Methods for dehydrogenating hydrocarbons utilizing moving bed reactors

Abstract

According to one or more embodiments, a method for dehydrogenating hydrocarbons comprises passing supplemental fuel, a feed stream comprising one or more hydrocarbons, and a particulate solid comprising an oxygen-carrier material into a reaction system comprising a moving bed reactor, wherein: the reaction system comprises a combustion zone, an oxygen treatment zone, and a dehydrogenation zone. The dehydrogenation zone is positioned in the moving bed reactor, and the combustion zone, the oxygen treatment zone, or both, are also positioned within the moving bed reactor. The particulate solid enters the dehydrogenation zone in an oxygen-rich state and is converted to a semi-oxygen-depleted state, is passed to the combustion zone where it is converted to an oxygen-depleted state, and then is passed to the oxygen treatment zone where it is converted back to the oxygen-rich state.

Description

86325-WO-PCT / DOW 86325 WO1METHODS FOR DEHYDROGENATING HYDROCARBONS UTILIZING MOVING BED REACTORSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U. S. Provisional Application Serial No.63 / 779,673 filed March 28, 2025, the contents of which are incorporated by reference in their entirety herein.TECHNICAL FIELD

[0002] Embodiments described herein generally relate to chemical processing and, more specifically, to processes and systems utilized for dehydrogenation of chemical species.BACKGROUND

[0003] Olefinic compounds, such as ethylene, propylene, butene, and styrene, may be utilized as base materials to produce many types of goods and materials. For example, ethylene may be utilized to manufacture polyethylene, ethylene chloride, or ethylene oxides. Such products may be utilized in product packaging, construction, textiles, etc. Thus, there is an industry demand for olefinic compounds. Such compounds may be formed by dehydrogenation of analogous alkanes, and improved dehydrogenation processes are needed.SUMMARY

[0004] One method for producing olefinic compounds is by dehydrogenating alkanes and / or alkyl aromatics. In some embodiments, the dehydrogenation reaction may be promoted by removing hydrogen formed during dehydrogenation by reacting the hydrogen with oxygen to form water, which pushes the equilibrium towards the light olefin products. In such embodiments, an oxygen-carrier material may be utilized to provide the oxygen that reacts with the hydrogen. The oxygen-carrier material may be included in a particulate solid. Such oxygen-carrier materials may cycle through a dehydrogenation zone, a combustion zone, and an oxygen treatment zone of a reaction system, where the content of oxygen in the oxygen carrier material may be increased in the oxygen treatment zone and decreased in each of the combustion zone and the dehydrogenation zone. In some embodiments, particularly where86325-WO-PCT / DOW 86325 WO2litle or no coke is formed, a supplemental fuel is additionally utilized in the combustion zone to heat at least the oxygen carrier material.

[0005] It has been presently discovered that it may be beneficial to position the dehydrogenation zone and one or both of the combustion zone and the oxygen treatment zone within the same moving bed as the dehydrogenation zone. The use of a reaction system wherein the dehydrogenation zone and one or both of the combustion zone and the oxygen treatment zone are positioned within the same moving bed may, in some embodiments, allow for improved combustion kinetics, improved yield and / or selectivity of desired products (e.g., ethylene), reduced attrition of the particulate solid, and reduced capital and / or operating costs.

[0006] Additionally, it has been presently discovered that positioning the dehydrogenation zone downstream of oxygen treatment zone and upstream of the combustion zone, with respect to the flow of the particulate solid, may result in improved conversion and selectivity' of the products produced. Without being limited by theory,, this is believed to be due to the improved combustion of hydrogen produced in the dehydrogenation reaction shifting the dehydrogenation reaction equilibrium towards the desired products.

[0007] According to one or more embodiments described herein, a method for dehydrogenating hydrocarbons may comprise: passing supplemental fuel, a feed stream comprising one or more hydrocarbons, and a particulate solid comprising an oxygen-carrier material into a reaction system comprising a moving bed reactor, wherein: the reaction system comprises a combustion zone, an oxygen treatment zone, and a dehydrogenation zone, the particulate solid enters the combustion zone, then is passed to the oxygen treatment zone, and then is passed to the dehydrogenation zone; the supplemental fuel enters the combustion zone, wherein, in the combustion zone, the supplemental fuel is combusted with oxygen from the oxygen-carrier material such that the oxygen-carrier material enters the combustion zone in a semi-oxygen-rich state and exits the combustion zone in an oxygen-depleted state; oxygen is passed to the oxygen treatment zone, wherein the oxygen-carrier material enters the oxygen treatment zone in the oxy gen-depleted state, is contacted by the oxygen, and exits the oxygen treatment zone in an oxygen-rich state; the feed stream enters the dehydrogenation zone, wherein, in the dehydrogenation zone, the one or more hydrocarbons of the feed stream are dehydrogenated to form molecular hydrogen and one or more products, and at least a portion of the molecular hydrogen is reacted with the oxygen from the oxygen-carrier material to86325-WO-PCT / DOW 86325 WO3form water, such that the oxygen-carrier material enters the dehydrogenation zone in the oxygen-rich state and exits the dehydrogenation zone in the semi-oxygen-rich state; and wherein the dehydrogenation zone is positioned within the moving bed reactor, and wherein the combustion zone, the oxygen treatment zone, or both, are positioned within the moving bed reactor.

[0008] It is to be understood that both the preceding 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. Additional features and advantages of the embodiments will be set forth in the detailed description and, in part, will be readily apparent to persons of ordinary’ skill in the art from that description, which includes the accompanying drawings and claims, or recognized by practicing the described embodiments. The drawings are included to provide a further understanding of the embodiments and, together with the detailed description, serves to explain the principles and operations of the claimed subject matter. However, the embodiments depicted in the drawings are illustrative and exemplary in nature, and not intended to limit the claimed subject matter.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Reference will now be made in greater detail to various embodiments, some of which are illustrated in the accompanying drawings, wherein:

[0010] FIG. 1 schematically depicts a reactor system, according to one or more embodiments of the present disclosure;

[0011] FIG. 2 schematically depicts another reactor system, according to additional embodiments of the present disclosure; and

[0012] FIG. 3 schematically depicts yet another reactor system, according to additional embodiments of the present disclosure.

[0013] When describing the simplified schematic illustrations of FIG. 1 to FIG. 3, the numerous pumps, valves, temperature sensors, electronic controllers, and the like, which may be used and are well known to a person of ordinary’ skill in the art, are not included. Further, accompanying components that are often included in such reactor systems, such as air supplies, heat exchangers, surge tanks, and the like are also not included. However, it should be understood that these components are within the scope of the present disclosure.86325-WO-PCT / DOW 86325 WO4DETAILED DESCRIPTION

[0014] Embodiments of the methods presently disclosed will now be described herein in detail in the context of the reaction systems of FIG. 1 to FIG. 3 operating to dehydrogenate hydrocarbons. However, it should be understood that the principles disclosed and taught herein may be applicable to other systems which utilize different system components oriented in different ways. It should be further understood that not all portions of the reaction systems of FIG. 1 to FIG. 3 should be construed as essential to the claimed subject matter. Moreover, while the recited method steps in the appended claims are described herein in the context of the reaction systems of FIG. 1 to FIG. 3, such recited method steps should be understood as adaptable to other systems, as would be understood by those skilled in the art. Several broad concepts will be discussed first and then each of the embodiments depicted in the figures will be described.

