85734-WO-PCT/DOW 85734 WO 1 OXYGEN CARRIER MATERIALS THAT INCLUDE SULFUR AND METHODS FOR PRODUCING OLEFINIC COMPOUNDS USING SUCH CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Serial No. 63/601,974 filed November 22, 2023, the contents of which are incorporated in their entirety herein. TECHNICAL FIELD [0002] Embodiments of the present disclosure generally relate to chemical processing and, in particular, to oxygen carrier materials utilized in chemical processing. BACKGROUND [0003] Some chemical processes that utilize oxygen as a reactant utilize oxygen carrier materials. In such processes, oxygen may be delivered or “carried” in a cycle via a reduction and subsequent oxidation of the oxygen carrier material. In such processes the oxygen carried by the oxygen carrier material may be utilized as the source of oxygen. In particular, oxygen carrier materials may be utilized in cyclical chemical processes where oxygen may be added to and removed from the oxygen carrier material as it is used throughout the entire process. Such materials may be utilized in a wide variety of chemical processing methods. SUMMARY [0004] There is a continued need for oxygen carrier materials that are suitable for use with particular chemical processes. Described herein are particular oxygen carrier materials that include at least one or more redox-active metal oxides and a promoter including at least sulfur, one or more alkali metals, optionally hydrogen, and oxygen, in particular amounts relative to one another. It has been found that the oxygen carrier materials described herein, according to one or more embodiments, may have relatively high selectivity for combusting hydrogen gas over combusting hydrocarbons. Such oxygen carrier materials may be utilized in processes that form olefinic compounds, among other contemplated uses, as described in detail herein.
85734-WO-PCT/DOW 85734 WO 2 [0005] According to one or more embodiments of the present disclosure, an oxygen carrier material may comprise one or more redox-active metal oxides and a promoter. The oxygen carrier material may comprises from 35 wt.% to 99.9 wt.% of the one or more redox-active metal oxides, and from 0.1 wt.% to 15 wt.% of the promoter. At least 95 wt.% of the promoter may consist of 1 part by mole of sulfur, from 0.1 parts by mole to 2 parts by mole of one or more alkali metals, from 0 parts by mole to 1 part by mole of hydrogen, and from 0.001 parts by mole to 4 parts by mole of oxygen. [0006] According to one or more additional embodiments of the present disclosure, olefinic compounds may be produced by a method that comprises passing a feed stream into a reactor, and passing an oxygen carrier material into the reactor. The feed stream may comprise one or more hydrocarbons. In the reactor, the one or more hydrocarbons may be dehydrogenated to form hydrogen and one or more olefinic compounds. Also in the reactor, at least a portion of the hydrogen may be reacted with oxygen from the oxygen carrier material to produce water. The oxygen carrier material may comprise one or more redox-active metal oxides and a promoter. The oxygen carrier material may comprises from 35 wt.% to 99.9 wt.% of the one or more redox- active metal oxides, and from 0.1 wt.% to 15 wt.% of the promoter. At least 95 wt.% of the promoter may consist of 1 part by mole of sulfur, from 0.1 parts by mole to 2 parts by mole of one or more alkali metals, from 0 parts by mole to 1 part by mole of hydrogen, and from 0.001 parts by mole to 4 parts by mole of oxygen. [0007] Additional features and advantages of the present disclosure will be set forth in the detailed description, which follows, and in part will be apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description, which follows the claims, as well as the appended drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawing(s), where like structure is indicated with like reference numerals and in which: [0009] FIG.1 is a schematic depiction of a reactor system suitable for use with an oxygen carrier material, according to one or more embodiments described herein.
85734-WO-PCT/DOW 85734 WO 3 [0010] Additional features and advantages of the present disclosure will be set forth in the detailed description, which follows, and in part will be apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description, which follows the claims, as well as the appended drawings. [0011] 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. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description, explain the principles and operations of the claimed subject matter. DETAILED DESCRIPTION [0012] Specific embodiments of the present application will now be described. The technical aspects of the present application may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth in this detailed description. [0013] Generally, described in this disclosure are various embodiments of oxygen carrier materials, and embodiments of methods of using oxygen carrier materials to form olefinic compounds. As described herein, the oxygen carrier materials may comprise one or more redox- active metal oxides and a promoter, which may include materials that, in general, contribute to the oxygen carrying functionality and/or the selectivity for hydrogen combustion of the oxygen carrier materials described herein. In general, in the embodiments described herein, at least 95 wt.% of the promoter may consist of sulfur (S), one or more alkali metals, hydrogen (H), and oxygen (O), in amounts defined by particular ratios between these various components. [0014] According to one or more embodiments, the oxygen carrier material may comprise from 35 wt.% to 99.9 wt.% of the one or more redox-active metal oxides. As described herein, “redox- active metal oxides” generally refer to a metal oxides capable of undergoing reduction and oxidation. The redox-active metal oxide may be capable of being reduced in the presence of a reducing agent, for example, hydrogen, and capable of undergoing oxidation in the presence of an oxidizing agent, for example, pure oxygen, air, or oxygen-enriched air.
85734-WO-PCT/DOW 85734 WO 4 [0015] According to one or more embodiments, the oxygen carrier material may comprise the one or more redox-active metal oxides in an amount of from 35 wt.% to 40 wt.%, from 40 wt.% to 45 wt.%, from 45 wt.% to 50 wt.%, from 50 wt.% to 55 wt.%, from 55 wt.% to 60 wt.%, from 60 wt.% to 65 wt.%, from 65 wt.% to 70 wt.%, from 70 wt.% to 75 wt.%, from 75 wt.% to 80 wt.%, from 80 wt.% to 85 wt.%, from 85 wt.% to 90 wt.%, from 90 wt.% to 95 wt.%, from 95 wt.% to 99.9 wt.%, or any combination of one or more of these ranges. [0016] In some embodiments, the oxygen carrier material may comprise less than or equal to 99.9 wt.% and at least 40 wt.%, at least 45 wt.%, at least 50 wt.%, at least 55 wt.%, at least 60 wt.%, at least 65 wt.%, at least 70 wt.%, at least 75 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, or even at least 95 wt.% of the one or more redox-active metal oxides. In some embodiments, the oxygen carrier material may comprise the one or more redox-active metal oxides in an amount of at least 35 wt.% and less than or equal to 95 wt.%, less than or equal to 90 wt.%, less than or equal to 85 wt.%, less than or equal to 80 wt.%, less than or equal to 75 wt.%, less than or equal to 70 wt.%, less than or equal to 65 wt.%, less than or equal to 60 wt.%, less than or equal to 55 wt.%, less than or equal to 50 wt.%, less than or equal to 45 wt.%, or even less than or equal to 40 wt.%. [0017] In one or more embodiments, the one or more redox-active metal oxides may be chosen from oxides comprising iron, manganese, cobalt, cerium, copper, nickel, or combinations thereof. According to some embodiments, any one, two, three, four, five, or all six of iron, manganese, cobalt, cerium, copper, or nickel may be utilized in the one or more redox-active metal oxides described herein. Disclosed herein are embodiments where any combination of one or more (e.g., one, two, three, four, five, or all six) of these elements are present in the one or more redox-active metal oxides. [0018] In one or more embodiments, the one or more redox-active metal oxides may be chosen from Fe2O3, Fe3O4, MnO2, Mn2O3, Mn3O4, CaMnO3, CaxSr1-xMnO3, FeTiO3, Fe2TiO5, CuO, Co3O4, LaxSr1-xFeO3, LaxSr1-xMnO3, LaxSr1-xCoO3, NiO, CeO2, or combinations thereof. According to some embodiments, any one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen or all sixteen of Fe2O3, Fe3O4, MnO2, Mn2O3, Mn3O4, CaMnO3, CaxSr1-xMnO3, FeTiO3, Fe2TiO5, CuO, Co3O4, LaxSr1-xFeO3, LaxSr1-xMnO3, LaxSr1-
xCoO
3, NiO, CeO
