Catalysts and processes for the dehydrogenation of alkanes to olefins.

Abstract

A method for converting alkanes to olefins includes contacting a feed stream comprising an alkane with an oxidative dehydrogenation catalyst without a tellurium catalyst in a reaction zone and dehydrogenating the alkane without a co-feed of oxygen to produce a product stream comprising an olefin. The oxidative dehydrogenation catalyst has the formula: Mo v V w Nb y Bi z O x (wherein v is 1.0, w is 0.1-0.5, y is 0.001-0.3, A is Bi, Sb, Pr, or a mixture thereof, z is 0.01-0.3, and x balances the charge of the structure). α It has a crystalline structure with the Pba2-32 space group characterized by reflections determined as follows using X-ray diffraction (XRD): [Table 1] JPEG2024532841000009.jpg41170

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 236,003, filed August 23, 2021, and entitled “CATALYST AND PROCESS FOR THE DEHYDROGENATION OF ALKANES TO OLEFINS,” which is incorporated by reference herein in its entirety.

[0002] FIELD OF THEINVENTION This specification relates generally to catalysts and processes for the dehydrogenation of alkanes to olefins, such as catalysts and processes for converting ethane to ethylene. [Background technology]

[0003] Conventional catalysts for converting alkanes to olefins, such as ethane to ethylene and acetic acid, are based on molybdenum (Mo), vanadium (V), and niobium (Nb) and include cocatalysts such as calcium (Ca), sodium (Na), antimony (Sb), or tellurium (Te). In particular, Te is a common cocatalyst included in conventional catalysts. Processes using such catalysts require a co-feed of oxygen and utilize an oxidative dehydrogenation process at low temperatures, such as below 500° C., and low pressures, such as below 300 pounds per square inch gauge (psig) (about 20 barg). Summary of the Invention

[0004] According to one embodiment, a method for converting alkanes to olefins includes contacting a feed stream comprising an alkane with a tellurium-free oxidative dehydrogenation catalyst in a reaction zone and dehydrogenating the alkane in the reaction zone without a co-feed of oxygen to produce a product stream comprising olefins, the oxidative dehydrogenation catalyst having the formula: Mo v V w Nb y Bi z Ox (wherein v is 1.0, w is 0.1-0.5, y is 0.001-0.3, A is Bi, Sb, Pr, or a mixture thereof, z is 0.01-0.3, and x is the oxygen content required for charge balance of the structure), and the oxidative dehydrogenation catalyst is a Cu-K α It has a crystalline structure with the Pba2-32 space group characterized by reflections determined as follows using X-ray diffraction (XRD):

[0005] [Table 1]

[0006] According to another embodiment, a method for converting alkanes to olefins comprises contacting a feed stream comprising an alkane with an oxidative dehydrogenation catalyst in a reaction zone, the oxidative dehydrogenation catalyst having the formula: Mo v V w Nb y Bi z O x where v is 1.0, w is 0.1-0.5, y is 0.001-0.3, z is 0.01-0.3, and x is the oxygen content required for charge balance of the structure, and the oxidative dehydration catalyst is Cu-K α having a crystalline structure having a Pba2-32 space group characterized by reflections determined using X-ray diffraction (XRD) as follows:

[0007] [Table 2] and dehydrogenating the alkane in the reaction zone to produce a product stream comprising olefins.

[0008] Additional features and advantages are set forth in the Detailed Description below, and in part will be readily apparent to those skilled in the art from that description, or will be learned by practicing the embodiments described herein, including in the Detailed Description below, and in the claims.

[0009] It is to be understood that both the foregoing general description and the following detailed description are intended to provide an overview or framework for describing the various embodiments and understanding the nature and character of the claimed subject matter. [Brief description of the drawings]

[0010] The Figure is a schematic diagram of a system for processing alkanes to olefins according to embodiments disclosed and described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Reference will now be made in detail to embodiments of processes for the dehydrogenation of alkanes to olefins and catalysts for the dehydrogenation of alkanes to olefins, such as processes and catalysts for converting ethane to ethylene.

[0012] One problem with conventional oxidative dehydrogenation processes is that they require a feed stream of oxygen gas (O2). This increases the cost of the process because it requires equipment capable of producing pure or nearly pure oxygen for use in the process. Furthermore, the presence of oxygen in the process increases the probability of undesirable and dangerous combustion, as a mixture of oxygen and hydrocarbons. Finally, due to the nature of the catalyst and the oxygen requirement to dehydrogenate alkanes, conventional oxidative dehydrogenation processes for converting alkanes to olefins are carried out in fixed bed reactors, which require downtime to remove, replace, and / or regenerate the catalyst. Thus, there is a need for improved catalysts capable of converting alkanes to olefins.

[0013] Unexpectedly, it has been found that, as disclosed and described herein, the composition of a conventional oxidative dehydrogenation catalyst can be altered to allow for a stable reduction and oxidation (redox) cycle of the material. The catalysts disclosed and described herein have a sufficiently high oxygen carrying capacity to obtain selective conversion of ethane to ethylene in a circulation reactor fed with oxygenated solids. By using the catalysts disclosed and described herein, industrially feasible circulation rates can be used in the circulation reactor, and adequate conversion and selectivity of ethane to ethylene is achieved. This eliminates the need to supply gas-phase oxygen to the reactor. In addition, air can be used to regenerate the spent catalyst. Furthermore, the reactor / regenerator system used to convert ethane is exothermic, so it can be operated without additional heat input.

[0014] The oxidative dehydrogenation catalysts comprising a crystal structure of one of the oxides of molybdenum, vanadium, niobium; and bismuth, antimony, or praseodymium as disclosed and described herein may be used in a process for converting alkanes (also referred to herein as "paraffins") in an alkane-containing feed stream to olefins. The processes disclosed and described herein may provide improved olefin selectivity with the oxidative dehydrogenation catalyst as time on stream increases. The processes disclosed and described herein generally include contacting a feed stream containing alkanes (paraffins) with an oxidative dehydrogenation catalyst in a reaction zone to convert at least a portion of the alkanes to olefins to obtain a product stream containing paraffins and olefins. Finally, the paraffins and olefins in the product stream are separated, and the paraffins may be recycled back to the feed stream, while the olefins are used in downstream systems or as materials in various products and processes. As the oxidative dehydrogenation catalyst in the reaction zone is utilized, its activity decreases. According to embodiments, the spent oxidative dehydrogenation catalyst is removed from the reaction zone and sent to a regeneration zone where it is regenerated with an oxygen-containing gas stream, such as air. The regenerated catalyst is then returned from the regeneration zone to the reaction zone where it is used to dehydrogenate alkanes in the feed stream to olefins. Processes according to embodiments disclosed and described herein are provided in more detail below.

