Catalysts and processes for the dehydrogenation of alkanes to olefins.

Abstract

Formula Mo u V v Nb w Sb y Bi z O x where u is 1, v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.2, z is 0.03 to 0.2, and x is the oxygen content required for charge balance of the structure. The oxidative dehydrogenation catalyst is a Cu-K catalyst as shown in Table (1). α It contains a crystalline structure (Pba2-32 space group) characterized by reflections determined using X-ray diffraction (XRD). [Table 1] JPEG2026507786000006.jpg29170

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to European Patent Application No. 23382181.8, filed February 28, 2023, entitled "CATALYST AND PROCESS FOR ANAEROBIC OXIDATIVE DEHYDROGENATION OF ETHANE," which is incorporated herein by reference in its entirety.

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

[0003] Conventional catalysts for converting alkanes to olefins, such as converting ethane to ethylene and acetic acid, are based on molybdenum (Mo), vanadium (V), and niobium (Nb) and include promoters such as calcium (Ca), sodium (Na), antimony (Sb), or tellurium (Te). Te, in particular, is a common promoter 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) (or about 20 barg). Summary of the Invention

[0004] According to one embodiment, the oxidative dehydrogenation catalyst is represented by the formula (i) Mo u V v Nb w Sb y Bi z O xwherein u is 1, v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.2, z is 0.03 to 0.2, and x is the oxygen content required for charge balance of the structure; and (ii) a Cu-K α and a crystalline structure having a Pba2-32 space group characterized by reflections determined using X-ray diffraction (XRD) as follows:

[0005] [Table 1]

[0006] According to another embodiment, a method for forming an oxidative dehydrogenation catalyst includes adding a molybdenum-containing compound, a vanadium-containing compound, a bismuth-containing compound, a niobium-containing compound, an antimony-containing compound, and one or more organic acids to a mixture of a complexing agent and water; and hydrothermally synthesizing the compound at a hydrothermal synthesis temperature for a period of time to form a complexing agent. u V v Nb w Sb y Bi z O x wherein u is 1, v is 0.1-0.5, w is 0.001-0.3, y is 0.001-0.2, z is 0.03-0.2, and x is the oxygen content required for charge balance of the structure; and u V v Nb w Sb y Bi z O x and separating the

[0007] In another embodiment, a method for converting paraffins to olefins comprises contacting a feed stream comprising paraffins with an oxidative dehydrogenation catalyst; converting at least a portion of the paraffins to olefins, thereby obtaining a product stream comprising paraffins and olefins; and separating the olefins from the paraffins in the product stream, wherein the oxidative dehydrogenation catalyst is a catalyst of formula (i) Mo u V v Nb w Sb y Bi z O x wherein u is 1, v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.2, z is 0.03 to 0.2, and x is the oxygen content required for charge balance of the structure; and (i) a Cu-K α and a crystalline structure (Pba2-32 space group) characterized by reflections determined using X-ray diffraction (XRD) as follows:

[0008] [Table 2]

[0009] As one skilled 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.

[0010] 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 and Claims below.

[0011] It is to be understood that both the foregoing general description and the following detailed description are intended to describe various embodiments and provide an overview or framework for understanding the nature and character of the claimed subject matter. [Brief explanation of the drawings]

[0012] The following detailed description can be better understood when read in conjunction with the following drawings. [Figure 1] 1 is a graph of ethylene productivity as a function of oxygen extracted from the catalyst at different space velocity conditions. DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference will now be made in detail to embodiments of catalysts for the dehydrogenation of alkanes to olefins, for example, catalysts for converting ethane to ethylene, and methods for making such catalysts.

[0014] One problem with conventional oxidative dehydrogenation processes is the need for a co-feed stream of oxygen (O). This increases the cost of the process by requiring 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 the oxygen mixes with hydrocarbons. Conventional catalysts also require a certain amount of oxygen to remain stable. Finally, due to the nature of the catalyst and the oxygen demand for dehydrogenating alkanes, conventional oxidative dehydrogenation processes for converting alkanes to olefins are conducted in fixed-bed reactors, which requires downtime to remove and replace or regenerate the catalyst. Therefore, there is a need for improved catalysts capable of converting alkanes to olefins. While conventional catalysts can be used in oxidative dehydrogenation, they exhibit limited stability when operated in a cyclic redox mode or under conditions with low partial pressures of O, typically encountered in the bottom of a fixed-bed reactor, due to chemical changes or reduction and loss of elements such as tellurium.

