Methods for producing olefinic compounds utilizing oxygen carrier materials that include iron

Abstract

Olefinic compounds may be produced by a method that may include passing a feed stream into a reactor, wherein the feed stream may include one or more hydrocarbons, and passing an oxygen carrier material into the reactor. In the reactor, the one or more hydrocarbons may be dehydrogenated to form hydrogen and one or more olefinic compounds, and 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 include a first composition. At least 95 wt.% of the first composition may consist of 1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

Description

METHODS FOR PRODUCING OLEFINIC COMPOUNDS UTILIZING OXYGEN CARRIER MATERIALS THAT INCLUDE IRONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 595,986 filed November 3, 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 chemical processing that produces olefinic materials.BACKGROUND

[0003] Olefinic compounds, such as light olefins (e.g., ethylene, butene, and propylene), may be used as base materials to produce many different materials, such as polyethylene, polypropylene, isopropanol, and acrylic acid, which may be used in, e.g., packaging, construction, and textiles. As a result of this utility, there is a worldwide demand for light olefins. Suitable processes for producing light olefins generally depend on the given chemical feed and include those that utilize fluidized catalysts. For example, light olefins may be formed by the catalytic dehydrogenation of alkanes in a fluidized bed reactor. However, there is a need for improvement in the methods used to make light olefins.SUMMARY

[0004] There is a continued need for methods for producing olefinic compounds. Described herein are methods for producing olefinic compounds by a method that may generally include forming olefinic compounds by dehydrogenation of hydrocarbons, such as alkanes. In such embodiments, an oxygen carrier material may be utilized that supplies oxygen to combust the hydrogen formed by the dehydrogenation reaction. Combusting the hydrogen may generally shift the dehydrogenation reaction equilibrium towards the products (hydrogen and olefinic compounds). It has been found that particular oxygen carrier materials, described herein, may be well suited for such a process by having relatively high selectivity for combusting hydrogen gas over combusting hydrocarbons. Particularly, oxygen carrier materials that include at least iron, one or more alkali metals, tungsten, and oxygen, in particular amounts relative to one another, as described herein, may have such selectivity and be well suited for the methods described herein.

[0005] According to one or more embodiments of the present disclosure, olefinic compounds may be produced by a method that may comprise passing a feed stream into a reactor, wherein thefeed stream may comprise one or more hydrocarbons, and passing an oxygen carrier material into the reactor. In the reactor, the one or more hydrocarbons may be dehydrogenated to form hydrogen and one or more olefinic compounds, and 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 include a first composition. At least 95 wt.% of the first composition may consist of 1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

[0006] 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

[0007] 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:

[0008] 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.

[0009] 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.

[0010] 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

[0011] 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.

[0012] Generally, described in this disclosure are various embodiments of methods for producing olefinic compounds. According to one or more embodiments of the present disclosure, the methods for producing olefinic compounds utilize the oxygen carrier materials described herein (sometimes described herein simply as “oxygen carriers”). For example, the processes may utilize an oxygen carrier material that includes at least iron, oxygen, one or more alkali metals, and tungsten.

[0013] 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.

[0014] 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 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.

[0015] 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 described indetail 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.

[0016] 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, propane, butane, or ethylbenzene. 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 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 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 even at least 99 wt. % of the sum of ethane, propane, butane, and ethylbenzene.

[0017] 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 oxygendiminished 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 oxygendiminished state oxygen carrier material.

[0018] 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.

[0019] 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. 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 a- butylene, cis-|3-butylene, trans-|3-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 reactionproducts that are not considered olefinic compounds. The olefinic compounds may be separated from unreacted components in subsequent separation steps.

[0020] 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 combustion of hydrocarbons with feed alkanes such as ethane and / or product olefinic compounds such as ethylene.

[0021] According to one or more embodiments, and as is described herein, the hydrogen formed by the dehydrogenation reaction is gaseous H2, 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 (H2) 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.

[0022] 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 passedfrom 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 oxygendiminished 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.

[0023] 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 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.

[0024] 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.

[0025] 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 amountof remaining oxygen is still suitable for supplying oxygen to the reactor 110 for combustion of hydrogen, as disclosed herein.

[0026] In embodiments disclosed herein, the oxygen carrier material may have a particular composition. As described herein, the oxygen carrier materials may comprise a first composition and, optionally, one or more additional materials. In one or more embodiments, the first composition may comprise or consist of active materials, which are materials that, in general, contribute to the oxygen carrying of the oxygen carrier materials described herein. Such active materials may also affect the combustion of fuels during regeneration, as is described hereinafter. In general, in the embodiments described herein, at least 95 wt.% of the first composition may consist of iron (Fe), one or more alkali metals, tungsten (W), oxygen (O), and optionally titanium (Ti), in amounts defined by particular ratios between these various components.

[0027] In embodiments, the oxygen carrier material, in addition to the first composition, 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, MgAbC , zirconia, inorganic clays (e.g., kaolin, other alumina-silicates), and glass materials (such as glass fibers).

[0028] According to one or more embodiments, the oxygen carrier material may comprise at least 75 wt.%, at least 80 wt.%, at least 85 wt.%, at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, at least 99.9 wt.%, or may consist of the combination of the first composition and the oneor more additional materials. For example, the oxygen carrier material may consist of the combination of the first composition and the one or more additional materials, where the one or more additional materials may act as binders and fill the balance of the oxygen carrier material that is not part of the first composition.

[0029] In one or more embodiments, the oxygen carrier material may comprise the first composition 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.%, 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 100 wt.%, or any combination of one or more of these ranges. For example, the oxygen carrier material may comprise 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.%, 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 first composition. In some embodiments, the oxygen carrier material may comprise the first composition in an amount of at least 99 wt.%, or at least 99.9 wt.%. In some embodiments, the oxygen carrier material may consist of the first composition.

[0030] In additional embodiments, the oxygen carrier material may comprise the one or more additional materials. According to 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 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.%.

[0031] As described herein, the relative amounts of the materials of the first composition are described in terms of relative amounts of atoms of each element that are included in the first composition. 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 one component with another, and does not restrict the total number or moles of a particular substituent. For example, iron may be present in an amount of 1 part by mole, and oxygen may be present in an amount of from 1 part by mole to 10 parts by mole, which means all compositions which meet this ratio of iron 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.

