FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION (See section 10, rule 13)
1. Title of the invention: CATALYST COMPOSITION WITH LOW TOTAL SURFACE
AREA FOR ISOMERIZATION OF PARAFFINS
2. Applicant(s)
NAME NATIONALITY ADDRESS
BHARAT PETROLEUM Indian BHARAT PETROLEUM
CORPORATION LTD. CORPORATION LTD. BHARAT
BHAVAN, 4&6 CURRIMBHOY ROAD, BALLARD ESTATE, MUMBAI - 400074, INDIA
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it
is to be performed.

TECHNICAL FIELD
[0001] The subject matter described herein in general relates to a catalyst composition for isomerization of paraffins comprising of at least one transitional metal, at least one acidic porous material with total surface area in a range of 20-100 m2/g, and a binder. The subject matter also relates to a process for the preparation of a catalyst composition for isomerization of paraffins. The subject matter further relates to a process for isomerization of paraffins using the catalytic composition. The subject matter also relates to an acidic porous material with total surface area in a range of 20-100 m2/g and a process for preparation of such material.
BACKGROUND [0002]Zeolites are crystalline aluminosilicates, either of natural or synthetic origin, with highly ordered structures. Zeolites 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 can be represented by the general formula:
My/n [(SiO2)x (AlO2)y].zH2O
where M is the charge compensating cation with the valency n. M represents the exchangeable cation (eg. alkali or alkaline earth metals or an organic cations). The ratio x/y can have the value 1 to α. 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. Zeolites are

also popularly known as ‘molecular sieves’ due to their ability to differentiate between molecules of different shapes and size. Zeolites have found widespread application as adsorbents, ion exchange materials, detergent builders and catalysts, especially in petroleum refining as fluidized catalytic cracking and hydroprocessing catalysts and in synthesis of petrochemicals. Typically, zeolites have high surface area, molecular dimensions of the pores, high adsorption capacity, molecular shape selectivity for reactants / products, and tunable acidity
[0003]Such unique properties of zeolites have led to their applications in the field of adsorption and catalysis. British patent no 574911 describes the use of zeolites and molecular sieves as commercial adsorbents for separation of branched and linear paraffins. The use of zeolites as catalysts has been a part of discussion in open as well as patented literature, especially in the area of oil refining where zeolite Y and ZSM-5 are used as solid acid catalysts. The publication in “Ind. Eng. Chem. Prod. Res. Dev. 3, 1964, 165” describes the use of Y zeolite as a component of FCC catalyst by Mobil for purpose of cracking Vacuum Gas Oils (VGOs) to product transportation fuels. [0004]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 basestocks 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 RON, winter grade diesel and lube oil base stock (LOBS) in oil refineries (Science and Engineering, 2007, 49:1, 33-139). [0005]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. On the other hand, for long chain n-paraffins (C12 plus)

isomerization, medium pore one-dimensional zeolites are found to be potential candidates. The one-dimensional framework plays an important role in the isomerisation process 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 optimum external surface area in order to obtain higher conversions and isomer selectivities in hydroisomerization reaction (J. Catal. 190, 1, 39-48). US patent 4986894 describes a process for producing lubricating oils with a reduced pour point using zeolite based catalyst. It further describes the synthesis of MCM-22 zeolite with a surface area of > 400 m2/gm. US patent 8772193 describes the synthesis of a catalyst for hydrogenation dewaxing, catalyst comprising of EU-2 zeolite synthesized using a phase transition controlled process with a surface area of 100 m2/gm or more. The catalyst when used for dewaxing of a waxy feed reduced the pour point to -14 oC from an initial pour point of 48 oC. US patent application no 2015/0057478 A1 describes the synthesis of a ZSM-22 zeolite with a external surface area of 40 m2/gm or greater for producing lubricating oils with low pour points. The external surface area is generally less than the total surface area in case of microporous materials. US patent 7390763 describes the synthesis of SSZ-32x zeolite with an external surface area in the range from 80-300 m2/gm. The inventors have disclosed that this zeolite has increased surface area, reduced cracking activity and in hydroisomerization of waxy paraffins leads to higher lube product yield in comparison with the standard SSZ-32 zeolite. The higher external surface area is a result of higher total surface areas in case of zeolites. In the paper entitled “Crystallization and porosity of ZSM-23” in Microporous and Mesoporous Materials 143 (2011) 253–262 the authors have pointed out in detail the effect of temperature, time and seeding on the textural properties of ZSM-23. It is shown that with increase in time and temperature there is an enhancement in the formation of crystoballite which blocks the pores thus reducing the surface area of ZSM-23 to 33m2/gm. The literature mentioned above clearly brings out the importance of high surface areas and external surface areas of zeolite required for hydroisomerization of