[0015] In cyclic redox mode, one important aspect is that the oxygen capacity of the catalyst must be sufficiently high (>0.8 wt%) to obtain substantial per-pass ethane conversion (>40%) at commercially feasible solids / ethane feed rates in various circulating bed reactor technologies. Previously disclosed MoVNbBiOx-type catalyst compositions typically have limited apparent oxygen capacities of approximately 0.4–0.5 wt% of the extractable lattice oxygen, which precludes them from delivering the amount of oxygen required for commercially feasible solids / ethane feed rates. On the other hand, while MoVNbSbOx-type catalysts exhibit higher oxygen capacities than MoVNbBiOx-type catalyst compositions, these MoVNbSbOx-type catalysts typically have low selectivity to ethylene (approximately 65%), resulting in the loss of a significant amount of their lattice oxygen to form CO and CO.

[0016] Unexpectedly, it has been discovered that the addition of small amounts of antimony (Sb) to the MoVNbBiOx-type materials disclosed and described herein substantially increases the oxygen capacity, enabling sustained ethane conversion at lower solids / ethane feed rates while maintaining high ethylene selectivity (>75%). The addition of Sb to the MoVNbBiOx structure significantly increases the apparent oxygen capacity of the catalyst from 0.4 wt% to approximately 0.7-1.2 wt%, depending on the exact composition of the MoVNbSb,BiOx material.

[0017] In one or more embodiments, the oxidative dehydrogenation catalyst has the following formula: Mo u V v Nb w Sb y Bi z O xwhere u is 1.0 (e.g., Mo is used as the atomic ratio standard), v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.2, z is 0.03 to 0.2, and x is the oxygen content required for charge balance of the structure. In embodiments, v is 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, w 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, y is 0.001 to 0.2, 0.001 to 0.01, 0.001 to 0.1, 0.001 to 0.05, 0.001 to 0.005, 0.01 to 0.1, 0.05 to 0.1, 0.001 to 0.002, or 0.001 to 0.005. 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 a compound represented by the following formula: MoV 0.2-0.3 Nb 0.005-0.02 Sb 0.05-0.15 Bi 0.05-0.15 O x where x is the oxygen content required for charge balance of the structure. v V w Nb y Bi z O xIt should be understood that embodiments of the catalyst have a Pba2-32 space that is essentially Te-free, such as having a Te / Mo atomic ratio of 0.01 or less.

[0018] The crystalline structure of the oxidative dehydrogenation catalysts disclosed and described herein can, in embodiments, be determined using X-ray diffraction (XRD). For example, as will be understood by those skilled in the art, the positions and relative intensities of XRD peaks at various 2θ angles can be used to describe the crystalline structure of the oxidative dehydrogenation catalyst. In embodiments, the oxidative dehydrogenation catalyst is a Cu-K catalyst, as shown in Table 1. α In Table 1 below, the relative intensity of the diffractogram feature is greatest at 2θ=22.17°, so this relative intensity is set to 100% and used as the basis for the remaining relative intensities shown in Table 1. As one skilled in the art will recognize, relative intensities can be affected by preferred orientation effects, and the relative intensities disclosed above take such effects into account.

[0019] [Table 3]

[0020] As described above, the use of certain hydrothermal methods for forming oxidative dehydrogenation catalysts allows for the formation of oxidative dehydrogenation catalysts having the desired Pba2-32 crystal structure. Embodiments of these hydrothermal methods for forming oxidative dehydrogenation catalysts are now described in more detail.

