Catalyst and process for dehydrogenation of alkanes to olefins

Abstract

< TableDetails num = '0001' > < Title / > < tbl: tgroup cool = '2' > < tbl: colspec cool = 'c001' cool width = '44%' / > < tbl: colspec cool width = 'c002' cool width = '1' > 2 theta (+ / -0.3 DEG) < / tbl: entry > < tbl: entry = '1' > relative

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority from European Patent Application No. 23382181.8, filed on February 28, 2023, and entitled “CATALYST AND PROCESS FOR ANAEROBIC OXIDATIVE DEHYDROGENATION OF ETHANE,” the entire contents of which are incorporated herein by reference. Background Art Technical Field

[0003] This specification generally relates to catalysts for the dehydrogenation of alkanes to olefins, such as catalysts for the conversion of ethane to ethylene. Technical Background

[0005] 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 promoters such as calcium (Ca), sodium (Na), antimony (Sb), or tellurium (Te). In particular, Te is a common promoter included in conventional catalysts. Processes using such catalysts require an oxygen co-feed and utilize oxidative dehydrogenation processes 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

[0006] According to one embodiment, the oxidative dehydrogenation catalyst comprises: (i) a catalyst having the formula Mo u V v Nb w Sb y Bi z O x The structure of an oxide of molybdenum (Mo), vanadium (V), niobium (Nb), antimony (Sb) and bismuth (Bi), 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 amount of oxygen required to balance the charge of the structure, and (ii) a crystal structure containing a Pba2-32 space group, the crystal structure being obtained by heating the structure with Cu-K α The reflections measured by X-ray diffraction (XRD) were characterized as follows

[0007] 2θ(±0.3°) Relative strength (%) 5.3 0.2–10 6.6 1.5–15 7.84 2.5–45 8.95 4–21 22.17 100 27.2 20–70

[0008] 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; synthesizing Mo by hydrothermal synthesis at a hydrothermal synthesis temperature for a certain period of time. 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 to balance the charge of the structure; and separating Mo from the retained liquid u V v Nb w Sb y Bi z O x .

[0009] In another embodiment, a process for converting paraffins to olefins comprises: contacting a feed stream comprising paraffins with the oxidative dehydrogenation catalyst; converting at least a portion of the paraffins to olefins, thereby producing a product stream comprising paraffins and olefins; and separating the paraffins from the olefins in the product stream, wherein the oxidative dehydrogenation catalyst comprises: (i) a catalyst having the formula Mo u V v Nb w Sb y Bi z O x The structure of an oxide of molybdenum (Mo), vanadium (V), niobium (Nb), antimony (Sb) and bismuth (Bi), 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 amount of oxygen required to balance the charge of the structure, and (ii) a crystal structure (Pba2-32 space group) obtained by heating the structure with Cu-K α The reflections measured by X-ray diffraction (XRD) were characterized as follows:

[0010] 2θ(±0.3°) Relative strength (%) 5.3 0.2–10 6.6 1.5–15 7.84 2.5–45 8.95 4–21 22.17 100 27.2 20–70

[0011] As one of ordinary skill in the art will recognize, relative intensities may be affected by preferential orientation effects, and the relative intensities disclosed above take such effects into account.

[0012] Additional features and advantages will be set forth in the detailed description which follows, and in part will become apparent to those skilled in the art from that description or may be learned by practicing the embodiments described herein, including the following detailed description and claims.

[0013] It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following detailed description may be better understood when read in conjunction with the following drawings, in which:

[0015] Figure 1 is a graph of ethylene productivity as a function of oxygen extracted from the catalyst at different hourly space velocities. DETAILED DESCRIPTION

[0016] Reference will now be made in detail to embodiments of catalysts for the dehydrogenation of alkanes to olefins, such as catalysts for the conversion of ethane to ethylene, and methods for preparing such catalysts.

[0017] A problem with conventional oxidative dehydrogenation methods is that they require a co-feed stream of oxygen (O 2 ). This increases the cost of the method due to the need to produce pure or almost pure oxygen for the equipment used in the method. In addition, since oxygen and hydrocarbons mix, the presence of oxygen in the method increases the probability of undesirable dangerous combustion. Conventional catalysts also require the presence of a certain amount of oxygen to keep the catalyst stable. Finally, due to the properties of the catalyst and the need for oxygen for alkane dehydrogenation, the conventional oxidative dehydrogenation method for converting alkanes into olefins is carried out in a fixed bed reactor, which requires downtime to remove and replace or regenerate the catalyst. Therefore, there is a need for improved catalysts that can convert alkanes into olefins. Although conventional catalysts can be used for oxidative dehydrogenation, due to chemical changes or reduction and loss of elements such as tellurium, when operated in a cyclic redox mode or under conditions with a low O 2 partial pressure (which are usually encountered at the bottom portion of a fixed bed reactor), these conventional catalysts show limited stability.

