Catalysts and processes for the dehydrogenation of alkanes to olefins.

Abstract

Formula Mo v V w A y Bi z O x (wherein v is 1, w is 0.2 to 0.5, A is W or Ta, y is 0.001 to 0.3, z is 0.01 to 0.3, and x is the oxygen content required for charge balance of the structure). The oxidative dehydrogenation catalyst is a Cu-K α Contains a crystalline structure (Pba2-32 space group) characterized by reflections determined using X-ray diffraction (XRD) as follows: 2θ (±0.3°) Relative Intensity (%) 5.3 0.2 -10 6.6 1.5 -15 7.8 42.5 -45 8.9 54 -21 22.1 7100 27.2 20 -70

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to European Patent Application No. 23382182.6, filed February 28, 2023, entitled "MIXED METAL OXIDE CATALYST FOR 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 v V w A y Bi z O x (ii) a structure comprising oxides of molybdenum (Mo), vanadium (V), tungsten (W) or tantalum (Ta), and bismuth (Bi), having the formula (wherein v is 1, w is 0.2 to 0.5, A is W or Ta, y is 0.001 to 0.3, z is 0.01 to 0.3, and x is the oxygen content required for charge balance of the structure); and (iii) a structure comprising oxides of Cu—Kα 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, and a tungsten- or tantalum-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. v V w A y Bi z O x (wherein v is 1, w is 0.2-0.5, A is W or Ta, 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 extracting Mo from the retained liquid. v V w A 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 v V w A y Bi z O x(ii) a structure comprising an oxide of molybdenum (Mo), vanadium (V), tungsten (W) or tantalum (Ta), and bismuth (Bi), having the formula (wherein v is 1, w is 0.2 to 0.5, A is W or Ta, y is 0.001 to 0.3, z is 0.01 to 0.3, and x is the oxygen content required for charge balance of the structure); and (iii) a structure comprising an oxide of 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. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 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 the presence of a certain amount of oxygen to remain stable. Furthermore, the oxidative dehydrogenation (ODH) of hydrocarbons such as ethane results in the formation of alkenes such as ethylene and HO. Unfortunately, typical catalysts used in ODH also result in the formation of undesirable by-products such as carbon oxides and oxygenated hydrocarbons, e.g., acetic acid. 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 carried out in fixed-bed reactors, which requires downtime for catalyst removal and replacement or regeneration. Therefore, there is a need for improved catalysts capable of converting alkanes to olefins. Although conventional catalysts can be used in oxidative dehydrogenation, they exhibit limited stability when operated in 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 transformation, reduction, and volatilization of elements such as tellurium.

[0014] It has been unexpectedly discovered that altering the composition of conventional oxidative dehydrogenation catalysts, as disclosed and described herein, allows for stable reduction and oxidation (redox) cycling 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, commercially feasible circulation rates can be used in the circulation reactor while achieving adequate conversion and selectivity of ethane to ethylene. This eliminates the need to supply oxygen to the reactor. Furthermore, air can be used to reoxidize spent catalyst. Furthermore, the reactor / regenerator system used to convert ethane is exothermic and can therefore be operated without additional heat input.

[0015] One known oxidative dehydrogenation catalyst is MoVNbTeO x Without being bound by any particular theory, MoVNbTeO x or a similar crystalline phase structure, e.g., the Pba2-32 space group, is believed to provide a structure that allows for high yields of the desired olefins. However, in the oxidative dehydrogenation process, this MoVNbTeO x The use of the catalyst in a reducing environment poses significant catalyst stability concerns because Te is volatile under reducing conditions, leading to reactor fouling by Te and potential disruption of the catalyst's favorable crystalline structure, which subsequently leads to a loss of activity / selectivity during alkane-to-olefin conversion.

[0016] In the embodiments disclosed and described herein, MoVNbTeO x Te in the catalyst composition can be completely replaced with bismuth (Bi), and Nb can further be completely replaced with tungsten (W) or tantalum (Ta). 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. xThus, the oxidative dehydrogenation catalyst according to the embodiment has a structure including molybdenum (Mo), vanadium (V), tungsten (W) or tantalum (Ta), and bismuth (Bi). The oxidative dehydrogenation catalyst mostly has a Pba2-32 space group crystal structure. When the volatile Te is replaced with Bi, it can be obtained similar to the known MoVNbTeO while providing similar alkane conversion. x This allows for improved material stability over conventional catalysts. For example, in embodiments, the oxidative dehydrogenation catalysts disclosed and described herein are surprisingly active (greater than 10% ethane conversion) and selective (greater than 75% ethylene selectivity), providing stable performance under cyclic redox reaction conditions.