[0021] Mo u V v Nb w Sb y Bi z O xIn 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, an antimony-containing compound, and a niobium-containing compound, and one or more organic acids to a mixture of alkylene glycol or alcohol amine and water to form a reaction mixture. In embodiments, the metal precursor is selected so that the precursor can dissolve / decompose under hydrothermal reaction conditions. Mo is then extracted from the reaction mixture by hydrothermal synthesis at the following hydrothermal synthesis temperature for a period of time: u V v Nb w Sb y Bi z O x After the above time has elapsed, Mo is synthesized from the retained liquid. u V v Nb w Sb y Bi z O x In one or more embodiments, the molybdenum-containing compound, the vanadium-containing compound, the bismuth-containing compound, the antimony-containing compound, the niobium-containing compound, and the one or more acids are added sequentially to a mixture of alkylene glycol and water.

[0022] In embodiments, the bismuth-containing compound is selected from the group consisting of bismuth oxide (BiO), bismuth sulfate (Bi(SO)), bismuth citrate (BiCHO), and bismuth nitrate (Bi(NO)). In embodiments, the niobium-containing compound is selected from the group consisting of niobium oxide, niobic acid (NbO·nHO), niobium ethoxide, and ammonium niobium oxalate hydrate ((NH)Nb(CO)·nHO). In embodiments, the molybdenum-containing compound is ammonium heptamolybdate (NH)MoO. 24or molybdenum trioxide (MoO), and the vanadium-containing compound may be ammonium metavanadate (NHVO), vanadyl sulfate (VOSO), or vanadium pentoxide (VO). In embodiments, the antimony-containing compound is selected from the group consisting of antimony trioxide (SbO) and antimony pentoxide (SbO). The molybdenum-containing compound and vanadium-containing compound are, in embodiments, MoO and VO, respectively. In some embodiments, decomposable mixtures of metal-containing compounds having precise stoichiometric ratios of one or more of Mo, V, Nb, Sb, and Bi can be used. Examples of such decomposable mixtures include (Mo,V)O x and BiNbO x , SbVOx, and BiMoOx. 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.

[0023] 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 240°C, 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 The heating temperature is 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.

[0024] 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 (4 bar (400 kPa) to 10 bar (1000 kPa), or 5 bar (500 kPa) to 10 bar (1000 kPa).

[0025] According to an embodiment, Mo is extracted from the retained liquid. u V v Nb w Sb y Bi z O x After separating the oxidative dehydrogenation catalyst, Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is dried and optionally dried Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is heated to a calcination temperature and u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is calcined by holding it at the calcination temperature for a period of time.

[0026] In an embodiment, Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst may be dried at any suitable temperature. However, to facilitate drying, in embodiments, the oxidative dehydrogenation catalyst may be dried at a temperature of 65°C to 200°C, 75°C to 200°C, 100°C to 200°C, 125°C to 200°C, 150°C to 200°C, 175°C to 200°C, 65°C to 175°C, 75°C to 175°C, 100°C to 175°C, 125°C to 175°C, 150°C to 175°C, 65°C to 150°C, 75°C to 150°C, 100°C to 150°C, 125°C to 150°C, 65°C to 125°C, 75°C to 125°C, 100°C to 125°C, 65°C to 100°C, 75°C to 100°C, or 65°C to 75°C. u V v Nb w Sby Bi z O x The oxidative dehydrogenation catalyst may be dried.

[0027] In embodiments, calcination is carried out in an inert atmosphere such as nitrogen (N), argon (Ar), or helium (He). In such embodiments, 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 °C~575°C, 500°C~575°C, 525°C~575°C, 550°C~575°C, 350°C~550°C, 375°C~550°C, 400°C~550°C, 425°C~550°C, 450°C~550°C, 475°C~550°C, 500°C~550°C, 525°C~550°C, 350°C~525°C, 375°C~525°C, 400°C~525°C, 425°C~525°C, 450°C~525°C, 475°C~525°C, 500°C~525°C, 350°C~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.

[0028] In embodiments, calcination is carried out in air. In such embodiments, the calcination temperature can be 200°C to 500°C, 200°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.

