CATALYST

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority from European Patent Application No.

20179231.4 filed June 10, 2020, hereby incorporated by reference in its entirety.

FIELD OF INVENTION

[0002] The invention generally concerns reconstructing a spent dehydrogenation catalyst. In particular the invention concerns reconstructing a spent dehydrogenation catalyst containing a group 13 metal, a group 1 metal, a rare earth metal, a group 8-11 metal, and a catalyst support.

BACKGROUND OF THE INVENTION

[0003] Unsaturated hydrocarbons such as ethylene, propylene, butylene, isobutylene and styrene are important raw materials for multiple end products like polymers, rubbers, plastics, octane booster compounds, etc. It is expected that demand for light alkenes will continue to grow. Unsaturated hydrocarbons can be produced by dehydrogenation of corresponding hydrocarbons. There are many types of catalyst used for dehydrogenation of hydrocarbons. For example, the fixed-bed CATOFIN® process utilizes chromia-alumina catalysts. Disposal of chromium (Cr) catalyst poses problems to the environment and can be costly. Further, long-term exposure to Cr has been associated with cancer in humans.

[0004] Alternatives to Cr based catalysts have been attempted. For example, Gallium

(Ga) and platinum (Pt) based catalysts have been recognized as promising dehydrogenation catalysts due to their ability to activate the C-H bond. However, noble metal-containing (e.g., Pt-containing) dehydrogenation catalysts lose catalytic activity, e.g., productivity and/or selectivity during use and need to be regenerated periodically. The loss of the catalytic activity can be due to a number of phenomena including but not limited to, collapse of pore structure, phase change of support, deposition of carbonaceous residues, contamination by catalytic poisons or change in surface structure of the catalyst. Once productivity and/or selectivity decreases beyond certain limit a catalyst needs to be regenerated before it can be used again. With use of the catalysts over multiple reaction and regeneration cycles, catalyst regeneration with conventional regeneration process, i.e., regeneration process currently in use, only provides inadequate results. Without intended to be limited by the theory it is believed that loss of catalytic activity due to deposition of carbonaceous residues, i.e., coke formation of the catalyst can generally be regained by conventional catalyst regeneration process. However after use of the catalyst over multiple reaction and regeneration cycles catalyst surface area decreases due to collapse of pore structure and/or phase change. Conventional catalyst regeneration process cannot regain loss of catalytic activity due to loss of catalyst surface area. Thus there remains a need for additional catalyst regeneration or reconstruction methods.

SUMMARY OF THU INVENTION

[0005] A discovery has been made that provides a solution to at least some of the aforementioned problems associated with regeneration of dehydrogenation catalyst. As illustrated in a non-limiting manner in the Examples section, it was surprisingly found that catalysts reconstructed with the methods of current invention show comparatively higher hydrocarbon conversion and unsaturated hydrocarbon yield for hydrocarbon dehydrogenation. [0006] One aspect of the present invention is directed to a process for reconstructing a spent dehydrogenation catalyst to form a reconstituted catalyst and producing an unsaturated hydrocarbon. The process can include two steps, (a) and (b). In step (a) a spent dehydrogenation catalyst can be contacted with a first stream containing oxygen (O2), at a first temperature for a first duration in a reactor. In some aspects, the spent dehydrogenation catalyst can contain a group 13 metal, a group 1 metal, a rare earth metal, a group 8-11 metal, and a catalyst support. In step (b), the resulting catalyst from step (a) can subsequently be contacted with a second stream containing a hydrocarbon at a second temperature for a second duration in the reactor to dehydrogenate at least a portion of the hydrocarbon and produce a products stream containing an unsaturated hydrocarbon. The first temperature can be higher than the second temperature, and/or the first duration can be longer than the second duration. In some aspects, the process can further include a step (i), where step (i) is an intermediate step between steps (a) and (b). Step (i) can include contacting the catalyst resulting from step (a) with a third stream containing a purge gas, and for a process that includes the step (i), in step (b) the catalyst resulting from step (i), instead of the catalyst resulting from step (a), can be contacted with the second stream. In some aspects, in step (i) the catalyst resulting from step (a) can be contacted with the third stream under a third condition. In some aspects, the process can further include steps (c), (d), (e) and (f). In step (c) a catalyst resulting from step (b) can be contacted with the first stream at the first temperature for the first duration in the reactor. In step (d) a catalyst resulting from step (c) can subsequently be contacted with the third stream, in the reactor. In some aspects, in step (d) the catalyst resulting from step (c) can be contacted with the third stream under the third condition. In step (e) a catalyst resulting from step (d) can subsequently be contacted with the second stream at the second temperature for a second duration, in the reactor. In step (f) a catalyst resulting from step (e) can subsequently be contacted with the third stream, in the reactor. In some aspects, in step (f) the catalyst resulting from step (e) can be contacted with the third stream under the third condition.

[0007] In some aspects, the process can further include repeating step (c), (d), (e) and

(f) where for a repeated step (c) a catalyst resulting from an immediate prior step (f), instead of the catalyst resulting from step (b) is contacted with the first stream. In some aspects, the steps (c), (d), (e) and (f) can be repeated in cycles for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 200, 300, 400, 500, 600, 700, 800, 900 or 1000 times; or 3 to 100, or 5 to 50, or 5 to 25 times. In some aspects, the first duration can be least 1.5 times, such as 1.5, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8 to 4 times longer, than the second duration. In some aspects, the first temperature can be 600 °C, 610 °C, 620 °C, 630 °C, 640 °C,

650 °C, 660 °C, 670 °C, 680 °C, 690 °C, 700 °C, 710 °C, 720 °C, 730 °C, 740 °C, 750 °C,

760 °C, 770 °C, 780 °C, 790 °C to 800 °C. In some aspects, the second temperature can be

500 °C, 510 °C, 520 °C, 530 °C, 540 °C, 550 °C, 560 °C, 570 °C, 580 °C, 590 °C, 600 °C,

610 °C, 620 °C, 630 °C, 640 °C, 650 °C, 660 °C, 670 °C, 680 °C, 690 °C to 700 °C. In some aspects, the purge gas can be nitrogen (N2), helium (He), or steam, or any combination thereof. In some aspects, the reactor can be a fixed bed reactor. In some aspects, the first stream can be fed to the reactor at a gas hourly space velocity (GHSV) h ¹ of 100 to 10000 h ¹ . In some aspects, the second stream can fed to the reactor at a GHSV h ¹ of 100 to 10000 h ¹ . In some aspects, the third stream can be fed the reactor at a GHSV h ¹ of 100 to 10000 h ¹ . In some aspects, the third condition can include decreasing temperature, i.e., decreasing reactor temperature from the first temperature to the second temperature. In some aspects, the hydrocarbon in the second stream can be an alkane and/or an alkyl aromatic compound. In some aspects, the hydrocarbon can be ethane, propane, n-butane, iso-butane, or ethyl benzene or any combination thereof. In some aspects, the hydrocarbon in the second stream can be obtained from shale oil condensate, naphtha, liquefied petroleum gas (LPG), or stream cracking and/or catalytic cracking of a second hydrocarbons stream.