[0015] Moving bed reactors, as described herein, are generally known to those skilled in the art for use in a wide variety of chemical conversion processes. As used herein, a “moving bed reactor” may refer to a reactor having a moving bed wherein solid particles move relatively slowly downwards in a controlled manner due primarily to gravity. In a moving bed, the particles generally maintain contact with one another and are not suspending in fluid, i.e., the moving bed reactor is not a fluidized bed reactor. In general the moving bed reactor can be thought of as a packed bed reactor that continuously moves generally downw ard through a reactor or reactor section. Advantages of using a moving bed reactor include reduced particle attrition, simplified process equipment (e.g.. through the removal of complex solid / vapor separators such as cyclones), and more precise control over oxidation states of the oxygencarrier material, relative to fluidized reactor based systems. Additionally, in fluidized bed systems, the individual particles of the particulate solid may each be reduced to a random degree which may decrease selectivity. However, in a moving bed reactor, the individual particles may not be mixed and thus may be reduced more uniformly, leading to improved reaction kinetics and enhancements in overall reaction selectivity of the dehydrogenation reaction. Further, this more precise control over the degree of reduction may help reduce chemical stress that arising from over-reduction. This reduced stress may increase oxygen carrier lifetime since lower stress may translate to lower rates of attrition. Further still, in some embodiments, combusting supplemental fuel (without air) in a counter-current moving86325-WO-PCT / DOW 86325 WO5bed may help achieve high levels of fuel conversion with high selectivity to CO2and H2O. Finally, the use of a moving bed may enable the use of larger oxygen carrier particles, such as those falling within the Geldart D classification. These larger oxygen carrier particles are believed to be less sensitive to problematic agglomeration.

[0016] As described herein, a reaction zone (e.g., combustion zone, dehydrogenation zone, or oxygen treatment zone) refers to a portion of a reactor where at least the named reaction is occurring. In embodiments, the named reaction may be the predominant reaction occurring in the reaction zone. Generally, a reaction zone may include a void space upstream of the reaction zone where reactants may be added (e.g., a series of frustums may be utilized in the reactor. " Combustion zone" refers to a reaction zone wherein combustion (e.g., the reaction of oxygen with other atoms to produce oxides such as CO2and H2O) is occurring. In some embodiments, the predominant reaction in the combustion zone may be combustion. For example, the predominant reaction may be the combustion of supplemental fuel with the oxygen from the oxygen-carrier material. '‘Dehydrogenation zone” refers to a reaction zone wherein dehydrogenation (e.g., the removal of hydrogen atoms from hydrocarbons) is occurring. In some embodiments, the predominant reaction in the dehydrogenation zone may be dehydrogenation. Additionally, in the dehydrogenation zone, molecular hydrogen produced in the dehydrogenation may be combusted to form water. The “oxygen treatment zone” refers to a zone of the reaction system wherein the particulate solid contacts oxygen gas (such as in air or enriched air) and the oxygen content of the oxygen-carrier material is increased.

[0017] Embodiments described herein may utilize a particulate solid that comprises the oxygen carrier material, and in some embodiments additionally comprises dehydrogenation catalyst. As used herein, the term “particulate solid” may refer to one or more solid particles. The particles may have a size and density such that they do not fluidize under the conditions in the moving bed reactor. The particulate solid may be prepared such that it meets the Geldart D classification. Group D particles tend to have particle sizes larger than 1000 pm and are characterized as spoutable. Very dense particles can also be characterized as Group D, even with particle sizes smaller than 1000 pm (e.g., metal particles). Unlike Group A or B particles that form fast clouded bubbles (i.e.. bubble rise velocity is higher than interstitial gas velocity, and gas circulates between bubble and cloud). Group D particles tend to form slow cloudless bubbles (i.e., interstitial gas velocity is higher than bubble rise velocity, and emulsion phase86325-WO-PCT / DOW 86325 WO6gas flows through the bubble phase from bottom to top with negligible circulation). Previously, it was believed that Group D particles are unsuitable for use in dehydrogenation reactions as they require such high velocities for fluidization that processing gasses (e.g., ethylene dehydrogenation) would be impractical as gas velocity would be too high for sufficient conversion. However, it has recently been discovered that the use of Group D particles in a moving bed can result in efficient and highly selective conversion.

[0018] The particulate solid may have an average particle size of from 0.3 mm to 5 mm, such as from 0.3 mm to 0.5 mm. from 0.5 mm to 0.75 mm, from 0.75 mm to 1.0 mm, from 1.0 mm to 1.5 mm, from 1.5 mm to 2.0 mm. from 2.0 mm to 2.5 mm. from 2.5 mm to 3.0 mm, from 3.0 mm to 3.5 mm, from 3.5 mm to 4.0 mm, from 4.0 mm to 4.5 mm, from 4.5 mm to 5.0 mm, or any combination of two or more of these ranges.

[0019] The particulate solid may have a density of from 1 g / cc to 5 g / cc, such as from 1 g / cc to 2 g / cc. from 2 g / cc to 3 g / cc, from 3 g / cc to 4 g / cc. from 4 g / cc to 5 g / cc, or any combination of two or more of these ranges.

[0020] In one or more embodiments, the particulate solid may comprise an “oxygen-carrier material” or both an oxygen-carrier material and a “dehydrogenation catalyst.” In some embodiments, at least 5 wt. %, at least 10 wt. %, at least 25 wt. %, at least 50 wt. %. at least 75 wt. %, at least 85 wt. %, at least 90 wt. %. at least 92 wt. %, at least 94 wt. %, at least 96 wt. %, at least 98 wt. %, or at least 99 wt. % of the particulate solid may be the oxygen-carrier material. In some embodiments, the particulate solid may consist of, or consist essentially of, the oxygen-carrier material. As used herein, “consists essentially of’ refers to materials with less than 1 wt. % of the non-recited materials (i. e., consisting essentially of A means A is at least 99 wt.% of the composition). In some embodiments, the particulate solid may not comprise a dehydrogenation catalyst material. In some embodiments, particulate solid may comprise the oxygen-carrier material and the dehydrogenation catalyst material as separate particles. In some embodiments, the oxygen-carrier material and the dehydrogenation catalyst may be contained in the same particles of the particulate solid. In some embodiments, the particulate solid may comprise a “dual-purpose material” that may act as both a dehydrogenation catalyst as well as an oxygen-carrier material. Such a dual-purpose material may be utilized either in replacement or in combination with the oxygen-carrier material or the dehydrogenation catalyst. In some embodiments, the particulate solid may encompass all solids in the system aside from coke.86325-WO-PCT / DOW 86325 WO7

[0021] In embodiments where the particulate solid comprises a dehydrogenation catalyst, the dehydrogenation of the one or more hydrocarbons may be at least partially by catalytic dehydrogenation. Catalytic dehydrogenation is the dehydrogenation of a hy drocarbon that is promoted by the use of a dehydrogenation catalyst. In embodiments, where the particulate solid does not comprise a dehydrogenation catalyst, the dehydrogenation of the one or more hydrocarbons may be by non-catalytic thermal dehydrogenation. Non-catalytic thermal dehydrogenation refers to the dehydrogenation of a hydrocarbon that occurs without the use of a dehydrogenation catalyst and instead may occur because of high temperature, pressure or combinations thereof.

[0022] As described herein, in one or more embodiments, the dehydrogenation catalyst and the oxygen-carrier material may be separate particles of the particulate solid. One contemplated advantage of such a system is that by adding, removing, or substituting one or both of the dehydrogenation catalyst and oxygen-carrier material, the functionality of the system can be altered, even when the system is on-line. For example, the reaction heat load could be adjusted by adding or removing one or both of the dehydrogenation catalyst and the oxygen-carrier material. This may be advantageous, in some embodiments, as compared with a dual purpose material, since the dual purpose particle's heat balance must be determined prior to reaction and cannot be easily adjusted by varying the amount of dehydrogenation catalyst versus oxygen-carrier material. Control of the ratio of dehydrogenation catalyst versus oxygen-carrier material may further be advantageous since reaction selectivity may be better tuned. For example, the amount of hydrogen in the system may be used to control the degree of combustion, or component balances may be used to optimize downstream separation processes.