[0029] Mo u V v Nb w Sb y Bi z O x After the oxidative dehydrogenation catalyst was formed, Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalysts can be used in processes for converting alkanes in an alkane-containing feed stream to olefins. The processes disclosed and described herein exhibit a high conversion of Mo to olefins as the time on stream increases. u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst can provide improved olefin selectivity. The process disclosed and described herein generally involves the reaction of a feed stream containing alkanes (paraffins) with Mo u V v Nb w Sb y Bi z O xThe method includes contacting a material comprising an oxidative dehydrogenation catalyst to convert at least a portion of the alkanes into olefins to obtain a product stream comprising paraffins and olefins. It should be understood that the oxidative dehydrogenation catalyst may be used alone or in combination with other additives. 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 embodiments. In embodiments, the reaction zone may be a fixed-bed reactor, a fluidized-bed reactor, a moving-bed reactor, an ebullated-bed reactor, a circulating-flow reactor, a countercurrent reactor, or an ebullated-bed reactor (each optionally with oxygen co-feed). The reaction zone is not particularly limited to a single reaction zone, but may consist of multiple reactors in a series or parallel configuration. 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. Processes according to embodiments disclosed and described herein are provided in more detail below.

[0030] According to embodiments, a feed stream is provided to the reaction zone, the feed stream comprising at least one alkane. In embodiments, the feed stream may be composed entirely of alkanes (e.g., 100% alkanes). In one or more embodiments, the feed stream may contain oxygen, steam, and / or inert gases. In embodiments, the feed stream may be comprised 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% to 90% alkanes, 85% to 90% alkanes. % alkanes by volume, 30% to 85% alkanes by volume, 35% to 85% alkanes by volume, 40% to 85% alkanes by volume, 45% to 85% alkanes by volume, 50% to 85% alkanes by volume, 55% to 85% alkanes by volume, 60% to 85% alkanes by volume, 65% to 85% alkanes by volume, 70% to 85% alkanes by volume, 75% to 85% alkanes by volume, 80% to 85% alkanes by volume, 30% to 80% alkanes by volume, 35% to 80% by volume alkanes, 40% to 80% by volume alkanes, 45% to 80% by volume alkanes, 50% to 80% by volume alkanes, 55% to 80% by volume alkanes, 60% to 80% by volume alkanes, 65% to 80% by volume alkanes, 70% to 80% by volume alkanes, 75% to 80% by volume alkanes, 30% to 75% by volume alkanes, 35% to 75% by volume alkanes, 40% to 75% by volume alkanes, 45% to 75% by volume alkanes, 50% by volume % to 75% by volume alkanes, 55% to 75% by volume alkanes, 60% to 75% by volume alkanes, 65% to 75% by volume alkanes, 70% to 75% by volume alkanes, 30% to 70% by volume alkanes, 35% to 70% by volume alkanes, 40% to 70% by volume alkanes, 45% to 70% by volume alkanes, 50% to 70% by volume alkanes, 55% to 70% by volume alkanes, 60% to 70% by volume alkanes, 65% to 70% by volume alkanes,30% to 65% by volume alkanes, 35% to 65% by volume alkanes, 40% to 65% by volume alkanes, 45% to 65% by volume alkanes, 50% to 65% by volume alkanes, 55% to 65% by volume alkanes, 60% to 65% by volume alkanes, 30% to 60% by volume alkanes, 35% to 60% by volume alkanes, 40% to 60% by volume alkanes, 45% to 60% by volume alkanes, 50% to 60% by volume alkanes, 55% to 60% by volume alkanes, 30% to 55% by volume alkanes, 35% to 5 The alkanes may include 5% by volume alkanes, 40% to 55% by volume alkanes, 45% to 55% by volume alkanes, 50% to 55% by volume alkanes, 30% to 50% by volume alkanes, 35% to 50% by volume alkanes, 40% to 50% by volume alkanes, 45% to 50% by volume alkanes, 30 volume percent (vol%) to 45% by volume alkanes, 35% to 45% by volume alkanes, 40% to 45% by volume alkanes, 30% to 40% by volume alkanes, 35% to 40% by volume alkanes, or 30% to 35% by volume alkanes.

[0031] In embodiments, the at least one alkane is selected from the group consisting of ethane, propane, and combinations thereof. In embodiments, the inert gas is selected from the group consisting of nitrogen, CO2, and combinations thereof.

[0032] According to one or more embodiments, Mo in the reaction zone u V v Nb w Sb y Bi z O xThe weight ratio of the oxidative dehydrogenation catalyst to the alkane in the reaction zone 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, 100-50, 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 alkane and the mass feed rate of catalyst to the reaction zone.