[0032] Now turning to the first composition of the oxygen carrier material, in one or more embodiments, 95 wt.% of the first composition may consist of iron; one or more alkali metals; tungsten; oxygen; and optionally titanium. 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 first composition may consist of iron; one or more alkali metals; tungsten; oxygen; and optionally titanium. In some embodiment, the first composition may consist of iron; one or more alkali metals; tungsten; oxygen; and optionally titanium.

[0033] In one or more embodiments, iron may be present in the first composition, where iron is present in the first composition 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 iron. Without being bound by any particular theory, it is believed that iron may work as the major constituent that binds and unbinds from oxygen in redox reactions by changing its oxidation state.

[0034] In 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 0.04 parts by mole to 0.8 parts by mole. Without being bound by anyparticular theory, it is believed that the presence of this amount of alkali metals may improve selectivity to hydrogen combustion over combustion of hydrocarbons.

[0035] 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 0.04 parts by mole to 0.8 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.

[0036] In some embodiments, the one or more alkali metals may be present in the first composition in a relative amount of less than or equal to 0.8 parts by mole and at least 0.08 parts by mole, at least 0.12 parts by mole, at least 0.16 parts by mole, at least 0.20 parts by mole, at least 0.24 parts by mole, at least 0.28 parts by mole, at least 0.32 parts by mole, at least 0.36 parts by mole, at least 0.40 parts by mole, at least 0.44 parts by mole, at least 0.48 parts by mole, at least 0.52 parts by mole, at least 0.56 parts by mole, at least 0.60 parts by mole, at least 0.64 parts by mole, at least 0.68 parts by mole, at least 0.72 parts by mole, or least 0.76 parts by mole.

[0037] In additional embodiments, the one or more alkali metals may be present in the first composition in a relative amount of at least 0.04 parts by mole and less than or equal to 0.76 parts by mole, less than or equal to 0.72 parts by mole, less than or equal to 0.68 parts by mole, less than or equal to 0.64 parts by mole, less than or equal to 0.60 parts by mole, less than or equal to 0.56 parts by mole, less than or equal to 0.52 parts by mole, less than or equal to 0.48 parts by mole, less than or equal to 0.44 parts by mole, less than or equal to 0.40 parts by mole, less than or equal to 0.36 parts by mole, less than or equal to 0.32 parts by mole, less than or equal to 0.28 parts by mole, less than or equal to 0.24 parts by mole, less than or equal to 0.20 parts by mole, less than or equal to 0.16 parts by mole, less than or equal to 0.12 parts by mole, or less than or equal to 0.08 parts by mole.

[0038] In additional embodiments, the one or more alkali metals may be present in the first composition in a relative amount of from 0.04 parts by mole to 0.08 parts by mole, from 0.08 parts by mole to 0.12 parts by mole, from 0.12 parts by mole to 0.16 parts by mole, from 0.16 parts bymole to 0.20 parts by mole, from 0.20 parts by mole to 0.24 parts by mole, from 0.24 parts by mole to 0.28 parts by mole, from 0.28 parts by mole to 0.32 parts by mole, from 0.32 parts by mole to 0.36 parts by mole, from 0.36 parts by mole to 0.40 parts by mole, from 0.40 parts by mole to 0.44 parts by mole, from 0.44 parts by mole to 0.48 parts by mole, from 0.48 parts by mole to 0.52 parts by mole, from 0.52 parts by mole to 0.56 parts by mole, from 0.56 parts by mole to 0.60 parts by mole, from 0.60 parts by mole to 0.64 parts by mole, from 0.64 parts by mole to 0.68 parts by mole, from 0.68 parts by mole to 0.72 parts by mole, from 0.72 parts by mole to 0.76 parts by mole, from 0.76 parts by mole to 0.80 parts by mole, or any combination of one or more of these ranges.

[0039] In one or more embodiments, tungsten may be present in the first composition, where the tungsten may be present in the first composition in a relative amount of from 0.02 parts by mole to 0.4 parts by mole. Without being bound by theory, it is believed that the presence of tungsten in this amount may regulated the oxygen release from iron, which may suppress the oxidation of hydrocarbons.

[0040] In some embodiments, tungsten may be present in the first composition in a relative amount of less than or equal to 0.4 parts by mole and at least 0.06 parts per mole, at least 0.08 parts per mole, at least 0.10 parts per mole, at least 0.12 parts per mole, at least 0.14 parts per mole, at least 0.16 parts per mole, at least 0.18 parts per mole, at least 0.20 parts per mole, at least 0.22 parts per mole, at least 0.24 parts per mole, at least 0.26 parts per mole, at least 0.28 parts per mole, at least 0.30 parts per mole, at least 0.32 parts per mole, at least 0.34 parts per mole, at least 0.36 parts per mole, or even at least 0.38 parts per mole.

[0041] In additional embodiments, tungsten may be present in the first composition in a relative amount of at least 0.02 parts by mole and less than or equal to 0.38 parts by mole, less than or equal to 0.36 parts by mole, less than or equal to 0.34 parts by mole, less than or equal to 0.32 parts by mole, less than or equal to 0.30 parts by mole, less than or equal to 0.28 parts by mole, less than or equal to 0.26 parts by mole, less than or equal to 0.24 parts by mole, less than or equal to 0.22 parts by mole, less than or equal to 0.20 parts by mole, less than or equal to 0.18 parts by mole, less than or equal to 0.16 parts by mole, less than or equal to 0.14 parts by mole, less than or equal to 0.12 parts by mole, less than or equal to 0.10 parts by mole, less than or equal to 0.08 parts by mole, less than or equal to 0.06 parts by mole, or even less than or equal to 0.04 parts by mole, and at least 0.02 parts by mole.