[0023] The oxygen-carrier material may refer to one or more materials which may comprise oxygen atoms and which may increase or decrease the number of oxygen atoms bound thereto based on reaction conditions. For example, the oxygen-carrier material may include one or more metal oxides. According to one or more embodiments, the one or more metal oxides may be a redox-active metal oxide or a mixture of redox-active metal oxides. The redoxactive metal oxide may include binary', ternary', or other mixed metal oxides capable of undergoing reduction in the presence of a reducing agent (for example, hydrogen) and oxidation in the presence of oxidizing agent (for example, oxygen or air). In some embodiments, the redox-active metal oxide may be a metal MOX, where M may be one or86325-WO-PCT / DOW 86325 WO8more metals of IUPAC group 6, 7, 8, 9, 10, 11, or 12 and£'x” is the number of associated oxygen atoms in the structure. For example the redox-active metal oxide may be M Os, Fe2O3, CO3O4, CuO, (LaSr)CoO3, (UaSr)MnOs, MgeMnOs, MgMnCh, MnCh, FesO-t, MnsO4, CU2O, NiO, Ni2O3, CrO, CnCh, CrCh, ZnO, or any combination of other IUPAC group 6-12 metal oxide. In some embodiments, the redox-active metal oxide may be cerium oxide. For example, the redox-active metal oxide may be Ce-Ch, Ce20s, or any other mixed metal oxide containing cerium. In further embodiments, the oxygen carrier material may include lanthanum oxide, La2O3, in combination with other reducible metal oxides. In some embodiments, the redox-active metal oxide may be chosen from M Os, Fe2O3. CO3O4. CuO, (LaSr)CoO3,(LaSr)MnO3, MgeMnOs, MgMnOs, MnO2, Fe3O4, Mn3O4, and CU2O. In some embodiments, the oxygen-carrier material may be a solid, such as solid particles. In specific embodiments, the oxygen-carrier material may be a crushed solid or powder. In other embodiments, the oxygen-carrier material may be formulate using a redox-active metal oxide and a binder and / or support material to produce the particulate solid with the required physical properties, for example, particle size distribution, density, and attrition resistance. The binder and / or support material may include alumina, silica, titania, magnesia, zirconia, or combinations thereof.

[0024] In one or more embodiments, the particulate solid may include a hydrogen-selective oxygen-carrier material that may include a promoter or a combination of various promoters. The addition of a promoter(s) may lead to the formation of a core-shell morphology'. The promoter(s) may include alkali or alkaline-earth metal oxides from IUPAC group 1 and 2 and / or compounds comprising alkali-transition metal oxides or alkaline-earth transition metal oxides. In some embodiments, alkali elements may include one or more of sodium, lithium, potassium, and cesium. In some embodiments, alkaline-earth elements may include one or more of calcium, magnesium, strontium, and barium. In some embodiments, transition metals may include one or more of tungsten and molybdenum. For example, the one or more alkali or alkaline-earth transition metal oxides may be Na2WO4, K2MoO4, Na2MoO4, K2WO4, U12WO4, CsWO4, L12MOO4, CaWO4, CaMoO4, MgW04, MgMoCU, SrWO4, SrMoO4, BaWO4and BaMoCU In some embodiments, the promoter may include one or more of alkali or alkaline-earth metal salts selected from Group 1 and 2 metal cations and a counterion. In some embodiments, alkali elements may include one or more of sodium, lithium, potassium, and cesium. In some embodiments, alkaline-earth elements may include one or more of86325-WO-PCT / DOW 86325 WO9calcium, magnesium, strontium, and barium. In some embodiments, the counterion may include carbonates, sulphates, sulphites, sulfides, silicates, phosphates, phosphites and borates. For example, the alkali or alkaline-earth metal salts may be Na2CO3, Na2SO4, Na3PO, Li2CO3, Li2SO4, Li3PO4, K2CO3, K2SO4, K3PO4, Cs2CO3, Cs2SO4. Cs3PO4, CaCO3, CaSO4, Ca3(PO4)2, SrCO3. SrSO4. Sr3(PO4)2. MgCO3. MgSO4, Mg3(PO4)2, BaCO3. BaSO4, Ba3(PO4)2, Na2HPO4, KHSO4, Na2SO3, K2B4O?, Na3BO3, or combinations thereof.

[0025] Some examples of suitable oxygen-carrier materials are disclosed in U. S. Pat. App. No 62 / 725,504, entitled ‘‘METHODS OF PRODUCING HYDROGEN-SELECTIVE OXYGEN CARRIER MATERIALS,” filed on, Aug. 31, 2018; U. S. Pat. App. No.62 / 725,508, entitled “HYDROGEN-SELECTIVE OXYGEN CARRIER MATERIALS AND METHODS OF USE,” filed on, Aug. 31, 2018; U. S. Pat. No. 5,430,209; U. S. Pat. No.7,122,495; and WO 2018 / 232133, each of which are incorporated by reference in their entireties.

[0026] The oxygen-carrier material may be reducible by releasing oxygen or may be oxidizable. Thus, the oxygen-carrier material may exist in one or more states, e.g., an “oxygen-rich state”, a “semi-oxygen-rich state”, and an “oxygen-depleted state”. Each of these states may refer to the bulk of the material in a portion of the reaction system, rather than to an individual particle. The oxygen-carrier material may comprise releasable oxygen. As described herein, “releasable oxygen” may refer to the oxygen that can be released through redox by the oxygen-carrier material, such as through redox reactions with molecular hydrogen. Other oxygen may also be present in the oxygen-carrier material that is not releasable through redox reactions. It should be understood that in some embodiments, the oxygen may be released from a surface of the oxygen-carrier material simultaneously with the combustion of hydrogen at the surface of the oxygen-carrier material.

[0027] The oxygen-rich state refers to an oxygen-carrier material having a relatively (compared to the semi-oxygen-rich state and the oxygen-depleted state) great amount of releasable oxygen. In some embodiments, the oxygen-rich state refers to when the oxygencarrier material comprises from about 1 wt. % to about 30 wt. % releasable oxygen based on total weight of the oxygen-carrier material in the relevant portion of the reactor (e.g., the outlet of the oxygen treatment zone). In other embodiments, the oxygen-carrier material in the oxygen-rich state comprises from 1 wt. % to 3 wt. %, from 3 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 2286325-WO-PCT / DOW 86325 WO10wt. %, from 22 wt. % to 24 wt. %, from 24 wt. % to 26 wt. %, from 26 wt. % to 28 wt. %, from 28 wt.% to 30 wt. %, from 30 wt. % to 99 wt. %, or any combination of two or more of these ranges of releasable oxygen.

[0028] The oxygen-carrier material may also exist in a ‘“semi-oxygen-rich state"’ and an “oxygen-depleted state”, based on its location within the reaction system. The semi-oxygen-rich state refers to when the oxygen-carrier material has more releasable oxygen than the oxygen-depleted state but less releasable oxygen than in the oxygen-rich state. However, even in the oxygen-depleted state, the oxygen-carrier material may still comprise at least some releasable oxygen.