[0033] In embodiments, the feed stream is essentially oxygen-free, meaning that the feed stream contains less than 2.0 percent by volume (vol%) oxygen, less than 1.5% by volume oxygen, or less than 0.5% by volume oxygen. In one or more embodiments, the feed stream is oxygen-free.

[0034] In one or more embodiments, an oxygen stream is added to the reaction zone. The oxygen concentration in the oxygen stream is not particularly limited. For example, the oxygen concentration in the oxygen stream may be 0.1% by volume to 99.9% by volume, such as 5.0% by volume to 95.0% by volume, 10.0% by volume to 90.0% by volume, 15.0% by volume to 85.0% by volume, 20.0% by volume to 80.0% by volume, 25.0% by volume to 75.0% by volume, 30.0% by volume to 70.0% by volume, 35.0% by volume to 65.0% by volume, 40.0% by volume to 60.0% by volume, or 45.0% by volume to 55.0% by volume. In one or more embodiments, the oxygen concentration in the oxygen stream is relatively low, e.g., 0.1% to 5.0% by volume, 0.2% to 5.0% by volume, 0.5% to 5.0% by volume, 0.8% to 5.0% by volume, 1.0% to 5.0% by volume, 1.2% to 5.0% by volume, 1.5% to 5.0% by volume, 1.8% to 5.0% by volume, 2.0% to 5.0% by volume, 2.2% to 5.0% by volume, 2.5% to 5.0% by volume, 2.8% to 5.0% by volume, 3.0% to 5.0% by volume, 3.2% to 5.0% by volume, 3.5% to 5.0% by volume, 3.8% to 5.0% by volume, 4.0% to 5.0% by volume, 4.2% to 5.0% by volume, 4.5% to 5.0% by volume, or 4.8% to 5.0% by volume. In an embodiment, the oxygen stream may be air, generally having an oxygen concentration of about 21.0% by volume.

[0035] In embodiments, the oxygen stream may be added to the reaction zone subsequent to the feed stream, such that the feed stream and oxygen stream are not added to the reaction zone simultaneously. It should be understood that in embodiments, the oxygen stream may be added at various points in the reaction process. This may be accomplished by introducing the oxygen stream to the reaction zone at different locations within the reaction zone and / or by introducing the oxygen stream at different time frames while the reaction is occurring.

[0036] In one or more embodiments, the oxygen stream is added to the reaction zone simultaneously with the feed stream. In such embodiments, the volumetric ratio of oxygen (in the oxygen stream) to alkane (in the feed stream) in the reaction zone is greater than 0.0 to 1.0, 0.1 to 1.0, 0.2 to 1.0, 0.3 to 1.0, 0.4 to 1.0, 0.5 to 1.0, 0.6 to 1.0, 0.7 to 1.0, 0.8 to 1.0, 0.9 to 1.0, or greater than 0.0 to 0.2, 0.0 to 0.3, 0.0 to 0.4, 0.0 to 0.5, 0.0 to 0.6, 0.0 to 0.7, 0.0 to 0.8, or 0.0 to 0.9.

[0037] The feed stream is reacted with Mo as disclosed and described herein in a reaction zone under reaction conditions sufficient to form a product stream comprising olefins. u V v Nb w Sb y Bi z The reaction conditions include a temperature range within the reaction zone, and according to one or more embodiments, the temperature within the reaction zone is between 300°C and 700°C, between 350°C and 700°C, between 400°C and 700°C, between 450°C and 700°C, between 500°C and 700°C, between 550°C and 700°C, between 600°C and 700°C, between 650°C and 700°C, between 300°C and 650°C, between 350°C and 650°C, between 400°C and 650°C, between 450°C and 650°C, between 500°C and 650°C, between 550°C and 650°C, between 600°C and 600°C, between 300°C and 600°C. , 350°C to 600°C, 400°C to 600°C, 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.