[0042] In additional embodiments, tungsten may be present in the first composition in a relative amount of from 0.02 parts by mole to 0.04 parts by mole, from 0.04 parts by mole to 0.06 parts by mole, from 0.06 parts by mole to 0.08 parts by mole, from 0.08 parts by mole to 0.10 parts by mole, from 0.10 parts by mole to 0.12 parts by mole, from 0.12 parts by mole to 0.14 parts by mole, from 0.14 parts by mole to 0.16 parts by mole, from 0.16 parts by mole to 0.18 parts by mole, from 0.18 parts by mole to 0.20 parts by mole, from 0.20 parts by mole to 0.22 parts by mole, from 0.22 parts by mole to 0.24 parts by mole, from 0.24 parts by mole to 0.26 parts by mole, from 0.26 parts by mole to 0.28 parts by mole, from 0.28 parts by mole to 0.30 parts by mole, from 0.30 parts by mole to 0.32 parts by mole, from 0.32 parts by mole to 0.34 parts by mole, from 0.34 parts by mole to 0.36 parts by mole, from 0.36 parts by mole to 0.38 parts by mole, from 0.38 parts by mole to 0.40 parts by mole, or any combination of one or more of these ranges.

[0043] In one or more embodiments, oxygen may be present in the first composition in a relative amount of from 1 part by mole to 10 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.

[0044] In some embodiments, oxygen may be present in the first composition in a relative amount of less than or equal 10 parts by mole and at least 1.25 parts per mole, at least 1.5 parts per mole, at least 1.75 parts per mole, at least 2 parts per mole, at least 2.25 parts per mole, at least 2.5 parts per mole, at least 2.75 parts per mole, at least 3 parts per mole, at least 3.25 parts per mole, at least 3.5 parts per mole, at least 3.75 parts per mole, at least 4 parts per mole, at least 4.25 parts per mole, at least 4.5 parts per mole, at least 4.75 parts per mole, at least 5 parts per mole, at least 5.25 parts per mole, at least 5.5 parts per mole, at least 5.75 parts per mole, at least 6 parts per mole, at least 6.25 parts per mole, at least 6.5 parts per mole, at least 6.75 parts per mole, at least 7 parts per mole, at least 7.25 parts per mole, at least 7.5 parts per mole, at least 7.75 parts per mole, at least 8 parts per mole, at least 8.25 parts per mole, at least 8.5 parts per mole, at least 8.75 parts per mole, at least 9 parts per mole, at least 9.25 parts per mole, at least 9.5 parts per mole, or even at least 9.75 parts per mole.

[0045] In additional embodiments, oxygen may be present in the first composition in a relative amount of at least 1 part by mole and less than or equal to 1.25 parts by mole, less than or equalto 1.5 parts by mole, less than or equal to 1.75 parts by mole, less than or equal to 2 parts by mole, less than or equal to 2.25 parts by mole, less than or equal to 2.5 parts by mole, less than or equal to 2.75 parts by mole, less than or equal to 3 parts by mole, less than or equal to 3.25 parts by mole, less than or equal to 3.5 parts by mole, less than or equal to 3.75 parts by mole, less than or equal to 4 parts by mole, less than or equal to 4.25 parts by mole, less than or equal to 4.5 parts by mole, less than or equal to 4.75 parts by mole, less than or equal to 5 parts by mole, less than or equal to 5.25 parts by mole, less than or equal to 5.5 parts by mole, less than or equal to 5.75 parts by mole, less than or equal to 6 parts by mole, less than or equal to 6.25 parts by mole, less than or equal to 6.5 parts by mole, less than or equal to 6.75 parts by mole, less than or equal to 7 parts by mole, less than or equal to 7.25 parts by mole, less than or equal to 7.5 parts by mole, less than or equal to 7.75 parts by mole, less than or equal to 8 parts by mole, less than or equal to 8.25 parts by mole, less than or equal to 8.5 parts by mole, less than or equal to 8.75 parts by mole, less than or equal to 9 parts by mole, less than or equal to 9.25 parts by mole, less than or equal to 9.5 parts by mole, or less than or equal to 9.75 parts by mole.

[0046] In additional embodiments, oxygen may be present in the first composition in a relative amount of from 1 part by mole to 1.25 parts by mole, from 1.25 parts by mole to 1.5 parts by mole, from 1.5 parts by mole to 1.75 parts by mole, from 1.75 parts by mole to 2 parts by mole, from 2 parts by mole to 2.25 parts by mole, from 2.25 parts by mole to 2.5 parts by mole, from 2.5 parts by mole to 2.75 parts by mole, from 2.75 parts by mole to 3 parts by mole, from 3 parts by mole to 3.25 parts by mole, from 3.25 parts by mole to 3.5 parts by mole, from 3.5 parts by mole to 3.75 parts by mole, from 3.75 parts by mole to 4 parts by mole, from 4 parts by mole to 4.25 parts by mole, from 4.25 parts by mole to 4.5 parts by mole, from 4.5 parts by mole to 4.75 parts by mole, from 4.75 parts by mole to 5 parts by mole, from 5 parts by mole to 5.25 parts by mole, from 5.25 parts by mole to 5.5 parts by mole, from 5.5 parts by mole to 5.75 parts by mole, from 5.75 parts by mole to 6 parts by mole, from 6 parts by mole to 6.25 parts by mole, from 6.25 parts by mole to 6.5 parts by mole, from 6.5 parts by mole to 6.75 parts by mole, from 6.75 parts by mole to 7 parts by mole, from 7 parts by mole to 7.25 parts by mole, from 7.25 parts by mole to 7.5 parts by mole, from 7.5 parts by mole to 7.75 parts by mole, from 7.75 parts by mole to 8 parts by mole, from 8 parts by mole to 8.25 parts by mole, from 8.25 parts by mole to 8.5 parts by mole, from 8.5 parts by mole to 8.75 parts by mole, from 8.75 parts by mole to 9 parts by mole, from 9 parts by mole to 9.25 parts by mole, from 9.25 parts by mole to 9.5 parts by mole, from 9.5 parts bymole to 9.75 parts by mole, from 9.75 parts by mole to 10 parts by mole, or any combination of one or more of these ranges.