[0015] According to an embodiment, and with reference to the drawings, a feed stream 100 is fed to a reaction zone 110, the feed stream 100 comprising at least one alkane. In an embodiment, the feed stream may comprise steam and / or an inert gas. In an embodiment, the feed stream may be composed entirely of alkanes (i.e., 100% alkane by volume). In one or more embodiments, the feed stream may be composed of 30 volume percent (vol%) to 90% alkanes, 35% to 90% alkanes, 40% to 90% alkanes, 45% to 90% alkanes, 50% to 90% alkanes, 55% to 90% alkanes, 60% to 90% alkanes, 65% to 90% alkanes, 70% to 90% alkanes, 75% to 90% alkanes, 80 ... 5% to 90% by volume of alkanes, 30% to 85% by volume of alkanes, 35% to 85% by volume of alkanes, 40% to 85% by volume of alkanes, 45% to 85% by volume of alkanes, 50% to 85% by volume of alkanes, 55% to 85% by volume of alkanes, 60% to 85% by volume of alkanes, 65% to 85% by volume of alkanes, 70% to 85% by volume of alkanes, 75% to 85% by volume of alkanes, 80% to 85% by volume of alkanes, 30% to 80% by volume Alkane, 35% to 80% by volume of alkanes, 40% to 80% by volume of alkanes, 45% to 80% by volume of alkanes, 50% to 80% by volume of alkanes, 55% to 80% by volume of alkanes, 60% to 80% by volume of alkanes, 65% to 80% by volume of alkanes, 70% to 80% by volume of alkanes, 75% to 80% by volume of alkanes, 30% to 75% by volume of alkanes, 35% to 75% by volume of alkanes, 40% to 75% by volume of alkanes, 45% to 75% by volume of alkanes, 50% to 75% by volume of alkanes, 55% to 75% by volume of alkanes, 60% to 75% by volume of alkanes, 65% to 75% by volume of alkanes, 70% to 75% by volume of alkanes, 30% to 70% by volume of alkanes, 35% to 70% by volume of alkanes, 40% to 70% by volume of alkanes, 45% to 70% by volume of alkanes, 50% to 70% by volume of alkanes, 55% to 70% by volume of alkanes, 60% to 70% by volume of alkanes,65% to 70% by volume of alkanes, 30% to 65% by volume of alkanes, 35% to 65% by volume of alkanes, 40% to 65% by volume of alkanes, 45% to 65% by volume of alkanes, 50% to 65% by volume of alkanes, 55% to 65% by volume of alkanes, 60% to 65% by volume of alkanes, 30% to 60% by volume of alkanes, 35% to 60% by volume of alkanes, 40% to 60% by volume of alkanes, 45% to 60% by volume of alkanes, 50% to 60% by volume of alkanes, 55% to 60% by volume of alkanes, 30% to 55% by volume % to 55% by volume of alkanes, 40% to 55% by volume of alkanes, 45% to 55% by volume of alkanes, 50% to 55% by volume of alkanes, 30% to 50% by volume of alkanes, 35% to 50% by volume of alkanes, 40% to 50% by volume of alkanes, 45% to 50% by volume of alkanes, 30% to 45% by volume of alkanes, 35% to 45% by volume of alkanes, 40% to 45% by volume of alkanes, 30% to 40% by volume of alkanes, 35% to 40% by volume of alkanes, or 30% to 35% by volume of alkanes. In an embodiment, the at least one alkane is selected from the group consisting of ethane, propane, and combinations thereof. The inert gas, in one or more embodiments, is selected from the group consisting of nitrogen, carbon dioxide, and combinations thereof.

[0016] In embodiments, the feed stream is essentially free of oxygen, meaning that the feed stream contains less than 2.0 volume percent (vol%) oxygen, less than 1.5 volume% oxygen, or less than 0.5 volume% oxygen. In one or more embodiments, the feed stream is free of oxygen.

[0017] The reaction zone is not particularly limited, and any type of reactor that allows for cyclic or continuous operation of the process may be used in the embodiments. The reaction zone is not particularly limited to a single reaction zone, and may consist of multiple reactors in a series or parallel configuration. In one or more embodiments, the reaction zone may be a fluidized bed reactor, a moving bed reactor, a fixed bed reactor, a countercurrent reactor, or an ebullated bed reactor. A feed stream 100 containing an alkane is fed to the reaction zone 110 and travels from a first end of the reaction zone 110 to a second end of the reaction zone 110 opposite the first end of the reaction zone 110. As the feed stream 100 travels from the first end of the reaction zone 110 to the second end of the reaction zone 110, the feed stream contacts an oxidative dehydrogenation catalyst loaded within the reaction zone 110. Upon contact with the oxidative dehydrogenation catalyst, the alkanes present in the feed stream 100 are converted to olefins at appropriate reaction conditions, which are described in more detail below. Thus, exiting the reaction zone 110 is an effluent stream 120 comprising alkanes and olefins.

[0018] According to one or more embodiments, the weight ratio of the oxidative dehydrogenation catalyst in reaction zone 110 to the alkane in reaction zone 110 is 250-10, 225-10, 200-10, 175-10, 150-10, 125-10, 100-10, 75-10, 50-10, 25-10, 250-25, 225-25, 200-25, 175-25, 150-25, 125-25, 100-25, 75-25, 50-25, 250-50, 225-50, 200-50, 175-50, 150-50, 125-50, 10 0~50, 75~50, 250~75, 225~75, 200~75, 175~75, 150~75, 125~75, 100~75, 250~100, 225~100, 200~100, 175~100, 150~100, 125~100, 250~125, 225~125, 200~125, 175~125, 150~125, 250~150, 225~150, 200~150, 175~150, 250~175, 225~175, 200~175, 250~200, 225~200, or 250~225. In embodiments where the reaction zone is a fluidized bed catalyst or the like, the ratio of catalyst to alkane is controlled by the mass feed rate of the alkane and the mass feed rate of the catalyst to the reaction zone.

[0019] An oxidative dehydrogenation catalyst as disclosed and described herein is contacted with the feed stream 100 in a reaction zone 110 under reaction conditions sufficient to form a product stream 120 comprising olefins. The reaction conditions, according to one or more embodiments, may be from 300° C. to 700° C., 350° C. to 700° C., 400° C. to 700° C., 450° C. to 700° C., 500° C. to 700° C., 550° C. to 700° C., 600° C. to 700° C., 650° C. to 700° C., 300° C. to 650° C., 350° C. to 650° C., 400° C. to 650° C., 450° C. to 650° C., 500° C. to 650° C., 550° C. to 650° C., 600° C. to 600° C., 300° C. to 600° C., 350° C. to 600° C., 400° C. to 600° C., The temperature in the reaction zone 110 may be 450°C to 600°C, 500°C to 600°C, 550°C to 600°C, 300°C to 550°C, 350°C to 550°C, 400°C to 550°C, 450°C to 550°C, 500°C to 550°C, 300°C to 500°C, 350°C to 500°C, 400°C to 500°C, 450°C to 500°C, 300°C to 450°C, 350°C to 450°C, 400°C to 450°C, 300°C to 400°C, 350°C to 400°C, or 300°C to 350°C.