2 may be utilized as described herein. Disclosed herein are embodiments where
85734-WO-PCT/DOW 85734 WO 5 any combination of one or more (e.g., one, two, three, four…, or all sixteen) of these oxides are present in the amount disclosed herein. [0019] As described, the oxygen carrier material may comprise from 0.1 wt.% to 15 wt.% of the promoter. In embodiments, the oxygen carrier material may comprise from 0.1 wt.% to 1 wt.%, from 1 wt.% to 2 wt.%, from 2 wt.% to 3 wt.%, from 3 wt.% to 4 wt.%, from 4 wt.% to 5 wt.%, from 5 wt.% to 6 wt.%, from 6 wt.% to 7 wt.%, from 7 wt.% to 8 wt.%, from 8 wt.% to 9 wt.%, from 9 wt.% to 10 wt.%, from 10 wt.% to 11 wt.%, from 11 wt.% to 12 wt.%, from 12 wt.% to 13 wt.%, from 13 wt.% to 14 wt.%, from 14 wt.% to 15 wt.%, or any combination of one or more of these ranges of the promoter. [0020] In some embodiments, the oxygen carrier material may comprise less than 15 wt.% and at least 1 wt.%, at least 2 wt.%, at least 3 wt.%, at least 4 wt.%, at least 5 wt.%, at least 6 wt.%, at least 7 wt.%, at least 8 wt.%, at least 9 wt.%, at least 10 wt.%, at least 11 wt.%, at least 12 wt.%, at least 13 wt.%, at least 14 wt.%, or even at least 15 wt.% of the promoter. In some additional embodiments, the oxygen carrier material may comprise at least 0.1 wt.% and less than or equal to 14 wt.%, less than or equal to 13 wt.%, less than or equal to 12 wt.%, less than or equal to 11 wt.%, less than or equal to 10 wt.%, less than or equal to 9 wt.%, less than or equal to 8 wt.%, less than or equal to 7 wt.%, less than or equal to 6 wt.%, less than or equal to 5 wt.%, less than or equal to 4 wt.%, less than or equal to 3 wt.%, less than or equal to 2 wt.%, or even less than or equal to 1 wt.% of the promoter. [0021] Now turning to the composition of the promoter of the oxygen carrier material, in one or more embodiments, at least 95 wt.% of the promoter may consist of sulfur; one or more alkali metals; oxygen; and optionally hydrogen, in amounts defined by particular ratios between these various components. For example, at least 96 wt.%, at least 97 wt.%, at least 98 wt.%, at least 99 wt.%, at least 99.5 wt.%, or at least 99.9 wt.% of the promoter may consist of sulfur, one or more alkali metals, oxygen, and optionally hydrogen. In some embodiments, the promoter may consist of sulfur, one or more alkali metals, oxygen, and optionally hydrogen. [0022] As described herein, the relative amounts of the materials of the promoter are described in terms of relative amounts of atoms of each element that are included in the promoter. Also, as described herein, the components of the oxygen carrier material may be described in amounts relative to other components. For example, described herein are components represented in amounts described as “parts by mole.” Parts by mole, as used herein, describes the molar ratio of
85734-WO-PCT/DOW 85734 WO 6 one component with another, and does not restrict the total number or moles of a particular substituent. For example, sulfur may be present in an amount of 1 part by mole, and oxygen may be present in an amount of from 0.001 parts by mole to 4 parts by mole, which means all compositions which meet this ratio of sulfur atoms to oxygen atoms fall within embodiments described herein regardless of the raw amount of these constituents. In general, and unless stated otherwise, where multiple elements or other materials are listed together as being in a specific amount, this refers to the total of the combination of all of these elements or other materials, even when not explicitly stating that the “sums” of these elements or the “combination” of these elements is in the amount specified. For example, when “one or more alkali metals” are listed in an amount, the amount refers to the combination of all alkali metals. [0023] In one or more embodiments, sulfur may be present in the promoter, where sulfur is present in the promoter in a relative amount of 1 part by mole. The amounts of the other constituents are generally compared to the 1 part by mole of sulfur. Without being bound by any particular theory, it is believed that sulfur may work as the major constituent that binds and unbinds from oxygen in redox reactions by changing its oxidation state. [0024] According to one or more embodiments, one or more alkali metals may be present in the first composition, where the one or more alkali metals may be present in the first composition in a relative amount of from 0.1 parts by mole to 2 parts by mole. Without being bound by any particular theory, it is believed that the presence of this amount of alkali metals may improve selectivity to hydrogen combustion over combustion of hydrocarbons. [0025] According to embodiments, the one or more alkali metals may be chosen from lithium, sodium, and potassium, where the combination of lithium, sodium, and potassium is in a relative amount of from 0.1 parts by mole to 2 parts by mole. In some embodiments, lithium is present in the first composition but sodium and potassium are not. In additional embodiments, sodium is present in the first composition but lithium and potassium are not. In additional embodiments, potassium is present in the first composition but sodium and lithium are not. In some yet additional embodiments, lithium and sodium are present in the first composition and potassium is not, sodium and potassium are present in the first composition at lithium is not, or potassium and lithium are present in the first composition and sodium is not. In some embodiments, lithium, sodium, and potassium are present in the first composition.
85734-WO-PCT/DOW 85734 WO 7 [0026] In additional embodiments, the one or more alkali metals may be present in the promoter in a relative amount of from 0.1 parts by mole to 0.2 parts by mole, from 0.2 parts by mole to 0.4 parts by mole, from 0.4 parts by mole to 0.6 parts by mole, from 0.6 parts by mole to 0.8 parts by mole, from 0.8 parts by mole to 1 part by mole, from 1 part by mole to 1.2 parts by mole, from 1.2 parts by mole to 1.4 parts by mole, from 1.4 parts by mole to 1.6 parts by mole, from 1.6 parts by mole to 1.8 parts by mole, from 1.8 parts by mole to 2 parts by mole, or any combination of one or more of these ranges. [0027] In some embodiments, the one or more alkali metals may be present in the promoter in a relative amount of less than or equal to 2 parts by mole and at least 0.2 parts by mole, at least 0.4 parts by mole, at least 0.6 parts by mole, at least 0.8 parts by mole, at least 1 part by mole, at least 1.2 parts by mole, at least 1.4 parts by mole, at least 1.6 parts by mole, or even at least 1.8 parts by mole. In additional embodiments, the one or more alkali metals may be present in the promoter in a relative amount of at least 0.1 parts by mole and less than or equal to 1.8 parts by mole, less than or equal to 1.6 parts by mole, less than or equal to 1.4 parts by mole, less than or equal to 1.2 parts by mole, less than or equal to 1 part by mole, less than or equal to 0.8 parts by mole, less than or equal to 0.6 parts by mole, less than or equal to 0.4 parts by mole, or even less than or equal to 0.2 parts by mole. [0028] According to one or more embodiments, the promoter may optionally comprise hydrogen. That is, in some embodiments, hydrogen may be present in the promoter and, in other embodiments, hydrogen may not be present in the promoter. In one or more embodiments, hydrogen may be present in the promoter in a relative amount of from 0 parts by mole to 1 part by mole. In some embodiments, hydrogen may be present in the promoter in a relative amount of from 0.001 parts by mole to 1 part by mole. Without being bound by theory, it is believed the presence of hydrogen in this amount balances the negative charge of sulfur and oxygen to stabilize the compounds. [0029] In additional embodiments, hydrogen may be present in the promoter in a relative amount of from from 0 parts by mole to 0.1 parts by mole, from 0.1 parts by mole to 0.2 parts by mole, from 0.2 parts by mole to 0.3 parts by mole, from 0.3 parts by mole to 0.4 parts by mole, from 0.4 parts by mole to 0.5 parts by mole, from 0.5 parts by mole to 0.6 parts by mole, from 0.6 parts by mole to 0.7 parts by mole, from 0.7 parts by mole to 0.8 parts by mole, from 0.8 parts by