[0018] In cyclic redox mode, a key aspect is that the oxygen capacity of the catalyst needs to be sufficiently high (>0.8 wt%) to achieve high single-pass ethane conversions (>40%) at industrially viable solids / ethane feed rates in various circulating bed reactor technologies. Previously disclosed MoVNbBiOx-based catalyst compositions typically have a limited apparent oxygen capacity of approximately 0.4 wt% to 0.5 wt% extractable lattice oxygen, which makes the previously disclosed MoVNbBiOx-based catalyst compositions unable to deliver the amount of oxygen required for industrially viable solids / ethane feed rates. On the other hand, catalysts of the MoVNbSbOx-based type show higher oxygen capacities than MoVNbBiOx-based catalyst compositions, but these MoVNbSbOx-based catalysts typically have lower selectivities for ethylene (approximately 65%), thereby losing a significant amount of their lattice oxygen to form CO and CO2.

[0019] It has been unexpectedly discovered that the addition of small amounts of antimony (Sb) to the MoVNbBiOx-based materials disclosed and described herein can result in a substantial increase in oxygen capacity, allowing for sustained ethane conversion at lower solids / ethane feed rates while maintaining high ethylene selectivity (>75%). Upon addition of Sb to the MoVNbBiOx structure, the apparent oxygen capacity of the catalyst increases significantly from 0.4 wt% to approximately 0.7 wt% to 1.2 wt%, depending on the exact composition of the MoVNbSb,BiOx material.

[0020] In one or more embodiments, the oxidative dehydrogenation catalyst has the following formula: Mo u V v Nb w Sb y Bi z O x, wherein u is 1.0 (e.g., Mo is used as the basis for the atomic ratio), 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 to balance the charge 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 embodiments, 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 embodiments, 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 embodiments, z is from 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 embodiments, the oxidative dehydrogenation catalyst has the 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 to make the structure charge balanced. It should be understood that Mo v V w Nb y Bi z O x Embodiments of the catalyst have a Pba2-32 space that is substantially free of Te, such as having a Te / Mo atomic ratio less than or equal to 0.01.

[0021] In embodiments, the crystal structure of the oxidative dehydrogenation catalysts disclosed and described herein can be measured using X-ray diffraction (XRD). For example, and as will be appreciated by one skilled in the art, the positions and relative intensities of the XRD peaks at various 2θ angles can be used to describe the crystal structure of the oxidative dehydrogenation catalyst. In embodiments, the oxidative dehydrogenation catalyst has a Cu-K α The reflections measured by XRD are shown in Table 1. In Table 1 below, the relative intensity (relative intensity / Rel.Intensity) is maximum at 2θ=22.17°, and therefore this relative intensity is set to 100% and used as the basis for the remaining relative intensities shown in Table 1. As will be appreciated by those skilled in the art, the relative intensity may be affected by preferential orientation effects, and the relative intensities disclosed above take such effects into account.

[0022] Table 1

[0023] 2θ(±0.3°) Relative strength (%) 5.3 0.2–10 6.6 1.5–15 7.84 2.5–45 8.95 4–21 22.17 100 27.2 20–70

[0024] As described above, the use of specific hydrothermal methods to form the oxidative dehydrogenation catalyst allows for the formation of an oxidative dehydrogenation catalyst having the desired Pba2-32 crystal structure. Embodiments of these hydrothermal methods for forming the oxidative dehydrogenation catalyst will now be described in more detail.

[0025] In one or more embodiments, having Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst of the structure is formed by a synthesis method 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 an alkylene glycol or an alcoholamine and water to form a reaction mixture. In an embodiment, the metal precursor is selected so that the precursor can be dissolved / digested under hydrothermal reaction conditions. Mo is then synthesized from the reaction mixture by hydrothermal synthesis at a hydrothermal synthesis temperature for a certain period of time as described below. u V v Nb w Sb y Bi z O x After this period of time, the Mo is separated from the retained liquid. u V v Nb w Sb y Bi z O xIn 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 the mixture of alkylene glycol and water.