waxy paraffins. However the concept of pore mouth catalysis which has been a topic of study in many of the papers, for e.g. Journal of Catalysis 190, 39–48 (2000), Journal of Catalysis 174, 177–184 (1998), Appl. Catal. 76, 131 (1991) and Angew. Chem., Int. Ed. Engl. 34, 22 (1995) brings out the importance of the structure and geometry of the pore mouth as an important criteria for achieving high selectivity in the isomerisation of paraffins with higher carbon numbers. The authors have explained that the catalytic conversion of alkanes on one-dimensional zeolites of TON family does not involve diffusional transportation through the micropores. Skeletal isomerization occurs on molecules adsorbed in pore mouths and on the external surfaces of the zeolite crystals. In the monobranching reaction of n-alkanes, only part of the molecule penetrates into a micropore opening. The skeletal rearrangement takes place in the pore mouth where there is less steric hindrance (pore mouth catalysis) and the molecule diffuses out after the branching. The occurrence of pour mouth catalysis is responsible for maintaining an ideal ratio of mono-branched to multi-branched isomers in the hydroisomerization of heavy paraffins.
SUMMARY [0006]In an aspect of the present disclosure, there is provided a catalyst composition comprising at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition; at least one acidic porous material with total surface area in range of 20-100 m2/g; and a binder, wherein the at least one acidic porous material to the binder ratio is in the range of 95:5 to 35:65. [0007]In an aspect of the present disclosure, there is provided a process for producing a catalyst composition including the steps of (a) preparing at least one acidic porous material with total surface area in range of 20-100 m2/g; (b) contacting the at least one acidic porous material with at least one transitional metal to obtain a transitional metal loaded acidic porous material; (c) contacting the transitional metal loaded acidic porous material with a binder to obtain a extruded catalyst; (d) calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1 to 6 hours to obtain a

catalyst composition, wherein the at least one acidic porous material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65 and at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition.
[0008]In an aspect of the present disclosure, there is provided a process for producing a catalyst composition including the step of (a) preparing a zeolite support by hydrothermal heating of the silica and alumina precursors along with a structure directing organic template in the presence of an alkali; (b) removing the structure directing agent to obtain a porous material; (c) converting the porous material to its acidic form by ion-exchanging with precursor salts which release ammonia at 500 oC to obtain an acidic porous material with total surface area in range of 20-100 m2/g; (d) contacting the at least one acidic porous material with at least one transitional metal to obtain a transitional metal loaded acidic porous material; (e) contacting the transitional metal loaded acidic porous material with a binder to obtain a extruded catalyst; (f) calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1 to 6 hours to obtain a catalyst composition, wherein the at least one acidic porous material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65, and at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition.
[0009]In an aspect of the present disclosure, there is provided a process for isomerization of paraffins comprising (a) contacting the paraffins and hydrogen with a a catalyst composition in a reactor; (b) wherein the catalyst composition comprises of at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition; (b) at least one acidic porous material with total surface area in range of 20-100 m2/g; and (c) a binder, wherein the at least one acidic porous material to the binder ratio is in the range of 95:5 to 35:65. [0010]In an aspect of the present disclosure, there is provided an acidic porous material with total surface area in the range of 20-100 m2/g,

[0011]In an aspect of the present disclosure, there is provided a process for preparing an acidic porous material with total surface area in range of 20-100 m2/g, the process comprising; (a) preparing a zeolite support by hydrothermal heating of the silica and alumina precursors along with a structure directing organic template in the presence of an alkali; (b) removing the structure directing agent to obtain a porous material; (c) converting the porous material to its acidic form by ion-exchanging with precursor salts which release ammonia at 500 oC to obtain an acidic porous material with low total surface area range of 20-100 m2/g.
[0012]These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
BREIF DESCRIPTION OF ACCOMPANYING DRAWINGS [0013]The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein. [0014]Figure 1 depicts the X-ray pattern of low surface area ZSM-22. [0015]Figure 2 depicts the X-ray pattern of low surface area ZSM-23.
DETAILED DESCRIPTION [0001] Those skilled in the art will be aware that the present disclosure is subject to variations and modifications other than those specifically described. It is to be understood that the present disclosure includes all such variations and modifications. The disclosure also includes all such steps, features, compositions and compounds

referred to or indicated in this specification, individually or collectively and any and
all combinations of any or more of such steps or features.
Definitions:
[0002] For convenience, before further description of the present disclosure, certain
terms employed in the specification, and examples are collected here. These
definitions should be read in the light of the remainder of the disclosure and
understood as by a person of skill in the art. The terms used herein have the meanings
recognized and known to those of skill in the art, however, for convenience and
completeness, particular terms and their meanings are set forth below.
[0003] The articles “a”, “an” and “the” are used to refer to one or to more than one
(i.e., to at least one) of the grammatical object of the article.
[0004] The terms “comprise” and “comprising” are used in the inclusive, open sense,
meaning that additional elements may be included. Throughout this specification,
unless the context requires otherwise the word “comprise”, and variations, such as
“comprises” and “comprising”, will be understood to imply the inclusion of a stated
element or step or group of element or steps but not the exclusion of any other element
or step or group of element or steps.
[0005] The term “catalyst composite(s)” and “catalyst composition(s)” are used
interchangeably in the present disclosure.
[0016]Ratios, concentrations, amounts, and other numerical data may be presented
herein in a range format. It is to be understood that such range format is used merely
for convenience and brevity and should be interpreted flexibly to include not only the
numerical values explicitly recited as the limits of the range, but also to include all the
individual numerical values or sub-ranges encompassed within that range as if each
numerical value and sub-range is explicitly recited.
[0017]The disclosure in general relates to a process for preparation of low total surface
area porous material and incorporating its acidic form with transitional metal and
binder for its use as a hydroisomerization catalyst. The formation of optimal pore
structure and not high surface area of the zeolites of the present disclosure is important