[0029] As described herein, in one or more embodiments, the particulate solid may comprise a dehydrogenation catalyst. In one or more embodiments, the dehydrogenation catalyst may include gallium, chromium, and / or platinum. As described herein, a gallium and / or platinum dehydrogenation catalyst comprises gallium, platinum, or both. The dehydrogenation catalyst may be carried by an alumina, silica-alumina, zirconia, or silica support, and may optionally comprise potassium. In one or more embodiments, the dehydrogenation catalysts may include catalysts disclosed in U. S. Pat. No. 8,669,406, which is incorporated herein by reference in its entirety, such as those including Ga, Cr, and / or Fe based catalysts. According to additional embodiments. Pt based catalysts may be utilized. In one or more embodiments, those catalysts disclosed in EP 0948475B1 and / or WO 2010 / 133565, which are each incorporated herein by reference in its entirety, may be utilized. Additional catalyst embodiments contemplated as suitable for use in the systems and methods described herein include those of U. S. Pat. No.8,669,406. which is incorporated herein by reference in its entirety. Such catalysts may contain relatively low amounts of Cr, such as less than 6%, or approximately 1.5%. However, it should be understood that other suitable dehydrogenation catalysts may be utilized to perform the dehydrogenation reaction.

[0030] In one or more embodiments, the dehydrogenation catalyst may exhibit suitable stability when in the presence of steam. As is described herein, the combustion of hydrogen may form steam, which may be in direct contact with the dehydrogenation catalyst. It is contemplated that not all dehydrogenation catalysts are equally effective in steam environments. In one or more embodiments, dehydrogenation catalysts are utilized which maintain a substantial amount of their reactivity and / or selectivity for the dehydrogenation of light alkanes. For example, one or more of the dehydrogenation catalysts utilized in the86325-WO-PCT / DOW 86325 WO11presently disclosed systems and methods may not deteriorate in alkane conversion and / or selectivity for dehydrogenation more than 25%, more than 20%, more than 15%, more than 10%, more than 5%, or may even have improved alkane conversion and / or selectivity for dehydrogenation when in the presence of steam in amounts consistent with the operation of the presently disclosed systems. In some embodiments, the dehydrogenation catalyst may function with such conversion and / or selectivity when exposed to at least 10 mol. % water (such as from 10 mol. % to 50 mol. % water) for a period of up to, e.g., 120 seconds (the time which the catalyst may be exposed to such conditions, according to some embodiments of the presently disclosed system).

[0031] Now referring to FIG. 1, an example reaction system 100 that may be suitable for use with the methods described herein is schematically depicted. The reaction system 100 may include dehydrogenation zone 120, combustion zone 130, and oxygen treatment zone 110. The reaction system 100 may include a moving bed reactor 102 comprising moving bed 104. As depicted in FIG. 1, in some embodiments, the oxygen treatment zone 110 and the dehydrogenation zone 120 may both be positioned within the moving bed 104. In some embodiments, as depicted in FIG. 1, the combustion zone 130 may be positioned outside of the moving bed 104 and even outside of the moving bed reactor 102 entirely.

[0032] The particulate solid may enter the oxygen treatment zone 110, be passed to the dehydrogenation zone 120, be passed to the combustion zone 130, and then passed back to the oxygen treatment zone 110. Thus, at least a portion of the particulate solid is recycled in a loop between the reaction zones. In embodiments, the particulate solid may be passed from the moving bed reactor 102 to the combustion zone 130 via particulate solid outlet 152. After the combustion zone 130, the particulate solid may be passed back to the moving bed reactor 102 by particulate solid feed 156. Within the moving bed reactor 102, the particulate solid may be passed from the oxygen treatment zone 110 to the dehy drogenation zone 120 without leaving the moving bed 104. The oxygen treatment zone 110 may be upstream of the dehydrogenation zone 120 with respect to the movement of the particulate solid. As the particulate solid moves in a loop, it should be understood that, in each pass, the particulate solid will pass from oxygen treatment zone 110 to the dehydrogenation zone 120 and then to the combustion zone 130, before beginning the next pass back to the oxygen treatment zone 110. Generally, when the dehydrogenation zone 120 is downstream of the oxygen treatment86325-WO-PCT / DOW 86325 WO12zone 110 and upstream of the combustion zone 130, the dehydrogenation process may operate at enhanced levels of overall activity and / or selectivity.

[0033] Although not depicted in the figures, each of the zones, including zones within the moving bed 104, may be separated by a gas seal (e.g., a space between two zones where another gas, such as steam or nitrogen, may be fed to prevent mixing of the reactants across zones). Additionally not depicted in the figures, in some embodiments, a portion of the catalyst exiting the oxygen treatment zone may be passed back to the combustion zone. Passing the catalyst from the oxygen treatment zone to the combustion zone may, in some embodiments, be utilized to balance the oxygen demands of the combustion zone.

[0034] Each of these unit operations will now be described in more detail.

[0035] The particulate solid, in its oxygen-depleted state, may be passed from the combustion zone 130 to the moving bed reactor 102, where it may enter the oxygen treatment zone 110. In the oxygen treatment zone 110, the oxygen carrier material may be converted from the oxygen-depleted state to the oxygen rich state. The oxygen carrier material in the oxygen rich state may then pass from the oxygen treatment zone 110 to the dehydrogenation zone 120 without leaving the moving bed 104 of the moving bed reactor 102. Additionally, an oxygen containing gas may enter oxygen treatment zone 110 via oxygen containing gas inlet 112 and leave oxygen treatment zone 110 via depleted oxygen containing gas outlet 114.

[0036] The oxygen containing gas passed to the oxygen treatment zone 110 may comprise air, oxygen-lean air, oxygen-enriched air, pure oxygen, or other gasses comprising molecular oxygen (e.g., mixtures of oxygen and inert gasses). In one or more embodiments, the oxygen containing gas may be air, enriched air, air mixed with steam, or flue gas. Enriched air is air with added oxygen gas. In some embodiments, the oxygen containing gas may include at least 28 mol.% oxygen. In other embodiments, the oxygen containing gas may include from about 2 moL% to about 28 mol.% oxygen. In some embodiments, the oxygen containing gas may comprise from 2 mol. % to 5 mol. %. from 5 mol. % to 10 mol. %, from 10 mol. %, to 15 mol. %, from 15 mol. % to 20 mol. %, from 20 mol. % to 25 mol. %, from 25 mol. % to 28 mol. %, from 28 mol. % to 30 mol. %, from 30 mol. % to 35 mol. %, from 35 mol. % to 40 mol. %, from 40 mol. % to 50 mol. %, from 50 mol. % to 60 mol. %, from 60 mol. % to 70 mol. %, from 70 mol. % to 80 mol. %, from 80 mol. % to 90 mol. %, from 90 mol. % to 100 mol. %, or any combination of two or more of these ranges of oxygen.86325-WO-PCT / DOW 86325 WO13

[0037] The oxygen treatment zone 110 may contact the particulate solid with the oxygen containing gas at a temperature of from 650 °C to 925 °C, such as from 650 °C to 700 °C, from 700 °C to 750 °C, from 750 °C to 800 °C, from 800 °C to 850 °C, from 850 °C to 900 °C, from 900 °C to 925, or any combination of two or more of these ranges.

[0038] As noted hereinabove, in the oxygen treatment zone 110, the particulate solid may be positioned within a moving bed 104. The oxygen-containing gas may be in co-current flow with the particulate solid or may be in counter-current flow with the particulate solid, in the oxygen treatment zone 110. " Co-current flow" means that the average velocities of the two substances (e.g., the oxygen containing gas and the particulate solid) are in the same direction. “Counter-current flow” means that the average velocities of the two substances (e.g., the oxygen containing gas and the particulate solid) are in opposite directions. Countercurrent flow may provide the advantage of maximizing the degree of oxidation of the oxygen carrier material since the highest concentrations of oxygen will the present when the oxygencarrier material has the highest oxidation state. Co-current flow may provide the advantage of improved control over the exact oxidation state of the oxygen-carrier material. However, in either case, the particulate solid is not fluidized within the moving bed 104.