[0020] The reaction conditions may also be, in embodiments, from 0 bar(g) (0 KPa) to 20 bar(g) (2000 KPa), from 5 bar(g) (500 KPa) to 20 bar(g) (2000 KPa), from 10 bar(g) (1000 KPa) to 20 bar(g) (2000 KPa), from 15 bar(g) (1500 KPa) to 20 bar(g) (2000 KPa), from 0 bar(g) (0 KPa) to 15 bar(g) (1500 KPa ), 5 bar(g)(500 KPa) to 15 bar(g)(1500 KPa), 10 bar(g)(1000 KPa) to 15 bar(g)(1500 KPa), 0 bar(g)(0 KPa) to 10 bar(g)(1000 KPa), 5 bar(g)(500 KPa) to 10 bar(g)(1000 KPa), or 0 bar(g)(0 KPa) to 5 bar(g)(500 KPa).

[0021] According to an embodiment, the weight hour space velocity (WHSV) of the alkane of the feed stream 100 in the reaction zone 110 is 0.1 / hour ( / h) to 10 / h, 1 / h to 10 / h, 2 / h to 10 / h, 3 / h to 10 / h, 4 / h to 10 / h, 5 / h to 10 / h, 6 / h to 10 / h, 7 / h to 10 / h, 8 / h to 10 / h, 9 / h to 10 / h, 1 / h to 9 / h, 2 / h to 9 / h, 3 / h to 9 / h, 4 / h to 9 / h, 5 / h to 9 / h, 6 / h to 9 / h, 7 / h to 9 / h, 8 / h to 9 / h, 1 / h to 8 / h, 2 / h to 8 / h, 3 / h to 8 / h, 4 / h~8 / h, 5 / h~8 / h, 6 / h~8 / h, 7 / h~8 / h, 1 / h~7 / h, 2 / h~7 / h, 3 / h~7 / h, 4 / h~7 / h, 5 / h~7 / h, 6 / h~7 / h, 1 / h~6 / h, 2 / h~6 / h, 3 / h~6 / h , 4 / h~6 / h, 5 / h~6 / h, 1 / h~5 / h, 2 / h~5 / h, 3 / h~5 / h, 4 / h~5 / h, 1 / h~4 / h, 2 / h~4 / h, 3 / h~4 / h, 1 / h~3 / h, 2 / h~3 / h, or 1 / h~2 / h.

[0022] According to an embodiment, the reaction zone 110 may be fluidly connected to the regeneration zone 200 via a conduit 111. The configuration of the conduit 111 is not particularly limited, so long as the conduit 111 is capable of transporting the spent oxidative dehydrogenation catalyst from the reaction zone 110 to the regeneration zone 200. In one or more embodiments, the regeneration zone 200 may be physically integrated with the reaction zone and, in embodiments, may be activated by providing an alternative feed gas (e.g., providing air instead of feeding a hydrocarbon or alkane). In the regeneration zone 200, the spent oxidative dehydrogenation catalyst is regenerated by contacting the spent oxidative dehydrogenation catalyst with an oxygen-containing gas stream 210. In an embodiment, the oxygen-containing gas stream 210 is air. The residence time with the oxygen-containing gas stream 210 regenerates the oxidative dehydrogenation catalyst such that the oxidative dehydrogenation catalyst regains its activity and selectivity for converting alkanes to olefins as the oxidative dehydrogenation catalyst moves from a first end of the regeneration zone 200 toward a second end of the regeneration zone 200. After the oxidative dehydrogenation catalyst is regenerated in the regeneration zone 200, the regenerated oxidative dehydrogenation catalyst is transferred from the regeneration zone 200 to the reaction zone 110 via a conduit 201. The configuration of the conduit 201 is not limited as long as it is capable of transferring the regenerated oxidative dehydrogenation catalyst from the regeneration zone 200 to the reaction zone 100. It should be understood that fresh catalyst can be introduced into the reaction zone 110 via a conduit (not shown) different from the conduit 201 for introducing the regenerated catalyst into the reaction zone 110. An effluent 220 exits from a second end of the regeneration zone 200. In an embodiment, the effluent 220 is nitrogen or air with oxygen removed.

[0023] In an embodiment, the oxygen-containing gas stream is 2% to 22% by volume O2, 5% to 22% by volume O2, 7% to 22% by volume O2, 10% to 22% by volume O2, 12% to 22% by volume O2, 15% to 22% by volume O2, 17% to 22% by volume O2, 20% to 22% by volume O2, 2% to 20% by volume O2, 5% to 20% by volume O2, 7% to 20% by volume O2, 10% to 20% by volume O2, 12% to 20% by volume O2, 15% to 20% by volume O2, 17% to 20% by volume O2, 2% to 17% by volume O2, 5% to 17% by volume O2, 7% to 1 The O2 may comprise 7% by volume, 10% to 17% by volume, 12% to 17% by volume, 15% to 17% by volume, 2% to 15% by volume, 5% to 15% by volume, 7% to 15% by volume, 10% to 15% by volume, 12% to 15% by volume, 2% to 12% by volume, 5% to 12% by volume, 7% to 12% by volume, 10% to 12% by volume, 2% to 10% by volume, 5% to 10% by volume, 7% to 10% by volume, 2% to 7% by volume, 5% to 7% by volume, or 2% to 5% by volume. In embodiments, the oxygen-containing gas stream is diluted or undiluted air, hi other embodiments, the oxygen-containing stream may have an oxygen concentration greater than air, such as greater than 50%, greater than 70%, or greater than 90% oxygen.