for achieving high isomerisation selectivity at appreciable conversion levels. Thus, present disclosure illustrates synthesis of low total surface area zeolites with the phase similar to ZSM-23 and ZSM-22 as confirmed by X-ray diffraction and use of these as supports for hydroisomerization of n-hexadecane and heavy paraffins to further produce dewaxed oil with excellent low temperature flow characteristics. [0018]In an embodiment of the present disclosure, there is provided a process for preparation of zeolite based hydroisomerisation catalyst with low total surface area while having appropriate pore geometry for selective isomerisation process. [0019]In an embodiment of the present disclosure, there is provided a catalyst composition comprising at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition; at least one acidic porous material with total surface area in range of 20-100 m2/g; and a binder, wherein the at least one acidic porous material to the binder ratio is in the range of 95:5 to 35:65. [0020]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one transitional metal is in an amount in the range of 0.1% to 6% w/w of the total weight of the composition. [0021]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one transitional metal is in an amount in the range of 0.1% to 2% w/w of the total weight of the composition. [0022]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one transitional metal is selected from the group consisting of Pt, Pd, and combinations thereof. [0023]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one transitional metal is Pt. [0024]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one transitional metal is Pt with a cluster size in the range of 12-18 nm.
[0025]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one acidic porous material is

selected from the group consisting of zeolite, molecular sieve, amorphous silica-alumina, solid acids and combinations thereof. [0026]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one acidic porous material is selected from the group consisting of ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-48, SSZ-32, and combinations thereof.
[0027]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one acidic porous material is selected from the group consisting of ZSM-22, ZSM-23, and combinations thereof. [0028]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the binder is selected from the group consisting of alumina, silica, zirconia, titania, niobia, magnesia, silica-alumina, silica-magnesia, silica-zirconia, and combinations thereof. [0029]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the binder is selected from the group consisting of alumina, silica-alumina, silica-magnesia, silica-zirconia and combinations thereof.
[0030]In an embodiment of the present disclosure, there is provided a catalyst composition as described herein, wherein the at least one acidic porous material to the binder ratio is in the range of 65:35 to 35:65. [0031]In an embodiment of the present disclosure, there is provided a catalyst composition comprising of Pt in an amount in the range of 0.1% to 2% w/w of the total weight of the composition; at least one acidic porous material with total surface area in range of 20-100 m2/g selected from ZSM-22 or ZSM-23; and a binder selected from the group consisting of alumina, silica-alumina, silica-magnesia, silica-zirconia, and combinations thereof, wherein the at least one acidic porous material to the binder ratio is in the range of 65:35 to 35:65.

[0032]In an embodiment of the present disclosure, there is provided a catalyst
composition as described herein, wherein the catalyst composition is used for
isomerization of n-paraffins.
[0033]In an embodiment of the present disclosure, there is provided a process for
producing a catalyst composition including the steps of (a) preparing at least one
acidic porous material with total surface area in the range of 20-100 m2/g; (b)
contacting the at least one acidic porous material with at least one transitional metal to
obtain a transitional metal loaded acidic porous material; (c) contacting the transitional
metal loaded acidic porous material with a binder to obtain a extruded catalyst; (d)
calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1
to 6 hours to obtain a catalyst composition, wherein the at least one acidic porous
material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65,
at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the
total weight of the composition.
[0034]In an embodiment of the present disclosure, there is provided a process for
producing a catalyst composition as described herein, wherein the at least one
transitional metal in an amount in the range of 0.1% to 2% w/w of the total weight of
the composition.
[0035]In an embodiment of the present disclosure, there is provided a process for
producing a catalyst composition as described herein, wherein the at least one
transitional metal is selected from the group consisting of Pt, Pd, and combinations
thereof.
[0036]In an embodiment of the present disclosure, there is provided a process for
producing a catalyst composition as described herein, wherein the at least one
transitional metal is Pt with a cluster size in the range of 12-18 nm.
[0037]In an embodiment of the present disclosure, there is provided a process for
producing a catalyst composition as described herein, wherein the at least one acidic
porous material is selected from the group consisting of ZSM-5, ZSM-22, ZSM-23,
ZSM-35, ZSM-48, SSZ-32, and combinations thereof.