85734-WO-PCT/DOW 85734 WO 8 mole to 0.9 parts by mole, from 0.9 parts by mole to 1 part by mole, or any combination of one or more of these ranges. [0030] In some embodiments, hydrogen may be present in the promoter in a relative amount of less than or equal to 1 part by mole and at least 0.1 parts by mole, at least 0.2 parts by mole, at least 0.3 parts by mole, at least 0.4 parts by mole, at least 0.5 parts by mole, at least 0.6 parts by mole, at least 0.7 parts by mole, at least 0.8 parts by mole, or at least 0.9 parts by mole. In additional embodiments, hydrogen may be present in the promoter in a relative amount of at least 0.001 parts by mole and less than or equal to 0.9 parts by mole, less than or equal to 0.8 parts by mole, less than or equal to 0.7 parts by mole, less than or equal to 0.6 parts by mole, less than or equal to 0.5 parts by mole, less than or equal to 0.4 parts by mole, less than or equal to 0.3 parts by mole, less than or equal to 0.2 parts by mole, or less than or equal to 0.1 parts by mole. [0031] According to one or more embodiments, oxygen may be present in the promoter in a relative amount of from 0.001 parts by mole to 4 parts by mole. The amount of oxygen may depend on the oxidation state of the oxygen carrier material, where more oxygen may be present in embodiments when the oxygen carrier material is storing oxygen atoms and less oxygen may be present once such oxygen has been provided for reaction and prior to regeneration. In general, the amount of oxygen may vary at different points in processing to form olefins, as is described herein. [0032] In additional embodiments, oxygen may be present in the promoter in a relative amount of from 0.001 parts by mole to 0.5 parts by mole, from 0.5 parts by mole to 1 part by mole, from 1 part by mole to 1.5 parts by mole, from 1.5 parts by mole to 2 parts by mole, from 2 parts by mole to 2.5 parts by mole, from 2.5 parts by mole to 3 parts by mole, from 3 parts by mole to 3.5 parts by mole, from 3.5 parts by mole to 4 parts by mole, or any combination of one or more of these ranges. [0033] In some embodiments, oxygen may be present in the promoter in a relative amount of less than or equal to 4 parts by mole and at least 0.25 parts by mole, at least 0.5 parts by mole, at least 0.75 parts by mole, at least 1 part by mole, at least 1.25 parts by mole, at least 1.5 parts by mole, at least 1.75 parts by mole, at least 2 parts by mole, at least 2.25 parts by mole, at least 2.5 parts by mole, at least 2.75 parts by mole, at least 3 parts by mole, at least 3.25 parts by mole, at least 3.5 parts by mole, or at least 3.75 parts by mole. In additional embodiments, oxygen may be present in the promoter in a relative amount of at least 0.001 parts by mole and less than or equal to 3.75 parts by mole, less than or equal to 3.5 parts by mole, less than or equal to 3.25 parts by
85734-WO-PCT/DOW 85734 WO 9 mole, less than or equal to 3 parts by mole, less than or equal to 2.75 parts by mole, less than or equal to 2.5 parts by mole, less than or equal to 2.25 parts by mole, less than or equal to 2 parts by mole, less than or equal to 1.75 parts by mole, less than or equal to 1.5 parts by mole, less than or equal to 1.25 parts by mole, less than or equal to 1 part by mole, less than or equal to 0.75 parts by mole, less than or equal to 0.5 parts by mole, or less than or equal to 0.25 parts by mole, [0034] According to one or more embodiments, the promoter may comprise K2SO4, Na2SO4, Li
2SO
4, K
2SO
3, Na
2SO
3, Li
2SO
3, KHSO
3, NaHSO
3, or combinations thereof. According to some embodiments, any one, two, three, four, five, six, seven, or all eight of K
2SO
4, Na
2SO
4, Li
2SO
4, K2SO3, Na2SO3, Li2SO3, KHSO3, or NaHSO3 may be utilized as described herein. Disclosed herein are embodiments where any combination of one or more (e.g., one, two, three, four…, or all eight) of these oxides are present in the ranges disclosed herein. [0035] In embodiments, the oxygen carrier material, in addition to the one or more redox-active metal oxides and the promoter, may further comprise one or more additional materials. In embodiments, the one or more additional materials may function as binders in the oxygen carrier materials. In some embodiments, the binders may not substantially contribute to the oxygen carrying and/or catalytic functionality of the oxygen carrier materials. Binders may generally enhance the physical properties of the oxygen carrier material. According to embodiments, the one or more additional materials may be chosen from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof. In general, the additional material or materials may not include elements that are present in the first composition, aside from oxygen. It is contemplated that mixtures of various oxides of an element may be included in the one or more additional materials. Without limitation, in one or more embodiments, additional materials may be chosen from those disclosed in "Progress in Chemical-Looping Combustion and Reforming technologies" Progress in Energy and Combustion Science 38 (2012) 215-282 and "Chemical Looping Systems for Fossil Energy Conversions", Liang-Shih Fan, published by WILEY 2010. For example, in certain embodiments, suitable additional materials that may act as binders include, without limitation, silica (colloidal, fumed, crystalline, amorphous), alumina (alpha, theta, or gamma crystal phases), CaAlxOy, MgAl2O4, zirconia, inorganic clays (e.g., kaolin, other alumina-silicates), and glass materials (such as glass fibers). [0036] According to one or more embodiments, the oxygen carrier material may comprise from 1 wt.% to 50 wt.% of the one or more additional materials. For example, the one or more additional
85734-WO-PCT/DOW 85734 WO 10 materials may be present in the oxygen carrier material in an amount of from 1 wt.% to 5 wt.%, from 5 wt.% to 10 wt.%, from 10 wt.% to 15 wt.%, from 15 wt.% to 20 wt.%, from 20 wt.% to 25 wt.%, from 25 wt.% to 30 wt.%, from 30 wt.% to 35 wt.%, from 35 wt.% to 40 wt.%, from 40 wt.% to 45 wt.%, from 45 wt.% to 50 wt.%, or any combination of one or more of these ranges. For example, the oxygen carrier material may comprise less than or equal to 50 wt.% and at least 5 wt.%, at least 10 wt.%, at least 15 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, or at least 45 wt.%, of the one or more additional materials. In additional embodiment, the oxygen carrier material may comprise the one or more additional material in an amount of at least 1 wt.% and less than or equal to 5 wt.%, less than or equal to 10 wt.%, less than or equal to 15 wt.%, less than or equal to 20 wt.%, less than or equal to 25 wt.%, less than or equal to 30 wt.%, less than or equal to 35 wt.%, less than or equal to 40 wt.%, or less than or equal to 45 wt.%. [0037] According to one or more embodiments, the oxygen carrier material may not include alkaline earth metals and/or boron, or may include alkaline earth metals and/or boron in relatively small amounts, as described herein. For example, the oxygen carrier material may include alkaline earth metals and/or boron in an amount of less than or equal to 10 wt.%, less than or equal to 8 wt.%, less than or equal to 6 wt.%, less than or equal to 4 wt.%, less than or equal to 2 wt.%, less than or equal to 1 wt.%, or even less than or equal to 0.1 wt.% [0038] According to one or more embodiments of the present disclosure, a method for producing olefinic compounds is provided that utilizes the oxygen carrier materials described herein. As used herein, the term “olefinic compounds” refers to hydrocarbons having one or more carbon-carbon double bonds apart from the formal double bonds in aromatic compounds. For example, ethylene and styrene are olefinic compounds, but ethylbenzene would not be an olefinic compound as the only double bonds present in ethylbenzene are formal double bonds present as part of the aromatic structure. [0039] Now referring to FIG. 1, a reactor system 100 that may be used with the methods of the present disclosure is shown, but other reactor systems that would be suitable for the presently disclosed methods are contemplated as suitable. FIG. 1 is a simplified system, and other systems are contemplated. Additionally, in FIG. 1, a wide variety of reactor types are contemplated as potentially suitable for the methods described herein. For example, the oxygen carrier materials of the present disclosure may be utilized in the systems and methods that are disclosed in at least