[0038] In embodiments, the reaction conditions may also be 0 barg (0 kPa) to 20 barg (2000 kPa), 5 barg (500 kPa) to 20 barg (2000 kPa), 10 barg (1000 kPa) to 20 barg (2000 kPa), 15 barg (1500 kPa) to 20 barg (2000 kPa), 0 barg (0 kPa) to 15 barg (1500 kPa). , 5 barg (500 kPa) to 15 barg (1500 kPa), 10 barg (1000 kPa) to 15 barg (1500 kPa), 0 barg (0 kPa) to 10 barg (1000 KPa), 5 barg (500 kPa) to 10 barg (1000 KPa), or 0 barg (0 kPa) to 5 barg (500 KPa).

[0039] According to embodiments, the weight hour space velocity (WHSV) of the alkane feed stream, and optionally the oxygen stream, in the reaction zone is between 0.1 / hour ( / h) and 10.0 / h, between 0.5 / h and 10.0 / h, between 1.0 / h and 10.0 / h, between 2.0 / h and 10.0 / h, between 3.0 / h and 10.0 / h, between 4.0 / h and 10.0 / h, between 5.0 / h and 10.0 / h, between 6.0 / h and 10.0 / h, between 7.0 / h and 10.0 / h, between 8.0 / h and 10.0 / h, between 9.0 / h and 10.0 / h, between 0.1 / h and 9.0 / h, between 0.5 / h and 9.0 / h, between 1.0 / h and 9.0 / h, between 2.0 / h and 9.0 / h. 0 / h, 3.0 / h~9.0 / h, 4.0 / h~9.0 / h, 5.0 / h~9.0 / h, 6.0 / h~9.0 / h, 7.0 / h~9.0 / h, 8.0 / h~9.0 / h, 0.1 / h~8.0 / h, 0.5 / h~8.0 / h, 1.0 / h~8.0 / h, 2.0 / h~8.0 / h, 3.0 / h~8.0 / h, 4.0 / h~8.0 / h, 5.0 / h~8.0 / h, 6.0 / h~8.0 / h, 7.0 / h~8.0 / h, 0.1 / h~7.0 / h, 0.5 / h~7.0 / h , 1.0 / h~7.0 / h, 2.0 / h~7.0 / h, 3.0 / h~7.0 / h, 4.0 / h~7.0 / h, 5.0 / h~7.0 / h, 6.0 / h~7.0 / h, 0.1 / h~6.0 / h, 0.5 / h~6.0 / h, 1.0 / h~ 6.0 / h, 2.0 / h~6.0 / h, 3.0 / h~6.0 / h, 4.0 / h~6.0 / h, 5.0 / h~6.0 / h, 0.1 / h~5.0 / h, 0.5 / h~5.0 / h, 1.0 / h~5.0 / h, 2.0 / h~5.0 / h, 3. 0 / h~5.0 / h, 4.0 / h~5.0 / h, 0.1 / h~4.0 / h, 0.5 / h~4.0 / h, 1.0 / h~4.0 / h, 2.0 / h~4.0 / h, 3.0 / h~4.0 / h, 0.1 / h~3.0 / h, 0.5 / h~3.0 / h, 1.0 / h~3.0 / h, 2.0 / h~3.0 / h, 0.1 / h~2.0 / h, 0.5 / h~2.0 / h, 1.0 / h~2.0 / h, 0.1 / h~1.0 / h, 0.5 / h~1.0 / h, or 0.1 / h~0.5 / h. [Example]

[0040] 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). With stirring, 2.7126 g of MoO3, 0.0.3427 g of V2O5, 0.4373 g of Bi2O3, 0.0421 g of (NH4)Nb(C2O4)2.xH2O, 0.1366 g of Sb2O3, 0.2711 g of citric acid, and 0.4775 g of oxalic acid were added sequentially and stirred for 10 minutes. The mixture was then heated at 190 °C in a rotating shaft oven at 10 rpm for 48 hours. The MoV 0.2 Nb 0.005 Bi 0.1 Sb 0.01 Ox was hydrothermally synthesized. The resulting material was purified using vacuum filtration with 200 mL of deionized water and then dried at 85 °C overnight.

[0041] After drying, the material was calcined under flowing N2 at 450 °C (heating rate 2 °C / min) 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. The reaction conditions are discussed in detail below.