[0038]In an embodiment of the present disclosure, there is provided a process for producing a catalyst composition as described herein, wherein the binder is selected from the group consisting of alumina, silica, zirconia, titania, niobia, magnesia, silica-alumina, silica-magnesia, silica-zirconia, and combinations thereof. [0039]In an embodiment of the present disclosure, there is provided a process for producing a catalyst composition including the step of (a) preparing at least one acidic porous material selected from ZSM-22 or ZSM-23 with total surface area in range of 20-100 m2/g; (b) contacting the at least one acidic porous material with Pt to obtain a Pt loaded acidic porous material; (c) contacting the Pt loaded acidic porous material with a binder selected from the group of alumina, silica-alumina, silica-magnesia, silica-zirconia, and combinations thereof to obtain a extruded catalyst; (d) calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1 to 6 hours to obtain a catalyst composition, wherein the at least one acidic porous material to the binder ratio in the catalyst composition is in the range of 65:35 to 35:65, Pt in an amount in the range of 0.1% to 2% w/w of the total weight of the composition. [0040]In an embodiment of the present disclosure, there is provided a process for producing a catalyst composition including the step of (a) preparing a zeolite support by hydrothermal heating of the silica and alumina precursors along with a structure directing organic template in the presence of an alkali; (b) removing the structure directing agent to obtain a porous material; (c) converting the porous material to its acidic form by ion-exchanging with precursor salts which release ammonia at 500 oC to obtain an acidic porous material with total surface area in range of 20-100 m2/g; (d) contacting the at least one acidic porous material with at least one transitional metal to obtain a transitional metal loaded acidic porous material; (e) contacting the transitional metal loaded acidic porous material with a binder to obtain a extruded catalyst; (f) calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1 to 6 hours to obtain a catalyst composition, wherein the at least one acidic porous material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65,

at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition.
[0041]In an embodiment of the present disclosure, there is provided a process for producing a catalyst composition which includes (a) preparing a low surface area zeolite (ZSM-22/23) support by hydrothermal heating of the silica and alumina precursors along with a structure directing organic template in the presence of an alkali to obtain low total surface area range of 20-100 m2/g, (b) converting the obtained zeolite support to its acidic form by ion-exchanging with such precursor salts which release ammonia at 500 oC, (c) loading the acidic form with noble metal by ion-exchanging with a noble metal precursor salt and (d) preparation of the final catalyst extrudate by mixing the noble metal exchanged acidic form of the zeolite with an appropriate binder in a composition that gives good mechanical properties to the catalyst extrudate. The so prepared catalyst exhibits dewaxing characteristics for n-paraffin feed with high selectivity for multibranched isomers leading to excellent low temperature flow properties.
[0042]In an embodiment of the present disclosure, there is provided a process for producing a catalyst composition, the process comprising: synthesis of a pore filled material under hydrothermal conditions using a structure directing agent; removal of the structure directing agent to obtain a porous material; converting the porous material to its acidic form using a inorganic precursor salt and calcination thereafter at 500 oC; incorporating the calcined acidic porous material with a noble metal to obtain a noble metal loaded acidic porous material; drying the noble metal loaded acidic porous material to obtain a dried material; extruding 50 % w/w to 95 % w/w of the dried material with 5 % w/w to 50 % w/w of a binder material to obtain a extruded catalyst; and calcining the extruded catalyst at 250-400 °C under constant air flow to obtain a dispersed noble metal-containing catalyst having dispersion of over 80%. The present disclosure further relates to a catalyst for hydroisomerization of long chain n-paraffins ranging from C12-C40 on the acidic sites loaded at pore mouths.

[0043]The present disclosure further relates to a process for isomerization of paraffins
comprising (a) contacting the paraffins and hydrogen with a a catalyst composition in a
reactor; (b) wherein the catalyst composition comprises of at least one transitional
metal in an amount in the range of 0.1% to 10% w/w of the total weight of the
composition; (b) at least one acidic porous material with total surface area in range of
20-100 m2/g; and (c) a binder, wherein the at least one acidic porous material to the
binder ratio is in the range of 95:5 to 35:65.
[0044]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one transitional
metal in an amount in the range of 0.1% to 6% w/w of the total weight of the
composition.
[0045]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one transitional
metal in an amount in the range of 0.1% to 2% w/w of the total weight of the
composition.
[0046]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one transitional
metal is selected from the group consisting of Pt, Pd, and combinations thereof.
[0047]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one transitional
metal is Pt.
[0048]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one transitional
metal is Pt with a cluster size in the range of 12-18 nm.
[0049]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one acidic porous
material is selected from the group consisting of zeolite, molecular sieve, amorphous
silica-alumina, solid acids and combinations thereof.

[0050]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one acidic porous
material is selected from the group consisting of ZSM-5, ZSM-22, ZSM-23, ZSM-35,
ZSM-48, SSZ-32, and combinations thereof.
[0051]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one acidic porous
material is selected from the group consisting of ZSM-22, ZSM-23, and combinations
thereof.
[0052]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the binder is selected from the
group consisting of alumina, silica, zirconia, titania, niobia, magnesia, silica-alumina,
silica-magnesia, silica-zirconia, and combinations thereof.
[0053]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the binder is selected from the
group consisting of alumina, silica-alumina, silica-magnesia, silica-zirconia and
combinations thereof.
[0054]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the at least one acidic porous
material to the binder ratio is in the range of 65:35 to 35:65.
[0055]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the paraffin is C12 to C40 linear
paraffin.
[0056]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein hydrogen is passed over the
catalyst composition at a rate of 10-100 mL/min.
[0057]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the process is carried out at a
temperature in the range of 150-400°C.