85734-WO-PCT/DOW 85734 WO 11 PCT International Application No. PCT/US23/73963, entitled “Methods For Dehydrogenating Hydrocarbons By Thermal Dehydrogenation” and International Patent Publication WO 2020/046978, entitled “Methods for Dehydrogenating Hydrocarbons,” the teachings of each of which are incorporated by reference in their entirety herein. The technical aspects of these disclosures may further describe the methods and systems described herein with respect to FIG. 1. Additionally, it is noted that the steps indicated by FIG. 1 are not to be interpreted as essential steps, particularly in view of the methods of the appended claims. [0040] Referring still to FIG. 1, the reactor system 100 may include a reactor 110 and a regeneration unit 120. In one or more embodiments, the reactor 110 may be a fluidized bed reactor. Generally, a feed stream 101 may be passed into the reactor 110 and be processed in the reactor 110 to form a product stream 102 that includes one or more olefinic compounds. As used herein, the term “olefinic compounds” refers to hydrocarbons having one or more carbon-carbon double bonds apart from the formal double bonds in aromatic compounds. For example, ethylene and styrene are olefinic compounds, but ethylbenzene would not be an olefinic compound as the only double bonds present in ethylbenzene are formal double bonds present as part of the aromatic structure. [0041] As described in detail herein, according to one or more embodiments, the oxygen carrier material may be cycled between the reactor 110 and the regeneration unit 120, where the oxygen carrier material enters the reactor 110 in an oxygen-rich state, provides oxygen in the reactor 110, leaves the reactor 110 in an oxygen-diminished state, and may be regenerated to an oxygen-rich state in the regeneration unit 120. [0042] In one or more embodiments, the feed stream 101 may comprise one or more hydrocarbons. As described herein, the feed stream 101 may be passed into the reactor 110. In one or more embodiments, the one or more hydrocarbons may comprise one or more of ethane, ethylbenzene, propane, or butane. According to one or more embodiments, the one or more hydrocarbons may comprise at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95 wt. % or even at least 99 wt. % of any of ethane. In additional embodiments, the one or more hydrocarbons may comprise at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95 wt. % or even at least 99 wt. % of ethylbenzene. In additional embodiments, the one or more hydrocarbons may comprise at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95 wt. % or
85734-WO-PCT/DOW 85734 WO 12 even at least 99 wt. % of propane. In additional embodiments, the one or more hydrocarbons may comprise at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95 wt. % or even at least 99 wt. % of butane. In additional embodiments, the one or more hydrocarbons may comprise at least 50 wt. %, at least 60 wt. %, at least 70 wt. %, at least 80 wt. %, at least 90 wt. %, at least 95 wt. % or even at least 99 wt. % of the sum of ethane, propane, butane, and ethylbenzene. [0043] According to embodiments, the oxygen carrier material may be passed to the reactor 110 in an oxygen-rich state. In the reactor 110, the one or more hydrocarbons of the feed stream 101 may be dehydrogenated to form hydrogen (i.e., gas phase H2) and one or more olefinic compounds. According to embodiments, at least a portion of the hydrogen may be reacted with oxygen from the oxygen carrier material to form water. Reacting the hydrogen with oxygen from the oxygen carrier material may reduce the oxygen carrier material and convert it to an oxygen- diminished state. As described herein, the oxygen-rich state of the oxygen carrier material has a greater amount of oxygen than the oxygen-diminished state of the oxygen carrier material. However, it should be understood that some oxygen may still be contained in the oxygen- diminished state oxygen carrier material. [0044] According to some embodiments, the dehydrogenation reaction in the reactor 110 may be thermally driven (i.e., non-catalytic) wherein, in such embodiments, a dehydrogenation catalyst is not utilized in the reactor 110. While the temperature of the reactor 110 may vary, in some embodiments, the reactor 110 may operate at a temperature of from 600 °C to 850 °C, which may be appropriate to promote thermal dehydrogenation. In additional embodiments, a dehydrogenation catalyst may be utilized to promote dehydrogenation in the reactor 110. The dehydrogenation catalyst may be passed along with the oxygen carrier material and cycled between the reactor 110 and the regeneration unit 120. In embodiments where a dehydrogenation catalyst is utilized, temperatures of from 600 °C to 850 °C may also be utilized. Suitable dehydrogenation catalysts include, without limitation, those including platinum, platinum and gallium, platinum and tin, or chromium. For example, suitable catalysts are described in Chem. Rev. 2014, 114, 20, 10613–10653, which is incorporated herein by reference in its entirety and U.S. Pat. No. 8,669,406, which is incorporated herein by reference in its entirety. [0045] The one or more olefinic compounds produced in the reactor 110, as well as unconverted hydrocarbons, water, and unconverted hydrogen, may exit the reactor 110 via product stream 102,
85734-WO-PCT/DOW 85734 WO 13 as an olefin-containing effluent. In one or more embodiments, the olefinic compounds may comprise one or more of ethylene, propylene, butylene, or styrene. The term butylene includes any isomers of butylene, such as α-butylene, cis-β-butylene, trans-β-butylene, and isobutylene. In some embodiments, the olefin-containing effluent may comprise at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, or even at least 60 wt. % of ethylene. In additional embodiments, the olefin-containing effluent may comprise at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, or even at least 60 wt. % of propylene. In additional embodiments, the olefin-containing effluent may comprise at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, or even at least 60 wt. % of butylene. In additional embodiments, the olefin- containing effluent may comprise at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, or even at least 60 wt. % of styrene. In additional embodiments, the olefin-containing effluent may comprise at least 20 wt. %, at least 30 wt. %, at least 40 wt. %, at least 50 wt. %, or even at least 60 wt. % of the sum of one or more of ethylene, propylene, butylene, and styrene. The product stream 102 may further comprise unreacted components of the feed stream 101, as well as other reaction products that are not considered olefinic compounds. The olefinic compounds may be separated from unreacted components in subsequent separation steps. [0046] As described herein, in the reactor 110, the one or more hydrocarbons, such as ethane, may be dehydrogenated to produce hydrogen, and that hydrogen may be reacted with oxygen via a combustion reaction to form water. The oxygen is supplied by the oxygen carrier material, and the reaction of the hydrogen into water pushes the dehydrogenation reaction equilibrium towards the products, such as ethylene. In such embodiments, it is advantageous that the oxygen carrier material promotes the combustion of hydrogen over reactions with hydrocarbons present in the reactor 110. Such hydrocarbons may include the feed hydrocarbons, such as ethane, as well as product olefinic compounds, such as ethylene. Reaction of these hydrocarbons with the oxygen from the oxygen carrier material may undesirably form carbon monoxide and/or carbon dioxide. Carbon dioxide and carbon monoxide in the product stream 102 may cause several issues, such as difficulty in separating such components from other compounds in the product stream 102 as well as the potential emission of carbon dioxide into the environment or need to sequester such carbon dioxide. For example, carbon monoxide may be an undesirable inhibitor in certain downstream unit operations like acetylene hydrogenation reactors. With this in mind, it has been found that the presently disclosed oxygen carrier materials may have relatively high selectivity for promoting hydrogen combustion to form water as compared with selectivity for promoting the undesirable
85734-WO-PCT/DOW 85734 WO 14 combustion of hydrocarbons with feed alkanes such as ethane and/or product olefinic compounds such as ethylene. [0047] According to one or more embodiments, and as is described herein, the hydrogen formed by the dehydrogenation reaction is gaseous H
2, which reacts with oxygen from the oxygen carrier material. This is in contrast to some other reaction mechanisms, such as oxidative dehydrogenation, where hydrogen is not formed. Rather, in such oxidative dehydrogenation reactions, alkanes are processed to olefins in a single reaction step where hydrogen (H