[0047] In one or more embodiments, the first composition may optionally comprise titanium. That is, in some embodiments, titanium may be present in the first composition and, in other embodiments, titanium may not be present in the first composition. In one or more embodiments, titanium may be present in the first composition in a relative amount of from 0 parts by mole to 3 parts by mole. In some embodiments, titanium may be present in the first composition in a relative amount of from 0.001 parts by mole to 3 parts by mole. Without being bound by theory, it is believed that the presence of titanium may improve mechanical stability of the oxygen carrier material. Moreover, titanium in combination with iron and alkali metals may form crystal phases containing alkali, iron, and titanium (e.g., prederite and hollandite) as opposed to ilmenite, which may unfavorably promote reduction.

[0048] In some embodiments, titanium may be present in the first composition in a relative amount of at least 0.25 parts per mole, at least 0.5 parts per mole, at least 0.75 parts per mole, at least 1 parts per mole, at least 1.25 parts per mole, at least 1.5 parts per mole, at least 1.75 parts per mole, at least 2 parts per mole, at least 2.25 parts per mole, at least 2.5 parts per mole, or at least 2.75 parts per mole, and less than or equal 3 parts by mole.

[0049] In additional embodiments, titanium may be present in the first composition in a relative amount of less than or equal to 0.25 parts by mole, less than or equal to 0.5 parts by mole, less than or equal to 0.75 parts by mole, less than or equal to 1 part by mole, less than or equal to 1.25 parts by mole, less than or equal to 1.5 parts by mole, less than or equal to 1.75 parts by mole, less than or equal to 2 parts by mole, less than or equal to 2.25 parts by mole, less than or equal to 2.5 parts by mole, or less than or equal to 2.75 parts by mole, and at least 0 parts by mole or at least 0.001 parts by mole.

[0050] In additional embodiments, titanium may be present in the first composition in a relative amount of from 0 parts by mole to 0.25 parts by mole, from 0.001 parts by mole to 0.25 parts by mole, from 0.25 parts by mole to 0.5 parts by mole, from 0.5 parts by mole to 0.75 parts by mole, from 0.75 parts by mole to 1 part by mole, from 1 part by mole to 1.25 parts by mole, from 1.25 parts by mole to 1.5 parts by mole, from 1.5 parts by mole to 1.75 parts by mole, from 1.75 parts by mole to 2 parts by mole, from 2 parts by mole to 2.25 parts by mole, from 2.25 parts by mole to 2.5 parts by mole, from 2.5 parts by mole to 2.75 parts by mole, from 2.75 parts by mole to 3 parts by mole, or any combination of one or more of these ranges.

[0051] In one or more embodiments, the oxygen-carrier material may be capable of fluidization. In some embodiments, the oxygen carrier material may have a median particle size (D50) of from 50 pm to 300 pm, such as from 50 pm to 250 pm, from 50 pm to 200 pm, from 50 pm to 150 pm, from 50 pm to 100 pm, from 100 pm to 300 pm, from 100 pm to 250 pm, from 100 pm to 200 pm, from 100 pm to 150 pm, from 150 pm to 300 pm, from 150 pm to 250 pm, from 150 pm to 200 pm, from 200 pm to 300 pm, from 200 pm to 250 pm, or from 250 pm to 300 pm.

[0052] In some embodiments, the oxygen-carrier material may exhibit properties known in the industry as “Geldart A” or “Geldart B” properties. Particles may be classified as “Group A” or “Group B” according to D. Geldart, Gas Fluidization Technology, John Wiley & Sons (New York, 1986), 34-37; and D. Geldart, “Types of Gas Fluidization,” Powder Technol. 7 (1973) 285-292, which are incorporated herein by reference in their entireties.

[0053] Group A is understood by those skilled in the art as representing an aeratable powder, having a bubble-free range of fluidization; a high bed expansion; a slow and linear deaeration rate; bubble properties that may include a predominance of splitting / recoalescing bubbles, with a maximum bubble size and large wake; high levels of solids mixing and gas backmixing, assuming equal U-Umf (U is the velocity of the carrier gas, and Umf is the minimum fluidization velocity, typically though not necessarily measured in meters per second, m / s, i.e., there is excess gas velocity); axisymmetric slug properties; and no spouting, except in very shallow beds. The properties listed tend to improve as the mean particle size decreases, assuming equal cfp; or as the <45 micrometers (pm) proportion is increased; or as pressure, temperature, viscosity, and density of the gas increase. In general, the particles may exhibit a small mean particle size and / or low particle density (<1.4 grams per cubic centimeter, g / cm3), fluidize easily, with smooth fluidization at low gas velocities, and may exhibit controlled bubbling with small bubbles at higher gas velocities.

[0054] Group B is understood by those skilled in the art as representing a “sand-like” powder that starts bubbling at Umf; that exhibits moderate bed expansion; a fast deaeration; no limits on bubble size; moderate levels of solids mixing and gas backmixing, assuming equal U-Umf; both axisymmetric and asymmetric slugs; and spouting in only shallow beds. These properties tend to improve as mean particle size decreases, but particle size distribution and, with some uncertainty, pressure, temperature, viscosity, or density of gas seem to do little to improve them. In general, most of the particles having a particle size (cfp) of 40 pm <cfp <500 pm when the density (pp) is1.4 <pp <4 g / cm3, and preferably 60 pm <cfp <500 pm when the density (pp) is 4 g / cm3and 250 pm <cfp <100 pm when the density (pp) is 1 g / cm3.

[0055] In one or more embodiments, the oxygen carrier materials described herein may be prepared by a variety of synthetic techniques including solid-state synthesis, or wet or dry impregnation followed by drying and high-temperature calcination, as known to those skilled in the art. In general, various components in the first composition can be added as solid powders in their oxide form, then well-mixed or homogenized, followed by calcination in air at high temperatures. Alternatively, some components in the first composition can be incorporated by completely (wet or dry impregnation) or partially (slurry impregnation) dissolving their precursors in water, and then combining them with solid powders of remaining components, followed by drying and high-temperature calcination in air. Optionally, small amount of the additional materials described herein can be added during the synthesis of the oxygen carrier to provide physical strength and stability.