[0008] The spent dehydrogenation catalyst is not a freshly synthesized and/or an unused catalyst. The spent dehydrogenation catalyst can be formed from a dehydrogenation catalyst, after use of the dehydrogenation catalyst for a dehydrogenation reaction. The spent dehydrogenation catalyst can have a surface area that is less than a surface area of the dehydrogenation catalyst at its freshly synthesized state. The spent dehydrogenation catalyst can have an activity less than the activity of the dehydrogenation catalyst at its freshly synthesized state. In some aspects, activity of the spent dehydrogenation catalyst can be at least 5 %, at least 10 %, at least 15 %, at least 20 %, at least 25 %, at least 30 %, at least 40%, about 50% or at least 50 % less than the activity of the dehydrogenation catalyst at its freshly synthesized state. The spent dehydrogenation catalyst support can include alumina, zirconia, titania, or silica, or any combination thereof, preferably alumina. In some aspects, the group 13 metal can be gallium (Ga). In some particular aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 35 wt. % or 1 wt. % to 20 wt. % or 1 wt. % to 10 wt. % of a group 13 metal oxide, e.g. a gallium oxide, represented as Ga2Cb. In some aspects, the gallium oxide can be Ga2Cb. In some aspects, the group 1 metal can be potassium (K). In some aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 3 wt. % or 0.2 wt. % to 3 wt. % or 0.2 wt. % to 2 wt. % of a group 1 metal oxide, such as a potassium oxide, represented as K2O. In some aspects, the potassium oxide can be K2O. In some aspects, the rare earth metal can be cerium (Ce). In some aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 5 wt. % or 0.1 wt. % to 3 wt. % or 0.1 wt. % to 2 wt. % of a rare earth metal oxide, such as a Ce oxide, represented as Ce2Cb. In some aspects, the cerium oxide can be Ce2Cb. In some aspects, the group 8-11 metal can be platinum (Pt). In some aspects, the spent dehydrogenation catalyst can contain 0.001 wt. % to 0.2 wt. % or 0.001 wt. % to 0.08 wt. % or 0.002 wt. % to 0.07 wt. % of a group 8-11 metal oxide, such as a Pt oxide, represented as PtC . In some aspects, the Pt oxide can be PtC . In some aspects, the spent dehydrogenation catalyst can contain Ga, K, Pt and Ce on a catalyst support comprising alumina. In some aspects, the spent dehydrogenation catalyst can contain a Ga oxide, a K oxide, a Pt oxide and a Ce oxide on a catalyst support containing alumina. In some particular aspects, the spent dehydrogenation catalyst can contain 1 wt. % to 35 wt. % of a Ga oxide, represented as Ga2Cb, 0.1 wt. % to 3 wt. % of a K oxide, represented as K2O, 0.1 wt. % to 3 wt. % of a cerium oxide represented as Ce2Cb, 0.001 wt. % to 0.08 % wt. of a Pt oxide represented as PtC , and a catalyst support comprising alumina.

[0009] In some aspects, the dehydrogenation catalyst can be made with a shaping method. The method can include any one of, any combination of, or all of the following steps (x), (y), and/or (z). In step (x) a group 13 metal precursor, a group 1 metal precursor, a rare earth metal precursor and a group 8-11 metal precursor and a catalyst support precursor can be combined together to form an shapeable material. In some aspects, the support precursor can be in particulate form. The catalyst support precursor can be an alumina (AI2O3) precursor, a zirconia (ZrCh) precursor, a titania (TiCte) precursor, a silica (S1O2) precursor, or any combination thereof. In step (y), the shapeable material can be shaped to form a wet shaped material. In step (z) the wet shaped material can be dried and calcined to form the dehydrogenation catalyst. In some aspects, the shapeable material can be in form of a dough. In some aspects the shaping process can include a extrusion process.

[0010] In some aspects, the combining in step (x) can include dissolving the metal precursors in an aqueous solution to form a precursor solution, and adding the precursor solution to the support precursor to form the shapeable material. In some particular aspects, 0.1 ml to 0.7 ml of the precursor solution can be added per gram of the catalyst support precursor. In some particular aspects, the aqueous solution and/or the precursor solution can include a peptizing agent such as an acidic additive. pH of the aqueous solution and/or the precursor solution can be less than 7.

[0011] In some other aspects, the combining in step (x) can include, preparing a solid mixture containing the metal precursors and the catalyst support precursor in solid form, and adding an aqueous solution to the solid mixture to form the shapeable material. In some particular aspects, the aqueous solution can contain a peptizing agent such as an acidic additive. In some particular aspects, 0.1 ml to 0.7 ml of the aqueous solution can be added per gram (gm) of the solid mixture. The pH of the aqueous solution can be less than 7.

[0012] In another aspect, the combining in step (x) can include dissolving at least one metal precursor of step (x) in an aqueous solution to form a precursor solution, preparing a solid mixture containing at least one metal precursor of step (x) and the catalyst support precursor in solid form, and adding the precursor solution to the solid mixture to form the shapeable material. The at least one metal precursor of step (x) dissolved in the aqueous solution may or may not be the same as the at least one metal precursor of step (x) used to prepare the solid mixture. In some particular aspects, 0.1 ml to 0.7 ml of the precursor solution can be added per gm of the solid material. In some particular aspects, the aqueous solution can include a peptizing agent such as an acidic additive. The pH of the aqueous solution and/or the precursor solution can be less than 7.

[0013] In some aspects, the group 13 metal precursor can be a gallium (Ga) precursor.

In some particular aspects, the Ga precursor can be a Ga salt and/or a Ga compound. In some aspects, the group 1 metal precursor can be a potassium (K) precursor. In some particular aspects, the K precursor can be a K salt and/or a K compound. In some aspects, the rare earth metal precursor can be a cerium (Ce) precursor. In some particular aspects, the Ce precursor can be a Ce salt and/or a Ce compound. In some aspects, the group 8-11 metal precursor can be a platinum (Pt) precursor. In some particular aspects, the Pt precursor can be a Pt salt and/or a Pt compound. The catalyst support precursor can be an alumina (AI2O3) precursor, a zirconia (ZrCh) precursor, a titania (TiC ) precursor, a silica (S1O2) precursor, or any combination thereof. In some aspects, the support precursor can contain an alumina precursor. In some aspects, catalyst support precursor can contain a hydroxide such as aluminum hydroxide, zirconium hydroxide, titanium hydroxide, silicon hydroxide, or any combination thereof. In some aspects, the alumina precursor can be aluminum (iii) hydroxide. In some aspects, zirconia precursor can be zirconium (iv) hydroxide. In some aspects, titania precursor can be titanium (iv) hydroxide. In some aspects, the silica precursor can be silicon (iv) hydroxide. In some aspects, the catalyst support precursor does not contain an aluminum alkoxide such as aluminum isopropoxide. In some particular aspects, the aluminum hydroxide can be gibbsite, bayerite, nordstrandite, boehmite, diaspore, amorphous aluminum hydroxide, or any combination thereof. In some aspects, the drying condition in step (z) can include heating at a temperature 50 °C to 180 °C for 0.1 hours to 25 hours. In some aspects, the acidic additive can be nitric acid, aluminum nitrate, cerium nitrate, or gallium nitrate or any combination thereof. In some aspects, a metal precursor such as gallium nitrate can be the acidic additive and additional acidic additives such as nitric acid might not be added.