[0039] Still referring to FIG. 1, the particulate solid may pass from the oxygen treatment zone 110 to the dehydrogenation zone 120 while remaining in the same moving bed 104 of the moving bed reactor 102. Additionally, a feed stream (e.g., feed stream 122) comprising one or more hydrocarbons may enter the dehydrogenation zone 120. In the dehydrogenation zone 120, the one or more hydrocarbons of the feed stream 122 may be dehydrogenated to form molecular hydrogen and one or more products. " Dehydrogenation" or “dehydrogenating" refers to a chemical reaction or process wherein the total amount, or relative amount, of hydrogen in a molecule may be reduced. For example, the total number of hydrogens in a hydrocarbon may be reduced, the number of hydrogens per carbon in the hydrocarbon may be reduced, or both. The one or more products may leave the dehydrogenation zone 120 via product outlet stream 124. In the dehydrogenation zone 120, the oxygen-carrier material may be converted from its oxygen-rich state to its semi-oxygen-rich state and then passed to combustion zone 130.

[0040] In one or more embodiments, the feed stream 122 may comprise one or more hydrocarbons. In one or more embodiments, the one or more hydrocarbons may comprise an alkyl moiety. As used in the present disclosure a hydrocarbon comprises an “alkyl moiety” if86325-WO-PCT / DOW 86325 WO14the molecule has at least one carbon-carbon single bond capable of being dehydrogenated to form a carbon-carbon double bond. 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 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.

[0041] In the dehydrogenation zone 120, the feed stream may be dehydrogenated. An example dehydrogenation process where the feed stream comprises ethane is shown in Equation 1.Equation 1: C2H6↔ C2H4+ H2

[0042] As can be seen from Equation 1, the dehydrogenation of the feed stream produces molecular hydrogen. Molecular hydrogen refers to hydrogen either unbound to other atoms or bound only to other hydrogen atoms (e g., not hydrogen atoms bound to other atoms such as carbon). However, this process may result in the buildup of molecular hydrogen, which may shift the dehydrogenation equilibrium to the left and away from the olefin products. Thus, it may be desirable to remove at least a portion of the molecular hydrogen in order to shift the dehydrogenation equilibrium back to the right. One way to remove at least a portion of the molecular hydrogen is to combust the molecular hydrogen with releasable oxygen from the oxygen-carrier material to form w ater. Thus, the use of oxygen carrier material in its oxygen rich state will maximize combustion of water and drive the above Equation 1 to the right. In doing so. the concentration of releasable oxygen in the oxygen-carrier material will be reduced, thus forming the oxygen-carrier material in its semi-oxygen-rich state.86325-WO-PCT / DOW 86325 WO15

[0043] In some embodiments, the releasable oxygen of the oxygen-carrier materials may be selective for combusting hydrogen over hydrocarbons. In some embodiments, at least about 60% of the releasable oxygen of the oxygen-carrier material is selective for hydrogen combustion. In other embodiments, at least about 55% of the releasable oxygen of the oxygen-carrier material is selective for hydrogen combustion.

[0044] In embodiments, when hydrogen (e.g., molecular hydrogen) is contacted by the oxygen-carrier material, some of the releasable oxygen is removed from the oxygen-carrier material, thereby producing water and oxygen-carrier material in the semi-oxygen-rich state. In some embodiments, contacting the hydrogen with the oxygen-carrier material removes from about 1 wt. % to 50 wt. % of the releasable oxygen from the oxygen-carrier material. In other embodiments, contacting the hydrogen with the oxygen-carrier material removes from about 10 wt. % to about 50 wt. %, from about 10 wt. % to about 25 wt. %, or from about 25 wt. % to about 50 wt. % of the releasable oxygen from the oxygen-carrier material.

[0045] In further embodiments, when the hydrogen (e.g., molecular hydrogen) is contacted by the oxygen-carrier material, the oxygen-carrier material combusts greater than about 50% of the hydrogen. In other embodiments, when the hydrogen is contacted by the oxygen-carrier material, the oxygen-carrier material combusts from 50 % to 60 %, from 60 % to 70 %, from 70 % to 80 %. from 80 % to 90 %. from 90 % to 95 %. from 95 % to 98 %. from 98 % to 99 %, or any combination of two or more of these ranges of the molecular hydrogen released in the dehydrogenation reaction.

[0046] The contacting of the oxygen-carrier material with the hydrogen may combust the hydrogen and form the oxygen-carrier material in its semi-oxygen-rich state. To form the semi oxygen-rich state, at least a portion of the oxygen-carrier material may be reduced to a lower oxidation state. Once the oxygen-carrier material has been reduced to form its semi oxygen-rich state, the oxygen-carrier material in the semi oxygen-rich state may be discharged from the dehydrogenation zone 120 via particulate solid outlet 152.

[0047] Referring again to dehydrogenation zone 120, the dehydrogenation zone 120 may be a portion of the same moving bed 104 as the oxygen treatment zone 110. In the dehydrogenation zone 120, the one or more hydrocarbons of the feed stream and the particulate solid may be in co-current flow or in counter-current flow. Generally, co-current flow results in greater selectivity and counter-current flow results in greater overall86325-WO-PCT / DOW 86325 WO16conversion. However, in either case, the particulate solid in the dehydrogenation zone 120 may be contained within the moving bed 104 and not fluidized.

[0048] Without being limited by theory,, it is believed that positioning two or more reaction zones (e.g., the oxygen treatment zone 110 and the dehydrogenation zone 120) in the same moving bed 104 may allow for the use of fewer solid / gas separation devices (e.g., cyclones), relative to systems whereby the oxygen treatment zone and the dehydrogenation zone are not positioned within the moving bed. This may help to both reduce capital costs and minimize attrition of the particulate solid, thereby reducing operating costs.

[0049] In one or more embodiments, the dehydrogenation zone 120 may operate at a temperature of greater than or equal to 550 °C and less than or equal to 850 °C. In some embodiments, the temperature in the dehydrogenation zone 120 may be from 550 °C or 600 °C to 770 °C. In other embodiments, the temperature in the dehydrogenation zone 120 may be from 700 °C to 750 °C, 750 °C to 800 °C, 800 °C to 850 °C, or any combination thereof. Without being bound by any particular theory, it is believed that too low of temperature (e.g., 550 °C or less) may limit the maximum conversion of the hydrocarbon due to equilibrium constraints as well as lowers the rate of dehydrogenation by the thermal and catalytic component. Too low of temperatures may also result in a slow rate of oxygen release from the oxygen-carrier material and low hydrogen combustion. On the other hand, high temperatures (e.g., greater than 850 °C) may result in thermal degradation of the products produced and may result in a lower product selectivity than is economically feasible. In some embodiments, the primary' feed component(s) may be propane, ethylbenzene, and / or butane, and the dehydrogenation zone 120 may operate at a temperature of greater than 600 °C. In additional embodiments, the primary feed component may be ethane, and the dehydrogenation zone 120 may operate at a temperature of at least 625 °C.

[0050] In some embodiments, the dehydrogenation zone 120 may operate at a pressure of at least atmospheric pressure (about 14.7 psia). In some embodiments, the dehydrogenation zone 120 may operate at a pressure of about 500 psia. In other embodiments, the dehydrogenation zone 120 may operate at a pressure from about 4 psia to about 160 psia, from about 20 psia to about 100 psia, or from about 30 psia to about 80 psia. In some embodiments, the pressure within the dehydrogenation zone 120 may be with a pressure of within 30 psi of the oxygen-treatment zone 110.86325-WO-PCT / DOW 86325 WO17

[0051] In one or more embodiments, the residence time of the one or more hydrocarbons of the feed stream in the dehydrogenation zone 120 may be less than 10 seconds (such less than 9 seconds, less than 8 seconds, less than 7 seconds, less than 6 seconds, less than 5 seconds, less than 4 seconds, or even less than 3 seconds).

