Hydrogen and nitrogen generation using chemical looping schemes

Abstract

Exemplary methods, systems, and techniques relate to generating nitrogen (N2), hydrogen (H2), and carbon dioxide (CO2). Certain embodiments of the instant disclosure include 3-reactor chemical looping systems that utilize biomass as a carbonaceous fuel to generate hydrogen. Certain embodiments on the instant disclosure may utilize nitrogen from depleted air or oxygen-free air from a combustor reactor. Generated nitrogen and hydrogen in an adjustable ratio may be sent to the Haber Bosch process for the formation of ammonia.

Description

Attorney Docket No. 029784-0010-WO01 HYDROGEN AND NITROGEN GENERATION USING CHEMICAL LOOPING SCHEMES CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No.63 / 569,521, filed on March 25, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure generally relates to production of nitrogen (N2), hydrogen (H2), and carbon dioxide (CO2) using chemical looping systems. Exemplary methods and operating strategies may be particularly suited for using carbonaceous fuel, such as biomass. INTRODUCTION

[0003] Rising global temperatures have caused increased concern among various industries about their carbon footprint. The majority of industries have traditionally relied on fossil fuels as their primary source of energy, which results in the emission of carbon dioxide, a greenhouse gas. Hence, there is a need to shift towards technologies that can minimize carbon emissions. Carbon- emitting industries need to take steps towards decarbonization to meet the net zero carbon emission goal by 2050. The ammonia industry is an industry that contributes significantly to carbon dioxide emissions, with an estimated emission of 500 million tons. Ammonia is a commodity chemical that serves as a feedstock for inorganic fertilizers and finds applications in refrigeration, food processing, pharmaceuticals, and textiles. Decarbonizing the ammonia industry would help reach the net zero carbon emission goal.

[0004] Ammonia (NH3) is produced by reacting hydrogen (H2), produced through steam methane reforming (SMR), with nitrogen (N2), obtained from an air separation unit (ASU), in a 3:1 ratio. This reaction takes place catalytically at high temperatures (350-500 °C) and pressures (150-300 bar) to form ammonia (NH3) through the Haber Bosch process. The primary source of carbon emissions in this process is the production of hydrogen, which occurs through SMR that utilizes fossil fuels such as coal or natural gas, leading to carbon dioxide emission as a by-product. The other major component involved in ammonia production is the sourcing of N2, which is MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 traditionally done using an air separation unit (ASU). This process is highly energy-intensive and serves as one of the major capital-intensive steps of the ammonia production process. SUMMARY

[0005] In one aspect, a method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, and a combustor reactor is disclosed. The example method may comprise: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O) and air or nitrogen (N2); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O); providing the partially oxidized oxygen carrier particles to the combustor reactor; providing an air stream to the combustor reactor, thereby generating the oxidized oxygen carrier particles and oxygen-depleted air; collecting a combustor output stream from the combustor reactor, the combustor output stream comprising oxygen- depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the combustor reactor to the reducer reactor.

[0006] In another aspect, a reactor system is disclosed. An example reactor system may comprise: a reducer reactor comprising: a reducer reactor fuel inlet in fluid communication with a carbonaceous fuel source; a reducer reactor solids inlet configured to receive oxidized oxygen carrier particles, whereby oxidized oxygen carrier particles react with the carbonaceous fuel in the reducer reactor and generate carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles; a reducer reactor solids outlet configured to discharge reduced oxygen carrier particles; a reducer reactor gas outlet configured to provide a reducer reactor output stream comprising 2 MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 carbon dioxide (CO2) and steam (H2O), the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; an oxidizer reactor comprising: an oxidizer reactor gas inlet in fluid communication with a steam source and either a depleted air source or a nitrogen (N2) source; an oxidizer reactor solids inlet in fluid communication with the reducer reactor solids outlet and configured to receive reduced oxygen carrier particles, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles; a oxidizer reactor gas outlet configured to discharge an oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O), wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 2.5:1 and 3.5:1; an oxidizer reactor solids outlet configured to provide partially oxidized oxygen carrier particles; a combustor reactor configured to generate oxidized oxygen carrier particles and oxygen- depleted air, the combustor reactor comprising: a combustor reactor solids inlet in fluid communication with the oxidizer reactor solids outlet; a combustor reactor gas inlet in fluid communication with an air source; a combustor reactor gas outlet configured to provide a depleted air stream; and a combustor reactor solids outlet configured to provide oxidized oxygen carrier particles.