[0014] In some aspects, the calcining condition in step (z) can include heating in presence of air and/or oxygen at a temperature 500 °C to 1000 °C, preferably at 700 °C to 950 °C for 0.1 hours to 8 hours. In some aspects in step (y) the shapeable material is shaped by an extrusion process.

[0015] In some aspects the surface area of the spent dehydrogenation catalyst is about

60 % lower than that of the surface area of the dehydrogenation catalyst at its freshly synthesized state, an preferably about 50% lower. More preferably the surface area of the spent dehydrogenation catalyst is 60 % lower, or 50% lower, than that of the surface area of the dehydrogenation catalyst at its freshly synthesized state

[0016] In some aspects the spent dehydrogenation catalyst is formed by use of the alkane dehydrogenation catalyst in an alkane dehydrogenation

[0017] In some aspects, the invention relates to a process for reconstructing a spent alkane dehydrogenation catalyst and producing an unsaturated hydrocarbon. The process includes the steps of (a) contacting a spent dehydrogenation catalyst consisting a Ga oxide, an alkali metal oxide, preferably K oxide, a Pt oxide and a Ce oxide on a catalyst support selected from alumina, silica, zirconia, titania or combination thereof, with a first stream containing oxygen (O2), at a first temperature for a first duration in a reactor; and (b) subsequently contacting the catalyst resulting from step (a) with a second stream comprising an alkane at a second temperature for a second duration in the reactor to dehydrogenate at least a portion of the alkane and produce a products stream containing an unsaturated hydrocarbon; wherein the first temperature is higher than the second temperature and the first duration is at least equal to that of the second duration; wherein the spent dehydrogenation catalyst is formed by use of the alkane dehydrogenation catalyst in an alkane dehydrogenation reaction; and wherein the surface area of the spent dehydrogenation catalyst is about 60 % lower than that of the surface area of the dehydrogenation catalyst at its freshly synthesized state.

[0018] Other embodiments of the invention are discussed throughout this application.

Any embodiment discussed with respect to one aspect of the invention applies to other aspects of the invention as well and vice versa. Each embodiment described herein is understood to be embodiments of the invention that are applicable to other aspects of the invention. It is contemplated that any embodiment discussed herein can be implemented with respect to any method or composition of the invention, and vice versa. Furthermore, compositions and systems of the invention can be used to achieve methods of the invention.

[0019] The following includes definitions of various terms and phrases used throughout this specification.

[0020] The phrase “group 8-11 metal” refers to a metal belonging to group 8, 9, 10 or

11 of the periodic table.

[0021] The term “hydrocarbon” refers to i) aliphatic or aromatic, and ii) saturated or unsaturated organic compounds. In some aspects, the hydrocarbon can be entirely comprised of carbon and hydrogen. The term “unsaturated hydrocarbon” refers to unsaturated aliphatic, aromatic, or unsaturated organic compounds. In some aspects, the unsaturated hydrocarbon can be entirely comprised of carbon and hydrogen.

[0022] The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment, the terms are defined to be within 10%, preferably within 5%, more preferably within 1%, and most preferably within 0.5%.

[0023] The terms “wt.%,” “vol.%,” or “mol.%” refers to a weight percentage of a component, a volume percentage of a component, or molar percentage of a component, respectively, based on the total weight, the total volume of material, or total moles, that includes the component. In a non-limiting example, 10 grams of component in 100 grams of the material is 10 wt.% of component.

[0024] The term “substantially” and its variations are defined to include ranges within

10%, within 5%, within 1%, or within 0.5%. “Essentially free” includes as having no more than about 0.1% of a component. % can be wt., vol., or mol.

[0025] The terms “inhibiting” or “reducing” or “preventing” or “avoiding” or any variation of these terms, when used in the claims and/or the specification includes any measurable decrease or complete inhibition to achieve a desired result.

[0026] The term “effective,” as that term is used in the specification and/or claims, means adequate to accomplish a desired, expected, or intended result.

[0027] The use of the words “a” or “an” when used in conjunction with any of the terms

“comprising,” “including,” “containing,” or “having” in the claims, or the specification, may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0028] The words “comprising” (and any form of comprising, such as “comprise” and

“comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0029] The process and systems of the present invention can “comprise,” “consist essentially of,” or “consist of’ particular ingredients, components, compositions, steps, etc. disclosed throughout the specification. With respect to the transitional phrase “consisting essentially of,” in one non-limiting aspect, a basic and novel characteristic of the catalysts, compositions, and processes of the present invention are process of reconstruction a spent dehydrogenation catalyst.

[0030] Other objects, features and advantages of the present invention will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not meant to be limiting. Additionally, it is contemplated that changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1: Isobutane conversion (A), isobutylene selectivity (B) and isobutylene yield (C) of catalyst of example 1.

[0032] FIG. 2: Isobutane conversion (A), isobutylene selectivity (B) and isobutylene yield (C) of the accelerated aged catalyst (Example-3) i.e. spent dehydrogenation catalyst during reconstitution of the spent dehydrogenation catalyst by the process of Example-4, Example-5, Example-6, and Example-7.

[0033] FIG. 3: Catalyst bed temperature pattern of the accelerated aged catalyst

(Example-3) i.e. spent dehydrogenation catalyst during reconstitution of the spent dehydrogenation catalyst by the process of Example-4, Example-5,

DFTATEFD DESCRIPTION OF THF INVENTION

[0034] A discovery has been made that provides a solution to at least some of the aforementioned problems associated with regeneration of noble metal-containing dehydrogenation catalysts. In one aspect, disclosed is a process for reconstruction of a spent dehydrogenation catalyst. The process includes contacting a spent dehydrogenation catalyst with a first stream containing oxygen (O2) and subsequently with a second stream containing a hydrocarbon, where the spent dehydrogenation catalyst is contacted with the first stream at a higher temperature and for a longer duration than the second stream.