[0042] Comparative Example 1 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, 0.0842 g of (NH4)Nb(C2O4)2.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 heated at 190 °C in a rotating shaft oven at 10 rpm for 48 hours. 0.3 Nb 0.01 Bi 0.1 Ox was hydrothermally synthesized. The resulting material was purified using vacuum filtration with 200 mL of deionized water and then dried at 85 °C overnight.

[0043] After drying, the material was calcined under flowing N2 at 450 °C (heating rate 2 °C / min) 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. The reaction conditions are discussed in detail below.

[0044] Reactor Testing Performance tests were conducted in a fixed-bed reactor setup in SINTEF (High-Pressure Reactor Assembly Module) with an SS316 reactor tube (3 mm internal diameter). For catalytic testing, 250–350 mg of 40–80 mesh catalyst particles were loaded into the reactor, and the reactor was operated in a cyclic mode, alternating periods of ethane exposure with inert gas purging and oxidative regeneration at the desired temperature.

[0045] The lattice oxidative dehydrogenation (LODh) step used a flow of 50% by volume ethane in helium of 15-20 mL / min at a pressure of 2.5 bar (absolute) and a WHSV of 1.7-3.0 h / min.

[0046] The regeneration step used a flow of 10 mL / min of 2.5% by volume O2 in helium at a pressure of 2.5 bar (absolute).

[0047] The reactor effluent composition is obtained by gas chromatography (GC) and the conversion and carbon-based selectivity are calculated using the following equations:

[0048] XC2H6(%) = [(ηC2H6, inlet - ηC2H6, outlet) / ηC2H6, inlet] 100, and (1) S j (%)=[αj·ηj,exit / Σαj·ηj,exit]·100 (2) where XC2H6 is defined as C2H6 conversion (%), η,inlet is defined as the molar inlet flow rate of the component (mol / min), η,outlet is the molar outlet flow rate of the component (mol / min), and S jis defined as the carbon-based selectivity (%) for product j, and αj is the number of carbon atoms in product j. Carbon balances for all experiments were within 99–102%.

[0049] The catalyst / ethane ratio (g / g) is calculated based on the time-on-stream (TOS, min) that the GC analyzes the reactor effluent. Catalyst / ethane = w / (TOS·ηC2H6, inlet·MW C2H6 ) (3) where w is defined as the catalyst mass, ηC2H6, inlet is the molar inlet flow rate of ethane (mol / min), and MW C2H6 is the molecular weight of ethane (30 g / mol).

[0050] Ethylene productivity (g / g catalyst / hr) is calculated using the following formula: C2H4 productivity = [ηC2H6, inlet × 60 × XC2H6 × S C2H4 / 100)×MW C2H4 ] / w In the formula, MW C2H4 is defined as the molecular weight of ethylene (28 g / mol).

[0051] The results of the catalyst test at 450°C are shown in Figure 1, which plots ethylene productivity as a function of oxygen extracted from the catalyst at different space velocity conditions.

[0052] It can be observed that the composition of Example 1 (solid line) can maintain a much higher ethylene productivity rate over a wider range of extracted lattice oxygen than the Sb-free composition of Comparative Example 1 (dashed line) for both low and high space velocity conditions. As can be observed from the dashed line, catalyst productivity drops to very low levels (<0.2 kg / kg cat-hr) once more than 0.4-0.5 wt.% lattice oxygen is extracted, regardless of space velocity. The catalyst according to the present invention can maintain higher productivity levels (>0.5 kg / kg cat-hr) even when >0.8 wt.% O is previously removed from the catalyst. This is due to the fact that the Sb-promoted MoVNbBiO xThis highlights the excellent oxygen capacity and availability of the material.

[0053] 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 they come within the scope of the appended claims and their equivalents.