[0058]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the process is carried out at a
pressure in the range of 5-60 bar.
[0059]In an embodiment of the present disclosure, there is provided a process for
isomerization of paraffins as described herein, wherein the paraffin weight hourly
space velocity is in the range of 0.01 to 100 hr-1.
[0060]The present disclosure describes an acidic porous material with total surface
area in range of 20-100 m2/g. The acidic porous material can selected from the group
consisting of zeolite, molecular sieve, amorphous silica-alumina, solid acids and
combinations thereof. In an embodiment of the present disclosure, there is provided an
acidic porous material as described herein, wherein the acidic porous material is
selected from the group consisting of ZSM-5, ZSM-22, ZSM-23, ZSM-35, ZSM-48,
SSZ-32, and combinations thereof.
[0061]In an embodiment of the present disclosure, there is provided an acidic porous
material as described herein, wherein the acidic porous material is selected from the
group consisting of ZSM-22, ZSM-23, and combinations thereof.
[0062]In an embodiment of the present disclosure, there is provided an acidic porous
material as described herein, wherein the acidic porous material is selected from the
group consisting of ZSM-22, ZSM-23, and combinations thereof having total surface
area range in of 20-60m2/gm.
[0063]In an embodiment of the present disclosure, there is provided an acidic porous
material as described herein, wherein the acidic porous material has BET surface area
range in of 20-60m2/gm.
[0064]In an embodiment of the present disclosure, there is provided an acidic porous material as described herein, wherein the acidic porous material has micropore surface area range in of 10-40m2/gm.
[0065]In an embodiment of the present disclosure, there is provided an acidic porous material as described herein, wherein the acidic porous material has external surface area range in of 5-25m2/gm.

[0066]The present disclosure describes a process for preparation of a low surface area
acidic porous material with appropriate number of pour mouths to ensure a good
balance of acidic and metallic sites.
[0067]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material with total surface area in range of 20-100 m2/g, the
process comprising; (a) preparing a zeolite support by hydrothermal heating of the
silica and alumina precursors along with a structure directing organic template in the
presence of an alkali; (b) removing the structure directing agent to obtain a porous
material; (c) converting the porous material to its acidic form by ion-exchanging with
precursor salts which release ammonia at 500 oC to obtain an acidic porous material
with total surface area in range of 20-100 m2/g.
[0068]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material as described herein, wherein the alumina precursor
is aluminium sulphate.18H2O.
[0069]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material as described herein, wherein the structure directing
organic template is hexamethylene diamine or DMF.
[0070]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material as described herein, wherein the alkali is
potassium hydroxide or sodium hydroxide.
[0071]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material as described herein, wherein the precursor salt is
ammonium nitrate. The organic structure directing agent can be removed at high
temperature by calcination and then the porous material can be converted to its acidic
form by exchanging the alkali metal cation to obtain the ammonium form of the zeolite
which when calcined results into corresponding acidic form.
[0072]In an embodiment of the present disclosure, there is provided a process for
preparing an acidic porous material as described herein, wherein the acidic porous
material has a total surface area in a range of 20-60m2/gm.

[0073]In an embodiment of the present disclosure, there is provided a process for preparing an acidic porous material as described herein, wherein the silica precursor is fumed silica.
[0074]In an embodiment of the present disclosure, there is provided a process for preparing an acidic porous material as described herein, wherein the acidic porous material is prepared from a mixture comprising: (a) a source of silicon, (b) a source of aluminium and / or gallium; (c) a source of monovalent cation; and (d) an organic structure directing agent. The synthesis is carried out under vigorous stirring in the range of 100 to 500 ppm.
[0075]In an embodiment of the present disclosure, there is provided a process for preparing noble metal loaded acidic form of the zeolite by exchanging some of the acidic sites with noble metal cations by use of certain noble metal precursor salts. Upon successful loading of noble metal, the acidic porous material can be obtained after filtration and drying. The dried acidic porous material can be combined with the binder material and formed into extrudates. The binder material can be selected from the group consisting of clays, silicas, aluminas, metal oxides, and mixtures thereof. The relative proportions of the zeolite and binder material may vary between 50 to 95 % of zeolite and about 5 to 50% of binder material. [0076]The catalyst composition so obtained by the process described herein has an optimum acid/metal balance leading to higher selectivity for isomerisation even at significantly high conversion values when used for hydroisomerization reaction. The catalyst of the present disclosure is used for hydroisomerization of long chain n-paraffins ranging from C12-C40. A catalyst with an excellent balance of metal/acidic sites is very much desirable for carrying out hydroisomerization reactions and is of prime importance to refining industry. The hydroisomerization process is responsible for the production of high octane gasoline; dewaxed diesel oil, and high quality lube oil with excellent cold low properties.
[0077]During the n-paraffin hydroisomerisation process, the paraffin first undergoes dehydrogenation to olefin at metallic site followed by isomerisation to branched olefin