[0017] In one or more embodiments, the oxidative dehydrogenation catalyst has the following formula: Mo v V w A y Bi z O x(wherein v is 1.0 (for example, Mo is used as the standard for atomic ratio), w is 0.2 to 0.5, A is W or Ta, y is 0.001 to 0.3, 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 0.2 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 a compound represented by the following formula: MoV 0.3 W 0.1 Bi 0.1 O x where x is the oxygen content required for charge balance of the structure. In embodiments, the oxidative dehydrogenation catalyst has the formula: MoV 0.3 Ta 0.1 Bi 0.1 O x where x is the oxygen content required for charge balance of the structure. v V w A y Bi z O x It should be understood that embodiments of the catalyst include Pba2-32 spaces that are essentially Te-free, such as having a Te / Mo atomic ratio of 0.01 or less.

[0018] Structural Mo v V w A y Bi z O x where A is W or Ta, and the presence of W or Ta in an oxidative dehydrogenation catalyst having the Pba2-32 space group crystal structure has been found to improve the activity and selectivity of the catalyst in a lattice oxidative dehydrogenation process (where oxygen for conversion is extracted from the lattice of the catalyst rather than through a molecular oxygen feed stream). Thus, in embodiments, the oxidative dehydrogenation catalyst has the formula Mo v V w A y Bi z O x It consists of a structure containing oxides of Mo, V, W or Ta, and Bi, and a Pba2-32 space group crystal structure.

[0019] The crystalline structure of the oxidative dehydrogenation catalysts disclosed and described herein may, in embodiments, also 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 may be a Cu-K oxidative dehydrogenation 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.

[0020] [Table 3]

[0021] 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.

[0022] Mo v V w A 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 tungsten-containing compound, or a tantalum-containing compound, and one or more organic acids to a mixture of alkylene glycol or alcohol amine and water to form a reaction mixture. It should be understood that throughout this application, when "A" is used in the catalyst structure, it is intended to refer to either tungsten (W) or tantalum (Ta). 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 the hydrothermal synthesis temperature for a period of time. v V w A y Bi z O x After the above time has elapsed, Mo is synthesized from the retained liquid. v V w A y Bi z O x In one or more embodiments, the molybdenum-containing compound, vanadium-containing compound, bismuth-containing compound, tungsten-containing compound, or tantalum-containing compound, and one or more acids are added sequentially to a mixture of alkylene glycol and water.

[0023] In embodiments, the bismuth-containing compound is selected from the group consisting of bismuth oxide (BiO), bismuth sulfate (Bi(SO)), bismuth citrate (BiCHO), bismuth molybdate (Bi(MoO)), bismuth vanadate (BiVO), and bismuth nitrate (Bi(NO)). In embodiments, the tungsten-containing compound is selected from the group consisting of tungsten trioxide (WO), bismuth tungstate (Bi(WO)), and ammonium metatungstate hydrate ((NH)HW). 12 O 40 In an embodiment, the tantalum-containing compound is selected from the group consisting of tantalum oxide, tantalum alkoxide, and tantalum oxalate. In an embodiment, the molybdenum-containing compound is ammonium heptamolybdate (NH4)6Mo7O 24 or molybdenum trioxide (MoO), and the vanadium-containing compound may be ammonium metavanadate (NHVO), vanadyl sulfate (VOSO), or vanadium pentoxide (VO). The molybdenum-containing compound and vanadium-containing compound, in embodiments, are MoO and VO, respectively. In some embodiments, digestible mixtures of metal-containing compounds having precise stoichiometric ratios of one or more of Mo, V, W, or Ta, and Bi can be used. Examples of such digestible mixtures include (Mo,V)O x , BiWO x , and BiTaO 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.

[0024] 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.

[0025] 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),In an embodiment, the hydrothermal pressure is autogenous to the hydrothermal synthesis temperature.

[0026] According to an embodiment, Mo is extracted from the retained liquid. v V w A y Bi z O x After separating the oxidative dehydrogenation catalyst, Mo v V w A y Bi z O x The oxidative dehydrogenation catalyst is dried and optionally dried Mo v V w A y Bi z O x The oxidative dehydrogenation catalyst is heated to a calcination temperature and v V w A y Bi z O x The oxidative dehydrogenation catalyst is calcined by holding it at the calcination temperature for a period of time.

[0027] In an embodiment, Mo v V w A 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. v V w A y Bi z O xThe oxidative dehydrogenation catalyst may be dried.

[0028] 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.

[0029] 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.