[0007] A method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, a moving bed combustor reactor, and a fluidized bed combustor reactor is also disclosed. The example method may comprise: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2); providing the partially oxidized oxygen carrier particles to the moving bed combustor reactor; providing an air stream to the moving bed combustor reactor, MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 thereby generating nitrogen (N2); collecting nitrogen (N2) from the moving bed combustor reactor; combining the nitrogen (N2) from the moving bed combustor reactor with the hydrogen (H2)from the oxidizer reactor output stream such that a molar ratio of hydrogen (H2) to nitrogen (N2) is between 2.5:1 and 3.5:1; providing partially oxidized oxygen carrier particles from the moving bed combustor to the fluidized bed combustor; providing an air stream to the fluidized bed combustor reactor, thereby generating oxygen-depleted air and the oxidized oxygen carrier particles; collecting a fluidized bed combustor output stream from the fluidized bed combustor reactor, the fluidized bed combustor output stream comprising oxygen-depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the fluidized bed combustor reactor to the reducer reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG.1 schematically illustrates an exemplary reactor system.

[0009] FIG.2 schematically illustrates another exemplary reactor system.

[0010] FIG.3 schematically illustrates another exemplary reactor system.

[0011] FIG.4 schematically illustrates another exemplary reactor system.

[0012] FIG.5 schematically illustrates another exemplary reactor system.

[0013] FIG.6 schematically illustrates another exemplary reactor system.

[0014] FIG.7 is a schematic illustration of an exemplary method of operation.

[0015] FIG.8 is a graph showing dry purity of carbon dioxide (CO2) experimentally generated from an exemplary reducer reactor.

[0016] FIG. 9 is a graph showing output gases (hydrogen (H2) and oxygen (O2)) experimentally generated from an exemplary oxidizer reactor.

[0017] FIG.10 schematically illustrates a system used for computational simulations. DETAILED DESCRIPTION

[0018] The present disclosure relates to methods, systems, and techniques for generating nitrogen (N2), hydrogen (H2), and carbon dioxide (CO2). The present disclosure may address challenges related to carbon emissions and the high energy intensity of ammonia production. In a conventional ammonia production process, hydrogen is generated through steam methane reforming and nitrogen may be obtained from an air separation unit. However, certain MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 embodiments of the instant disclosure include 3-reactor chemical looping systems that utilize biomass as a carbonaceous fuel to generate hydrogen. Certain embodiments on the instant disclosure may utilize nitrogen from depleted air or oxygen-free air from a combustor reactor. The nitrogen and hydrogen in an adjustable ratio may then be sent to the Haber Bosch process for the formation of ammonia. I. Definitions

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0020] The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of” and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.

[0021] For the recitation of numeric ranges herein, each intervening number therebetween with the same degree of precision is contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the numbers 6.0, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are contemplated. For another example, when a pressure range is described as being between ambient pressure and another pressure, a pressure that is ambient pressure is expressly contemplated.

[0022] Definitions of specific functional groups and chemical terms are described in more detail below. For purposes of this disclosure, the chemical elements are identified in accordance with the Periodic Table of the Elements, CAS version, Handbook of Chemistry and Physics, 75thEd., inside cover, and specific functional groups are generally defined as described therein. Additionally, general principles of organic chemistry, as well as specific functional moieties and MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 reactivity, are described in Organic Chemistry, Thomas Sorrell, University Science Books, Sausalito, 1999; Smith and March March's Advanced Organic Chemistry, 5thEdition, John Wiley & Sons, Inc., New York, 2001; Larock, Comprehensive Organic Transformations, VCH Publishers, Inc., New York, 1989; Carruthers, Some Modern Methods of Organic Synthesis, 3rdEdition, Cambridge University Press, Cambridge, 1987; the entire contents of each of which are incorporated herein by reference.

[0023] As used herein, the term “fluidized bed reactor” means a reactor where fluid is passed through catalyst material at a sufficient speed to suspend the solid catalyst material. Typically, oxygen carrier solids may move in any direction, bounded by the walls of the reactor.