2) is not formed as an intermediary. This concept is described in detail in, for example, “Oxidative Dehydrogenation of Ethane: Common Principles and Mechanistic Aspects,” Gartner et al. ChemCatChem 2013, 5, 3196-3217. [0048] As described herein, the oxygen carrier material is passed into the reactor 110 and subsequently out of the reactor 110. Referring again to FIG. 1, in some embodiments, the oxygen carrier material is cycled between the reactor 110 and a regeneration unit 120. The oxygen carrier material may pass from the reactor 110 to the regeneration unit 120 via stream 103 and be passed from the regeneration unit 120 back to the reactor 110 via stream 104, and be continuously looped. In general, the oxygen carrier material may enter the reactor 110 in an oxygen-rich state, lose some or all oxygen atoms in the reactor 110 (to combust with hydrogen gas), and exit the reactor 110 in an oxygen-diminished state via stream 103. The oxygen carrier material in the oxygen- diminished state may be passed to the regeneration unit 120 where it is exposed to oxygen and regenerated into its oxygen-rich state. This oxygen carrier material in the oxygen-rich state may be passed from the regeneration unit 120 via stream 104 back to the reactor 110. [0049] According to one or more embodiments, in the regeneration unit 120, the oxygen carrier material may be exposed to oxygen, such as by exposure to air, oxygen enriched air, or even pure oxygen. This exposure allows the oxygen carrier material to be replenished with oxygen. Additionally, in the regeneration unit 120, a fuel gas may be combusted in order to heat the oxygen carrier material. This heat may be the main source of heat to maintain temperatures in the reactor 110, which is using heat by the dehydrogenation reaction. The fuel gas may comprise a variety of combustible compounds, such as hydrogen, methane, ethane, propane, etc. In some embodiments, methane may be the primary constituent of the fuel gas. In embodiments, the regeneration unit 120 may operate at elevated temperatures, such as from 600 °C to 900 °C, or temperatures that
85734-WO-PCT/DOW 85734 WO 15 would be sufficient to heat the oxygen carrier materials to a temperature such that their heat can be utilized in the reactor 110 to drive the dehydrogenation reaction. [0050] As described herein, a fuel gas, such as one comprising methane, may be combusted in the regeneration unit 120. It has been discovered that the composition of the oxygen carrier material may affect the fuel gas combustion rate, according to some embodiments. As such, it is undesirable to utilize an oxygen carrier material that has a composition that will slow the combustion of hydrocarbons. This is particularly a problem, since the oxygen carrier materials may be chosen such that they promote combustion of hydrogen but not alkanes and/or alkenes in the reactor 110. However, it has been observed that the presently disclosed oxygen carrier materials, according to one or more embodiments, may have acceptable levels of promotion of alkane combustion, such as methane combustion, in the regeneration unit 120 while having good selectivity for hydrogen combustion over ethane combustion in the reactor 110. [0051] In some embodiments the oxygen-rich state oxygen carrier material may be partially reduced before being passed to the reactor 110. This may include exposing the oxygen carrier material in stream 104 to a reducing gas such as H2 and/or methane. Such treatment may allow for removal of some oxygen from the lattice of the oxygen carrier material. However, the amount of remaining oxygen is still suitable for supplying oxygen to the reactor 110 for combustion of hydrogen, as disclosed herein. [0052] The present disclosure includes numerous aspects, described as aspects 1-15, hereinbelow. [0053] Aspect 1. An oxygen carrier material comprising: one or more redox-active metal oxides, wherein the oxygen carrier material comprises from 35 wt.% to 99.9 wt.% of the one or more redox-active metal oxides; and a promoter, wherein the oxygen carrier material comprises from 0.1 wt.% to 15 wt.% of the promoter, and wherein at least 95 wt.% of the promoter consists of: 1 part by mole of sulfur; from 0.1 parts by mole to 2 parts by mole of one or more alkali metals; from 0 parts by mole to 1 part by mole of hydrogen; and from 0.001 parts by mole to 4 parts by mole of oxygen. [0054] Aspect 2. The oxygen carrier material of aspect 1, wherein the one or more redox-active metal oxides are chosen from oxides comprising iron, manganese, cobalt, cerium, copper, nickel, or combinations thereof.
85734-WO-PCT/DOW 85734 WO 16 [0055] Aspect 3. The oxygen carrier material of aspect 1, wherein the one or more redox-active metal oxides are chosen from Fe2O3, Fe3O4, MnO2, Mn2O3, Mn3O4, CaMnO3, CaxSr1-xMnO3, FeTiO3, Fe2TiO5, CuO, Co3O4, LaxSr1-xFeO3, LaxSr1-xMnO3, LaxSr1-xCoO3, NiO, CeO2, or combinations thereof. [0056] Aspect 4. The oxygen carrier material of any previous aspect, wherein the promoter comprises K2SO4, Na2SO4, Li2SO4, K2SO3, Na2SO3, Li2SO3, KHSO3, NaHSO3, or combinations thereof. [0057] Aspect 5. The oxygen carrier material of any previous aspect, wherein the oxygen carrier material comprises hydrogen. [0058] Aspect 6. The oxygen carrier material of any of aspects 1-4, wherein the oxygen carrier material does not include hydrogen. [0059] Aspect 7. The oxygen carrier material of any previous aspect, further comprising one or more additional materials chosen from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof. [0060] Aspect 8. The oxygen carrier material of aspect 7, wherein the one or more additional materials function as binders. [0061] Aspect 9. The oxygen carrier material of aspect 7, wherein the oxygen carrier material comprises from 1 wt.% to 50 wt.% of the one or more additional materials. [0062] Aspect 10. The oxygen carrier material of aspect 7, wherein the oxygen carrier material comprises at least 99 wt.% of the one or more redox-active metal oxides, the promoter, and the one or more additional materials. [0063] Aspect 11. A method for producing olefinic compounds, the method comprising: passing a feed stream into a reactor, wherein the feed stream comprises one or more hydrocarbons; passing an oxygen carrier material into the reactor, wherein in the reactor: the one or more hydrocarbons are dehydrogenated to form hydrogen and one or more olefinic compounds; and at least a portion of the hydrogen is reacted with oxygen from the oxygen carrier material to produce water; wherein the oxygen carrier material comprises: one or more redox-active metal oxides, wherein the oxygen carrier material comprise from 35 wt.% to 99.9 wt.% of the one or more redox-active metal oxides; and a promoter, wherein the oxygen carrier materials comprise from 0.1 wt.% to 15 wt.% of the promoter, and wherein at least 95 wt.% of the promoter consists of: 1 part by mole of sulfur; from
85734-WO-PCT/DOW 85734 WO 17 0.1 parts by mole to 2 part by mole of one or more alkali metals; from 0 parts by mole to 1 part by mole of hydrogen; and from 0.001 parts by mole to 4 parts by mole of oxygen. [0064] Aspect 12. The method of aspect 11, wherein: the one or more hydrocarbons comprise ethane, ethylbenzene, propane, butane, or combinations thereof; and the one or more olefinic compounds comprise ethylene, styrene, propylene, butylene, or combinations thereof. [0065] Aspect 13. The method of aspect 11 or 12, wherein the oxygen carrier material is cycled between the reactor and a regeneration unit, wherein the oxygen carrier material exiting the reactor is in an oxygen-diminished state and the oxygen carrier material exiting the regeneration unit is in an oxygen-rich state. [0066] Aspect 14. The method of aspect 13, wherein a fuel gas is combusted in the regeneration unit to heat the oxygen carrier material. [0067] Aspect 15. The method of aspect 14, wherein the fuel gas comprises hydrogen, methane, ethane, propane, or combinations thereof. EXAMPLES [0068] The various embodiments of the present disclosure will be further clarified by the following examples. The examples are illustrative in nature and should not be understood to limit the subject matter of the present disclosure. [0069] Example 1 – Sample Preparation [0070] Comparative Sample A was quartz chips sourced commercially from Pyromatics and sieved to 100-200 mesh before use. [0071] Comparative Sample A1 was Si-doped alumina (Al
2O
3) obtained commercially from Sasol. [0072] Comparative Sample A2 was prepared by mixing Comparative Sample A1 with potassium sulfate, K
2SO
4 (Sigma Aldrich) with a small amount of water, such that the total amount of K2SO4 in the final mixture was 13 wt.% post drying. [0073] Comparative Sample A3 was prepared by mixing Comparative Sample A1 with sodium sulfate, Na
2SO
4 (Sigma Aldrich) with a small amount of water, such that the total amount of Na2SO4 in the final mixture was 30 wt.% post drying.