[0056] In some embodiments, as described hereinabove, the oxygen carrier can be prepared by impregnation. The impregnation may utilize wet impregnation or dry impregnation (sometimes referred to as incipient wetness impregnation). The impregnation may utilize an aqueous solution that includes some components of the first composition For example, in various embodiments, the aqueous solution may comprise the one or more precursors of alkali metals and / or tungsten. In some embodiments, the aqueous solution may comprise potassium tungstate, potassium carbonate, potassium sulfate, potassium nitrate, potassium acetate, ammonium para tungstate, ammonium meta tungstate, tungstic acid, or combinations thereof. In one or more embodiments, the aqueous solution may have a pH of greater than 7. For example, the aqueous solution may have a pH of greater than 7.5, greater than 8, greater than 8.5, greater than 9, greater than 9.5, greater than 10, greater than 10.5, greater than 11, or even greater than 11.5. In some embodiments, multiple impregnation steps may occur to impregnate different materials.

[0057] The impregnated material may then be dried after impregnation. In some embodiments, the impregnated material may be dried under air. In one or more embodiments, the impregnated material may be dried at a temperature of less than 200 °C, such as less than 175 °C, less than 150 °C, less than 125 °C, less than 100 °C, less than 75 °C, or even less than 50 °C. In certain embodiments, impregnation can be done more than once with the aqueous solution, the impregnated material may be dried between each impregnation.

[0058] The dried impregnated material may then be calcined to produce the oxygen-carrier material. In one or more embodiments, the calcination may be at a temperature of greater than 600 °C, such as greater than 700 °C, greater than 800 °C, greater than 900 °C, greater than 1000 °C, greater than 1100 °C, or even greater than 1200 °C. In one or more embodiments, the dried impregnated material may be calcined under air. In embodiments where multiple impregnation steps are utilized, the impregnated material may be calcined between each impregnation. In embodiments, the dried impregnated material may be calcined in air for more than 1 hour. For example, the dried impregnated material may be calcined in air for more than 2 hours, more than 4 hours, more than 10 hours, or even more than 20 hours.

[0059] In some embodiments, the oxygen-carrier materials may be utilized in processes comprising fluidized beds or moving beds or circulating fluidized bed (CFB). In such embodiments, it may be desirable to have oxygen carries as engineered particles with “Geldart A” or “Geldart B” properties. Without being limited by theory, in one or more embodiments, it is believed that the choice in methods of making engineered particles of oxygen-carrier materials such as manufacturing techniques like spray drying, high-shear granulation, and fluidized bed granulation can be utilized followed by drying and high temperature calcination to achieve fluidizable particles.

[0060] The present disclosure includes numerous aspects, including aspects 1-15 described herein.

[0061] Aspect 1. 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 a first composition, wherein at least 95 wt.% of the first composition consists of: 1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

[0062] Aspect 2. The method of aspect 1, 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.

[0063] Aspect 3. The method of any previous aspect, 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.

[0064] Aspect 4. The method of aspect 3, wherein a fuel gas is combusted in the regeneration unit to heat the oxygen carrier material.

[0065] Aspect 5. The method of aspect 4, wherein the fuel gas comprises hydrogen, methane, or combinations thereof.

[0066] Aspect 6. The method of aspect 4, wherein the fuel gas comprises methane, ethane, propane, or combinations thereof.

[0067] Aspect 7. The method of any previous aspect, wherein the reactor operates as a fluidized bed reactor.

[0068] Aspect 8. The method of any previous aspect, wherein the reactor operates at a temperature of from 600 °C to 850 °C.

[0069] Aspect 9. The method of any previous aspect, wherein a dehydrogenation catalyst is not utilized in the dehydrogenation reactor.

[0070] Aspect 10. The method of any previous aspect, wherein the first composition comprises titanium.

[0071] Aspect 11. The method of any previous aspect, wherein the first composition does not comprise titanium.

[0072] Aspect 12. The method of any previous aspect, wherein the first composition consists of the: 1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

[0073] Aspect 13. The method of any previous aspect, wherein the oxygen carrier material further comprises one or more additional materials chosen from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof.

[0074] Aspect 14. The method of aspect 13, wherein the one or more additional materials function as binders.

[0075] Aspect 15. The method of aspect 13, wherein the oxygen carrier material comprises from 1 wt.% to 50 wt.% of the one or more additional materials.EXAMPLES

[0076] 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.

[0077] Example 1 - Sample Preparation

[0078] Comparative Sample A was non-redox-active inert quartz chips that were obtained commercially from Pyromatics and sieved to 100-200 mesh before use.

[0079] Comparative Sample B was tungsten oxide (WO3) that was obtained commercially from Sigma- Aldrich and sieved to 100-200 mesh before use.

[0080] Comparative Sample C was first prepared by adding small amounts of water to ilmenite powder (Alfa Aesar) to make a paste. The paste was transferred to an alumina crucible and calcined in air at 950 °C for 6 hours.

[0081] Comparative Samples Cl, C2, and C4 were prepared by dissolving a stoichiometric amount of K2CO3, NaNOs, Na2WO4, or ammonium meta tungstate hydrate (Alfa Aesar) in deionized water. The solution was then added to ilmenite powder (Alfa Aesar) to create a paste. The paste was thoroughly ground by mortar and pestle and then transferred to an alumina crucible for calcination at 950 °C in air for 6 hours.

[0082] Comparative Samples C3, C5, and C6 were prepared by thoroughly dry mixing a stoichiometric amount of WO3 or tungstic acid with ilmenite powder (Alfa Aesar), then adding small amounts of deionized water to form a paste. The paste was thoroughly ground by mortar and pestle and then transferred to an alumina crucible for calcination in air at 950 °C for 6 hours.

[0083] Comparative Samples C7 and C8 were prepared by thoroughly dry mixing a stoichiometric amount of K2WO4 (Alfa Aesar) with ilmenite powder (Alfa Aesar), then adding small amounts of deionized water to form a paste. The paste was thoroughly ground by mortar and pestle and then transferred to an alumina crucible for calcination in air at 950 °C for 6 hours.

