 60 bar pressure. The activity and selectivity data for different catalysts are tabulated in the Table 2.
[0093] Table 2 shows a comparative analysis of all the catalysts based on their n-C16hydroisomerizationperformance. All catalysts except Cat-5, Cat-6 and Cat-9 prepared using the ZSM-22/23intergrowth zeolite showed better selectivity for isomers as compared to then Cat-1 (prepared using ZSM-22with bulk molar ratio of Si/Al = 60) and Cat-2 (prepared using ZSM-23 with bulk molar ratio of Si/Al = 60).
Table 2: Comparison of activity and selectivity of different catalysts for n-C16 hydroisomerization at similar n-C16 conversion*
Catalyst Reference No. Zeolite from Example No. Temperature (°C) Conversion (%) Isomer yield (%) Selectivity (%)
Cat-1 1 305 88.6 75.6 85.3
Cat-2 2 305 89.8 77.5 86.3
Cat-3 3 326 88.5 79.3 89.5
Cat-4 4 303 88.7 78.7 88.7
Cat-5 5 312 91.5 77.4 84.5
Cat-6 6 300 90.6 76.7 84.7
Cat-8 8 323 90.3 78.3 86.7
Cat-9 9 333 89.9 74.7 83.1
* Cat 7 not evaluated due to amorphous phase
[0094] Out of all the catalysts prepared using the ZSM-22/23 intergrowth zeolite Cat-4 including ZSM-22/23 intergrowth (bulk molar ratio of Si/Al = 60) prepared using gel composition of 57DMF/3DAH/47Na2O/Al2O3/120SiO2/3670H2O showed better activity and isomer selectivity. Superior performance of Cat-4 for n-C16 hydroisomerization was attributed to its smaller zeolite crystal size, better surface area, higher external surface area and moderate acidity. These experiments clearly elicit the advantage of using ZSM-22/23 intergrowth zeolite in hydroisomerization catalyst.
[0095] Although the subject matter has been described herein with reference to certain preferred embodiments thereof, other embodiments are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiment contained therein. Furthermore, precise and systematic details on all above aspects are currently being made. Work is still underway on this invention. It will be obvious to those skilled in the art to make various changes, modifications and alterations to the invention described herein. To the extent that these various changes, modifications and alterations do not depart from the scope of the present invention, they are intended to be encompassed therein.

ADVANTAGES OF THE INVENTION
[0096] The present disclosure provides a TON/MTT intergrowth zeolite with dominion of TON character.
[0097] The present disclosure provides a ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character.
[0098] The present disclosure provides a catalyst containing TON/MTT intergrowth zeolite with dominion of TON character that exhibits desired crystal size, optimum acidity and high surface area.
[0099] The present disclosure provides a catalyst containing ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character that exhibits desired crystal size, optimum acidity and high surface area.
[00100] The present disclosure provides a catalyst containing ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.
[00101] The present disclosure provides a catalyst containing TON/MTT intergrowth zeolite with dominion of TON character that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.
[00102] The present disclosure provides a method for preparation of a TON/MTT intergrowth zeolite with dominion of TON character.
[00103] The present disclosure provides a method for preparation of a ZSM-22/ZSM-23 intergrowth zeolite with dominion of ZSM-22 character.
[00104] The present disclosure provides a method for preparation of a TON/MTT intergrowth zeolite with dominion of TON character that is cost effective.
[00105] The present disclosure provides a catalyst including a TON/MTT intergrowth zeolite with dominion of TON character.
[00106] The present disclosure provides a method for preparation of a TON/MTT intergrowth zeolite with dominion of TON character that finds utility in preparation of hydroisomerization catalysts.
[00107] The present disclosure provides a method for preparation of a catalyst containing TON/MTT intergrowth zeolite with dominion of TON character that exhibits desired crystal size, optimum acidity and high surface area.
[00108] The present disclosure provides a method for preparation of a catalyst containing TON/MTT intergrowth zeolite with dominion of TON character that exhibits high activity towards hydroisomerization reaction and high isomerization selectivity.

CLAIMS:
1. A TON/MTT intergrowth zeolite, wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character.
2. The zeolite as claimed in claim 1, wherein the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite, and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character.
3. The zeolite as claimed in claim 1, wherein the TON/MTT intergrowth zeolite comprises silica and alumina in a molar ratio ranging from 60 to 240, and wherein the TON/MTT intergrowth zeolite exhibits surface area of more than 210 m2/gm, crystal size of less than 1 micron, and external surface area ranging from 10 m2/gm to 80 m2/gm.
4. A catalyst comprising:
at least one TON/MTT intergrowth zeolite; and
at least one noble metal supported thereon,
wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character.
5. The catalyst as claimed in claim 4, wherein the at least one noble metal is selected from a metal of Group-VIII selected from any or a combination of platinum and palladium.
6. The catalyst as claimed in claim 4, wherein the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite, and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character.