[0035] One aspect of the present invention is directed to a process for reconstructing a spent dehydrogenation catalyst and producing an unsaturated hydrocarbon. The process can include providing a spent dehydrogenation catalyst in a reactor and periodically contacting the catalyst in the reactor with a first stream containing Oxygen (O2), followed by contact with a second stream containing a hydrocarbon to form a reconstituted catalyst. The catalyst in the reactor can be contacted with the first stream at a first temperature and for a first duration. The catalyst in the reactor can be contacted with the second stream at a second temperature and for a second duration. A products stream containing an unsaturated hydrocarbon can be formed by the contact of the second stream with the catalyst in the reactor. The first duration can be longer than the second duration. In some aspects, the first duration can be at least 1.5 times longer or 1.5 to 4 times or at least any one of, equal to any one of, or between any two of 1.5, 1.6, 1.8, 2, 2.2, 2.4, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, and 4 times longer than the second duration. In some aspects, the first duration can be 8 min to 60 min or at least any one of, equal to any one of, or between any two of 8, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55 and 60 min. In some aspects, the second duration can be 5 min to 25 min or at least any one of, equal to any one of, or between any two of 5, 10, 15, 20, and 25 min. In some aspects, the first temperature can be higher than the second temperature. In some aspects, the first temperature can be at least 50 °C, or 50 °C to 100 °C or at least any one of, equal to any one of, or between any two of 55, 60, 65, 70, 75, 80, 85, 90, 95 and 100 °C higher than second temperature. In some aspects, the first temperature can be 600 °C, to 800 °C, at least any one of, equal to any one of, or between any two of 600 °C,

610 °C, 620 °C, 630 °C, 640 °C, 650 °C, 660 °C, 670 °C, 680 °C, 690 °C, 700 °C, 710 °C, 720 °C, 730 °C, 740 °C, 750 °C, 760 °C, 770 °C, 780 °C, 790 °C, and 800 °C. In some aspects, the second temperature can be 500 °C, to 700 °C, at least any one of, equal to any one of, or between any two of 500 °C, 510 °C, 520 °C, 530 °C, 540 °C, 550 °C, 560 °C, 570 °C, 580 °C, 590 °C, 600 °C, 610 °C, 620 °C, 630 °C, 640 °C, 650 °C, 660 °C, 670 °C, 680 °C, 690 °C to 700 °C. In some aspects, the catalyst in the reactor can be periodically contacted with the first stream and the second stream for a period of 1 to 1000 cycles or at least any one of, equal to any one of, or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 220, 240, 260, 280, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, and 1000 cycles, where a cycle includes contacting the catalyst in the reactor with the first stream and subsequently with the second stream, for cycle 1 the catalyst in the reactor is the spent dehydrogenation catalyst and for subsequent cycles, the catalyst in the reactor is a catalyst resulting from the immediate prior cycle. In some aspects, the first stream can be fed to the reactor at a GHSV h ¹ 100 to 10000 h ¹ or at least or at least any one of, equal to any one of, or between any two of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 and 10000 h ¹ . In some aspects, the second stream can be fed to the reactor at a GHSV h ¹ 100 to 10000 h ¹ or at least or at least any one of, equal to any one of, or between any two of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 and 10000 h ¹ .

[0036] In some aspects, a third stream containing a purge gas can be contacted with the catalyst in the reactor, between contacting the catalyst in the reactor with the first stream and the second stream. In some aspects, the third stream can be contacted with the catalyst in the reactor under a third condition. In some aspects, the third condition can include decreasing the temperature, i.e., decreasing the reactor temperature from the first temperature to the second temperature. In some aspects, the purge gas can be an inert gas such as nitrogen (N2), helium (He), steam, or any combination thereof. In some aspects, the third stream can be fed to the reactor at a GHSV h ¹ 100 to 10000 h ¹ or at least or at least any one of, equal to any one of, or between any two of 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, 3000, 4000, 5000, 6000, 7000, 8000, 9000 and 10000 h ¹ . The third stream can remove at least a portion of hydrocarbon and/or air from the reactor. In some aspects, the reactor can be a fixed bed reactor. [0037] The spent dehydrogenation catalyst can include a group 13 metal oxide, a group

1 metal oxide, a rare earth metal oxide, a group 8-11 metal oxide, and a catalyst support. In some aspects, the Group 13 metal can be Ga. In some aspects, the group 1 metal can be lithium (Li), sodium (Na), potassium (K), rubidium (Rb), or cesium (Cs). In some particular aspects, the group 1 metal can be K. In some aspects, the rare earth metal can be cerium (Ce). In some aspects, the group 8-11 metal can be ruthenium (Ru), rhodium (Rh), iridium (Ir), palladium (Pd), or platinum (Pt). In some particular aspects, the group 8-11 metal can be Pt.In some particular aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 35 wt. % or at least any one of, equal to any one of, or between any two of 0.1 wt. %, 0.5 wt. %, 1 wt. %, 2 wt. %, 3 wt. %, 4 wt. %, 5 wt. %, 6 wt. %, 7 wt. % 8 wt. %, 9 wt. %, 10 wt. %, 12 wt. %, 14 wt. %, 16 wt. %, 18 wt. %, 20 wt. %, 22 wt. %, 24 wt. %, 26 wt. %, 28 wt. %, 30 wt. %, 32 wt. %, 34 wt. %, and 35 wt. % of the group 13 metal oxide, such as Ga oxide, represented as Ga2Ch. In some aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 3 wt. % or at least any one of, equal to any one of, or between any two of 0.1 wt. %, 0.2 wt. %, 0.3 wt. %, 0.4 wt. %, 0.5 wt. %, 0.6 wt. %, 0.7 wt. %, 0.8 wt. %, 0.9 wt. %, 1 wt. %, 1.1 wt. %, 1.2 wt. %, 1.3 wt. %, 1.4 wt. %, 1.5 wt. %, 1.6 wt. %, 1.7 wt. %, 1.8 wt. %, 1.9 wt. %, 2 wt. %, 2.1 wt. %, 2.2 wt. %, 2.3 wt. %, 2.4 wt. %, 2.5 wt. %, 2.6 wt. %, 2.7 wt. %, 2.8 wt. %, 2.9 wt. %, and 3 wt. % of a group 1 metal oxide, such as a K oxide represented as K2O. In some aspects, the spent dehydrogenation catalyst can contain 0.1 wt. % to 5 wt. %, or 0.1 wt. % to 3 wt. % or at least any one of, equal to any one of, or between any two of 0.1 wt. %, 0.2 wt. %, 0.3 wt. %, 0.4 wt. %, 0.5 wt. %, 0.6 wt. %, 0.7 wt. %, 0.8 wt. %, 0.9 wt. %, 1 wt. %, 1.1 wt. %, 1.2 wt. %, 1.3 wt. %, 1.4 wt. %, 1.5 wt. %, 1.6 wt. %, 1.7 wt. %, 1.8 wt. %, 1.9 wt. %, 2 wt. %, 2.1 wt. %, 2.2 wt. %, 2.3 wt. %, 2.4 wt. %, 2.5 wt. %, 2.6 wt. %, 2.7 wt. %, 2.8 wt. %, 2.9 wt. %, 2.9 wt. %, 3 wt. %, 3.5 wt. %, 4 wt. %, and 5 wt. % of a rare earth metal oxide, such as a Ce oxide, represented as can be Ce2Ch. In some aspects, the spent dehydrogenation catalyst can contain 0.001 wt. % to 0.2 % wt % or 0.001 wt. % to 0.08 wt. % or at least any one of, equal to any one of, or between any two of 0.001 wt. %, 0.002 wt. %, 0.005 wt. %, 0.01 wt. %, 0.015 wt. %, 0.02 wt. %, 0.025 wt. %, 0.03 wt. %, 0.035 wt. %, 0.04 wt. %, 0.045 wt. %, 0.05 wt. %, 0.055 wt. %, 0.06 wt. %, 0.065 wt. %, 0.07 wt. %, 0.075 wt. %, 0.08 wt. %, 0.1 wt. %, 0.15 wt. % and 0.2 wt. %, of a group 8-11 metal oxide, such as a Pt oxide represented as PtCh. In some aspects, the catalyst support can contain alumina. In some particular aspects, the alumina can be gamma-alumina, eta-alumina, delta-alumina, theta-alumina, rho-alumina, chi-alumina, kappa-alumina or any combination thereof. In some aspects, the catalyst support can include alumina, zirconia, titania, or silica, or any combination thereof, preferably alumina.