[0030] Mo v V w A y Bi z O x After the oxidative dehydrogenation catalyst was formed, Mo v V w A 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. v V w A y Bi z O x The oxidative dehydrogenation catalyst can provide improved olefin selectivity. The process disclosed and described herein generally involves treating a feed stream containing alkanes (paraffins) with Mo in a reaction zone. v V w A y Bi z O xThe method includes contacting a material comprising an oxidative dehydrogenation catalyst with the material to convert at least a portion of the alkanes to olefins, thereby obtaining 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.

[0031] 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 The alkanes include 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% 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.

[0032] 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.

[0033] According to one or more embodiments, Mo in the reaction zone v V w A 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.

[0034] 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.

[0035] 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 embodiments, the oxygen stream may be air having an oxygen concentration of generally about 21.0% by volume.

[0036] 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 within 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.

[0037] 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.

[0038] 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. v V w A y Bi z O x 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.

[0039] The reaction conditions may also be, in embodiments, 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).

[0040] 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 / h ( / hour) 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]

[0041] 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). While stirring the mixture, 2.7126 g of MoO3, 0.5141 g of VO5, 0.4373 g of Bi2O3, 0.4391 g of WO3, 0.5141 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 minutes. 0.3 W 0.1 Bi 0.1 O x Hydrothermal synthesis of was carried out in a rotating shaft oven at 190 °C for 48 h with rotation at 10 rpm. The material obtained from hydrothermal synthesis was purified with 200 mL of deionized water using vacuum filtration. The sample was then dried overnight at 85 °C.

[0042] 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.

[0043] 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). While the mixture was being stirred, 2.7126 g of MoO3, 0.5141 g of VO5, 0.4373 g of Bi2O3, 0.5446 g of Bi2(WO4)3, 0.5422 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 minutes. 0.3 W 0.75 Bi 0.15 O x Hydrothermal synthesis of was carried out in a rotating shaft oven at 190 °C for 48 h with rotation at 10 rpm. The material obtained from hydrothermal synthesis was purified using vacuum filtration with 200 mL of deionized water. The material was then dried overnight at 85 °C.

[0044] 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.

[0045] Example 3 A mixture of 34 mL of H2O and 157 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 VO2, 0.4373 g of Bi2O3, 0.3643 g of Ta2O5, 0.5413 g of citric acid, and 0.2388 g of oxalic acid were added sequentially and stirred for 10 minutes. 0.3 Ta 0.087 Bi 0.1 O x Hydrothermal synthesis of was carried out in a rotating shaft oven at 200 °C for 48 h with rotation at 10 rpm. The material obtained from hydrothermal synthesis was purified using vacuum filtration with 200 mL of deionized water. The sample was then dried overnight at 85 °C.

[0046] After drying, the material was calcined under flowing N2 at 450 °C (heating rate 5 °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.

[0047] Comparative Example 1 In a glass beaker, 1.33 g of (NH)MoO was dissolved in water by magnetic stirring at room temperature. 24 In a separate beaker, 2.118 g of VOSO4·xH2O was dissolved in 90 mL of H2O. The contents of both beakers were then mixed in a 120 mL Teflon-inserted autoclave (Model 4748 General Purpose Acid Digestion Vessel, Parr). While stirring, 0.080 g of (NH4)6H2W 12 O 400.052 g of W·6H2O, 0.052 g of Cu(NH4)2Cl4·2H2O, and 0.109 g of Sb2O3 were added to the mixture in this order and stirred for 10 minutes. The pH value remained constant at pH = 2.4 before and after the addition of the W, Sb, and Cu compounds. The MoV 0.25 W 0.1 Sb 0.05 Cu 0.1 Ox was hydrothermally synthesized. 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.

[0048] Reactor Testing Performance tests were carried out 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 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.

[0049] The lattice oxidative dehydrogenation (LODh) step with a 6 minute ethane feed pulse used a flow of 50% by volume ethane in helium of 15 mL / min at a pressure of 2.5 bar (absolute) and a WHSV of 1.6 / hr.

[0050] A 75 minute regeneration step used a flow of 2.5 vol% O2 in helium at 10 mL / min at a pressure of 2.5 bar (absolute).

[0051] The reactor effluent composition is obtained by gas chromatography (GC) and the conversion and carbon-based selectivity are calculated using the following equations: 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 j is defined as the carbon-based selectivity (%) for product j, where α is the number of carbon atoms in product j. The carbon balance for all experiments was within 99–102% for all experiments.

[0052] 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).

[0053] The results of the catalytic tests at 450°C are shown in Table 2 below.