Claims

1. 1. An oxidative dehydrogenation catalyst comprising: (i) formula Mo ｕ V ｖ Nb ｗ Sb ｙ Bi ｚ O ｘ wherein u is 1, v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.2, z is 0.03 to 0.2, and x is the oxygen content required for charge balance of the structure; (ii) a crystallographic structure having a Pba2-32 space group characterized by reflections determined using Cu-Kα X-ray diffraction (XRD) as follows: Table 1

2. 1. An oxidative dehydrogenation catalyst comprising: Formula Mo ｕ V ｖ Nb ｗ Sb ｙ Bi ｚ O ｘ 2. The oxidative dehydrogenation catalyst according to claim 1, comprising a structure comprising oxides of molybdenum (Mo), vanadium (V), niobium (Nb), antimony (Sb), and bismuth (Bi), having the formula:

3. 10. The oxidative dehydrogenation catalyst of claim 1, essentially free of tellurium (Te).

4. 1. A method for forming an oxidative dehydrogenation catalyst, comprising: adding a molybdenum-containing compound, a vanadium-containing compound, a bismuth-containing compound, a niobium-containing compound, an antimony-containing compound, and one or more organic acids to a mixture of an alkylene glycol or alcohol amine and water to form a starting mixture; treating the starting mixture by hydrothermal synthesis at a hydrothermal synthesis temperature of 150°C to 250°C; Mo from the retained liquid ｕ V ｖ Nb ｗ Sb ｙ Bi ｚ O ｘ and Including, The starting mixture is molybdenum trioxide (MoO ３ ) and vanadium pentoxide (V ２ O ５ ) .

5. The one or more organic acids are citric acid (C ６ H ８ O ７ ), oxalic acid (C ２ H ２ O ４ 5. A method for forming the oxidative dehydrogenation catalyst of claim 4, comprising at least one of:

6. The niobium-containing compound is niobium oxide, niobic acid (Nb ２ O ５ ・xH ２ O), ammonium niobium oxalate hydrate ((NH ４ )Nb(C ２ O ４ ) ２ .nH ２ 6. A method for forming the oxidative dehydrogenation catalyst of claim 4 or claim 5, wherein the catalyst is selected from the group consisting of niobium ethoxide, niobium ethoxide, and mixtures thereof.

7. The bismuth-containing compound is bismuth oxide (Bi ２ O ３ ), bismuth sulfate (Bi ２ (SO ４ ) ３ ), bismuth citrate (BiC ６ H ５ O ７ ), and bismuth nitrate (Bi(NO ３ ) ３ 7. A method for forming the oxidative dehydrogenation catalyst of claim 4, wherein the oxidative dehydrogenation catalyst is selected from the group consisting of:

8. The antimony-containing compound is antimony trioxide (Sb ２ O ３ ) and antimony pentoxide (Sb ２ O ５ 8. A method for forming the oxidative dehydrogenation catalyst of claim 4, wherein the oxidative dehydrogenation catalyst is selected from the group consisting of:

9. The alkylene glycol is ethylene glycol (C ２ H ６ O ２ 9. The method of forming the oxidative dehydrogenation catalyst of claim 4, wherein

10. 10. The method for forming an oxidative dehydrogenation catalyst according to any one of claims 5 to 9, wherein the hydrothermal synthesis temperature is from 150°C to 250°C, for example from 180°C to 220°C, more preferably from 180°C to 210°C.

11. The starting mixture is MoO ３ and V ２ O ５ A method for forming the oxidative dehydrogenation catalyst of any one of claims 5 to 10, comprising:

12. 1. A method for converting paraffins to olefins, comprising: contacting a feed stream comprising paraffins with a material comprising the oxidative dehydrogenation catalyst of any one of claims 1 to 4; converting at least a portion of the paraffins to olefins, thereby obtaining a product stream comprising paraffins and olefins; separating the olefins from the paraffins in the product stream; A method comprising:

13. 13. The method of claim 12, further comprising contacting a second stream comprising oxygen with the feed stream comprising the paraffins and the oxidative dehydrogenation catalyst.

14. 15. The process of claim 13, wherein the conversion occurs at an alkane weight hourly space velocity (WHSV) that is between 0.1 / hr and 10 / hr.

15. The oxidative dehydrogenation catalyst is represented by the following formula: MoV ０．２－０．３ Nb ０．００５－０．０２ Sb ０．０５－０．１５ Bi ０．０５－０．１５ O ｘ 15. The method of any one of claims 1 to 14, wherein x is the oxygen content required for charge balance of the structure.

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