[0052] The residence time of the particulate solid in the dehydrogenation zone 120 may typically vary from 0.5 seconds (sec) to 360 sec. In other embodiments, the residence time of the particulate solid may be from about 0.5 sec to 200 sec, such as from 0.5 sec to 1 sec, from 1 sec to 2 sec, from 2 sec to 5 sec, from 5 sec to 10 sec, from 10 sec to 20 sec, from 20 sec to 40 sec. from 40 sec to 60 sec, from 60 sec to 80 sec, from 80 sec to 100 sec, from 100 sec to 125 sec, from 125 sec to 150 sec, from 150 sec to 175 sec, from 175 sec to 200 sec, or an combination of two or more of these ranges.

[0053] In some embodiments, the weight ratio of the particulate solid to the feed stream entering the dehydrogenation zone 120 may range from 5 to 150 on a weight to weight (w / w) basis. In some embodiments, the ratio may range from 5 to 10, 10 to 20, 20 to 40, 40 to 60, 60 to 80, 80 to 100, 100 to 125, 125 to 150, 10 to 40, 12 to 36, 12 to 24, or any combination of two or more of these ranges.

[0054] In additional embodiments, the flux of the particulate solid entering the dehydrogenation zone 120 may be from 1 pound per square foot-second (lb / ft2-s) (about 4.89 kg / m2-s) to 300 lb / ft2-s (to about 97.7 kg / m2-s), such as from 1-20 lb / ft2-s, 20 to 40 lb / ft2-s, 40 to 60 lb / ft2-s, 60 to 80 lb / ft2-s, 80 to 100 lb / ft2-s, 100 to 150 lb / ft2-s, 150 to 200 lb / ft2-s, 200 to 250 lb / ft2-s, 250 to 300 lb / ft2-s, or any combination of two or more of these ranges.

[0055] Still referring to FIG. 1, the one or more products may exit the dehydrogenation zone 120 of the moving bed reactor 102 via product outlet stream 124. Product outlet stream 124 may be further processed such as by one or more subsequent separation steps or further reacted. It is contemplated that product outlet stream 124 may be utilized as a feed for another reactor system or sold as a chemical product. In some embodiments, the water produced from the combustion of the molecular hydrogen may be removed from product outlet stream 124 and the one or more products utilizing a condenser.

[0056] As described above, in some embodiments, product outlet stream 124 may comprise one or more products. In one or more embodiments, the one or more products may comprise one or more olefinic compounds. As used herein, the term “olefinic compounds’7refers to hydrocarbons having one or more carbon-carbon double bonds apart from the formal double86325-WO-PCT / DOW 86325 WO18bonds 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. In one or more embodiments, the one or more olefinic compounds may comprise one or more of ethylene, propylene, butylene, or styrene. In some embodiments, the one or more products 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 ethylene. In additional embodiments, the one or more products 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 propylene. In additional embodiments, the one or more products 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 butylene. In additional embodiments, the one or more products 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 styrene. In additional embodiments, the one or more products 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 one or more of ethylene, propylene, butylene, and styrene. In some embodiments, the product outlet stream 124 may comprise at least 50 wt. %. at least 75 wt. %, at least 80 wt. %, at least 85 wt. %, at least 90 wt. %, at least 95 wt. %, at least 98 wt. %, or even at least 99 wt. % of the one or more products.

[0057] Still referring to FIG. 1, the particulate solid may exit the dehydrogenation zone 120 with the oxygen-carrier material in an semi oxygen-rich state via particulate solid outlet 152 and be passed to combustion zone 130. The oxygen content of the oxygen-carrier material may be further decreased in the combustion zone 130 such that the particulate solid may exit the combustion zone 130 via particulate solid feed 156 with the oxygen-carrier material in its oxygen-depleted state. Additionally, in order to carry out the combustion, supplemental fuel may be passed to the combustion zone 130 via supplemental fuel stream 132 and waste gasses (e g., combustion products such as CO and CO2) may be removed from the combustion zone 130 via combustion products stream 134.

[0058] The particulate solid may be passed to the combustion zone 130 in its semi oxygenrich state. Within the combustion zone 130, the supplemental fuel may be combusted with oxygen from the oxygen-carrier material, thereby reducing the oxygen-carrier material to its86325-WO-PCT / DOW 86325 WO19oxygen-depleted state. The oxygen-carrier material, in its oxygen-depleted state, may then pass to the oxygen treatment zone 110. Without being limited by theory, reducing the oxygencarrier material to its oxygen depleted state may help to even out the oxidation state among the individual particles of the oxygen-carrier material, thereby improving selectivity of the later dehydrogenation reactions. Additionally, the combustion process produces heat to raise the temperature of the particulate solid to the desired reaction temperature for dehydrogenation reactions in the dehydrogenation zone 120. In some embodiments, additional oxygen-containing gasses (e.g., air, enriched air, pure oxygen) may be added to the combustion zone in order to combust the supplemental fuel. In alternate embodiments, no additional oxy gen-containing gasses may be supplied to the combustion zone 130.

[0059] The combustion zone 130 may operate at a temperature of from 650 °C to 925 °C, such as from 650 °C to 700 °C, from 700 °C to 750 °C, from 750 °C to 800 °C, from 800 °C to 850 °C, from 850 °C to 900 °C, from 900 °C to 925 °C. or any combination of two or more of these ranges.

[0060] In the combustion zone 130, the particulate solid may be positioned outside the moving bed 104, such as in a fluidized bed. The supplemental fuel may be in co-current flow with the particulate solid or may be in counter-current flow with the particulate solid, in the combustion zone 130. " Co-current flow" means that the average velocities of the two substances (e.g., the supplemental fuel and the particulate solid) are in the same direction. “Counter-current flow’' means that the average velocities of the two substances (e.g., the supplemental fuel and the particulate solid) are in opposite directions. Counter-current flow may provide the advantage of improved overall combustion since partially combusted fuel is in contact with the oxygen carrier material when it is most active. In some embodiments, cocurrent flow may provide the advantage of removing design constraints on the combustor as preventing fluidization is no longer required. Further, in some embodiments, co-current flow may provide sufficient contact time such that coke deposited on the particulate solid by carbon-based supplemental fuels may be completely gasified, thus preventing the escape of coke-laden particulate solids. However, in either case, the particulate solid is not fluidized within the moving bed 104.

[0061] The supplemental fuel stream 132 provided to the combustion zone 130 may comprise supplemental fuel. The supplemental fuel may comprise any fuel suitable to at least partially react with the oxygen from the oxygen-carrier material and raise the temperature of86325-WO-PCT / DOW 86325 WO20the particulate solid. In some embodiments, the supplemental fuel may be gaseous. Suitable supplemental fuels may include hydrogen and gaseous hydrocarbons, such as methane, ethane, propane, natural gas, or combinations thereof. The supplemental fuel provided to the combustion zone 130 may comprise at least 80 wt. %, at least 90 wt. %, at least 95 wt. %. at least 98 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the combined weight of hydrogen and gaseous hydrocarbons (such as methane, ethane, propane, natural gas, or combinations thereof), on the basis of the total weight of the supplemental fuel supplied to the combustion zone 130. In embodiments where coke is formed, the coke may be burned rather than supplying supplemental fuel, or both coke and supplemental fuel may be burned.

[0062] In one or more embodiments, at least 80 wt. %, at least 90 wt. %, at least 95 wt. %, at least 99 wt. %, or even at least 99.9 wt. % of the reactive compounds in the combustion zone 130 may comprise the combined weight of the supplemental fuel and the particulate solid.