[0026] 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 ethoxide, and ammonium niobium oxalate hydrate ((NH4)Nb(C2O4)2·nH2O). In an embodiment, the molybdenum-containing compound may be ammonium heptamolybdate (NH4)6Mo7O 24 or molybdenum trioxide (MoO3), and the vanadium-containing compound may be ammonium metavanadate (NH4VO3), vanadium oxysulfate (VOSO4), or vanadium pentoxide (V2O5). In embodiments, the antimony-containing compound is selected from the group consisting of antimony trioxide (Sb2O3) and antimony pentoxide (Sb2O5). In embodiments, the molybdenum-containing compound and the vanadium-containing compound are MoO3 and V2O5, respectively. In some embodiments, a digestible mixture of metal-containing compounds having the correct stoichiometric ratio of one or more of Mo, V, Nb, Sb, and Bi may be used. Examples of such digestible 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 an embodiment, the alkylene glycol is ethylene glycol.

[0027] In an 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℃ to 220℃, 160℃ to 220℃, 170℃ to 220℃, 180℃ to 220℃, 190℃ to 220℃, 200℃ to 220℃, 210℃ to 220℃, 150℃ to 210℃, 160℃ to 210℃, 170℃ to 210℃, 180℃ to 210℃, 190℃ to 210℃, 200℃ to 210℃, 150℃ to 200℃ , 160°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.

[0028] In embodiments, the hydrothermal pressure is from 4 bar (400 kPa) to 40 bar (4000 kPa), such as from 5 bar (500 kPa) to 40 bar (4000 kPa), from 10 bar (1000 kPa) to 40 bar (4000 kPa), from 15 bar (1500 kPa) to 40 bar (4000 kPa), from 20 bar (2000 kPa) to 40 bar (4000 kPa), from 25 bar (2500 kPa) to 40 bar (4000 kPa), from 30 bar (3000 kPa) to 40 bar (4000 kPa), from 35 bar (3500 kPa) to 40 bar (4000 kPa), from 4 bar (4000 kPa), from 5 bar (5000 kPa) to 40 bar (4000 kPa), from 6 bar (6000 kPa) to 6 bar (4000 kPa), from 7 bar (7000 kPa) to 7 bar (4000 kPa), from 8 bar (7000 kPa) to 8 bar (4000 kPa), from 9 bar (8000 kPa) to 9 bar (4000 kPa), from 10 bar (1000 kPa) to 10 bar (4000 kPa), from 15 bar (1500 kPa) to 10 bar (4000 kPa), from 20 bar (2000 kPa) to 10 bar (4000 kPa), from 25 bar (2500 kPa) to 10 bar (4000 kPa), from 30 bar (3000 kPa) to 10 bar (4000 kPa), from 35 bar (3500 kPa) to 10 bar (4000 kPa), from 4 bar (40 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 ( 1000kPa) to 30 bar (3000kPa), 15 bar (1500kPa) to 30 bar (3000kPa), 20 bar (2000kPa) to 30 bar (3000kPa), 25 bar (2500kPa) to 30 bar (3000kPa), 4 bar (400kPa) to 25 bar (2500kPa), 5 bar (500kPa) to 25 bar (2500kPa), 10 bar (1000kPa) to 25 bar (2500kPa), 15 bar (1500kPa) to 25 bar (2500kPa), 20 bar (2000kPa) to 25 bar (2500kPa) ), 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).

[0029] According to the embodiment, when Mo u V v Nb w Sb y Biz O x After the oxidative dehydrogenation catalyst is separated from the retained liquid, the Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is dried and optionally added by mixing the dried Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is heated to the calcination temperature and the Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst is calcined by maintaining it at the calcination temperature for a certain period of time.

[0030] 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 expedite drying, in embodiments, the Mo u V v Nb w Sb y Bi z O x 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.