[0084] Comparative Sample D was prepared by first combining a stoichiometric amount of Fe2O3 (Noah Technologies Corporation) with TiCh (Sigma- Aldrich, 21 nanometer nanopowder) weighted in a mortar. The dry powders were ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Subsequently, 5 to 10 milliliters (mL) of deionized water was added to the mortar and the mixture was ground into a paste for 5 minutes. The paste was transferred to an alumina crucibleand dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 24 hours.

[0085] Comparative Sample DI was prepared by first weighing a stoichiometric amount of powdered Fe2O3 and TiCh (Sigma- Aldrich, 21 nm nanopowder) in a mortar. The dry powders were ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered NaNCh was dissolved in about 10 mT of deionized water and added to the mortar. The mixture was ground into a paste for 5 minutes, then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0086] Comparative Samples D2, D3, and D5were prepared in the same manner as DI with a stoichiometric amount of K2CO3, Fe2O3, and TiCh as the initial powder mixture.

[0087] Comparative Sample D4 was prepared by first weighing a stoichiometric amount of powdered Fe2O3 and WO3 (Sigma- Aldrich, < 25 pm) in a mortar. The dry powders were thoroughly ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Subsequently, 5 to 10 mF of deionized water was added to the mortar and the mixture was ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0088] Comparative Samples D6 and D7 were both prepared in the same manner as Comparative Sample D2, with different stoichiometric amounts of K2CO3, Fe2O3, and TiCh.

[0089] Comparative Sample D8 was prepared by first weighing a stoichiometric amount of Fe2O3 and TiCh (Evonik, AEROXIDE P25) in a mortar. The dry powders were thoroughly ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered K2WO4 was dissolved in about 10 mL of deionized water. The alkali solution was introduced to the mortar and the mixture was ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 24 hours.

[0090] Comparative Samples E, F, and G were all prepared in the same manner as Comparative Sample D, where the calcination temperatures were 800 °C, 850 °C and 900 °C, respectively.

[0091] Comparative Sample H was prepared in the same manner as Comparative Sample D4, except ammonium meta tungstate ((NH^eEhW C o xEhO, Sigma- Aldrich) was used instead of WO3.

[0092] Comparative Sample I was prepared by first thoroughly dry mixing a stoichiometric amount of Fe2O3 (Noah Chemicals) and TiCh (Evonik, AEROXIDE P25). The powdered mixture was then transferred to a mortar. In a separate vial, a stoichiometric amount of ammonium meta tungstate hydrate (Alfa Aesar) was dissolved in deionized water. The solution was added dropwise to the powdered mixture to form a paste, which was thoroughly ground and then transferred to an alumina crucible. The sample was heated to 90 °C for at least 2 hours and then calcined in air at 950 °C for 6 hours.

[0093] Comparative Sample J was prepared by first thoroughly dry mixing a stoichiometric amount of Fe2O3 (Noah Chemicals) and TiCh (Evonik, AEROXIDE P25). The powdered mixture was then transferred to a mortar. In a separate vial, a stoichiometric amount of K2CO3 (Alfa Aesar) was dissolved in deionized water. The solution was added dropwise to the powdered mixture to form a paste, which was thoroughly ground and then transferred to an alumina crucible. The sample was heated to 90 °C for at least 2 hours and then calcined in air at 950 °C for 6 hours.

[0094] Samples 1-3 were prepared by first thoroughly dry mixing a stoichiometric amount of K2WO4 (Alfa Aesar) with ilmenite powder. A small amount of deionized water was then added to form a paste. The paste was thoroughly ground by mortar and pestle and then transferred to an alumina crucible and calcined in air at 950 °C for 6 hours.

[0095] Sample 4 was prepared by dissolving a stoichiometric amount of K2CO3, NaNCh, Na2WC , or ammonium meta tungstate hydrate (Alfa Aesar) in deionized water. The solution was then added to ilmenite powder (Alfa Aesar) to create a paste. The paste was thoroughly ground by mortar and pestle and then transferred to an alumina crucible for calcination at 950 °C in air for 6 hours.

[0096] Samples 5-7 were prepared in the same manner as Comparative Sample D8 with different stoichiometric amounts of K2WO4, Fe2O3 and TiCh (Evonik, AEROXIDE P25). In samples in which the K2WO4 could not be fully dissolved in the about 10 mL of deionized water, the whole slurry was introduced to the dry powder mixture.

[0097] Sample 8 was prepared by first weighing a stoichiometric amount of Fe20s and TiCh (Evonik, AEROXIDE P25) in a mortar. The dry powders were thoroughly ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered K2WO4 and K2CO3 was dissolved in about 10 mE of deionized water. The alkali solution was then introduced into the mortar containing the mixed metal oxide powders and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0098] Sample 9 was prepared in the same manner as Sample 8 with different stoichiometric amounts for K2WO4, K2CO3, Fe2O3 and TiCh (Evonik, AEROXIDE P25).

[0099] Samples 10 and 11 were prepared in the same manner as Sample 8 with different stoichiometric amounts of K2WO4, K2CO3 and FeTiO3.

[0100] Samples 12 and 13 were prepared by adding a stoichiometric amount of Fe2O3 (Noah Chemicals), TiO2 (Evonik, AEROXIDE P25), K2WO4 into a mortar, thoroughly mixing the dry powders, and then adding a small amount of water to form a paste. The paste was transferred to an alumina crucible and calcined at 950 °C for at least 6 hours.

[0101] Samples 14 and 15 were prepared by first sourcing commercially Fe2O3 with different particle sizes from two different vendors. A stoichiometric amount of Fe2O3 and K2WO4 were thoroughly mixed in a mortar. A small amount of water was added to form a paste. The paste was then transferred to an alumina crucible and calcined at 950 °C for at least 6 hours.

[0102] Sample 16 was prepared in the same manner as Sample 2.

[0103] Sample 17 was prepared by first fully dissolving a stoichiometric amount of K2WO4 in a small amount of deionized water at room temperature. Ilmenite powder was added to an alumina crucible and the alkali solution was transferred to the crucible. The slurry was well mixed before calcination. The slurry was then transferred to an alumina crucible to dry at 90 °C for at least 6 hours and calcined in air at 950 °C for 6 hours.