[0063] As depicted in FIG. 1, the combustion zone 130 may be outside of the moving bed 104 of the moving bed reactor 102. For example, the combustion zone 130 may be in a separate reactor from the moving bed reactor 102. In embodiments, the combustion zone 130 may be in a fluidized bed reactor. Generally, the use of a fluidized bed reactor for the combustion zone 130 may ensure rapid, space efficient, and / or complete reduction of the oxygen-carrier material, which may in turn help to provide consistent performance in the oxygen treatment zone 110 and dehydrogenation zone 120. The reactor in which the combustion zone 130 is located may for example be a riser or a downer. In embodiments, the oxygen containing gas may be in co-current flow or in counter-current flow with the particulate solid in the combustion zone 130.

[0064] Referring now to FIG. 2, another reaction system 200 is depicted. The reaction system 200 is similar or identical to the reaction system 100 of FIG. 1, except where described otherwise. In particular, in the reaction system 200 of FIG. 2, the dehydrogenation zone 220 and combustion zone 230 are positioned within the moving bed 204 of the moving bed reactor 202 while the oxygen treatment zone 210 is positioned outside of the moving bed reactor 202. It should be understood that the oxygen treatment zone 210 is still upstream of the dehydrogenation zone 220 with respect to the movement of the particulate solid (e.g., the particulate solid passes from the oxygen treatment zone 210 to the dehydrogenation zone 220 before passing to the combustion zone 230 and back to the oxygen treatment zone 210 again).86325-WO-PCT / DOW 86325 WO21

[0065] In FIG. 2, the particulate solid comprising the oxygen-carrier material is passed from the oxygen treatment zone 210 to the dehydrogenation zone 220 of the moving bed reactor 202 by particulate solid feed 256 in the oxygen-rich state. The dehydrogenation zone 220 operates substantially as dehydrogenation zone 120, with the feed stream being supplied by feed stream 222 and the one or more products being removed by product outlet stream 224. The dehydrogenation zone 220 also converts the oxygen-carrier material from the oxygenrich state to the semi-oxygen-rich state.

[0066] The particulate solid comprising the oxygen-carrier material now in its semi-oxygen-rich state is passed from the dehydrogenation zone 220 to the combustion zone 230 without leaving the moving bed 104 of moving bed reactor 102. The combustion zone 230 operates substantially as combustion zone 130 to convert the oxygen-carrier material from the oxygen-depleted state to the oxygen-rich state. Additionally, the supplemental fuel is passed to combustion zone 230 via supplemental fuel stream 232 and the combustion products are removed via combustion products stream 234. However, unlike combustion zone 130, combustion zone 230 is part of the moving bed 204 and is not be fluidized.

[0067] Without being limited by theory,, it is believed that positioning two or more reaction zones (e.g., the combustion zone and the dehydrogenation zone) in the same moving bed may allow for the use of fewer solid / gas separation devices (e.g., cyclones), relative to systems whereby the combustion zone and the dehydrogenation zone are not positioned within the moving bed. This may help to both reduce capital costs and minimize attrition of the particulate solid, thereby reducing operating costs.

[0068] The particulate solid comprising the oxygen-carrier material now in its oxygen-depleted state is passed from the combustion zone 230 to oxygen treatment zone 210 via particulate solid outlet 252. Additionally, the oxygen treatment zone 210 is fed the oxygen containing gas by oxygen containing gas inlet 212 and exhausting the depleted oxygen containing gas via depleted oxygen containing gas outlet 214. Oxygen treatment zone 210 operates substantially as oxygen treatment zone 110 except that oxygen treatment zone 210 is not located within the moving bed reactor 202 and need not be a moving bed. In some embodiments, oxygen treatment zone 210 is fluidized.

[0069] Referring now to FIG. 3, another reaction system 300 is depicted. The reaction system 300 is similar or identical to the reaction system 100 of FIG. 1, except where described otherwise. In particular, in the reaction system 300 of FIG. 3, all of the combustion zone 330,86325-WO-PCT / DOW 86325 WO22oxygen treatment zone 310. and dehydrogenation zone 320 and are positioned within the moving bed 304 of the moving bed reactor 302. It should be understood that while the combustion zone 330, dehydrogenation zone 320, and oxygen treatment zone 310 are all depicted as being in a specific order in the moving bed reactor 302 of FIG. 3. alternate embodiments are contemplated where other orders are utilized. However, in all embodiments, the oxygen-treatment zone is upstream of the dehydrogenation zone and downstream of the combustion zone, with respect to the movement of the particulate solid. As the particulate solid moves in a loop, it should be understood that, in each pass the particulate solid will pass from the oxygen treatment zone to the dehydrogenation zone before passing through the combustion zone and then eventually back to the oxygen treatment zone.

[0070] Without being limited by theory, it is believed that positioning all three reaction zones (e.g., the oxygen treatment zone, the dehydrogenation zone, and the combustion zone) in the same moving bed may allow for the use of fewer (or complete elimination of) solid / gas separation devices (e.g., cyclones), relative to systems whereby only one or two reaction zones are positioned within the moving bed. This may help to both reduce capital costs and minimize attrition of the particulate solid, thereby reducing operating costs.

[0071] In FIG. 3, the particulate solid comprising the oxygen-carrier material in its semi-oxygen-rich state is passed from the dehydrogenation zone 320 to the combustion zone 330. Additionally, supplemental fuel is passed to the combustion zone 330 via supplemental fuel inlet 332 and combustion products are removed via combustion products stream 334. Combustion zone 330 operates substantially as combustion zone 130 to convert the oxygen-carrier material from the semi-oxygen-rich state to the oxygen-depleted state. However, in the embodiments of FIG. 3, combustion zone 330 is situated within the moving bed 304 and is not fluidized.

[0072] The particulate solid comprising the oxygen-carrier material in its oxygen-depleted state is passed from the combustion zone 330 to the oxygen treatment zone 310. Additionally, the oxygen containing gas is passed to the oxygen treatment zone 310 via oxygen containing gas inlet 312 and the depleted gas is released via depleted oxygen containing gas outlet 314. The oxygen treatment zone 310 operates substantially as oxygen treatment zone 210, converting the oxygen-carrier material from the oxygen-depleted state to the oxygen-rich state.86325-WO-PCT / DOW 86325 WO23

[0073] Then, the particulate solid comprising the oxygen-carrier material, now in its oxygen-rich state, is passed from the oxygen treatment zone 310 to the dehydrogenation zone 320. Additionally, the feed stream 322 provides the feed stream comprising the one or more hydrocarbons to the dehydrogenation zone 320. The dehydrogenation zone 320 operates substantially as dehydrogenation zone 120, converting the one or more hydrocarbons to the one or more products and exhausting the one or more products via product outlet stream 324. Additionally, the dehydrogenation zone 320 converts the oxygen-carrier material from the oxygen-rich state to the semi-oxygen-rich state. The particulate solid comprising the oxygencarrier material in the semi-oxygen rich state is then passed back to the combustion zone 330, such as by transfer line 352.