[0024] According to an embodiment, the pressure in the regeneration zone 200 during regeneration can be in the range of 0 bar(g) (0 KPa) to 21 bar(g) (2100 KPa), 2 bar(g) (200 KPa) to 21 bar(g) (2100 KPa), 4 bar(g) (400 KPa) to 21 bar(g) (2100 KPa), 6 bar(g) (600 KPa) to 21 bar(g) (2100 KPa), 8 bar(g) (800 KPa) to 21 bar(g) (2100 KPa), 10 bar(g) (1000 KPa) to 21 bar(g) (2100 KPa), 12 bar(g) (1200 KPa) to 21bar(g)(2100KPa), 14bar(g)(1400KPa)~21bar(g)(2100KPa), 16bar(g)(1600KPa)~21bar(g)(2100KPa), 18bar(g)(1800KPa)~21bar(g)(2100KPa) , 20bar(g)(2000KPa)~21bar(g)(2100KPa), 0bar(g)(0KPa)~20bar(g)(2000KPa), 2bar(g)(200KPa)~20bar(g)(2000KPa), 4bar(g)(400KPa)~20bar( g)(2000KPa), 6bar(g)(600KPa)~20bar(g)(2000KPa), 8bar(g)(800KPa)~20bar(g)(2000KPa), 10bar(g)(1000KPa)~20bar(g)(2000KPa), 12bar(g)( 1200KPa)~20bar(g)(2000KPa), 14bar(g)(1400KPa)~20bar(g)(2000KPa), 16bar(g)(1600KPa)~20bar(g)(2000KPa), 18bar(g)(1800KPa)~20bar(g) (2000KPa), 0bar(g)(0KPa)~14bar(g)(1400KPa), 2bar(g)(140KPa)~14bar(g)(1400KPa), 4bar(g)(400KPa)~14bar(g)(1400KPa), 6bar(g)(600KPa) ~14bar(g)(1400KPa), 8bar(g)(800KPa)~14bar(g)(1400KPa), 10bar(g)(1000KPa)~14bar(g)(1400KPa), 12bar(g)(1200KPa)~14bar(g)(1400KPa),0bar(g)(0KPa)~12bar(g)(1200KPa), 2bar(g)(120KPa)~12bar(g)(1200KPa), 4bar(g)(400KPa)~12 bar(g)(1200KPa), 6bar(g)(600KPa)~12bar(g)(1200KPa), 8bar(g)(800KPa)~12bar(g)(1200KPa), 1 0bar(g)(1000KPa)~12bar(g)(1200KPa), 0bar(g)(0KPa)~10bar(g)(1000KPa), 2bar(g)(100KPa)~10 bar(g)(1000KPa), 4bar(g)(400KPa)~10bar(g)(1000KPa), 6bar(g)(600KPa)~10bar(g)(1000KPa), 8 bar(g)(800KPa)~10bar(g)(1000KPa), 0bar(g)(0KPa)~8bar(g)(800KPa), 2bar(g)(80KPa)~8bar(g) )(800KPa), 4bar(g)(400KPa)~8bar(g)(800KPa), 6bar(g)(600KPa)~8bar(g)(800KPa), 0bar(g)(0KP a) to 6bar(g)(600KPa), 2bar(g)(60KPa) to 6bar(g)(600KPa), 4bar(g)(400KPa) to 6bar(g)(600KPa), 0bar(g)(0KPa) to 4bar(g)(400KPa), 2bar(g)(40KPa) to 4bar(g)(400KPa), or 0bar(g)(0KPa) to 2bar(g)(200 KPa).

[0025] In an embodiment, the product stream 120 includes various oxygenates in combination with alkanes and olefins. Thus, in an embodiment, the product stream 120 is transferred from the reaction zone 110 to an oxygenate scrubber 300 where oxygenates are removed from the product stream 120. The oxygenate scrubber 300 may be any conventional oxygenate scrubber and is not limited herein. The product stream 120 enters a first end of the oxygenate scrubber 300 and travels to a second end of the oxygenate scrubber 300, where a water stream 301 is added to the oxygenate scrubber 300 near the second end of the oxygenate scrubber 300. As the product stream 120 travels from the first end of the oxygenate scrubber 300 to the second end of the oxygenate scrubber 300, oxygenates are removed from the product stream 120. The oxygenate stream 302 exits the oxygenate scrubber 300 near a first end of the oxygenate scrubber 300 .

[0026] The oxygenate stream 302 is then transferred from the oxygenate scrubber 300 to the oxygenate purifier 400 where the oxygenates and water present in the oxygenate stream 302 are separated. The oxygenate purifier 400 may be any conventional oxygenate purifier and is not limited herein. The oxygenate stream 302 enters a first end of the oxygenate purifier 400 and travels to a second end of the oxygenate purifier 400. As the oxygenate stream 302 travels from the first end of the oxygenate purifier 400 to the second end of the oxygenate purifier 400, the oxygenates are separated from the water in the oxygenate stream 302. At the second end of the oxygenate purifier 400, the oxygenate stream 401 and the water stream 402 exit the oxygenate purifier 400.

[0027] A purified product stream 310 exits the second end of the oxygenate scrubber 300. The purified product stream 310 contains significantly fewer oxygenates than the product stream 120 that exited the reaction zone 110. However, the purified product stream 310 contains carbon monoxide (CO) and carbon dioxide (CO2) in addition to alkanes and olefins. Thus, the purified product stream 310 is transferred to a compressor where the purified product stream 310 is further processed by compressing it. The compressor 500 may be any conventional compressor and is not limited herein. Once compressed, the compressed purified product stream 510 is transferred to a CO2 separator 600.

[0028] In the CO2 separator 600, the CO2 is separated from the CO, alkanes, and olefins in the compressed, purified product stream 510. The CO2 separator may be any conventional CO2 separator and is not limited herein. Carbon dioxide 601 is purged from the CO2 separator and a separated product stream 602 exits the CO2 separator for further processing. The separated product stream 602 includes CO, alkanes, and olefins.

[0029] The separated product stream 602 is transferred to a CO separator 700, where the CO is separated from the alkanes and olefins in the separated product stream 602. The CO separator may be any conventional CO separator and is not limited herein. The carbon monoxide 701 is purged from the CO separator and the further separated product stream 702 exits the CO separator for further processing. The further separated product stream 702 includes alkanes and olefins.

[0030] The components of the further separated product stream 702 may be separated in a conventional separation unit, which may optionally be part of an existing cracker separation system. In an embodiment, the further separated product stream 702 is transferred to an olefin / paraffin splitter 800. In the splitter 800, alkanes are separated from the olefins in the further separated product stream 702. The splitter may be any conventional cracker and is not limited herein. A final product stream 801 comprising olefins such as ethylene exits the first end of the cracker 800, and an alkane recycle reflux stream 802 exits the cracker 800 and is returned to the reaction zone 110.

[0031] Next, a catalyst for dehydrogenating alkanes to olefins according to embodiments disclosed and described herein will be described.

[0032] One of the oxidative dehydrogenation catalysts currently in use is MoVNbTeO x Including MoVNbTeO x The crystalline phase structure of the catalyst formed by (Pba2-32 space group) or similar crystalline phase structures provides a structure that allows for the production of desired olefins. However, the use of this catalyst in an oxidative dehydrogenation process significantly destabilizes the catalyst because Te is volatile under reducing conditions, causing reactor fouling with Te as well as potential disruption of the preferred crystalline structure of the catalyst. This subsequently results in a loss of activity / selectivity during the conversion of alkanes to olefins.

[0033] In the embodiments disclosed and described herein, MoVNbTeO x The Te in the catalyst composition can be completely replaced with a promoter. In embodiments, the promoter is selected from the group consisting of bismuth (Bi), antimony (Sb), or praseodymium (Pr). In one or more embodiments, the promoter is bismuth (Bi). Furthermore, by using certain hydrothermal synthesis methods disclosed in more detail herein, the catalyst can be prepared as MoVNbTeO for the conversion of alkanes to olefins to provide the desired olefins. xThe oxidative dehydrogenation catalyst has a Pba2-32 space group crystal structure. This structure allows the replacement of the volatile Te with the more stable Bi, Sb, Pr, or combinations thereof to provide similar alkane conversion while still providing similar alkane conversion to the known MoVNbTeO. x This allows for improved stability over the catalysts disclosed and described herein. For example, in embodiments, the oxidative dehydrogenation catalysts disclosed and described herein have both activity (greater than 10% ethane conversion), selectivity (greater than 65% ethylene selectivity), and provide stable performance under reaction conditions. In one or more embodiments, the catalysts described herein may be further promoted with sodium (Na) or calcium (Ca).