[0038] In some the dehydrogenation catalyst can be prepared by a shaping method. The method can include any one of, any combination of, or all of steps (x), (y), and/or (z). In step (x) a group 13 metal precursor, and a group 1 metal precursor can be combined with a catalyst support presursor thereof to form a shapeable material. In some aspects, in step (x) a rare earth metal precursor, and a group 8-11 metal precursor along with the group 13 metal precursor, the group 1 metal precursor can be combined with the catalyst support presursor to form the shapeable material. In step (y), the shapeable material can be shaped to form an wet shaped material. In step (z) the wet shaped material can be dried and calcined to form the dehydrogenation catalyst. In some aspects, the group 13 metal can be gallium (Ga) and the group 13 metal precursor can be gallium hydroxide (Ga(OH)3), gallium nitrate (Ga(NCh)3), gallium fluoride (GaBn), gallium bromide (GaBn), gallium iodide (Gab), gallium sulfate (Ga2(SC>4)3), gallium oxide (Ga2Cb), gallium citrate (GaCLtbO?) or gallium acetate (Ga(C2H302)3) or any combination thereof. In some aspects, the group 1 metal can be lithium (Li), sodium (Na), potassium (K), rubidium (Rb), or cesium (Cs), or any combination thereof. In some aspect, the group 1 metal can be K and the group 1 metal precursor can be potassium nitrate (KNCh), potassium acetate (KC2H3O2), potassium citrate (K3C6H5O7), potassium oxalate (C2K2O4), potassium carbonate (K2CO3), or potassium hydroxide (KOH) or any combination thereof. In some aspects, the rare earth metal can be cerium (Ce) and the rare earth metal precursor can be cerium nitrate cerium hydroxide (Ce(OH)3), cerium oxide (CeCh) such as colloidal cerium oxide, (Ce(NCh)3), cerium acetate (CeCLtbO?), ammonium ceric nitrate ((NH4)2Ce(N03)6), ammonium ceric sulfate ((NH4)4Ce(S04)4), ceric oxide (CeCh), or ceric chloride (CeCb) or any combination thereof. In some aspects, the group 8-11 metal can be ruthenium (Ru), rhodium (Rh), iridium (Ir), palladium (Pd), or platinum (Pt), or any combination thereof. In some aspects, the group 8-11 metal can be Pt and the group 8-11 metal precursor can be tetraamineplatinum nitrate (Pt(NH3)4(N03)2), platinum(II) acetate Pt(C2H302)2, platinum(II) chloride (PtCb), potassium tetracholroplatinate (K2PtCl4), ammonium hexachloroplatinate ((NH4)2[PtCl6]), chloroplatinic acid (H2PtCl6), platinum dioxide (PtCk), or potassium hexachloroplatinate (K2PtCl6) or any combination thereof. In some aspects, the catalyst support precursor can contain an alumina precursor, a zirconia precursor, a titania precursor, a silica precursor, or any combination thereof. In some aspects, the alumina precursor can be aluminum hydroxide (Al(OH)3). In some aspects, the zirconia precursor can be zirconium(iv) hydroxide, zirconium(iv) oxynitrate, zirconium(iv) oxychloride, zirconium (iv) chloride, zirconium (iv) oxide such as colloidal zirconium oxide or any combination thereof. In some aspects, the titania precursor can be titanium (iv) hydroxide, titanium (iv) chloride, titanium (iv) oxide such as colloidal titanium dioxide, or any combination thereof. In some aspects, the silica precursor can be orthosilicic acid (Si(OH)4), alkali metal silicates, colloidal silica, silica gel or any combination thereof. In some aspects, the catalyst support precursor does not include an aluminum alkoxide such as aluminum isopropoxide, a zirconium alkoxide such as zirconium (iv) propoxide, a titanium alkoxide such as titanium (iv) isopropoxide, and/or a silicon alkoxide such as tetraethyl orthosilicate. In some aspects, the catalyst support precursor does not include aluminum, zirconium, titanium and/or silicon compound that liberates organic compounds upon hydrolysis. In some aspects, the calcination process does not liberates volatile organic compounds.

[0039] In some aspects, the combination in step (x) can include dissolving the metal precursors in an aqueous solution to form a precursor solution and adding the precursor solution to the catalyst support precursor. In some aspects, 0.1 ml to 0.7 ml or at least any one of, equal to any one of, or between any two of 0.1 ml, 0.15 ml, 0.2 ml, 0.25 ml, 0.3 ml, 0.35 ml, 0.4 ml, 0.45 ml, 0.5 ml, 0.55 ml, 0.6 ml, 0.65 ml, and 0.7 ml, of the precursor solution can be added per gm of the catalyst support precursor. In some aspects, the aqueous solution and/or the precursor solution can contain a peptizing agent. The peptizing agent is added to get catalyst with required mechanical strength. In some aspects, the peptizing agent can be an acidic additive. In some aspects, the acidic additive can be nitric acid, aluminum nitrate, cerium nitrate, or gallium nitrate or any combination thereof. In some aspects, the aqueous solution and/or the precursor solution can contain 1 wt. % to 40 wt. % or at least any one of, equal to any one of, or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 wt. % of nitric acid. In some particular aspects, a Ga precursor, a K precursor, a Ce precursor and a Pt precursor can be dissolved in an aqueous solution containing 1 to 40 wt. % of a peptizing agent, e.g., nitric acid to form a precursor solution. In some particular aspects, gallium nitrate Ga(N03)3, tetraamineplatinum nitrate (Pt(NH ₃ )4(N03)2), cerium nitrate Ce(NCb)3, and potassium nitrate (KNCb) can be dissolved in a aqueous solution containing 1 to 40 wt. % of peptizing agent, e.g., nitric acid to form a precursor solution.