[0031] In an embodiment, the calcination is carried out in an inert atmosphere, such as nitrogen (N2), 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 ... to 625°C, 525°C to 625°C, 550°C to 625°C, 575°C to 625°C, 600°C to 625°C, 350°C to 600°C, 375°C to 600°C, 400°C to 600°C, 425°C to 600°C, 450°C to 600°C, 475°C to 600°C, 500°C to 600°C, 525°C to 600°C, 550°C to 600°C, 575°C to 600°C, 350°C to 575°C, 375°C to 575°C, 400°C to 575°C, 425°C to 575°C, 450°C to 575°C, 475 ℃ to 575℃, 500℃ to 575℃, 525℃ to 575℃, 550℃ to 575℃, 350℃ to 550℃, 375℃ to 550℃, 400℃ to 550℃, 425℃ to 550℃, 450℃ to 550℃, 475℃ to 550℃, 500℃ to 550℃, 525℃ to 550℃, 350℃ to 525℃, 375℃ to 525℃, 400℃ to 525℃, 425℃ to 525℃, 450℃ to 525℃, 475℃ to 525℃, 500℃ to 525℃, 350℃ to 500℃, 375℃ to 525℃ ℃ to 500℃, 400℃ to 500℃, 425℃ to 500℃, 450℃ to 500℃, 475℃ to 500℃, 350℃ to 475℃, 375℃ to 475℃, 400℃ to 475℃, 425℃ to 475℃, 450℃ to 475℃, 350℃ to 450℃, 375℃ to 450℃, 400℃ to 450℃, 425℃ to 450℃, 350℃ to 425℃, 375℃ to 425℃, 400℃ to 425℃, 350℃ to 400℃, 375℃ to 400℃, or 350℃ to 375℃.

[0032] In embodiments, calcination is carried out in air. In such embodiments, the calcination temperature may be from 200°C to 500°C, from 200°C to 500°C, from 400°C to 500°C, from 425°C to 500°C, from 450°C to 500°C, from 475°C to 500°C, from 350°C to 475°C, from 375°C to 475°C, from 400°C to 475°C, from 425°C to 475°C, from 450°C to 475°C, from 350°C to 450°C, from 375°C to 450°C, from 400°C to 450°C, from 425°C to 450°C, from 350°C to 425°C, from 375°C to 400°C, or from 350°C to 375°C.

[0033] In the already formed Mo u V v Nb w Sb y Bi z O x After the oxidative dehydrogenation catalyst, Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst can be used in a process for converting alkanes in an alkane-containing feed stream into olefins. As the run time increases, the process disclosed and described herein can be further dehydrogenated by Mo u V v Nb w Sb y Bi z O x The oxidative dehydrogenation catalyst provides improved olefin selectivity. The process disclosed and described herein generally comprises reacting a feed stream comprising alkanes (paraffins) with a feed stream comprising Mo u V v Nb w Sb y Bi z O xThe material of oxidative dehydrogenation catalyst contacts in reaction zone, converts at least a portion of alkane into alkene, produces the product stream comprising paraffin and alkene.It should be understood that oxidative dehydrogenation catalyst can be used alone or together with other additives.Reaction zone is not particularly limited, and in an embodiment, can use the reactor of any type that allows the circulation or continuous operation of the method.In an embodiment, reaction zone can be fixed bed reactor, fluidized bed reactor, moving bed reactor, bubbling bed reactor, circulating fluidized bed reactor, countercurrent reactor or ebullated bed reactor (each optionally with oxygen co-feed).Reaction zone is not particularly limited to single reaction zone, and can be made up of a plurality of reactors of series or parallel configuration.Finally, the paraffin in the product stream is separated from the alkene, paraffin can be recycled back in the feed stream, and alkene is used in downstream system or as the material in various products and methods.Hereinafter, the method according to the embodiment disclosed and described herein will be provided in more detail.