[0034] In one or more embodiments, the oxidative dehydrogenation catalyst has the following formula: Mo v V w Nb y A z O x[wherein v is 1.0 (e.g., Mo is used as the standard for atomic ratios), w is 0.1 to 0.5, y is 0.001 to 0.3, A is Bi, Sb, Pr, or a combination thereof, z is 0.01 to 0.3, and x is the oxygen content required for charge balance of the structure. In an embodiment, w is 0.1 to 0.5, 0.2 to 0.5, 0.3 to 0.5, 0.4 to 0.5, 0.1 to 0.4, 0.2 to 0.4, 0.3 to 0.4, 0.1 to 0.3, 0.2 to 0.3, or 0.1 to 0.2. In an embodiment, y is 0.01 to 0.3, 0.05 to 0.3, 0.1 to 0.3, 0.15 to 0.3, 0.2 to 0.3, 0.25 to 0.3, 0.001 to 0.25, 0.01 to 0.25, 0.05 to 0.25, 0.1 to 0.25, 0.15 to 0.25, 0.2 to 0.25, 0.01 to 0.2, 0.05 to 0.2, 0.1 to 0.2, 0.15 to 0.2, 0.01 to 0.15, 0.05 to 0.15, 0.1 to 0.15, 0.01 to 0.1, 0.05 to 0.1, or 0.01 to 0.05. In an embodiment, z is 0.05 to 0.3, 0.10 to 0.3, 0.15 to 0.3, 0.2 to 0.3, 0.25 to 0.3, 0.01 to 0.25, 0.05 to 0.25, 0.10 to 0.25, 0.15 to 0.25, 0.2 to 0.25, 0.01 to 0.2, 0.05 to 0.2, 0.10 to 0.2, 0.15 to 0.2, 0.01 to 0.15, 0.05 to 0.15, 0.10 to 0.15, 0.01 to 0.1, 0.05 to 0.1, or 0.01 to 0.05. In an embodiment, the oxidative dehydrogenation catalyst is represented by the following formula: MoV 0.2-0.3 Nb 0.1 A 0.1 O x where x is the oxygen content required for charge balance of the structure, and A is selected from the group consisting of Bi, Sb, Pr, or combinations thereof. In embodiments, A is one of Bi or Sb. Mo having the Pba2-32 space group v V w Nb y A z O x It should be understood that embodiments of the catalyst are essentially Te-free, such as having a Te / Mo ratio of less than 0.01.

[0035] Structure Mo v V w Nb y A z O x It has been found that the presence of Nb in an oxidative dehydrogenation catalyst having a crystal structure of Pba2-32 and Pba2-32 space group improves the activity and selectivity of the catalyst in a lattice oxidative dehydrogenation process (where the oxygen for conversion is extracted from the lattice of the catalyst rather than through a gaseous oxygen stream). Thus, in an embodiment, the oxidative dehydrogenation catalyst is of the formula Mo v V w Nb y Bi z O x and Pba2-32 space group crystal structure, which contains oxides of Mo, V, Nb, and Bi.

[0036] The crystal structure of the oxidative dehydrogenation catalysts disclosed and described herein may, in embodiments, also be measured using x-ray diffraction (XRD). For example, as will be appreciated by those skilled in the art, the relative intensities of XRD peaks at various angles can be used to describe the crystal structure of the oxidative dehydrogenation catalyst. In embodiments, the oxidative dehydrogenation catalyst may be a Cu-K catalyst as shown in Table 1. α The reflections are as determined by XRD. In Table 1 below, the relative intensity is maximum at 22.2° 2θ, so this relative intensity is set to 100% and used as the basis for the remaining relative intensities shown in Table 1.

[0037] [Table 3]

[0038] As one of ordinary skill in the art will recognize, the relative intensities may be affected by preferential orientation effects, and the relative intensities disclosed above take such effects into account.

[0039] When a catalyst comprising Bi, Pr, or a combination thereof as disclosed above is used in the reaction zone, an oxygen stream 130 may optionally be added to the reaction zone 110. It should be understood that an oxygen stream 130 is not required, and the embodiments disclosed and described herein do not include adding an oxygen stream 130 to the reaction zone 110. However, in embodiments, an oxygen stream 130 may be added to facilitate the reaction within the reaction zone 110. The oxygen concentration in the oxygen stream 130 is not particularly limited. For example, the oxygen concentration in the oxygen stream 130 may be between 0.1 vol.% and 99.9 vol.%, e.g., between 5.0 vol.% and 95.0 vol.%, between 10.0 vol.% and 90.0 vol.%, between 15.0 vol.% and 85.0 vol.%, between 20.0 vol.% and 80.0 vol.%, between 25.0 vol.% and 75.0 vol.%, between 30.0 vol.% and 70.0 vol.%, between 35.0 vol.% and 65.0 vol.%, between 40.0 vol.% and 60.0 vol.%, or between 45.0 vol.% and 55.0 vol.%. In one or more embodiments, the oxygen concentration in the oxygen stream is relatively low, e.g., between 0.1% and 5.0% by volume, between 0.2% and 5.0% by volume, between 0.5% and 5.0% by volume, between 0.8% and 5.0% by volume, between 1.0% and 5.0% by volume, between 1.2% and 5.0% by volume, between 1.5% and 5.0% by volume, between 1.8% and 5.0% by volume, between 2.0% and 5.0% by volume, 2.2 volume% to 5.0 volume%, 2.5 volume% to 5.0 volume%, 2.8 volume% to 5.0 volume%, 3.0 volume% to 5.0 volume%, 3.2 volume% to 5.0 volume%, 3.5 volume% to 5.0 volume%, 3.8 volume% to 5.0 volume%, 4.0 volume% to 5.0 volume%, 4.2 volume% to 5.0 volume%, 4.5 volume% to 5.0 volume%, or 4.8 volume% to 5.0 volume%.

[0040] In an embodiment, oxygen stream 130 may be added to reaction zone 110 subsequent to feed stream 100 such that feed stream 100 and oxygen stream 130 are not added to reaction zone 110 simultaneously.

[0041] In one or more embodiments, oxygen stream 130 is added to reaction zone 110 simultaneously with feed stream 100. In such embodiments, the volumetric ratio of oxygen (in oxygen stream 130) to alkane (in feed stream 100) in reaction zone 110 is greater than 0.0 to 3.0, 0.5 to 3.0, 1.0 to 3.0, 1.5 to 3.0, 2.0 to 3.0, 2.5 to 3.0, greater than 0.0 to 2.5, 0.5 to 2.5, 1.0 to 2.5, 1.5 to 2.5, 2.0 to 2.5, greater than 0.0 to 2.0, 0.5 to 2.0, 1.0 to 2.0, 1.5 to 2.0, greater than 0.0 to 1.5, 0.5 to 1.5, 1.0 to 1.5, greater than 0.0 to 1.0, 0.5 to 1.0, or greater than 0.0 to 0.5.