85734-WO-PCT/DOW 85734 WO 18 [0074] Comparative Sample A4 was calcium sulfate (CaSO
4) commercially procured from Sigma Aldrich. [0075] Comparative Sample A5 was potassium sulfate (K2SO4) commercially procured from Sigma Aldrich. [0076] Comparative Sample B was procured commercially with an average particle size ranging from 70-150 µm and used as-received. [0077] Comparative Sample C was prepared by firs weighing a stoichiometric amount of CaCO
3 and MnO
2 in a mortar. The dry powders were ground with a pestle for 5 minutes. The powders were then shaken for 1 minute in a separate container and replaced back into the mortar. The mixing and shaking were repeated two times (for a total of 10 minutes grinding and 2 minutes shaking). Subsequently, the powders were ground and pasted for 5 minutes after introducing 5-10 mL of deionized H2O. The paste was transferred to an alumina crucible and dried for at least 5 hours at 120 °C in air. The dried mixture was calcined in air at 800 °C for 2 hours, and finally at 1200 °C for 48 hours. [0078] Comparative Sample D was prepared similarly to Comparative Sample C with a stoichiometric amount of CaCO3, SrCO3, and MnO2. The strontium carbonate (SrCO3, Sigma- Aldrich 99.9 %) was sourced commercially and used as-is. [0079] Comparative Sample E was prepared similarly to Comparative Sample C, except the calcination was conducted at 1000 °C for 48 hours. [0080] Comparative Sample F was ilmenite powder (FeTiO
3) procured commercially from Sigma Aldrich. A small amount of deionized water was added to the ilmenite powder to make a paste, and the paste was then calcined at 950 °C for 6 hours in air. [0081] Comparative Sample G was prepared by combining Comparative Sample F with a stoichiometric amount of CaSO
4 (Sigma Aldrich) and some amount of water to make a paste, and then calcining the mixture at 950 °C for 6 hours in air. [0082] Comparative Sample H was prepared by mixing a 1:1 (w/w) ratio of milled Comparative Sample B with PURALOX, adding water to the dry mixture to make a paste, and calcining the paste at 1000 °C in air.
85734-WO-PCT/DOW 85734 WO 19 [0083] Comparative Sample I was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with PURALOX and then adding the required amount of CaSO4 and some amount of water to make a paste. The mixture was then calcined at 1000 °C in air. [0084] Comparative Sample J was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with PURALOX, adding water to the dry mixture to make a paste, and calcining the paste at 1300 °C in air. [0085] Comparative Sample K was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with PURALOX and then adding the required amount of CaSO
4. A small amount of water was added to the dry mixture to make a paste. The paste was then calcined at 1300 °C in air. [0086] Comparative Sample L was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with ZrO2 (Sigma Aldrich), adding a small amount of water to make a paste, and then calcining the paste at 1000 °C in air. [0087] Comparative Sample M was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with ZrO2 (Sigma Aldrich) and then adding the required amount of CaSO4 and a small amount of water to make a paste. The paste was then calcined at 1000 °C in air. [0088] Comparative Sample N was prepared by mixing a 1:1 (w/w) ratio of Fe
2O
3 (PPT) with CATAPAL and calcining the mixture at 1000 °C in air. [0089] Comparative Sample O was prepared by mixing a 1:1 (w/w) ratio of Fe2O3 (PPT) with CATAPAL and then adding the required amount of CaSO
4. The mixture was then calcined at 1000 °C in air. [0090] Comparative Sample P was prepared by mixing a 1:1 (w/w) ratio of Fe2O3 (Noah Chemicals) with CATAPAL, adding a small amount of water to make a paste, and calcining the paste at 1000 °C in air. [0091] Comparative Sample Q was prepared by mixing a 1:1 (w/w) ratio of Fe2O3 (Noah Chemicals) with CATAPAL and then adding the required amount of CaSO4. The mixture was then calcined at 1000 °C in air.
85734-WO-PCT/DOW 85734 WO 20 [0092] Samples 1-3 were prepared by impregnating Comparative Sample B with an aqueous solution of K2SO4 in required amounts and then calcining the impregnated solid at 950 °C for 6 hours in air. [0093] Sample 4 was prepared by first preparing a promoter solution by dissolving a desired amount of K2SO4 solid into deionized H2O. Potassium sulfate (K2SO4, Sigma-Aldrich 99.0 %) was sourced commercially and used as-is. Then, Comparative Sample C was impregnated with the promoter solution. The impregnated material was dried at less than 200 °C, followed by calcination in air at less than 1000 °C for 6 hours. [0094] Sample 5 was prepared similarly to Sample 4, where Comparative Sample D was impregnated, instead of Comparative Sample C, with the corresponding promoter solutions containing K
2SO
4. [0095] Sample 6 was prepared by first weighing a stoichiometric amount of CaCO3 and MnO2 in a mortar. The dry powders were ground with a pestle for 5 minutes. The powders were then shaken for 1 minute in a separate container and replaced back into the mortar. The mixing and shaking were repeated for two times (for a total of 10 minutes grinding and 2 minutes shaking). Separately, K2SO4 solid was dissolved in less than 10 mL of deionized H2O to form a clear solution, according to a molar ratio of K : Ca : Mn = 0.05 : 0.95 : 1. The dry powders were introduced with the K
2SO
4 solution and subsequently ground and pasted for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 5 hours at 120 °C in air. The dried mixture was then calcined in air at 1000 °C for 48 hours. [0096] Sample 7 was prepared by combining Comparative Sample F with K
2SO
4 (Sigma Aldrich) and some amount of water to make a paste, and then calcining the mixture at 950 °C for 6 hours in air. [0097] Sample 8 was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with PURALOX and then adding the required amount of K2SO4 and some amount of water to make a paste. The paste was then calcined at 1000 °C in air. [0098] Sample 9 was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with PURALOX and then adding the required amount of K2SO4 and some amount of water to make a paste. The paste was then calcined at 1300 °C in air.