[0034] According to an embodiment, a feed stream is fed into the reaction zone, and the feed stream comprises at least one alkane. In an embodiment, the feed stream can completely comprise alkanes (e.g., 100% alkanes). In one or more embodiments, the feed stream can contain oxygen, steam, and / or an inert gas. In an embodiment, the feed stream comprises 30 volume percent (vol%) to 90vol% alkanes, 35vol% to 90vol% alkanes, 40vol% to 90vol% alkanes, 45vol% to 90vol% alkanes, 50vol% to 90vol% alkanes, 55vol% to 90vol% alkanes, 60vol% to 90vol% alkanes, 65vol% to 90vol% alkanes, 70vol% to 90vol% alkanes, 75vol% to 90vol% alkanes, 80vol% to 90vol% alkanes, 85vol% to 90vol% alkanes, 30vol% to 85vol% Alkanes, 35 vol% to 85 vol% alkanes, 40 vol% to 85 vol% alkanes, 45 vol% to 85 vol% alkanes, 50 vol% to 85 vol% alkanes, 55 vol% to 85 vol% alkanes, 60 vol% to 85 vol% alkanes, 65 vol% to 85 vol% alkanes, 70 vol% to 85 vol% alkanes, 75 vol% to 85 vol% alkanes, 80 vol% to 85 vol% alkanes, 30 vol% to 80 vol% alkanes, 35 vol% to 80 vol% alkanes, 40 vol% to 80 vol% alkanes, 45 vol% to 80 vol% alkanes hydrocarbons, 50 vol% to 80 vol% alkanes, 55 vol% to 80 vol% alkanes, 60 vol% to 80 vol% alkanes, 65 vol% to 80 vol% alkanes, 70 vol% to 80 vol% alkanes, 75 vol% to 80 vol% alkanes, 30 vol% to 75 vol% alkanes, 35 vol% to 75 vol% alkanes, 40 vol% to 75 vol% alkanes, 45 vol% to 75 vol% alkanes, 50 vol% to 75 vol% alkanes, 55 vol% to 75 vol% alkanes, 60 vol% to 75 vol% alkanes, 65 vol% to 75 vol% alkanes , 70vol% to 75vol% alkanes, 30vol% to 70vol% alkanes, 35vol% to 70vol% alkanes, 40vol% to 70vol% alkanes, 45vol% to 70vol% alkanes, 50vol% to 70vol% alkanes, 55vol% to 70vol% alkanes, 60vol% to 70vol% alkanes, 65vol% to 70vol% alkanes, 30vol% to 65vol% alkanes, 35vol% to 65vol% alkanes, 40vol% to 65vol% alkanes, 45vol% to 65vol% alkanes, 50vol% to 65vol% alkanes,55vol% to 65vol% alkanes, 60vol% to 65vol% alkanes, 30vol% to 60vol% alkanes, 35vol% to 60vol% alkanes, 40vol% to 60vol% alkanes, 45vol% to 60vol% alkanes, 50vol% to 60vol% alkanes, 55vol% to 60vol% alkanes, 30vol% to 55vol% alkanes, 35vol% to 55vol% alkanes, 40vol% to 55vol% alkanes, 45vol% to 5 5 vol% alkanes, 50 vol% to 55 vol% alkanes, 30 vol% to 50 vol% alkanes, 35 vol% to 50 vol% alkanes, 40 vol% to 50 vol% alkanes, 45 vol% to 50 vol% alkanes, 30 vol% to 45 vol% alkanes, 35 vol% to 45 vol% alkanes, 40 vol% to 45 vol% alkanes, 30 vol% to 40 vol% alkanes, 35 vol% to 40 vol% alkanes, or 30 vol% to 35 vol% alkanes.

[0035] 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.

[0036] According to one or more embodiments, the 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 to 10, 225 to 10, 200 to 10, 175 to 10, 150 to 10, 125 to 10, 100 to 10, 75 to 10, 50 to 10, 25 to 10, 250 to 25, 225 to 25, 200 to 25, 175 to 25, 150 to 25, 125 to 25, 100 to 25, 75 to 25, 50 to 25, 250 to 50, 225 to 50, 200 to 50, 175 to 50, 150 to 50, 125 to 50, 100 to 50, 75 to 50, 250 to 75, or 225 to 75, 200 to 75, 175 to 75, 150 to 75, 125 to 75, 100 to 75, 250 to 100, 225 to 100, 200 to 100, 175 to 100, 150 to 100, 125 to 100, 250 to 125, 225 to 125, 200 to 125, 175 to 125, 150 to 125, 250 to 150, 225 to 150, 200 to 150, 175 to 150, 250 to 175, 225 to 175, 200 to 175, 250 to 200, 225 to 200, or 250 to 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.

[0037] In embodiments, the feed stream is substantially free of oxygen, meaning that the feed stream comprises less than 2.0 volume percent (vol%) oxygen, less than 1.5 vol% oxygen, or less than 0.5 vol% oxygen.In one or more embodiments, the feed stream is free of oxygen.