[0040] In some aspects, the combination in step (x) can include preparing a solid mixture containing the metal precursors and the catalyst support precursor in solid form and adding an aqueous solution to the solid mixture to form the shapeable material. In some aspects, 0.1 ml to 0.7 ml or at least any one of, equal to any one of, or between any two of 0.1 ml, 0.15 ml, 0.2 ml, 0.25 ml, 0.3 ml, 0.35 ml, 0.4 ml, 0.45 ml, 0.5 ml, 0.55 ml, 0.6 ml, 0.65 ml, and 0.7 ml of the aqueous solution can be added per gm of the solid mixture. In some aspects, the aqueous solution can contain a peptizing agent. In some aspects, the peptizing agent can be an acidic additive. In some aspects, the acidic additive can be nitric acid, aluminum nitrate, cerium nitrate, gallium nitrate, or a combination thereof. In some aspects, the aqueous solution can contain 1 wt. % to 40 wt. % or at least any one of, equal to any one of, or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, to 40 wt. % of a peptizing agent, e.g., nitric acid.

[0041] In some aspects, combination in step (x) can include dissolving at least one metal precursor from step (x) in an aqueous solution to form a precursor solution, preparing a solid mixture containing at least one metal precursor from step (x) and the catalyst support precursor in solid form, and adding the precursor solution to the solid mixture to form the shapeable material. In some particular aspects, the group 13 metal precursor, the group 1 metal precursor, and the rare metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 8-11 metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor, the group 1 metal precursor, and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the rare earth metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor, the rare earth metal precursor, and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor and the catalyst support precursor. In some particular aspects, the group 1 metal precursor, the rare earth metal precursor, and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 13 metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor and the group 1 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 8-11 metal precursor, the rare earth metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor and the rare earth metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor, the group 8-11 metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor, the rare earth metal precursor and the catalyst support precursor. In some particular aspects, the group 1 metal precursor and the rare earth metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 13 metal precursor, the group 8-11 metal precursor and the catalyst support precursor. In some particular aspects, the group 1 metal precursor and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 13 metal precursor, the rare earth metal precursor and the catalyst support precursor. In some particular aspects, the rare earth metal precursor and the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 13 metal precursor, the group 1 metal precursor and the catalyst support precursor. In some particular aspects, the group 1 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 13 metal precursor, the rare earth metal precursor, the group 8-11 metal precursor and the catalyst support precursor. In some particular aspects, the rare earth metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor, the group 13 metal precursor, the group 8-11 metal precursor and the catalyst support precursor. In some particular aspects, the group 8-11 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor, the rare earth metal precursor, the group 13 metal precursor and the catalyst support precursor. In some particular aspects, the group 13 metal precursor can be dissolved in the aqueous solution to form the precursor solution, and the solid mixture can contain the group 1 metal precursor, the rare earth metal precursor, the group 8-11 metal precursor and the catalyst support precursor. In some aspects, 0.1 ml to 0.7 ml or at least any one of, equal to any one of, or between any two of 0.1 ml, 0.15 ml, 0.2 ml, 0.25 ml, 0.3 ml, 0.35 ml, 0.4 ml, 0.45 ml, 0.5 ml, 0.55 ml, 0.6 ml, 0.65 ml, and 0.7 ml of the precursor solution can be added per gm of the solid mixture. In some aspects, the aqueous solution and/or the precursor solution can contain a peptizing agent. In some aspects, the peptizing agent can be an acidic additive. In some aspects, the acidic additive can be nitric acid, nitric acid, aluminum nitrate, cerium nitrate, or gallium nitrate or any combination thereof. In some aspects, the acid can be nitric acid. In some aspects, the aqueous solution can contain 1 wt. % to 40 wt. % or at least any one of, equal to any one of, or between any two of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, to 40 wt. % of peptizing agent e.g. nitric acid.

[0042] The shapeable material of the current invention can be a sufficiently pliable semisolid mass that can be shaped with a shaping process to form a wet shaped material having a desired geometric shape. In some aspects, the shaping process can be an extrusion process, the shapeable material can be an extrudable material, and the wet shaped materiel can be a wet extrudate. The extrudable material can be pushable and/or drawable through an extrusion die and/or an orifice to form the wet extrudate having a desired shape or cross-sectional shape or configuration. The extrusion of the extrudable material can be performed with any suitable extruder and/or suitable extrusion die and/or orifice, as will be appreciated by those of skill. The die opening and the cross-section of the wet extrudate can have any suitable regular and/or irregular shape. Non-limiting shapes include circular, oval, square, rectangular, pentagonal, hexagonal, rounded square, rounded rectangular, rounded pentagonal, rounded hexagonal, and star shaped. The extrusion die can have one or more opening(s). The extrusion process can be carried out using ram extruder, single screw extruder or twin screw extruder. In some particular aspects, the extrusion die can have circular opening with 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 to 10 mm diameter. In some aspects, the extrusion can be performed at room temperature, however extruder barrel temperature can vary. The extruder speed may depend on type of extruder and manufacturer. The dehydrogenation catalyst made with the shaping method can contain macro sized particles. In some aspects, the macro-sized particles can have at least one dimension such as length, width, height, diameter equal to or greater than 0.5 mm. The dehydrogenation catalyst e.g. the macro-sized particles of the dehydrogenation catalyst can have a desired geometric shape. The desired geometric shape includes but is not limited to spherical, cube, cuboidal, cylindrical, puck, oval, buckyball, and oblong shapes. Macro-sized particles having other shapes can also be made. In some aspects, the macro-sized particles can have cylindrical shape with a circular, elliptical, ovular, triangular, square, rectangular, pentagonal, or hexagonal cross section, although cylindrical shaped macro-sized particles having a cross- section of other shapes can also be made. In some aspects, the macro-sized particles can have mechanical strength to support its weight and/or withstand the shaping step, drying step, and/or calcination step. In some aspects, the dehydrogenation catalyst e.g. the macro-sized particles of the shaped dehydrogenation catalyst can have an average radial crush strength greater than about 0.5 daN/mm, or preferably greater than about 1 daN/mm, such as 0.5 daN/mm to 3.5 daN/mm, preferably 1 daN/mm to 3.5 daN/mm. In some aspects, the macro-sized particles of the shaped dehydrogenation catalyst can have a particle size i.e. diameter 0.5 mm to 5 mm, or at least any one of, equal to any one of, or between any two of 0.5, 1, 2, 3, 4, and 5 mm. In some aspects, the macro-sized particles of the shaped dehydrogenation catalyst can have a diameter 0.5 mm to 10 mm, or at least any one of, equal to any one of, or between any two of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 and 10 mm and/or a length 2 mm to 15 mm or at least any one of, equal to any one of, or between any two of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15 mm. [0043] In some aspects, drying in step (z) can include heating at a temperature 50 °C to

180 °C or at least any one of, equal to any one of, or between any two of 70 °C, 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C, 150 °C, 160 °C, 170 °C and 180 °C for 0.1 hour (h) to 25 h or at least any one of, equal to any one of, or between any two of 0.1 h, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 21 h, 22 h, 23 h, 24 h and 25 h. In some aspects, calcining in step (z) can include heating in presence of air and/or O2 at a temperature of 500 °C to 1000 °C or at least any one of, equal to any one of, or between any two of 500 °C, 550 °C, 600 °C, 650 °C, 700 °C, 750 °C, 800 °C, 850 °C, 900 °C, 950 °C and 1000 °C for 0.1 h to 8 h or at least any one of, equal to any one of, or between any two of 0.1 h, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, and 8 h. In some aspects, the wet extrudate can be dried at a temperature about 120 °C for about 16 hours in an air oven followed by calcination at about 750 °C for about 2 hours with heating rate about 5 °C/min in the presence of air at flow rate about 8 ml gamin ¹ to form the dehydrogenation catalyst.