85734-WO-PCT/DOW 85734 WO 21 [0099] Sample 10 was prepared by mixing a 1:1 (w/w) ratio of Comparative Sample B with ZrO2 (Sigma Aldrich) and then adding the required amount of K2SO4 and a small amount of water to make a paste. The paste was then calcined at 1000 °C in air. [0100] Sample 11 was prepared by mixing a 1:1 (w/w) ratio of Fe
2O
3 (PPT) with CATAPAL and then adding the required amount of K2SO4 and a small amount of water to make a paste. The paste was then calcined at 1000 °C in air. [0101] Sample 12 was prepared by mixing 1:1 (w/w) ratio of Fe
2O
3 (Sigma Aldrich) with CATAPAL and then adding the required amount of K
2SO
4 and a small amount of water to make a paste. The paste was then calcined at 1000 °C in air. [0102] Sample 13 was prepared by impregnating Comparative Sample B with an aqueous solution of Na
2SO
4 in the required amount and then calcining the impregnated solid at 950 °C for 6 hours in air. [0103] Samples 14-16 were prepared by impregnating Comparative Sample B with an aqueous solution of K
2SO
4 in the required amounts and then calcining the impregnated solids at 950 °C for 6 hours in air. [0104] Sample 17 was prepared by impregnating Comparative Sample B with an aqueous solution containing potassium nitrate (KNO
3) and ammonium sulfate ((NH
4)
2SO
4) in the required amounts and then calcining the impregnated solid at 950 °C for 6 hours in air. [0105] Example 2 – Selective Hydrogen Combustion Performance [0106] The selective hydrogen combustion performance of the samples was evaluated in a U- shape fixed-bed reactor made from quartz. First, a 125 milligram (mg) sample was sized to 100- 200 mesh and diluted with 400 mg of quartz chips (100-200 mesh) before loaded into the reactor. Once the sample was loaded, the upstream empty space was filled with 18-35 mesh quartz chips. The sample was then heated to 750 °C under air flow, purged with helium, and subjected to three cycles of 750 °C under 12 standard cubic centimeters (sccm) total gas flow rate. Within each cycle, the sample was first exposed to 90% ethane/10% nitrogen for 1 minute, purged with helium, and then regenerated in air for 15 minutes. The outlet gas composition was analyzed using gas chromatography after 23 seconds of ethane exposure. Table 1 presents the measured data, which are the mean values across three cycles, including the average C2H6 conversion, C2H4 selectivity, CO
x selectivity, and H
2/C
2H
4 ratio.
85734-WO-PCT/DOW 85734 WO 22 [0107] Ethane conversion and carbon-based selectivities were calculated using the following equations, where [X] corresponds to the molar fraction and [IS] corresponds to internal standard. ^
^^^^^ ^^^ ^^ (1) ^
^^^ − ^^^ ^^^^ ^
^ ^ ^ ^ ^
^^^ ^^^^^^^^^^ ^%^ = ^^ ^^^ ^
^ × 100% ^^^ ^^^ ^^^^^^
Table 1: Selective hydrogen combustion performance of materials evaluated using the method of Example 2
85734-WO-PCT/DOW 85734 WO 23
[0108] As shown in Table 1, the presence of a promoter greatly improves the C2H4 selectivity, CO
x selectivity, and/or H
2/C
2H
4 ratio as compared to samples that do not have a promoter. For example, Samples 1-3, with K
2SO
4 present as the promoter, have greatly improved C
2H
4 selectivity and COx selectivity than Comparative Sample B, with no promoter. More specifically, for example, Sample 1 has a C
2H
4 selectivity of 94.3% and a CO
x selectivity of 0.4%, whereas Comparative Sample B has a C
2H
4 selectivity of 87.8% and a CO
x selectivity of 7%.
85734-WO-PCT/DOW 85734 WO 24 [0109] Further, the presence of a promoter including an alkali metal, such as potassium, improves the C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio as compared to samples that do not have a promoter including an alkali metal. For example, Comparative Sample G, with the promoter CaSO
4, has a C
2H
4 selectivity of 91% and a CO
x selectivity of 4.3%. Sample 7, with the promoter K2SO4, has a C2H4 selectivity of 93.8% and a COx selectivity of 1%. [0110] Finally, Table 1 indicates that the presence of both a redox-active metal oxide and a promoter improves performance of the oxygen carrier material. For example, Samples 1-17, with both a redox-active metal oxide and a promoter, all have improved H
2/C
2H
4 ratios than Comparative Sample A, which has no redox-active metal oxide or promoter. [0111] Thus, Table 1 indicates that oxygen carrier materials with a redox-active metal oxide and a promoter containing sulfur and an alkali metal improves the selectivity of hydrogen in the reactor, thus greatly improving C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio. [0112] Example 3 – Selective Hydrogen Combustion Performance [0113] Testing of the oxygen carriers was performed in a fixed bed laboratory reactor. A 0.5 gram (g) portion of the sample was loaded into a 0.5 inch outer diameter (OD) quartz bulb connected to a 0.25 inch outer diameter (OD) quartz tubing. The sample bed was supported on a pill of quartz wool and a layer of 0.5 to 1 mm quartz chips. The reactor was installed into a clamshell furnace and a flow of nitrogen at 40 sccm was introduced through the reactor tube. The reactor was then heated under 40 sccm of air flow, from room temperature to 780 °C. The oxygen carrying materials were subjected to several cyclic sequences. Each cycle included ethane dehydrogenation and, regeneration in air, with inert helium purging in the reactor tube between dehydrogenation and regeneration pulses. The ethane dehydrogenation step was done at a weight hourly space velocity (WHSV) of 7.0 hr
-1. Specifically, 53 sccm of a gas mixture containing 90 mol% ethane and 10 mol% helium was fed through the reactor for 60 seconds while the reactor was held at 780 °C. Analysis of the product gas composition was taken at 30 seconds into the dehydrogenation reaction pulse (halfway through). During the regeneration in air step, 40 sccm of air was fed through the reactor for 10 minutes. while the reactor was held at 780 °C. The product gas composition was analyzed by a Siemens Maxim Process Gas Chromatograph. For each oxygen carrying materials, multiple replicate reduction-oxidation cycles were performed and the average ethane conversion, ethylene selectivity, CO
x selectivity, and hydrogen to ethylene ratio are reported.
85734-WO-PCT/DOW 85734 WO 25 Table 2: Selective hydrogen combustion performance of materials evaluated using the method of Example 3
[0114] As shown in Table 2, the presence of a redox-active metal oxide greatly improves the C
2H
4 selectivity, CO
x selectivity, and/or H
2/C
2H
4 ratio as compared to samples that do not have a redox-active metal oxide. For example, Samples 13-17, with CaMnO3 as the redox-active metal oxide, all have improved H2/C2H4 ratios than Comparative Samples A1-A5, which have no redox- active metal oxide. Such comparative samples show high COx selectivity and/or little activity towards hydrogen combustion. For example, Comparative Sample A2 has a C2H4 selectivity of 79.9%, COx selectivity of 11.2%, and a H2/C2H4 ratio of 0.91. Sample 13 has a C2H4 selectivity of 93.3%, CO
x selectivity of 0.5%, and a H
2/C
2H
4 ratio of 0.69. [0115] Additionally, the presence of a promoter including sulfur and an alkali metal, such as sodium or potassium, greatly improves performance of the oxygen carrier material. For example, Comparative Sample B, with no promoter, has worse C
2H
4 selectivity and CO
x selectivity than Samples 13-16, which have Na
2SO
4 or K
2SO
4 present as the promoter.
85734-WO-PCT/DOW 85734 WO 26 [0116] Thus, Table 2 indicates that oxygen carrier materials with a redox-active metal oxide and a promoter containing sulfur and an alkali metal improves the selectivity of hydrogen in the reactor, thus greatly improving C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio. [0117] It will be apparent to those skilled in the art that various modifications and variations can be made to the presently disclosed technology without departing from the spirit and scope of the technology. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the presently disclosed technology may occur to persons skilled in the art, the technology should be construed to include everything within the scope of the appended claims and their equivalents. Additionally, although some aspects of the present disclosure may be identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not limited to these aspects. [0118] It is noted that the various details described in this disclosure should not be taken to imply that these details relate to elements that are essential components of the various embodiments described in this disclosure, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Unless specifically identified as such, no feature disclosed and described herein should be construed as “essential”. Contemplated embodiments of the present technology include those that include some or all of the features of the appended claims. [0119] For the purposes of describing and defining the present disclosure it is noted that the term “about” are utilized in this disclosure to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “about” are also utilized in this disclosure to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. [0120] In relevant cases, where a composition is described as “comprising” one or more elements, embodiments of that composition “consisting of” or “consisting essentially of” those one or more elements is contemplated herein. [0121] It should be appreciated that compositional ranges of a chemical constituent in a stream or in a reactor should be appreciated as containing, in some embodiments, a mixture of isomers of that constituent. For example, a compositional range specifying butene may include a mixture of various isomers of butene. It should be appreciated that the examples supply compositional
85734-WO-PCT/DOW 85734 WO 27 ranges for various streams, and that the total amount of isomers of a particular chemical composition can constitute a range. [0122] It is noted that one or more of the following claims and the detailed description utilize the terms “where” or “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.” [0123] It should be understood that any two quantitative values assigned to a property may constitute a range of that property, and all combinations of ranges formed from all stated quantitative values of a given property are contemplated in this disclosure. Where multiple ranges for a quantitative value are provided, these ranges may be combined to form a broader range, which is contemplated in the embodiments described herein. [0124] As would be understood in the context of the term as used herein, the term “passing” may include directly passing a substance between two portions of the disclosed system and, in some other instances, to mean indirectly passing a substance between two portions of the disclosed system. For example, indirect passing may include steps where the named substance passes through an intermediate operations unit, valve, sensor, etc.