[0038] 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 can be 0.1 vol% to 99.9 vol%, such as 5.0 vol% to 95.0 vol%, 10.0 vol% to 90.0 vol%, 15.0 vol% to 85.0 vol%, 20.0 vol% to 80.0 vol%, 25.0 vol% to 75.0 vol%, 30.0 vol% to 70.0 vol%, 35.0 vol% to 65.0 vol%, 40.0 vol% to 60.0 vol%, or 45.0 vol% to 55.0 vol%. In one or more embodiments, the oxygen concentration in the oxygen stream is relatively low, such as 0.1 vol% to 5.0 vol%, 0.2 vol% to 5.0 vol%, 0.5 vol% to 5.0 vol%, 0.8 vol% to 5.0 vol%, 1.0 vol% to 5.0 vol%, 1.2 vol% to 5.0 vol%, 1.5 vol% to 5.0 vol%, 1.8 vol% to 5.0 vol%, 2.0 vol% to 5.0 vol%, 2. vol%, 2.5 vol% to 5.0 vol%, 2.8 vol% to 5.0 vol%, 3.0 vol% to 5.0 vol%, 3.2 vol% to 5.0 vol%, 3.5 vol% to 5.0 vol%, 3.8 vol% to 5.0 vol%, 4.0 vol% to 5.0 vol%, 4.2 vol% to 5.0 vol%, 4.5 vol% to 5.0 vol%, or 4.8 vol% to 5.0 vol%. In embodiments, the oxygen stream can be air, which typically has an oxygen concentration of about 21.0 vol%.

[0039] In embodiments, the oxygen stream can be added to the reaction zone sequentially with the feed stream, such that the feed stream and the oxygen stream are not added to the reaction zone simultaneously. It should be understood that in embodiments, the oxygen stream can be added at different points during the reaction. This can be achieved by introducing the oxygen stream into the reaction zone at different locations within the reaction zone and / or introducing the oxygen stream at different time periods while the reaction is occurring.

[0040] In one or more embodiments, the oxygen stream is added to the reaction zone simultaneously with the feed stream. In such embodiments, the volume 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.

[0041] 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 the temperature in the reaction zone, which, according to one or more embodiments, ranges 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, 3 ... 0°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.

[0042] In embodiments, the reaction conditions further comprise a pressure inside the reaction zone of 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).

[0043] According to embodiments, the weight hourly space velocity (WHSV) of the alkane feed stream and, optionally, the oxygen stream in the reaction zone is from 0.1 hour ( / h) to 10.0 / h, 0.5 / h to 10.0 / h, 1.0 / h to 10.0 / h, 2.0 / h to 10.0 / h, 3.0 / h to 10.0 / h, 4.0 / h to 10.0 / h, 5.0 / h to 10.0 / h, 6.0 / h to 10.0 / h, 7.0 / h to 10.0 / h, 8.0 / h to 10.0 / h, 9.0 / h to 10.0 / h, 0.1 / h to 9.0 / h, 0.5 / h to 9.0 / h, 1.0 / h to 9.0 / h, 2.0 / h to 9.0 / h, 3.0 / h to 9.0 / h, 4.0 / h to 9.0 / h, 5.0 / h to 9.0 / h, 6.0 / h to 9.0 / h, 7.0 / h to 9.0 / h, 8.0 / h to 9.0 / h, 0.1 / h to 8.0 / h, 0.5 / h to 8.0 / h, 1.0 / h to 8.0 / h, 2.0 / h to 8.0 / h, 3.0 / h to 8.0 / h, 4.0 / h to 8.0 / h, 5.0 / h to 8.0 / h, 6.0 / h to 8.0 / h, 7.0 / h to 8.0 / h, 0.1 / h to 7.0 / h, 0.5 / h to 7.0 / h, 1.0 / h to 7.0 / h, 2.0 / h to 7.0 / h, 3.0 / h to 7.0 / h, 4.0 / h to 7.0 / h, 5.0 / h to 7.0 / h, 6.0 / h to 7.0 / h, 0.1 / h to 6.0 / h, 0.5 / h to 6.0 / h, 1.0 / h to 6.0 / h, 2.0 / h to 6.0 / h, 3.0 / h to 6.0 / h, 4.0 / h to 6.0 / h, 5.0 / h to 6.0 / h, 0.1 / h to 5.0 / h, 0.5 / h to 5.0 / h, 1.0 / h to 5.0 / h, 2.0 / h to 5.0 / h, 3.0 / h to 5.0 / h, 4.0 / h to 5.0 / h, 0.1 / h to 4.0 / h, 0.5 / h to 4.0 / h, 1.0 / h to 4.0 / h, 2.0 / h to 4.0 / h, 3.0 / h to 4.0 / h, 0.1 / h to 3.0 / h, 0.5 / h to 3.0 / h, 1.0 / h to 3.0 / h, 2.0 / h to 3.0 / h, 0.1 / h to 2.0 / h, 0.5 / h to 2.0 / h, 1.0 / h to 2.0 / h, 0.1 / h to 1.0 / h, 0.5 / h to 1.0 / h, or 0.1 / h to 0.5 / h.