[0104] Sample 18 was prepared by first fully dissolving 16 separate impregnations of K2WO4 in deionized water. The amount of water required to form a paste with ilmenite powder was empirically found to identify the minimum number of separate impregnations to reach the total stoichiometric amounts of K2WO4. After each impregnation, the paste was heated from room temperature to 90 °C in 30 minutes, held at 90 °C for 3 hours to completely dry before proceedingto the next impregnation. After the 16thimpregnation, the sample was calcined at 950 °C for 6 hours.

[0105] Sample 19 was prepared by first weighing a stoichiometric amount of Fe2O3, TiCh (Evonik, AEROXIDE P25) and WO3 (Sigma- Aldrich, < 25 pm) in a mortar. The dry powders were thoroughly ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered K2CO3 was dissolved in about 10 mE of deionized water. The alkali solution was then introduced into the mortar containing the mixed metal oxide powders and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0106] Sample 20 was prepared in the same manner as Sample 19 with different stoichiometric amounts for K2CO3, WO3, Fe2O3 and TiCh (Evonik, AEROXIDE P25).

[0107] Sample 21 was prepared in the same manner as Sample 20 with a different source for TiO2 (Noah Technologies Corporation, anatase).

[0108] Sample 22 was prepared by first weighing a stoichiometric amount of Fe2O3, FeTiO3 (Thermoscientific) and WO3 in a mortar. The dry powders were thoroughly ground with a pestle for 5 minutes. The powders were shaken in a separate container for 1 minute and then returned to the mortar. The grinding and shaking steps were repeated twice, for a total of 10 minutes of grinding and 2 minutes of shaking. Separately, a stoichiometric amount of powdered K2CO3 was dissolved in about 10 mF of deionized water. The alkali solution was then introduced into the mortar containing the mixed metal oxide powders and the mixture was thoroughly ground into a paste for 5 minutes. The paste was then transferred to an alumina crucible and dried for at least 2 hours at 120 °C in air. The dried mixture was then calcined in air at 950 °C for 6 hours.

[0109] Sample 23 was prepared in the same manner as Sample 22 with different stoichiometric amounts of K2CO3, WO3, Fe2O3 and FeTiC .

[0110] Samples 24 and 25 were prepared by first dissolving a stoichiometric amount of ammonium meta tungstate hydrate in deionized water. The solution was then added dropwise to a sample of previously calcined Sample K to form a paste. The paste was then dried in an alumina crucible at 90 °C for 2 hours and then calcined in air at 950 °C for 6 hours.

[0111] Sample 26 was prepared by first dissolving a stoichiometric amount of K2CO3 in deionized water. The solution was then added dropwise to a sample of previously calcined Sample L to form a paste. The paste was then dried in an alumina crucible at 90 °C for 2 hours and then calcined in air at 950 °C for 6 hours.

[0112] Sample 27 was prepared by first dry mixing a stoichiometric amount of Fe2O3 (Noah Chemicals) and TiCh (Evonik, AEROXIDE P25) in a mortar. In two separate vials, stoichiometric amounts of K2CO3 and ammonium meta tungstate hydrate were dissolved in deionized water, respectively. Each solution was then added dropwise to the dry mixed metal oxide powders to form a paste, which was thoroughly ground. The paste was then transferred to an alumina crucible to dry at 90 °C for 2 hours and calcined in air at 950 °C for 6 hours.

[0113] Example 2 - Selective Hydrogen Combustion Performance

[0114] The selective hydrogen combustion performance of the samples was evaluated in a U- shape fixed-bed reactor made from quartz. First, a 125 mg sample was sized to 100-200 mesh and diluted with 400 milligrams (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 (seem) 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. For each oxygen carrier, three replicate reduction-oxidation cycles were performed and the average ethane conversion, ethylene selectivity, COXselectivity, and hydrogen to ethylene ratio are reported at cycle 50.

[0115] 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.Table 1: Selective hydrogen combustion performance of materials evaluated using the method of Example 2

[0116] As shown in Table 1, the addition of both an alkali metal (potassium or sodium) and tungsten improves ethylene selectivity and reduces the COXselectivity as compared to samples that do not have an alkali metal, tungsten, or both, is Samples without an alkali metal or tungsten (z. e. , Comparative Sample C) have poorer ethylene selectivity than samples with only an alkali metal (z.e., Comparative Samples Cl and C2), samples with only tungsten (z.e., Comparative Samples C3-C6), and samples with both an alkali metal and tungsten (z.e., Samples 1-3). This indicates that the presence of an alkali metal, tungsten, and especially both increases ethylene selectivity. Further, samples with both an alkali metal and tungsten have greatly improved COXselectivity than samples without an alkali metal and tungsten. For example, Samples 1-3 have a COXselectivity of 0.6 % or less, whereas Comparative Sample C has a COXselectivity of 5.2 %.

[0117] Samples with both an alkali metal and tungsten also have a greatly improved hydrogen to ethylene ratio than samples with only one of an alkali metal and tungsten or neither. For example, Samples 1-3, which have both potassium and tungsten, have H2 / C2H4 ratios of less than 0.50, whereas Comparative Samples C-C8 have H2 / C2H4 ratios of greater than 0.50. This indicates that the presence of the potassium and tungsten improves hydrogen selective combustion in the reactor.

[0118] The same improvement of ethylene selectivity, COXselectivity, and H2 / C2H4 ratio can be seen throughout Table 1. For example, Comparative Sample D, which has no alkali metal or tungsten, has worse ethylene selectivity, COXselectivity, and H2 / C2H4 ratio than Samples 5-15 which have potassium and tungsten present. Therefore, Table 1 indicates that the presence of both an alkali metal and tungsten, in addition with iron, improves the selectivity of hydrogen combustion over hydrocarbons resulting in lower amounts of COXformation, thus greatly improving ethylene selectivity, COXselectivity, and / or H2 / C2H4 ratio.Table 2: Selective hydrogen combustion performance of materials evaluated using the method of Example 2

[0119] As shown in Table 2, samples with an alkali metal (potassium) and tungsten (z.e., Samples 16-18) show better H2 / C2H4 ratios than samples without potassium and tungsten (z.e., Comparative Samples E-H). For example, Sample 16 has a H2 / C2H4 ratio of 0.3 whereas Comparative Sample E has a H2 / C2H4 ratio of 0.62. Further, samples with potassium and tungsten show vastly improved COXselectivities than those without potassium and tungsten. For example, Samples 16-18 have a COXselectivity of 0.4 % to 0.6%, whereas Comparative Samples E-G without potassium or tungsten have COXselectivities of greater than 13%. Additionally, Comparative Sample H indicates that adding only tungsten improves COXselectivity to only 5.5%. Therefore, the presence of both an alkali metal and tungsten in the oxygen-carrier material results in greatly improved COXselectivity as compared to samples without an alkali metal or tungsten or only one of an alkali metal or tungsten.