at zeolite pore-mouth and then hydrogenation to form saturated branched paraffin which is desirable. If the number of acidic sites is very high, it would lead to the hydrocracking of multibranched isomers leading to loss in yields of the desirable products. Herein, the effect of optimum metal/acid sites and presence of pore mouths is described, which is again based on the total and external surface areas of the catalyst samples is shown.
[0078]Although the subject matter has been described in considerable detail with reference to certain embodiments thereof, other embodiments are possible.
EXAMPLES
[0079]The following examples are given by way of illustration of the present invention and should not be construed to limit the scope of present disclosure. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the claimed subject matter.
Example 1
Synthesis of low surface area ZSM-22:
[0080]A gel was prepared by mixing fumed silica, Aluminium sulphate. 18H2O, Hexamethylenediamine as the structure directing agent and KOH using molar gel composition of 27NH2(CH2)6NH2:12K2O:Al2O3:90SiO2:3670H2O. The gel was transferred to a 1000 ml autoclave and crystallized under hydrothermal conditions at 160 oC for 16 hrs. The XRD pattern of the synthesized ZSM-22 is shown in Figure 1 and the comparison of peak positions and intensities of low surface area and high surface area zeolite ZSM-22 are given in Table 1.
Comparative Example 1
Synthesis of high surface area ZSM-22:
A gel was prepared by mixing colloidal silica (40% SiO2), Aluminium sulphate.
18H2O, Hexamethylenediamine as the structure directing agent and KOH using molar

gel composition of 27NH2(CH2)6NH2:12K2O:Al2O3:90SiO2:3670H2O. The gel was transferred to a 1000 ml autoclave and crystallized under hydrothermal conditions at 160 oC for 16 hrs.
Table 1: Comparison of peak positions and intensities of low surface area and high surface area zeolite ZSM-22

High surface area z eolite Low surface area z eolite
2 theta d-spacing Relative intensity 2 theta d-spacing Relative intensity
8.22 10.70 59.03 8.16 10.82 50.59
10.21 8.65 9.76 10.19 8.67 9.80
12.83 6.89 12.45 12.77 6.93 13.27
16.54 5.35 8.64 16.60 5.33 8.37
19.51 4.54 10.88 19.45 4.56 10.64
20.44 4.34 100 20.41 4.35 100
24.32 3.65 75.42 24.25 3.66 78.46
24.69 3.60 59.03 24.64 3.61 67.58
25.75 3.45 34.45 25.71 3.46 39.71
26.68 3.34 6.95 26.66 3.34 6.81
27.13 3.28 8.08 27.10 3.28 7.05
33.04 2.71 3.25 32.96 2.71 3.22
35.73 2.51 18.40 35.65 2.51 20.09
36.97 2.43 8.97 36.90 2.43 9.56
38.13 2.35 5.49 38.08 2.36 5.98
Example 2
Synthesis of low surface area ZSM-23:

[0081]A gel was prepared by mixing HiSil-233D , Aluminium sulphate. 18H2O, Dimethylformamide as the structure directing agent and NaOH using molar gel composition of 120SiO2:1Al2O3:72NaOH:67DMF:4500H2O. The gel was transferred to a 1000 ml autoclave and crystallized under hydrothermal conditions at 160 oC for 46 hrs. The XRD pattern of the synthesized ZSM-23 is shown in Figure 2 and the comparison of peak positions and intensities of low surface area and high surface area zeolite ZSM-23 are given in Table 2.
Comparative Example 2
Synthesis of high surface area ZSM-23:
[0082]Sodium silicate (28.7% by weight (wt%) of Si02, 8.5% by wt. of Na2O and 62.9 % by wt. of H2O) and distilled water were mixed together in 50:50 weight ratio with stirring until the solution was clear, colorless, and uniform. Then a second solution was prepared by adding 2.4 grams of aluminum sulfate.16H2Oand 1.8 grams H2SO4 to 83.9 grams of distilled water under continuous stirring until complete dissolution, after which 13.1 grams of the Diquat-7 salt was added to the solution. A homogenous gel was obtained by adding the second solution to the sodium silicate solution under continous stirring. The gel was transferred to a 300 ml capacity stainless-steel autoclave and heated at 160 oC for about 4 days.
Table 2: Comparison of peak positions and intensities of low surface area and high surface area zeolite ZSM-23

High surface area zeolite Low surface area zeolite
2 theta d-spacing Relative intensity 2 theta d-spacing Relative intensity
8.492 10.404 82.32 8.36 10.57 92.19
11.73 7.539 33.89 11.68 7.57 39.73