[0044] Example

[0045] Example 1

[0046] A mixture of 34 mL of H2O and 80 μL of ethylene glycol was added to a 45 mL Teflon insert autoclave (Universal Acid Digestion Vessel Model 4744, Parr). While 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 in sequence and stirred for 10 minutes. 0.2 Nb 0.005 Bi 0.1 Sb 0.01 The hydrothermal synthesis of Ox was carried out in a rotary oven at 190° C., 10 rpm for 48 hours. The material obtained from the hydrothermal synthesis was purified using vacuum filtration with 200 mL of deionized water and then dried at 85° C. overnight.

[0047] After drying, the material was calcined at 450°C (at a heating rate of 2°C / min) for 2 hours under a stream of N2. The material was compacted under a pressure of 7 tons, crushed and sieved to 40-80 mesh, and then loaded into the reactor. The reaction conditions will be discussed in detail below.

[0048] Comparative Example 1

[0049] A mixture of 34 mL of H2O and 160 μL of ethylene glycol was added to a 45 mL Teflon insert autoclave (Universal Acid Digestion Vessel Model 4744, Parr). While 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 in sequence and stirred for 10 minutes. 0.3 Nb 0.01 Bi 0.1 The hydrothermal synthesis of Ox was carried out in a rotary oven at 190° C., 10 rpm for 48 hours. The material obtained from the hydrothermal synthesis was purified using vacuum filtration with 200 mL of deionized water and then dried at 85° C. overnight.

[0050] After drying, the material was calcined at 450°C (at a heating rate of 2°C / min) for 2 hours under a stream of N2. The material was compacted under a pressure of 7 tons, crushed and sieved to 40-80 mesh, and then loaded into the reactor. The reaction conditions will be discussed in detail below.

[0051] Reactor testing

[0052] The performance tests were carried out in a fixed-bed reactor setup with a SS316 reactor tube (I.D. 3 mm) from SINTEF (high-pressure reactor assembly module). For the catalytic tests, 250 mg - 350 mg of 40 - 80 mesh catalyst particles were loaded in the reactor, and the reactor was operated in a cyclic mode at the desired temperature in which the ethane exposure period was alternated with inert gas purge and oxidative regeneration:

[0053] At a pressure of 2.5 bar (absolute) and a WHSV of 1.7 / hr - 3.0 / hr, the lattice oxidative dehydrogenation (LODh) step used a 50 vol.% ethane / helium flow rate of 15 mL / min - 20 mL / min.

[0054] At a pressure of 2.5 bar (absolute), the regeneration step used a 2.5 vol.% O2 / helium flow rate of 10 mL / min.

[0055] The reactor effluent composition was obtained by gas chromatography (GC), and the conversion and carbon-based selectivity were calculated using the following equations:

[0056] XC2H6 (%) = [(ηC2H6,in – ηC2H,out) / ηC2H6,in]·100; and (1) < / /

[0057] S j (%) = [αj·ηj,out / ∑αj·ηj,out]·100 (2)

[0058] Where XC2H6 is defined as the 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), S j is defined as the carbon-based selectivity (%) of product j, and αj is the number of carbon atoms in product j. The carbon balance for all experiments was in the range of 99% - 102%.

[0059] The catalyst / ethane ratio (g / g) was calculated based on the run time (TOS, minutes), where GC analyzed the reactor effluent:

[0060] Catalyst / ethane = w / (TOS·ηC2H6,in·MW C2H6 ) (3)

[0061] 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).

[0062] The ethylene productivity (g / g catalyst / h) was calculated using the following equation:

[0063] C2H4 production rate = [ηC2H6,in*60*XC2H6*S C2H4 / 100)*MW C2H4 ] / w

[0064] MW C2H4 Defined as the molecular weight of ethylene (28 g / mol).

[0065] The results of the catalytic test at 450 °C are shown in Figure 1 , which plots ethylene productivity as a function of oxygen extracted from the catalyst at different hourly space velocities.