Table 1: Selective hydrogen combustion performance of materials evaluated using the method of Example 2
85734-WO-PCT/DOW 85734 WO 23
[0108] As shown in Table 1, the presence of a promoter greatly improves the C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio as compared to samples that do not have a promoter. For example, Samples 1-3, with K2SO4 present as the promoter, have greatly improved C2H4 selectivity and COx selectivity than Comparative Sample B, with no promoter. More specifically, for example, Sample 1 has a C2H4 selectivity of 94.3% and a COx selectivity of 0.4%, whereas Comparative Sample B has a C2H4 selectivity of 87.8% and a COx selectivity of 7%.
85734-WO-PCT/DOW 85734 WO 24 [0109] Further, the presence of a promoter including an alkali metal, such as potassium, improves the C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio as compared to samples that do not have a promoter including an alkali metal. For example, Comparative Sample G, with the promoter CaSO4, has a C2H4 selectivity of 91% and a COx selectivity of 4.3%. Sample 7, with the promoter K2SO4, has a C2H4 selectivity of 93.8% and a COx selectivity of 1%. [0110] Finally, Table 1 indicates that the presence of both a redox-active metal oxide and a promoter improves performance of the oxygen carrier material. For example, Samples 1-17, with both a redox-active metal oxide and a promoter, all have improved H2/C2H4 ratios than Comparative Sample A, which has no redox-active metal oxide or promoter. [0111] Thus, Table 1 indicates that oxygen carrier materials with a redox-active metal oxide and a promoter containing sulfur and an alkali metal improves the selectivity of hydrogen in the reactor, thus greatly improving C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio. [0112] Example 3 – Selective Hydrogen Combustion Performance [0113] Testing of the oxygen carriers was performed in a fixed bed laboratory reactor. A 0.5 gram (g) portion of the sample was loaded into a 0.5 inch outer diameter (OD) quartz bulb connected to a 0.25 inch outer diameter (OD) quartz tubing. The sample bed was supported on a pill of quartz wool and a layer of 0.5 to 1 mm quartz chips. The reactor was installed into a clamshell furnace and a flow of nitrogen at 40 sccm was introduced through the reactor tube. The reactor was then heated under 40 sccm of air flow, from room temperature to 780 °C. The oxygen carrying materials were subjected to several cyclic sequences. Each cycle included ethane dehydrogenation and, regeneration in air, with inert helium purging in the reactor tube between dehydrogenation and regeneration pulses. The ethane dehydrogenation step was done at a weight hourly space velocity (WHSV) of 7.0 hr-1. Specifically, 53 sccm of a gas mixture containing 90 mol% ethane and 10 mol% helium was fed through the reactor for 60 seconds while the reactor was held at 780 °C. Analysis of the product gas composition was taken at 30 seconds into the dehydrogenation reaction pulse (halfway through). During the regeneration in air step, 40 sccm of air was fed through the reactor for 10 minutes. while the reactor was held at 780 °C. The product gas composition was analyzed by a Siemens Maxim Process Gas Chromatograph. For each oxygen carrying materials, multiple replicate reduction-oxidation cycles were performed and the average ethane conversion, ethylene selectivity, COx selectivity, and hydrogen to ethylene ratio are reported.
85734-WO-PCT/DOW 85734 WO 25 Table 2: Selective hydrogen combustion performance of materials evaluated using the method of Example 3
[0114] As shown in Table 2, the presence of a redox-active metal oxide greatly improves the C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio as compared to samples that do not have a redox-active metal oxide. For example, Samples 13-17, with CaMnO3 as the redox-active metal oxide, all have improved H2/C2H4 ratios than Comparative Samples A1-A5, which have no redox- active metal oxide. Such comparative samples show high COx selectivity and/or little activity towards hydrogen combustion. For example, Comparative Sample A2 has a C2H4 selectivity of 79.9%, COx selectivity of 11.2%, and a H2/C2H4 ratio of 0.91. Sample 13 has a C2H4 selectivity of 93.3%, COx selectivity of 0.5%, and a H2/C2H4 ratio of 0.69. [0115] Additionally, the presence of a promoter including sulfur and an alkali metal, such as sodium or potassium, greatly improves performance of the oxygen carrier material. For example, Comparative Sample B, with no promoter, has worse C2H4 selectivity and COx selectivity than Samples 13-16, which have Na2SO4 or K2SO4 present as the promoter.
85734-WO-PCT/DOW 85734 WO 26 [0116] Thus, Table 2 indicates that oxygen carrier materials with a redox-active metal oxide and a promoter containing sulfur and an alkali metal improves the selectivity of hydrogen in the reactor, thus greatly improving C2H4 selectivity, COx selectivity, and/or H2/C2H4 ratio. [0117] It will be apparent to those skilled in the art that various modifications and variations can be made to the presently disclosed technology without departing from the spirit and scope of the technology. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the presently disclosed technology may occur to persons skilled in the art, the technology should be construed to include everything within the scope of the appended claims and their equivalents. Additionally, although some aspects of the present disclosure may be identified herein as preferred or particularly advantageous, it is contemplated that the present disclosure is not limited to these aspects. [0118] It is noted that the various details described in this disclosure should not be taken to imply that these details relate to elements that are essential components of the various embodiments described in this disclosure, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Unless specifically identified as such, no feature disclosed and described herein should be construed as “essential”. Contemplated embodiments of the present technology include those that include some or all of the features of the appended claims. [0119] For the purposes of describing and defining the present disclosure it is noted that the term “about” are utilized in this disclosure to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “about” are also utilized in this disclosure to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue. [0120] In relevant cases, where a composition is described as “comprising” one or more elements, embodiments of that composition “consisting of” or “consisting essentially of” those one or more elements is contemplated herein. [0121] It should be appreciated that compositional ranges of a chemical constituent in a stream or in a reactor should be appreciated as containing, in some embodiments, a mixture of isomers of that constituent. For example, a compositional range specifying butene may include a mixture of various isomers of butene. It should be appreciated that the examples supply compositional
85734-WO-PCT/DOW 85734 WO 27 ranges for various streams, and that the total amount of isomers of a particular chemical composition can constitute a range. [0122] It is noted that one or more of the following claims and the detailed description utilize the terms “where” or “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.” [0123] It should be understood that any two quantitative values assigned to a property may constitute a range of that property, and all combinations of ranges formed from all stated quantitative values of a given property are contemplated in this disclosure. Where multiple ranges for a quantitative value are provided, these ranges may be combined to form a broader range, which is contemplated in the embodiments described herein. [0124] As would be understood in the context of the term as used herein, the term “passing” may include directly passing a substance between two portions of the disclosed system and, in some other instances, to mean indirectly passing a substance between two portions of the disclosed system. For example, indirect passing may include steps where the named substance passes through an intermediate operations unit, valve, sensor, etc.