20.01 4.434 90.72 19.95 4.44 98.43
21.3 4.168 79.04 21.30 4.16 82.52
23.23 3.826 83.26 23.13 3.84 89.31
24.28 3.663 100 24.18 3.67 100
26.47 3.364 37.70 26.4 3.37 45.01
35.938 2.4969 44.53 35.89 2.50 45.84
37.1 2.421 18.56 36.89 2.43 14.51
38.03 2.364 9.75 38.87 2.31 6.73
Example 3
Preparation of acidic form of zeolites:
[0083]All the crystallized samples were filtered, washed several times with de-ionized water, dried overnight at 110 oC. The sample was calcined in air at 540oC for 12 h. The proton form of the sample was obtained by exchanging the sample three times with ammonium nitrate under reflux at 90 oC for 3-4 hrs followed by calcination at 550 oC for 4 hrs.
Example 4:
Characterization of catalysts sample:
[0084]All the four catalysts were characterized for their textural properties. The textural properties of the samples were evaluated using nitrogen adsorption/desorption measurements utilizing ASAP 2020 (Micromeritics, USA) unit. Nitrogen adsorption/desorption isotherms were measured at 77 K after degassing samples below 10-3 torr at 573 K for 4 h. BET surface area (SBET)was estimated using adsorption data as per the ASTM method 4365 applicable for microporous solids. The total pore volume (Vt) was estimated from the amount adsorbed at a relative pressure of about 0.95. The external surface area (Sext) was estimated by employing DeBoer’s t-plot method. The values are given the table below.

Table 3: Textural properties of the zeolites samples synthesized using different silica sources

Sample BET surface area (m2/g) Micropore surface area (m2/g) External surface area (m2/g) Pore
volume
(cc/g)
Ex-1 56 37 19 0.012
Comp-Ex-1 220 169 49 0.074
Ex-2 24 16 8 0.009
Comp-Ex-2 226 190 36 0.14
Example 5:
Preparation of Platinum exchanged zeolite:
[0085]The proton form of all the samples was loaded with 0.5 wt% Pt using tetramine platinum (II) nitrate by ion-exchange procedure. The zeolite powder was suspended in an aqueous solution of tetramine platinum (II) nitrate at pH 10.5 with continuous stirring of the solution. The stirring was continued until there was no change in the pH. The solution was filtered and dried at 110 oC. Platinum content was estimated using Inductively coupled Plasma-Atomic emission spectroscopy. The sample was prepared by dissolving in mineral acids either hydrochloric acid or nitric acid and heated in a microwave oven at 160 oC for 30 minutes after which the solution was filtered and diluted to 100 ml with Millipore water and analysed for the Platinum content
Example 6:
Preparation of catalyst formulation:
Pt loaded zeolite samples (50 wt%) were mixed with 50 wt% low acidity alumina for the preparation of cylindrical shape extrudates with 1.6 mm diameter and approximately 3 mm length. Calcination of the extrudates was carried out at 400 oC under continuous flow of air for 5 h.

Example 7:
Hydroiomerisation of n-hexadecane:
[0086]All the catalyst recipes were tested for hydroisomerization selectivity using 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 130oC under nitrogen flow and reduced at 320oC 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 280-320oC, WHSV of 0.8-1.2 h-1, with H2/ HC ratio of 1000 at 60 bar pressure. The activity and selectivity data for different catalysts are tabulated in the Table 3.
Table 4: Conversion, Selectivity & Yield as a function of temperature (WHSV= 1.1g of n-Hexadecane /C g of catalyst hr, H2/HC = 10.9, p = 60 bar)

Catalyst Temperature (oC) % Conversion of n-C16H34 %Selectivity of isomers
Example 1 340 89.7 77.0
Comparative Example 1 340 99.5 67.4
Example 2 340 88.8 85.8
Comparative Example 2 340 99.6 68.3
Table 5: Distribution of multi and mono branched isomers obtained for various catalysts at constant conversion levels (WHSV = 1.1 hr-1)

Catalyst Temperature (oC) % Mono-branched isomers %Multi-branched isomers % Cracked products Mono to Multi ratio
Conversion at similar temperatures
Example 1 340 54.6 14.1 21.0 3.8
Comparative Example 1 340 46.9 24.5 32.1 1.9
Example 2 340 60.7 15.5 14 3.9
Comparative Example 2 340 44.2 24.1 31.3 1.8
[0087]The reaction temperature was adjusted such that all the catalysts investigated showed appreciable conversion n-hexadecane and the obtained results are compiled in Table 4. Such evaluation is important for envisaging a commercial process so that formed product can be effectively used as a blend stock. Accordingly, at similar temperatures, selectivities of 77% and 85% were obtained on catalysts of examples 1 and 2 while the high surface area catalysts of comparative examples 1 and 2 gave lesser selectivities for isomers even though they were more active than the low surface area catalysts of examples 1 and 2. The mono to multi ratio obtained on all the samples are given in Table 5. The results obtained indicate that the catalysts of examples 1 and 2 are useful for producing base oils with high VI and appreciably low pour points.
Advantages gained in the example illustrative compositions of this subject matter:
[0088]The present disclosure describes the use of microporous materials with low total surface area. The formation of optimal pore structure and not high surface area is

important for achieving high isomerisation selectivity at appreciable conversion levels. Thus, present disclosure illustrates synthesis of low surface area zeolites with the phase similar to ZSM-23 and ZSM-22 as confirmed by X-ray diffraction and use of these as supports for hydroisomerization of n-hexadecane and heavy paraffins to further produce dewaxed oil with excellent low temperature flow characteristics. Although the subject matter has been described in considerable detail with reference to certain examples and implementations thereof, other implementations are possible. As such, the spirit and scope of the appended claims should not be limited to the description of the preferred examples and implementations contained therein.