[0074] According to one or more aspects:

[0075] Aspect 1. A method for dehydrogenating hydrocarbons, the method comprising:

[0076] passing supplemental fuel, a feed stream comprising one or more hydrocarbons, and a particulate solid comprising an oxygen-carrier material into a reaction system comprising a moving bed reactor, wherein: the reaction system comprises a combustion zone, an oxygen treatment zone, and a dehydrogenation zone, the particulate solid enters the combustion zone, then is passed to the oxygen treatment zone, and then is passed to the dehydrogenation zone; the supplemental fuel enters the combustion zone, wherein, in the combustion zone, the supplemental fuel is combusted with oxygen from the oxygen-carrier material such that the oxygen-carrier material enters the combustion zone in a semi-oxygen-rich state and exits the combustion zone in an oxygen-depleted state; oxygen is passed to the oxygen treatment zone, wherein the particulate solid enters the oxygen treatment zone in the oxygen-depleted state, is contacted by the oxygen, and exits the oxygen treatment zone in an oxygen-rich state; the feed stream enters the dehydrogenation zone, wherein, in the dehydrogenation zone, the one or more hydrocarbons of the feed stream are dehydrogenated to form molecular hydrogen and one or more products, and at least a portion of the molecular hydrogen is reacted with the oxygen from the oxygen-carrier material to form water, such that the oxygen-carrier material enters the dehydrogenation zone in the oxygen-rich state and exits the dehydrogenation zone in the semi-oxygen-rich state; and wherein the dehydrogenation zone is positioned within the moving bed reactor, and wherein the combustion zone, the oxygen treatment zone, or both, are positioned within the moving bed reactor.86325-WO-PCT / DOW 86325 WO24

[0077] Aspect 2. The method of aspect 1, wherein the combustion zone is positioned in the moving bed reactor, downstream of the dehydrogenation zone, relative to the general direction of flow of the particulate solid.

[0078] Aspect 3. The method of either of aspects 1 or 2. wherein the oxygen treatment zone is positioned in the moving bed reactor, upstream of the dehydrogenation zone, relative to the general direction of flow of the particulate solid.

[0079] Aspect 4. The method of any one of aspects 1 to 3, wherein both the combustion zone and the oxygen treatment zone are positioned in the moving bed reactor.

[0080] Aspect 5. The method of any one of aspects 1 to 4, wherein the feed stream and the particulate solid are in co-current flow relative to one another in the dehydrogenation zone.

[0081] Aspect 6. The method of any one of aspects 1 to 4, wherein the feed stream and the particulate solid are in counter-current flow relative to one another in the dehydrogenation zone.

[0082] Aspect 7. The method of any one of aspects 1 to 6, wherein the supplemental fuel and the particulate solid are in counter-current flow relative to one another in the oxygen treatment zone.

[0083] Aspect 8. The method of any one of aspects 1 to 7, wherein the particulate solid moves downward through the moving bed reactor under the force of gravity and is not fluidized.

[0084] Aspect 9. The method of any one of aspects 1 to 8, wherein the oxygen-carrier material comprises one or more reducible metal oxides.

[0085] Aspect 10. The method of any one of aspects 1 to 9. wherein the particulate solid further comprises one or more alkali earth metals, one or more alkaline earth metals, or both.

[0086] Aspect 11. The method of any one of aspects 1 to 10, wherein the particulate solid exhibits Geldart D properties in the moving bed reactor.

[0087] Aspect 12. The method of any one of aspects 1 to 11, wherein the particulate solid further comprises a dehydrogenation catalyst.

[0088] Aspect 13. The method of any one of aspects 1 to 12, wherein the oxygen is passed to the oxygen treatment zone in an oxygen containing gas.

[0089] Aspect 14. The method of any one of aspects 1 to 13, wherein the supplemental fuel comprises hydrogen or a hydrocarbon gas.86325-WO-PCT / DOW 86325 WO25

[0090] Aspect 15. The method of any one of aspects 1 to 14, wherein the one or more hydrocarbons comprise ethane and the one or more products comprise ethylene.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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 examples86325-WO-PCT / DOW 86325 WO26supply compositional ranges for various streams, and that the total amount of isomers of a particular chemical composition can constitute a range.

[0096] 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.’’

[0097] In some embodiments, chemicals or chemical streams are described as “passing” from one system unit or portion of a system unit to another. As described herein, such passing may include direct passing or indirect passing. For example, when passing from “unit A” to “unit B”, direct passing has no intermediate destination between unit A and unit B (i.e., directly through a pipe or other transport passage), and indirect passing may include one or more intermediate destinations between unit A and unit B. For example, a stream passing from unit A to unit B may passed through, without limitation, a heat exchanger, treatment device, etc.

[0098] 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.

Claims

86325-WO-PCT / DOW 86325 WO27CLAIMS1. A method for dehydrogenating hydrocarbons, the method comprising:passing supplemental fuel, a feed stream comprising one or more hydrocarbons, and a particulate solid comprising an oxygen-carrier material into a reaction system comprising a moving bed reactor, wherein:the reaction system comprises a combustion zone, an oxygen treatment zone, and a dehydrogenation zone,the particulate solid enters the combustion zone, then is passed to the oxygen treatment zone, and then is passed to the dehydrogenation zone;the supplemental fuel enters the combustion zone, wherein, in the combustion zone, the supplemental fuel is combusted with oxygen from the oxygen-carrier material such that the oxygen-carrier material enters the combustion zone in a semi- oxygen-rich state and exits the combustion zone in an oxygen-depleted state;oxygen is passed to the oxygen treatment zone, wherein the particulate solid enters the oxygen treatment zone in the oxygen-depleted state, is contacted by the oxygen, and exits the oxygen treatment zone in an oxygen-rich state;the feed stream enters the dehydrogenation zone, wherein, in the dehydrogenation zone, the one or more hydrocarbons of the feed stream are dehydrogenated to form molecular hydrogen and one or more products, and at least a portion of the molecular hydrogen is reacted with the oxygen from the oxygen-carrier material to form water, such that the oxygen-carrier material enters the dehydrogenation zone in the oxygen-rich state and exits the dehydrogenation zone in the semi-oxygen-rich state; andwherein the dehydrogenation zone is positioned within the moving bed reactor, and wherein the combustion zone, the oxy gen treatment zone, or both, are positioned within the moving bed reactor.

2. The method of claim 1, wherein the combustion zone is positioned in the moving bed reactor, downstream of the dehydrogenation zone, relative to the general direction of flow of the particulate solid.86325-WO-PCT / DOW 86325 WO283. The method of either of claims 1 or 2, wherein the oxygen treatment zone is positioned in the moving bed reactor, upstream of the dehydrogenation zone, relative to the general direction of flow of the particulate solid.

4. The method of any one of claims 1 to 3, wherein both the combustion zone and the oxygen treatment zone are positioned in the moving bed reactor.

5. The method of any one of claims 1 to 4, wherein the feed stream and the particulate solid are in co-current flow relative to one another in the dehydrogenation zone.

6. The method of any one of claims 1 to 4, wherein the feed stream and the particulate solid are in counter-current flow relative to one another in the dehydrogenation zone.

7. The method of any one of claims 1 to 6, wherein the supplemental fuel and the particulate solid are in counter-current flow relative to one another in the oxygen treatment zone.

8. The method of any one of claims 1 to 7. wherein the particulate solid moves downward through the moving bed reactor under the force of gravity and is not fluidized.

9. The method of any one of claims 1 to 8, wherein the oxygen-carrier material comprises one or more reducible metal oxides.

10. The method of any one of claims 1 to 9, wherein the particulate solid further comprises one or more alkali earth metals, one or more alkaline earth metals, or both.

11. The method of any one of claims 1 to 10, wherein the particulate solid exhibits Geldart D properties in the moving bed reactor.

12. The method of any one of claims 1 to 11, wherein the particulate solid further comprises a dehydrogenation catalyst.86325-WO-PCT / DOW 86325 WO2913. The method of any one of claims 1 to 12, wherein the oxygen is passed to the oxygen treatment zone in an oxygen containing gas.

14. The method of any one of claims 1 to 13, wherein the supplemental fuel comprises hydrogen or a hydrocarbon gas.

15. The method of any one of claims 1 to 14, wherein the one or more hydrocarbons comprise ethane and the one or more products comprise ethylene.

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