EXAMPLES

[0044] As part of the disclosure of the present invention, specific examples are included below. The examples are for illustrative purposes only and are not intended to limit the invention. Those of ordinary skill in the art will readily recognize parameters that can be changed or modified to yield essentially the same results.

Example-1 (Catalyst preparation) [0054] The catalyst was prepared by co-extrusion method using peptizing agent.

Gallium nitrate hydrate (Ga(NCb)3.xH20), tetraamineplatinum nitrate (Pt(NH3)4(N03)2), cerium nitrate hexahydrate (Ce(N03)3.6H20), potassium nitrate (KNCb) and boehmite (G-250) materials were used as precursors of gallium, platinum, cerium, potassium and alumina, respectively. Prior to preparing catalyst, metal salts containing diluted nitric acid solution was prepared. To 36 ml of 70 wt % nitric acid water added and made the solution to 500 ml. To prepare metal salts containing nitric acid solution, 8.25 g of gallium nitrate (anhydrous basis), 5 mL of 1.5 % tetraamineplatinum nitrate solution (1.5 g /100 mL solution), 2.32 g of cerium nitrate hexahydrate, and 1.466 g potassium nitrate salts were dissolved in 60 ml of above nitric acid solution and formed clear solution. The formed solution was used as peptizing agent for the preparation of catalyst. To boehmite powder (94.66 g) was added dropwise nitric acid solution containing metal salts and the mixture was mixed for about 30 minutes. The obtained dough was then extruded using a lab extruder (Sunsai), using a die having circular openings with 3.5 mm diameter. The prepared wet extrudates were dried at 120 °C for 16 hours in air oven. The dried sample was then calcined at 750 °C for 2 hours with heating rate 5 °C/min in the presence of air (flow rate = 8 ml gamin ¹ ) in down flow tubular reactor. After calcination, the catalyst was cooled in presence of air and was stored in an airtight container. The final calculated composition of the catalyst corresponds to Ga2Cb - 4 wt. %, Pt - 500 ppm, Ce203 - 1.2 wt. %, K2O - 0.9 wt. % with remaining part comprising AI2O3. The obtained extrudate catalyst (size: ~3 mm diameter and ~6 - 8 mm length) having surface area of 213 m ² /g was used for isobutane dehydrogenation reaction.

Example-2 (Catalyst Testing)

[0045] The catalyst prepared in Example 1 were tested for dehydrogenation of isobutane to isobutylene. The dehydrogenation reaction was carried out in a tubular fixed-bed quartz reactor. The details of catalyst loading and reactor were as follows: catalyst weight = 4.0 g, catalyst particle size = 0.4 - 0.5 mm, reactor ID = 16 mm, reactor OD = 19 mm. Isobutane (99.9 vol. %) was used as the feed. Quartz chips with size of 1 to 1.4 mm were loaded above the catalyst bed. Nitrogen purge separated between dehydrogenation and regeneration/oxidation steps. The total feed flow in the dehydrogenation step is corresponds to GHSV = 600 mLh^g ¹ . The reactor outlet gases were analyzed by online gas chromatograph (Agilent 6890, Agilent Scientific Instruments, USA) equipped with a flame ionization detector for hydrocarbon analysis and thermal conductivity detector for hydrogen analysis. The reactant and products flow rates were measured using Ritter type wet gas flow meter. The reactor was operated at atmospheric pressure in a cyclic mode with the following steps:

1. Oxidation in air at 650°C for 20 min;

2. Purge with nitrogen at 650°C for 5 min;

3. Cooling with nitrogen from 650°C to 585°C and hold for 20 min at 585°C for temperature stabilization;

4. Start isobutane feed flow for dehydrogenation at 585°C for 21 min; and

5. GC analysis at 20 ^th minute from the start of the isobutane feed.

6. Steps 1-5 were repeated for 43 cycles.

[0046] The performance of the catalyst is shown in Figure-1 A (conversion), B (selectivity) and C (yield). The results clearly show that the initial isobutane conversion is around 62% and decreased to -55% after 15 ^th cycle and without significant change in conversion afterwards. Isobutylene selectivity is almost constant at 89% for all cycles and yield is decreased from 55% to 48% from 1 ^st to 15 ^th cycle and without significant change in yield afterwards.

Example -3 (Accelerated aging)

[0047] The catalyst of example 1, after the 43 cycles, as described in Example 2, was subjected to accelerated aging conditions to obtain a spent catalyst. Accelerated aging was carried out at 820 °C for 3 days. The other details are as follows: catalyst weight = 4.0 g, GHSV for air = 1200 mL g ¹ h ¹ , GHSV for N2 = 1500 mL g ¹ h ¹ and GHSV for isobutane = 400 mL g ¹ h ¹ .

1. Oxidation in air at 820°C for 15 min;

2. Purge with nitrogen at 820°C for 3 min;

3. Isobutane feed flow for dehydrogenation at 820°C for 3 min;

4. Purge with nitrogen at 820°C for 3 min;

5. Steps 1-4 were repeated for 135 cycles (3 days).

Example -4

(Spent dehydrogenation catalyst regeneration, comparative example )

[0048] Catalyst performance was carried out under normal reaction conditions for spent dehydrogenation catalyst (after accelerated aging, Example 3). The dehydrogenation activity of the catalyst was measured in a tubular fixed-bed quartz reactor. The details of catalyst loading and reactor were as follows: catalyst weight = 4.0 g, catalyst particle size = 0.4 - 0.5 mm, reactor ID = 16 mm, reactor OD = 19 mm. Isobutane (99.9 vol. %) was used as the feed. Quartz chips with size of 1 - 1.4 mm were loaded above the catalyst bed. Nitrogen purge separated between dehydrogenation and regeneration/oxidation steps. The total feed flow in the dehydrogenation step is corresponds to GHSV = 600 mLh^g ¹ . The reactor outlet gases were analyzed by online gas chromatograph (Agilent 6890, Agilent Scientific Instruments, USA) equipped with a flame ionization detector for hydrocarbon analysis and thermal conductivity detector for hydrogen analysis. The reactant and products flow rates were measured using Ritter type wet gas flow meter. The reactor was operated at atmospheric pressure in a cyclic mode with the following steps:

1. Oxidation in air at 650°C for 20 min;

2. Purge with nitrogen at 650°C for 5 min;

3. Cooling with nitrogen from 650°C to 585°C and hold for 20 min at 585°C for temperature stabilization;

4. Start isobutane feed flow for dehydrogenation at 585°C for 21 min; and

5. GC analysis at 20 ^th minute from the start of the isobutane feed.

6. Steps 1 to 5 were repeated for 15 cycles.

[0049] Catalytic performance is shown in Figure-2A (conversion), B (selectivity) and

C (yield). The results clearly show that the initial isobutane conversion is around 59% and decreased to 46% at 15 ^th cycle. Average isobutylene selectivity is -92% for all cycles and yield is decreased from -51% to -42% from 1 to 15 ^th cycle.