I/We Claim:
1. A catalyst composition comprising:
at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition;
at least one acidic porous material with total surface area in range of 20-100 m2/g; and a binder, wherein the at least one acidic porous material to the binder ratio is in the range of 95:5 to 35:65.
2. The catalyst composition as claimed in claim 1, wherein the at least one transitional metal is selected from the group consisting of Pt, Pd, and combinations thereof.
3. The catalyst composition as claimed in claim 1, wherein the at least one acidic porous material is selected from the group consisting of ZSM-22, ZSM-23, and combinations thereof.
4. The catalyst composition as claimed in claim 1, wherein the binder is selected from the group consisting of alumina, silica-alumina, silica-magnesia, silica-zirconia and combinations thereof.
5. The catalyst composition as claimed in claim 1, wherein the catalyst composition is used for isomerization of n-paraffins.
6. A process for producing a catalyst composition as claimed in claim 1, the
process comprising;
preparing at least one acidic porous material with total surface area in range of 20-100 m2/g;
contacting the at least one acidic porous material with at least one transitional metal to
obtain a transitional metal loaded acidic porous material;
contacting the transitional metal loaded acidic porous material with a binder to obtain a
extruded catalyst;
calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1
to 6 hours to obtain a catalyst composition, wherein the at least one acidic porous
material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65,

and at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition.
7. The process as claimed in claim 6, wherein the at least one transitional metal is selected from the group consisting of Pt, Pd, and combinations thereof.
8. The process as claimed in claim 6, wherein the binder is selected from the group consisting of alumina, silica, zirconia, titania, niobia, magnesia, silica-alumina, silica-magnesia, silica-zirconia, and combinations thereof.
9. A process for producing a catalyst composition as claimed in claim 1, the process comprising;
preparing a zeolite support by hydrothermal heating of the silica and alumina
precursors along with a structure directing organic template in the presence of an
alkali; removing the structure directing agent to obtain a porous material;
converting the porous material to its acidic form by ion-exchanging with precursor
salts which release ammonia at 500 oC to obtain an acidic porous material with total
surface area in range of 20-100 m2/g;
contacting the at least one acidic porous material with at least one transitional metal to
obtain a transitional metal loaded acidic porous material;
contacting the transitional metal loaded acidic porous material with a binder to obtain a
extruded catalyst;
calcining the extruded catalyst at a temperature range of 250-600°C for a period of 1 to
6 hours to obtain a catalyst composition, wherein the at least one acidic porous
material to the binder ratio in the catalyst composition is in the range of 95:5 to 35:65,
at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the
total weight of the composition.
10. A process for isomerization of paraffins comprising contacting the paraffins
and hydrogen with a a catalyst composition in a reactor;
wherein the catalyst composition comprises of at least one transitional metal in an amount in the range of 0.1% to 10% w/w of the total weight of the composition;

at least one acidic porous material with total surface area in range of 20-100 m2/g; and a binder, wherein the at least one acidic porous material to the binder ratio is in the range of 95:5 to 35:65.
11. The process as claimed in claim 10, wherein the at least one transitional metal is selected from the group consisting of Pt, Pd, and combinations thereof.
12. The process as claimed in claim 10, wherein the at least one acidic porous material is selected from the group consisting of ZSM-22, ZSM-23, and combinations thereof.
13. The process as claimed in claim 10, wherein the binder is selected from the group consisting of alumina, silica-alumina, silica-magnesia, silica-zirconia and combinations thereof.
14. The process as claimed in claim 10, wherein the paraffin is C12 to C40 linear paraffin.
15. A process for preparing an acidic porous material with total surface area in range of 20-100 m2/g, the process comprising;

(a) preparing a zeolite support by hydrothermal heating of the silica and alumina precursors along with a structure directing organic template in the presence of an alkali;
(b) removing the structure directing agent to obtain a porous material;
(c) converting the porous material to its acidic form by ion-exchanging with precursor salts which release ammonia at 500 oC to obtain an acidic porous material with total surface area in range of 20-100 m2/g.

16. The process as claimed in claim 15, wherein the acidic porous material has a total surface area in range of 20-60m2/gm.
17. An acidic porous material with total surface area in range of 20-100 m2/g.

18. The acidic porous material as claimed in claim 17, wherein the acidic porous material is selected from the group consisting of ZSM-22, ZSM-23, and combinations thereof having total surface area range in of 20-60m2/gm.