[0120] Table 2 also indicates that the presence of potassium and tungsten improves C2H4 selectivity. For example, Comparative Sample E has a C2H4 selectivity of 77.3% and Sample 18 has a C2H4 selectivity of 95.0%. The H2 / C2H4 ratios also improve, as indicated by Sample 16 with an H2 / C2H4 ratio of 0.3 and Comparative Sample E with an H2 / C2H4 ratio of 0.62.

[0121] Example 3 - Selective Hydrogen Combustion Performance

[0122] 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 6.5 millimeter (mm) OD quartz tubing. The sample bed was supported on a pill of quartz wool and a layer of 0.5 to 1.0 mm quartz chips. The reactor was installed into a clamshell furnace and a flow of helium at 50 seem was introduced through the reactor tube. The reactor was then heated under 50 seem of air flow, from room temperature to 780 °C. The oxygen carrying materials were subjected to several cyclic sequences. Each cycle included ethane dehydrogenation, a first regeneration in air, fuel combustion, then a second regeneration in air with inert helium purging in the reactor tube between reduction and oxidation pulses. The ethane dehydrogenation step was done at a weight hourly space velocity (WHSV) of 5.3 hr'1. Specifically,40 seem 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 first regeneration in air step, 40 seem of air was fed through the reactor for 2 minutes. The fuel combustion step was performed at a WHSV of 0.079 hr'1. Specifically, 40 seem of a gas mixture containing 2.5 mol% methane, 9 mol% oxygen in balance nitrogen was fed through the reactor for 180 seconds while the reactor was held at 780 °C. Analysis of the product gas composition was taken at 60 seconds into the fuel combustion pulse. Finally, 40 seem of air was fed through the reactor for 4 minutes to conduct the second air regeneration step. 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, COXselectivity, and hydrogen to ethylene ratio are reported.Table 3: Selective hydrogen combustion performance of materials evaluated using the method of Example 3

[0123] As shown in Table 3, the presence of additional promoters such as potassium and tungsten (z.e., Samples 19-23) greatly improves C2H4 selectivity compared to oxygen-carriers without those additional promoters (z.e., Comparative Sample D). For example, Sample 19, with Ao 26 and Wo 13 has an ethylene selectivity of 95.2%, whereas Comparative Sample D, with no Kand W, has an ethylene selectivity of 77.0%. Further, the presence of both potassium and tungsten improves hydrogen to ethylene ratios. Comparative Sample D has a H2 / C2H4 ratio of 0.37 and Samples 19-23 have H2 / C2H4 ratios of 0.2 or less.

[0124] The presence of potassium and tungsten (z. e. , Samples 24-27) also greatly improves C2H4 selectivity, as compared to samples with only potassium (z.e., Comparative Sample J) or only tungsten (z.e., Comparative Sample I). For example, Comparative Sample I with no A and Wo 12 has C2H4 selectivity of 91 % and Comparative Sample J with Ao 22 and no W has a C2H6 conversion of 28%, C2H4 selectivity of 84.9%. Sample 25, with both potassium and tungsten present, has a C2H6 conversion of 25.7% and a C2H4 selectivity of 95.4%. Additionally, the presence of both potassium and tungsten greatly improves COXselectivity and hydrogen to ethylene ratio. For example, Comparative Samples D, I, and J have COXselectivities of 17.1%, 5.9%, and 10.6%, respectively, whereas Samples 19-27 all have a COXselectivity of 1.8% or less.

[0125] 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.

[0126] 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.

[0127] 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 quantitativerepresentation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0128] 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.

[0129] 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 ranges for various streams, and that the total amount of isomers of a particular chemical composition can constitute a range.

[0130] 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.”

[0131] 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.

[0132] 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.

Claims

CLAIMS1. 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 a first composition, wherein at least 95 wt.% of the first composition consists of:1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

2. The method of claim 1, 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.

3. The method of any previous claim, 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.

4. The method of claim 3, wherein a fuel gas is combusted in the regeneration unit to heat the oxygen carrier material.

5. The method of claim 4, wherein the fuel gas comprises hydrogen, methane, or combinations thereof.

6. The method of claim 4, wherein the fuel gas comprises methane, ethane, propane, or combinations thereof.

7. The method of any previous claim, wherein the reactor operates as a fluidized bed reactor.

8. The method of any previous claim, wherein the reactor operates at a temperature of from 600 °C to 850 °C.

9. The method of any previous claim, wherein a dehydrogenation catalyst is not utilized in the dehydrogenation reactor.

10. The method of any previous claim, wherein the first composition comprises titanium.

11. The method of any previous claim, wherein the first composition does not comprise titanium.

12. The method of any previous claim, wherein the first composition consists of the:1 part by mole of iron; from 0.04 parts by mole to 0.8 parts by mole of one or more alkali metals; from 0.02 parts by mole to 0.4 parts by mole of tungsten; from 0 parts by mole to 3 parts by mole of titanium; and from 1 part by mole to 10 parts by mole of oxygen.

13. The method of any previous claim, wherein the oxygen carrier material further comprises one or more additional materials chosen from oxides of silicon, aluminum, calcium, magnesium, zirconium, niobium, or combinations thereof.

14. The method of claim 13, wherein the one or more additional materials function as binders.

15. The method of claim 13, wherein the oxygen carrier material comprises from 1 wt.% to50 wt.% of the one or more additional materials.

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