[0050] The regenerated discharged catalyst from the reactor having a surface area of

128 m ² /g is used for Example 5, 6 and 7.

Example-5

(Spent dehydrogenation catalyst regeneration)

[0051] Catalyst performance was carried out under normal reaction conditions for the spent dehydrogenation catalyst (after accelerated aging, Example 3). The dehydrogenation activity of the catalyst was measured in a tubular fixed-bed quartz reactor. The details of catalyst loading and reactor were as follows: catalyst weight = 4.0 g, catalyst particle size = 0.4 - 0.5 mm, reactor ID = 16 mm, reactor OD = 19 mm. Isobutane (99.9 vol. %) was used as the feed. Quartz chips with size of 1 - 1.4 mm were loaded above the catalyst bed. Nitrogen purge separated between dehydrogenation and regeneration/oxidation steps. The total feed flow in the dehydrogenation step is corresponds to GHSV = 600 mLh^g ¹ . The reactor outlet gases were analyzed by online gas chromatograph (Agilent 6890, Agilent Scientific Instruments, USA) equipped with a flame ionization detector for hydrocarbon analysis and thermal conductivity detector for hydrogen analysis. The reactant and products flow rates were measured using Ritter type wet gas flow meter. The reactor was operated at atmospheric pressure in a cyclic mode with the following steps:

1. Oxidation in air at 650°C for 60 min;

2. Purge with nitrogen at 650°C for 5 min;

3. Cooling with nitrogen from 650°C to 585°C and hold for 20 min at 585°C for temperature stabilization;

4. Start isobutane feed flow for dehydrogenation at 585°C for 21 min; and

5. GC analysis at 20th minute from the start of the isobutane feed.

6. Steps 1-5 were repeated for 15 cycles.

[0052] Catalytic performance of catalyst is shown in Figure-2A (conversion), B

(selectivity) and C (yield). The results clearly show that the initial isobutane conversion is around 62% and decreased to ~51% at 15 ^th cycle. Average isobutylene selectivity is -92% for all cycles and yield is decreased from -55% to -48% from 1 to 15 ^th cycle.

Example-6

(Spent dehydrogenation catalyst regeneration)

[0053] Catalyst performance was carried out under normal reaction conditions for the spent dehydrogenation catalyst (after accelerated aging, Example 3). The dehydrogenation activity of the catalyst was measured in a tubular fixed-bed quartz reactor. The details of catalyst loading and reactor were as follows: catalyst weight = 4.0 g, catalyst particle size = 0.4 - 0.5 mm, reactor ID = 16 mm, reactor OD = 19 mm. Isobutane (99.9 vol. %) was used as the feed. Quartz chips with size of 1 - 1.4 mm were loaded above the catalyst bed. Nitrogen purge separated between dehydrogenation and regeneration/oxidation steps. The total feed flow in the dehydrogenation step is corresponds to GHSV = 600 mLh^g ¹ . The reactor outlet gases were analyzed by online gas chromatograph (Agilent 6890, Agilent Scientific Instruments, USA) equipped with a flame ionization detector for hydrocarbon analysis and thermal conductivity detector for hydrogen analysis. The reactant and products flow rates were measured using Ritter type wet gas flow meter. The reactor was operated at atmospheric pressure in a cyclic mode with the following steps:

1. Oxidation in air at 700°C for 20 min; 2. Purge with nitrogen at 700°C for 5 min;

3. Cooling with nitrogen from 700°C to 585°C and hold for 20 min at 585°C for temperature stabilization;

4. Start isobutane feed flow for dehydrogenation at 585°C for 21 min; and

5. GC analysis at 20th minute from the start of the isobutane feed.

6. Steps 1-5 were repeated for 15 cycles.

[0054] Catalytic performance of catalyst is shown in Figure-2A (conversion), B

(selectivity) and C (yield). The results clearly show that the initial isobutane conversion is around -57% and stable for all cycles. Average isobutylene selectivity is (-92%) and yield (-53%) constant for all cycles.

Example-7

(Spent dehydrogenation catalyst regeneration)

[0055] Catalyst performance was carried out under normal reaction conditions for the spent dehydrogenation catalyst (after accelerated aging, Example 3). The dehydrogenation activity of the catalyst was measured in a tubular fixed-bed quartz reactor. The details of catalyst loading and reactor were as follows: catalyst weight = 4.0 g, catalyst particle size = 0.4 - 0.5 mm, reactor ID = 16 mm, reactor OD = 19 mm. Isobutane (99.9 vol. %) was used as the feed. Quartz chips with size of 1 - 1.4 mm were loaded above the catalyst bed. Nitrogen purge separated between dehydrogenation and regeneration/oxidation steps. The total feed flow in the dehydrogenation step is corresponds to GHSV = 600 mLh^g ¹ . The reactor outlet gases were analyzed by online gas chromatograph (Agilent 6890, Agilent Scientific Instruments, USA) equipped with a flame ionization detector for hydrocarbon analysis and thermal conductivity detector for hydrogen analysis. The reactant and products flow rates were measured using Ritter type wet gas flow meter. The reactor was operated at atmospheric pressure in a cyclic mode with the following steps:

1. Oxidation in air at 700°C for 60 min;

2. Purge with nitrogen at 700°C for 5 min;

3. Cooling with nitrogen from 700°C to 585°C and hold for 20 min at 585°C for temperature stabilization;

4. Start isobutane feed flow for dehydrogenation at 585°C for 21 min; and

5. GC analysis at 20th minute from the start of the isobutane feed.

6. Steps 1-5 were repeated for 10 cycles. [0056] Catalytic performance of catalyst is shown in Figure-2A (conversion), B

(selectivity) and C (yield). The results clearly show that the initial isobutane conversion is around -57% and stable for all cycles. Average isobutylene selectivity is (-92%) and yield (-53%) constant for all cycles. [0057] The results clearly show that isobutane conversion increased around 5% for dehydrogenation catalyst activated i.e. reconstituted by increasing regeneration time from 20 min to 60 min and regeneration temperature from 650 to 700 °C. Catalyst bed temperature pattern during reconstitution for Example-4, and Example-5 is shown in Figure 3. The pattern clearly show that exothermicity is being completing within 10 min of regeneration, which could be due to coke burning. Hence, an improvement of performance for longer regeneration could be due to surface restructuring of the catalyst.

[0058] Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.