[0066] It can be observed that the composition of Example 1 (solid line) is able to maintain a much higher ethylene productivity over a wider range of extracted lattice oxygen than the Sb-free composition of Comparative Example 1 (dashed line) for both low and high hourly space velocity conditions. As can be seen from the dashed line, regardless of the hourly space velocity, when the extracted lattice oxygen exceeds 0.4 wt%-0.5 wt%, the catalyst productivity drops to very low levels (<0.2 kg / kg catalyst-hr). Even when >0.8 wt% O has been removed from the catalyst, the catalyst according to the present invention is able to maintain a relatively high productivity level (>0.5 kg / kg catalyst / hour). This highlights the advantages of Sb-promoted MoVNbBiO x Excellent oxygen capacity and availability of the material.

[0067] It will be apparent to those skilled in the art that various modifications and variations may be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Therefore, this specification is intended to cover modifications and variations of the various embodiments described herein, provided that such modifications and variations fall within the scope of the appended claims and their equivalents.

Claims

1. An oxidative dehydrogenation catalyst, comprising: (i) has the formula Mo u V v Nb w Sb y Bi z O x The structure of a mixed oxide comprising molybdenum (Mo), vanadium (V), niobium (Nb), antimony (Sb) and bismuth (Bi), 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 to charge balance the structure; and (ii) a crystal structure containing a Pba2-32 space group, which was obtained by using Cu-K α The reflections measured by X-ray diffraction (XRD) were characterized as follows:

2. The oxidative dehydrogenation catalyst according to claim 1, wherein the oxidative dehydrogenation catalyst is composed of a catalyst having the formula Mo u V v Nb w Sb y Bi z O x The structure comprises oxides of molybdenum (Mo), vanadium (V), niobium (Nb), antimony (Sb) and bismuth (Bi), wherein u is 1, v is 0.1 to 0.5, w is 0.001 to 0.3, y is 0.001 to 0.1, and z is 0.03 to 0.2, and x is the oxygen content required to make the structure charge balanced.

3. The oxidative dehydrogenation catalyst according to claim 1, wherein the oxidative dehydrogenation catalyst is substantially free of tellurium (Te).

4. A method for forming an oxidative dehydrogenation catalyst, the method 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 an alcoholamine 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.; and Separation of Mo from the retained liquid u V v Nb w Sb y Bi z O x , The starting mixture comprises at least one of molybdenum trioxide (MoO3) and vanadium pentoxide (V2O5).

5. The method for forming an oxidative dehydrogenation catalyst according to claim 4, wherein the one or more organic acids include at least one of citric acid (C6H8O7), oxalic acid (C2H2O4), and mixtures thereof.

6. A method for forming an oxidative dehydrogenation catalyst according to any one of claims 4 or 5, wherein the niobium-containing compound is selected from the group consisting of niobium oxide, niobic acid (Nb2O5·xH2O), ammonium niobium oxalate hydrate ((NH4)Nb(C2O4)2·nH2O), niobium ethoxide, and mixtures thereof.

7. The method for forming an oxidative dehydrogenation catalyst according to any one of claims 4 to 6, wherein 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).

8. The method for forming an oxidative dehydrogenation catalyst according to any one of claims 4 to 7, wherein the antimony-containing compound is selected from the group consisting of antimony trioxide (Sb2O3) and antimony pentoxide (Sb2O5).

9. The method for forming an oxidative dehydrogenation catalyst according to any one of claims 4 to 8, wherein the alkylene glycol is ethylene glycol (C2H6O2).

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

11. The method for forming an oxidative dehydrogenation catalyst according to any one of claims 5 to 10, wherein the starting mixture comprises MoO3 and V2O5.

12. A method for converting paraffins to olefins, the method comprising: contacting a feed stream comprising paraffins with a material comprising an oxidative dehydrogenation catalyst according to any one of claims 1 to 4; converting at least a portion of the paraffins to olefins, thereby producing a product stream comprising paraffins and olefins; as well as The olefins are separated from the paraffins in the product stream.

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

14. The process of any one of claims 13 and 14, wherein the conversion occurs at an alkane weight hourly space velocity (WHSV) of 0.1 / hr to 10 / hr.

15. The process according to any one of claims 1 to 14, wherein the dehydrogenation catalyst has the 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 to make the structure charge balanced.

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