[0054] [Table 4]

[0055] As can be observed from Table 2, Examples 1-3 exhibit high activity for ethane conversion with high selectivity (>75%) for ethylene, highlighting the superior performance of these newly discovered W / Ta, Bi-containing materials that crystallize in the Pba2-32 crystal structure.

[0056] In contrast, Comparative Example 1 exhibits lower activity and lower selectivity, highlighting the importance of both W and Bi in the structure.

[0057] Example 2 was also tested in an oxidative dehydrogenation process using an O2-co feed at a constant pressure of 8 bar and 315°C, and was varied with respect to the feed composition of various amounts of ethane, oxygen, water (steam), and inert gases (helium and nitrogen).

[0058] Catalyst screening was carried out in a dedicated module of a high-throughput (HT) parallel fixed-bed reactor (PFBR) containing 16 quartz reactor tubes enclosed in a stainless steel bell jar that could be pressurized with N2 to the same pressure as the process pressure. This allowed the use of quartz reactors and minimized the number of seals exposed to high pressure differentials. Two of the 16 microreactors were used as blanks, i.e., loaded with quartz chips to monitor the feed composition throughout the experiment. The other reactors were loaded as follows (bottom to top): Q-felt, a layer of quartz chips, catalyst bed, a layer of quartz chips, and Q-felt, with the aim of preparing approximately the same (total) volume each time. After starting the test by purging with nitrogen while increasing the temperature and pressure to the desired process values, various compositions of ethane, oxygen, steam (water), and inert gases (helium, nitrogen) were fed at a total flow rate of approximately 14 sccm per reactor tube.

[0059] [Table 5]

[0060] The catalyst performance data shown below in Table 4 are average values ​​calculated from three or more independent GC analyses collected approximately every 3.5 hours over a fixed process segment lasting a minimum of 12 hours.

[0061] [Table 6]

[0062] Table 4 above demonstrates that the novel W, Bi-containing compositions can also selectively convert ethane to ethylene with >75% selectivity over the ethane:O2 ratio range of 2-6.

[0063] 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 ｖ V ｗ A ｙ Bi ｚ O ｘ (In the formula, a structure comprising a mixed oxide of molybdenum (Mo), vanadium (V), tungsten (W) or tantalum (Ta), and bismuth (Bi), wherein v is 1, w is 0.2-0.5, A is W or Ta, 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; (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. Formula Mo ｖ V ｗ A ｙ Bi ｚ O ｘ 2. The oxidative dehydrogenation catalyst according to claim 1, comprising a structure comprising an oxide of molybdenum (Mo), vanadium (V), tungsten (W) or tantalum (Ta), and bismuth (Bi), having the formula: (wherein v is 1, w is 0.2 to 0.5, A is W or Ta, y is 0.001 to 0.3, z is 0.01 to 0.3, and x is the oxygen content required for charge balance of the structure).

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

4. The following formula: MoV ０．２－０．３ W ０．０５－０．１５ Bi ０．１－０．１５ O ｘ The oxidative dehydrogenation catalyst according to any one of claims 1 to 3, comprising:

5. The following formula: MoV ０．２－０．５ Ta ０．０５－０．１８ Bi ０．１－０．１５ O ｘ The oxidative dehydrogenation catalyst according to any one of claims 1 to 3, comprising:

6. 1. A method for forming an oxidative dehydrogenation catalyst, comprising: adding a molybdenum-containing compound, a vanadium-containing compound, a bismuth-containing compound, and a tungsten- or tantalum-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 ｖ V ｗ A ｙ Bi ｚ O ｘ wherein A is W or Ta; The starting mixture is molybdenum trioxide (MoO ３ ) and vanadium pentoxide (V ２ O ５ ) .

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

8. The tungsten-containing compound is tungsten trioxide (WO ３ ), bismuth tungstate (Bi ２ (W.O. ４ ) ３ ), and ammonium metatungstate hydrate ((NH ４ ) ６ H ２ W １２ O ４０ 8. A method for forming the oxidative dehydrogenation catalyst of claim 6 or claim 7, wherein the catalyst is selected from the group consisting of:

9. 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 9. A method for forming the oxidative dehydrogenation catalyst of claim 6, wherein the oxidative dehydrogenation catalyst is selected from the group consisting of:

10. The alkylene glycol is ethylene glycol (C ２ H ６ O ２ 10. The method of forming the oxidative dehydrogenation catalyst of claim 6, wherein

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; and separating said olefins from said paraffins in said product stream.

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. 14. The method of claim 13, wherein the conversion occurs at a temperature of from 300°C to 700°C and a pressure of from 0 barg to 20 barg.

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

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