[0042] As described above, the use of certain hydrothermal methods for forming the oxidative dehydrogenation catalyst allows for the formation of oxidative dehydrogenation catalysts having the desired Pba2-32 crystal structure. Embodiments of these hydrothermal methods for forming the oxidative dehydrogenation catalyst are now described in more detail.

[0043] Mo v V w Nb y Bi z O x In one or more embodiments, an oxidative dehydrogenation catalyst having the structure is formed through a synthesis process that begins by adding a molybdenum-containing compound, a vanadium-containing compound, a bismuth-containing compound, a niobium-containing compound, and one or more organic acids to a mixture of an alkylene glycol or alcohol amine and water to form a reaction mixture. In embodiments, the metal precursor is selected such that the precursor can dissolve / decompose under hydrothermal reaction conditions. Mo is then extracted from the reaction mixture by hydrothermal synthesis at a hydrothermal synthesis temperature for a period of time. v V w Nb y Bi z O x After the above time has elapsed, Mo is synthesized from the retained liquid. v V w Nb y Bi z O xIn one or more embodiments, the molybdenum-containing, vanadium-containing, bismuth-containing, niobium-containing compound, and one or more acids are added sequentially to a mixture of alkylene glycol and water.

[0044] In an embodiment, the bismuth-containing compound is selected from the group consisting of bismuth oxide (Bi2O3), bismuth sulfate (Bi2(SO4)3), bismuth citrate (BiC6H5O7), and bismuth nitrate (Bi(NO3)3). In an embodiment, the niobium-containing compound is selected from the group consisting of niobium oxide, niobic acid (Nb2O5·nH2O), niobium ethoxylate, and ammonium niobium oxalate and water (NH4Nb(C2O4)2·nH2O). In an embodiment, the molybdenum-containing compound is ammonium heptamolybdate (NH4)6Mo7O 24 or molybdenum trioxide (MoO3), and the vanadium-containing compound may be ammonium metavanadate (NH4VO3), vanadyl sulfate (VOSO4), or vanadium pentoxide (VO5). The molybdenum-containing compound and the vanadium-containing compound are, in embodiments, MoO3 and VO5, respectively. In some embodiments, the antimony-containing compound is selected from the group consisting of antimony oxide (Sb2O3 or Sb2O5), antimony sulfate (Sb2(SO4)3), and antimony acetate ((CH3CO2)3Sb). In one or more embodiments, the praseodymium-containing compound is praseodymium oxide (PrO2, Pr2O3, or Pr6O 11 In some embodiments, a digestible mixture of metal-containing compounds having precise stoichiometric ratios of one or more of Mo, V, Nb, and Bi can be used. An example of such a digestible mixture is (Mo,V)O x and BiNbO x In one or more embodiments, the acid is selected from the group consisting of citric acid (C6H8O7), oxalic acid (C2H2O4), and mixtures thereof. In embodiments, the alkylene glycol is ethylene glycol.

[0045] In the embodiment, the hydrothermal synthesis temperature is 150°C to 250°C, 160°C to 250°C, 170°C to 250°C, 180°C to 250°C, 190°C to 250°C, 200°C to 250°C, 210°C to 250°C, 220°C to 250°C, 230°C to 250°C, 240°C to 250°C, 150°C to 240°C, 160°C to 240°C, 170°C to 24 ... 0℃, 180℃~240℃, 190℃~240℃, 200℃~240℃, 210℃~240℃, 220℃~240℃, 230℃~240℃, 150℃~230℃, 160℃~230℃, 170℃~230℃, 180℃~230℃, 190℃~230℃, 200℃~230℃, 210℃~230℃, 220℃~230℃, 150℃~220℃, 160℃~220℃, 170℃~220℃, 180℃~220℃, 190℃~220℃, 200℃~220℃, 210℃~220℃, 150℃~210℃, 160℃~210℃, 170℃~210℃, 180℃~210℃, 190℃~210℃, 200℃~210℃, 150℃~200℃, 16 0°C to 200°C, 170°C to 200°C, 180°C to 200°C, 190°C to 200°C, 150°C to 190°C, 160°C to 190°C, 170°C to 190°C, 180°C to 190°C, 150°C to 180°C, 160°C to 180°C, 170°C to 180°C, 150°C to 170°C, 160°C to 170°C, or 150°C to 160°C.

[0046] In the embodiment, the hydrothermal pressure is 4 bar (400 kPa) to 40 bar (4000 kPa), for example 5 bar (500 kPa) to 40 bar (4000 kPa), 10 bar (1000 kPa) to 40 bar (4000 kPa), 15 bar (1500 kPa) to 40 bar (4000 kPa), 20 bar (2000 kPa) to 40 bar (4000 kPa), 25 bar (2500 kPa) to 40 bar (4000 kPa), 30 bar (3000 kPa) to 40 bar (4000 kPa), 35 bar (3500 kPa) to 40 bar (4000 kPa), 4 bar (400 kPa) to 35 bar (3500 kPa), 5 bar (500 kPa) to 35 bar (3500 kPa), 10 bar (1000 kPa) to 35 bar (3500 kPa), 15 bar (1500 kPa) to 35 bar (3500 kPa), 20 bar (2000 kPa) to 35 bar (3500 kPa), 25 bar (2500 kPa) to 35 bar (3500 kPa), 30 bar (3000 kPa) to 35 bar (3500 kPa), 4 bar (400 kPa) to 30 bar (3000 kPa), 5 bar (500 kPa) to 30 bar (3000 kPa), 10 bar (1000 kPa) to 30 bar (3000 kPa), 15 bar (1500 kPa) to 30 bar (3000 kPa), 20 bar (2000 kPa) to 30 bar (3000 kPa), 25 bar (2500 kPa) to 30 bar (3000 kPa), 4 bar (400 kPa) to 25 bar (2500 kPa), 5 bar (500 kPa) to 25 bar (2500 kPa), 10 bar (1000 kPa) to 25 bar (2500 kPa), 15 bar (1500 kPa) to 25 bar (2500 kPa), 20 bar (2000 kPa) to 25 bar (2500 kPa), 4 bar (400 kPa) to 20 bar (2000 kPa), 5 bar (500 kPa) to 20 bar (2000 kPa), 10 bar (1000 kPa) to 20 bar (2000 kPa), 15 bar (1500 kPa) to 20 bar (2000 kPa), 4 bar (400 kPa) to 15 bar (1500 kPa), 5 bar (500 kPa) to 15 bar (1500 kPa), 10 bar (1000 kPa) to 15 bar (1500 kPa),4 bar (400 kPa) to 10 bar (1000 kPa), or 5 bar (500 kPa) to 10 bar (1000 kPa).

[0047] According to an embodiment, Mo is extracted from the retained liquid. v V w Nb y A z O x After isolating the oxidative dehydrogenation catalyst, Mo v V w Nb y A z O x The oxidative dehydrogenation catalyst is dried and, optionally, dried Mo v V w Nb y A z O x The oxidative dehydrogenation catalyst is heated to a calcination temperature and the Mo v V w Nb y A z O x The oxidative dehydrogenation catalyst is calcined by holding it at the calcination temperature for a period of time.