7. The catalyst as claimed in claim 4, wherein the catalyst comprises the at least one noble metal in an amount ranging from 0.05 wt% to 3 wt%, and wherein the catalyst exhibits dispersion of the at least one noble metal over at least 10% of its total surface area.
8. A method for preparation of a TON/MTT intergrowth zeolite, the method comprising the step of: effecting hydrothermal crystallization of at least one silica precursor and at least one alumina precursor in presence of at least one alkali and a combination of structure directing agents, wherein at least one of said combination of structure directing agents imparts, at least in part, a MTT character to said TON/MTT intergrowth zeolite, and wherein the other structure directing agent of said combination of structure directing agents imparts, at least in part, a TON character to said TON/MTT intergrowth zeolite, characterized in that, the method affords preparation of the TON/MTT intergrowth zeolite with dominion of TON character.
9. The method as claimed in claim 8, wherein the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite, and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character.
10. The method as claimed in claim 8, wherein the step of effecting hydrothermal crystallization is conducted at a temperature ranging from 130°C to 180°C for a time period ranging from 10 hours to 96 hours.
11. The method as claimed in claim 8, wherein the combination of structure directing agents comprises 1,6-diaminohexane (DAH) and N,N-dimethyl formamide (DMF) in a mole ratio ranging from 1:57 to 1:10, and wherein the at least one silica precursor is selected from a group comprising silica sols, tetraalkylorthosilicates and silicon dioxides including fumed silicas and precipitated silicas, and wherein the at least one alumina precursor is Al2(SO4)3.18H2O, further wherein the at least one alkali is selected from any or a combination of sodium hydroxide and potassium hydroxide.
12. The method as claimed in claim 8, wherein the TON/MTT intergrowth zeolite comprises silica and alumina in a molar ratio ranging from 60 to 240.
13. A method for preparation of a catalyst comprising at least one TON/MTT intergrowth zeolite with dominion of TON character and at least one noble metal, the method comprising the steps of:
effecting conversion of said at least one TON/MTT intergrowth zeolite with dominion of TON character to its acidic form; and
contacting said acidic form with at least one precursor of the at least one noble metal to effect preparation of the catalyst.
14. The method as claimed in claim 13, wherein the step of effecting conversion of said at least one TON/MTT intergrowth zeolite to its acidic form comprises effecting ion-exchange by contacting said at least one TON/MTT intergrowth zeolite with a precursor that releases ammonia, and wherein the step of contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal comprises effecting ion-exchange by contacting said acidic form of the at least one TON/MTT intergrowth zeolite with the at least one precursor of the at least one noble metal.
15. The method as claimed in claim 13, wherein said acidic form exhibits surface area of more than 210 m2/gm, crystal size of less than 1 micron, external surface area ranging from 10 m2/gm to 80 m2/gm, and titrable acidity ranging from 50 µmol/gm to 200 µmol/gm.
16. The method as claimed in claim 13, wherein the precursor of the at least one noble metal is tetra-ammonium platinum nitrate complex.
17. The method as claimed in claim 13, wherein the method further comprises the steps of:
drying the catalyst;
effecting mixing of an appropriate amount of said catalyst with an appropriate amount of at least one binder to form a coherent mass, wherein the binder is selected from any or a combination of a clay, silica, alumina and a metal oxide;
effecting extrusion of said mixture, wherein the extruded mixture comprises the catalyst in an amount ranging from 30% to 70% by weight of the extruded mixture; and
effecting calcination of the said extruded mixture at a temperature ranging from 250°C to 400°C under constant air flow.
18. A catalyst for effecting hydroisomerization of C12 to C40 n-paraffins, the catalyst comprising:
at least one TON/MTT intergrowth zeolite; and
at least one noble metal supported thereon,
wherein said TON/MTT intergrowth zeolite exhibits dominion of TON character.
19. The catalyst as claimed in claim 18, wherein the TON/MTT intergrowth zeolite is a ZSM-22/ZSM-23 intergrowth zeolite, and wherein said ZSM-22/ZSM-23 intergrowth zeolite exhibits dominion of ZSM-22 character, and wherein the at least one noble metal is selected from a metal of Group-VIII comprising any or a combination of platinum and palladium.
20. The catalyst as claimed in claim 18, wherein the TON/MTT intergrowth zeolite includes silica and alumina in a molar ratio ranging from 60 to 240, and wherein the catalyst includes the at least one noble metal in an amount ranging from 0.05 wt% to 3 wt%.
21. The catalyst as claimed in claim 18, wherein the catalyst effects hydroisomerization of C12 to C40 n-paraffins to mid-branched isomers thereof in a yield ranging from 10% to 60% by weight of the C12 to C40 n-paraffins.
22. The catalyst as claimed in claim 18, wherein the catalyst effects hydroisomerization of n-hexadecane (C16) to mid-branched isomers thereof in a yield ranging from 10% to 60% by weight of the n-hexadecane (C16).