[0048] In an embodiment, the calcination is carried out in an inert atmosphere such as nitrogen (N2), argon (Ar), or helium (He). In such an embodiment, the calcination temperature is 350°C to 650°C, 375°C to 650°C, 400°C to 650°C, 425°C to 650°C, 450°C to 650°C, 475°C to 650°C, 500°C to 650°C, 525°C to 650°C, 550°C to 650°C, 575°C to 650°C, 600°C to 650°C, 625°C to 650°C, 350°C to 625°C, 375°C to 625°C, 400°C to 625°C, 425°C to 625°C, 450°C to 625°C, 475°C to 625°C, 50 ... 0℃~625℃, 525℃~625℃, 550℃~625℃, 575℃~625℃, 600℃~625℃, 350℃~600℃, 375℃~600℃, 400℃~600℃, 425℃~600℃, 450℃~600℃, 475℃~600℃, 500℃~600℃, 525℃~600℃, 550℃~600℃, 575℃~600℃, 350℃~575℃, 375℃~575℃, 400℃~575℃, 425℃~575℃, 450℃~575℃, 475 ℃~575℃, 500℃~575℃, 525℃~575℃, 550℃~575℃, 350℃~550℃, 375℃~550℃, 400℃~550℃, 425℃~550℃, 450℃~550℃, 475℃~550℃, 500℃~550℃, 525℃~550℃, 350℃~525℃, 375℃~525℃, 400℃~525℃, 425℃~525℃, 450℃~525℃, 475℃~525℃, 500℃~525℃, 350℃~500℃, 375℃ ~500°C, 400°C~500°C, 425°C~500°C, 450°C~500°C, 475°C~500°C, 350°C~475°C, 375°C~475°C, 400°C~475°C, 425°C~475°C, 450°C~475°C, 350°C~450°C, 375°C~450°C, 400°C~450°C, 425°C~450°C, 350°C~425°C, 375°C~425°C, 400°C~425°C, 350°C~400°C, 375°C~400°C, or 350°C~375°C.

[0049] In an embodiment, the calcination is carried out in air. In such an embodiment, the calcination temperature can be 200°C to 500°C, 375°C to 500°C, 400°C to 500°C, 425°C to 500°C, 450°C to 500°C, 475°C to 500°C, 350°C to 475°C, 375°C to 475°C, 400°C to 475°C, 425°C to 475°C, 450°C to 475°C, 350°C to 450°C, 375°C to 450°C, 400°C to 450°C, 425°C to 450°C, 350°C to 425°C, 375°C to 425°C, 400°C to 425°C, 350°C to 400°C, 375°C to 400°C, or 350°C to 375°C. EXAMPLES

[0050] Example 1 A mixture of 34 mL of H2O and 80 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). While stirring the mixture, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.4373 g of Bi2O3, 0.286 g of Nb2O5·xH2O, 0.2711 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 min. The MoV was then cooled to 100°C in a rotary shaft oven rotating at 10 rpm for 48 h. 0.3 Nb 0.1 Bi 0.1 O x The material obtained from the hydrothermal synthesis was purified with 90 mL of deionized water using vacuum filtration and then dried at 85 °C overnight.

[0051] After drying, the material was calcined at 450°C (heating rate 2°C / min) for 2 hours under flowing N2. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at an ethane pressure of 1.25 bar(a) with a WHSV of 3.2 / hr.

[0052] Example 2 A mixture of 34 mL of H2O and 160 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). With stirring, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.4373 g of Bi2O3, 0.286 g of Nb2O5.xH2O, 0.5422 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 minutes. The MoV was then cooled in a rotary shaft oven at 190 °C rotating at 10 rpm for 48 hours. 0.3 Nb 0.1 Bi 0.1 O x The material obtained from the hydrothermal synthesis was purified with 90 mL of deionized water using vacuum filtration and then dried at 85 °C overnight.

[0053] After drying, the material was calcined at 450°C (heating rate 2°C / min) for 2 hours under flowing N2. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at an ethane pressure of 1.25 bar(a) (125 kPa) with a WHSV of 3.2 / hr.

[0054] Example 3 A mixture of 34 mL of H2O and 80 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). With stirring, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.4373 g of Bi2O3, 0.8416 g of (NH4)Nb(C2O4)2.xH2O, and 0.2711 g of citric acid were added sequentially and stirred for 10 min. The MoV was then cooled in a rotary shaft oven at 190 °C rotating at 10 rpm for 48 h. 0.3 Nb 0.1 Bi 0.1 O x The material obtained from the hydrothermal synthesis was purified using vacuum filtration with 90 mL of deionized water and then dried at 85 °C overnight.

[0055] After drying, the material was calcined at 450°C (heating rate 2°C / min) for 2 hours under flowing N2. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at an ethane pressure of 1.25 bar(a) (125 kPa) with a WHSV of 3.2 / hr.

[0056] Comparative Example 1 MoV according to the procedure described in U.S. Pat. No. 9,156,764(B2) 0.3 Nb 0.17 Te 0.23 O x The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at an ethane pressure of 1.25 bar(a) (125 kPa) with a WHSV of 3.2 hr-1.

[0057] Example 4 A mixture of 34 mL of H2O and 80 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). With stirring, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.3033 g of Sb2O5, 0.8416 g of (NH4)Nb(C2O4)2.xH2O, and 0.2711 g of citric acid were added sequentially and stirred for 10 min. The MoV was then cooled in a rotary shaft oven at 190 °C rotating at 10 rpm for 48 h. 0.3 Nb 0.1 Sb 0.1 O x The material obtained from the hydrothermal synthesis was purified with 90 mL of deionized water using vacuum filtration and then dried at 85 °C overnight.

[0058] After drying, the material was calcined at 450°C (heating rate 2°C / min) for 2 hours under flowing N2. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at an ethane pressure of 1.25 bar(a) (125 kPa) with a WHSV of 3.2 / hr.

[0059] Example 5 A mixture of 34 mL of H2O and 160 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). With stirring, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.4373 g of Bi2O3, 0.6389 g of Pr6O 11 0.286 g of Nb2O5.xH2O, 0.5422 g of citric acid, and 0.2388 g of oxalic acid were added in sequence and stirred for 10 minutes. MoV was then cooled in a rotary shaft oven at 190 °C rotating at 10 rpm for 48 hours. 0.3 Nb 0.1 Bi 0.1 Pr 0.2 O x The material obtained from the hydrothermal synthesis was purified with 90 mL of deionized water using vacuum filtration and then dried at 85 °C overnight.

[0060] After drying, the material was calcined at 450 °C (heating rate 2 °C / min) under N2 flow for 2 h. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and calcined for 3.2 hr. -1 The gas was tested at an ethane pressure of 1.25 bar(a) with a WHSV of 1.

[0061] Performance Testing Performance tests were conducted in a fixed-bed reactor setup. For catalytic testing, an appropriate amount of 40-80 mesh catalyst particles was loaded into the reactor and the reactor was operated in a cyclic mode where periods of ethane exposure were alternated with oxidative regeneration at the desired temperature. The LODh step used a feed stream containing 50% by volume of ethane in He / N2. The partial pressure of ethane (P エタン ) was between 1.25 bar(a) and 2.5 bar(a), with a WHSV of 2.3 / h to 3.2 / h. The regeneration step involved reoxidation in diluted (2.5% by volume O2) air at pressures between 2.5 bar(a) and 5 bar(a).

[0062] The reactor effluent composition was obtained by gas chromatography (GC) and the conversion and carbon-based selectivity were calculated using the following equations: XC2H6(%)=[(ηC2H6,in-ηC2H6,out) / ηC2H6,in]·100, and (1) S j (%)=[αj·ηj,out / Σαj·ηj,out]·100 (2) [where XC2H6 is defined as C2H6 conversion (%), η,in is defined as the molar inlet flow rate of the component (mol / min), η,out is the molar outlet flow rate of the component (mol / min), and S j is defined as the carbon-based selectivity (%) for product j, where αj is the number of carbon atoms in product j. Carbon balances for all experiments were within 99–102% for all experiments.

[0063] Based on the time-on-stream (TOS, min) that the GC analyzes the reactor effluent, calculate the catalyst / ethane ratio (g / g): Catalyst / ethane = w / (TOS·ηC2H6,in·MW C2H6 ) (3) where w is defined as the catalyst mass, ηC2H6,in is the molar inlet flow rate of ethane (mol / min), and MW C2H6 is the molecular weight of ethane (30 g / mol)].

[0064] [Table 4]

[0065] Example 6 Example 6 utilizes the same catalyst as Example 2 with a WHSV of 2.3 / hr and an ethane partial pressure of 2.5 bar(a), but was tested at 425°C.

[0066] Example 7 A mixture of 34 mL of H2O and 160 microliters of ethylene glycol was added to a 45 mL Teflon-inserted autoclave (Model 4744 General Purpose Acid Digestion Vessel, Parr). With stirring, 2.7126 g of MoO3, 0.5141 g of V2O5, 0.2186 g of Bi2O3, 0.1517 g of Sb2O5, 0.286 g of Nb2O5·xH2O, 0.5422 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 min. The MoV was then incubated at 190 °C for 48 h in a rotary shaft oven rotating at 10 rpm. 0.3 Nb 0.1 Sb 0.05 Bi 0.05 O x The material obtained from the hydrothermal synthesis was purified with 90 mL of deionized water using vacuum filtration and then dried at 85 °C overnight.

[0067] After drying, the material was calcined at 450°C (heating rate 2°C / min) under flowing N2 for 2 hours. The material was pressed under 7 tons of pressure, crushed, and sieved to 40-80 mesh before being charged into the reactor and tested at 450°C, 2.5 bar(a) ethane pressure with a WHSV of 3.2 / hr.

[0068] [Table 5]

[0069] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Accordingly, this specification is intended to cover all such modifications and variations of the various embodiments described herein, provided such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. 1. A process for converting alkanes to olefins, comprising: contacting a feed stream comprising an alkane with a tellurium-free oxidative dehydrogenation catalyst in a reaction zone; dehydrogenating alkanes in said reaction zone without a co-feed of oxygen to produce a product stream comprising olefins; Including, The oxidative dehydrogenation catalyst has the following formula: Mo ｖ V ｗ Nb ｙ A ｚ O ｘ (In the formula, v is 1.0, w is 0.1 to 0.5; y is 0.001 to 0.3; A is Bi, Sb, Pr, or a mixture thereof; z is 0.01 to 0.3; x is the oxygen content required for charge balance of the structure and The oxidative dehydrogenation catalyst is Cu—K α having a crystalline structure having a Pba2-32 space group characterized by reflections determined using X-ray diffraction (XRD) as follows: 【Table 1】

2. 1. A process for converting alkanes to olefins, comprising: contacting a feed stream comprising an alkane with an oxidative dehydrogenation catalyst in a reaction zone, said oxidative dehydrogenation catalyst having a molar ratio of 1 to 10% by mass of an alkane having the formula: Mo ｖ V ｗ Nb ｙ Bi ｚ O ｘ (In the formula, v is 1.0, w is 0.1 to 0.5; y is 0.001 to 0.3; z is 0.01 to 0.3; x is the oxygen content required for charge balance of the structure and The oxidative dehydration catalyst is Cu—K α having a crystalline structure having a Pba2-32 space group characterized by reflections determined using X-ray diffraction (XRD) as follows: 【Table 2】 dehydrogenating alkanes in said reaction zone to produce a product stream comprising olefins; A method comprising:

3. 3. The method of claim 2, wherein the dehydrogenation occurs in the presence of molecular oxygen.

4. 10. The process of claim 1, wherein the dehydrogenation occurs in the absence of oxygen.

5. 5. The process of any one of claims 1 to 4, wherein the dehydrogenation comprises contacting the feed stream with the oxidative dehydration catalyst in the reaction zone at a temperature of from 300°C to 700°C.

6. 5. The process of any one of claims 1 to 4, wherein the dehydrogenation comprises contacting the feed stream with the oxidative dehydration catalyst in the reaction zone at a temperature of from 400°C to 500°C.

7. 5. The process of any one of claims 1 to 4, wherein the dehydrogenation comprises contacting the feed stream with the oxidative dehydration catalyst in the reaction zone at a pressure of from 0 bar(g) (0 KPa) to 20 bar(g) (2000 KPa).

8. 5. The process of any one of claims 1 to 4, wherein the dehydrogenation comprises contacting the feed stream with the oxidative dehydration catalyst in the reaction zone at a pressure of from 0 bar(g) (0 KPa) to 10 bar(g) (1000 KPa).

9. 5. The process of any one of claims 1 to 4, wherein the dehydrogenation comprises contacting the feed stream with the oxidative dehydration catalyst in the reaction zone, and wherein the feed stream has a weight hourly space velocity (WHSV) of from 1 / hr to 10 / hr.

10. 5. The process of any one of claims 1 to 4, wherein the reaction zone is selected from the group consisting of a fluidized bed reactor, a moving bed reactor, a fixed bed reactor, an upflow reactor, or an ebullated bed reactor.

11. 11. The process of claim 10, wherein the reaction zone is a fluidized bed reactor.

12. 11. The method of claim 10, wherein the oxidative dehydration catalyst is regenerated in the regeneration zone using an oxygen-containing gas stream having from 2% to 22% oxygen by volume.

13. 13. The method of claim 12, wherein the oxygen-containing gas stream is diluted or undiluted air.

14. 12. The method of claim 11, wherein the pressure in the regeneration zone is from 0 bar(g) (100 KPa) to 21 bar(g) (1000 KPa).

15. 5. The method of any one of claims 1 to 4, wherein the product stream is further processed to remove at least one of oxygenates, carbon monoxide, carbon dioxide, and alkanes from the product stream.

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