[0024] As used herein, the term “fixed bed reactor” means defined as a reactor where catalyst material is fixed in a packed bed. Fluid is passed through catalyst material, but the fluid does not suspend the catalyst material, as in a fluidized bed reactor.

[0025] As used herein, the term “moving bed reactor” means a reactor where catalytic material flows in a single direction, generally, from top to bottom. The fluid material can flow in the same direction as the catalytic material (co-current movement). The fluid material can flow in an opposite direction as the catalytic material (countercurrent movement). II. Exemplary Materials

[0026] Exemplary systems, methods and techniques disclosed and contemplated herein may use and generate various materials, such as oxygen carrier particles, carbonaceous fuel streams, oxidizer reactor input streams, air streams, reducer reactor output streams, oxidizer reactor output streams, and combustor output streams. Various aspects of each are described below. A. Exemplary Oxygen Carrier Particles

[0027] Exemplary oxygen carrier particles may comprise support material and transition metal oxides. Exemplary oxygen carrier particles may further comprise dopants. Exemplary oxygen carrier particles may comprise either a single phase or a mixture of phases.

[0028] Exemplary transition metal oxides may comprise iron oxide (Fe2O3), copper oxide (CuO), manganese oxide (Mn2O3), cobalt oxide (Co3O4), calcium iron oxides (Ca2Fe2O5), or combinations thereof. These exemplary transition metal oxides possess high oxygen-carrying MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 capacity and good reactivity when compared to other transition metal oxides.

[0029] Exemplary support material may increase the recyclability and strength of exemplary oxygen carrier particles. Exemplary support material may include SiC and / or oxides of lithium (Li), beryllium (Be), boron (B), sodium (Na), magnesium (Mg), aluminum (Al), silicon (Si), potassium (K), calcium (Ca), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), zinc (Zn), gallium (Ga), germanium (Ge), rubidium (Rb), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), cadmium (Cd), indium (In), tin (Sn), antimony (Sb), cesium (Cs), barium (Ba), lanthanum (La), cerium (Ce), thorium (Th), or combinations thereof. In some instances, exemplary support material may include SiO2, MgO, Al2O3, TiO2, SiC, or a combination that comprises two or more of the support materials.

[0030] Exemplary oxygen carrier particles may further comprise dopants. Exemplary dopants may be nickel (Ni), cobalt (Co), copper (Cu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), or gold (Au). Exemplary dopants may provide active sites on the transition metal oxide surface for adsorption of the reducing gas molecule along with the creation of vacancies in the transition metal oxide lattice.

[0031] Exemplary oxygen carrier particles may have various sizes. Exemplary oxygen carrier particles may be characterized in terms of DV90 sizes. In some implementations, exemplary oxygen carrier particles may comprise DV90 sizes between 0.1 mm and 2 mm. In various instances, exemplary oxygen carrier particles may comprise DV90 sizes between 0.1 mm and 2 mm; 0.5 mm and 2 mm; 1 mm and 2 mm; 1.5 mm and 2 mm; 0.1 mm and 1.5 mm; 0.1 mm and 1 mm; or 0.1 mm and 0.5 mm. In various instances, exemplary oxygen carrier particles may comprise DV90 sizes no less than 0.1 mm; no less than 0.2 mm; no less than 0.4 mm; no less than 0.6 mm; no less than 0.8 mm; no less than 1.0 mm; no less than 1.2 mm; no less than 1.4 mm; no less than 1.6 mm; no less than 1.8 mm; or no less than 2 mm. In various instances, exemplary oxygen carrier particles may comprise DV90 sizes no greater than 2 mm; no greater than 1.8 mm; no greater than 1.6 mm; no greater than 1.4 mm; no greater than 1.2 mm; no greater than 1 mm; no greater than 0.8 mm; no greater than 0.6 mm; no greater than 0.4 mm; no greater than 0.2 mm; or no greater than 0.1 MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 mm.

[0032] At various stages in exemplary processes, oxygen carrier particles may have various degrees of reduction or oxidation. The degree of reduction for oxygen carrier particles is represented by the ratio of the amount of lattice oxygen lost from oxygen carrier particles to theinitial amount of lattice oxygen present in the oxygen carrier particles, as shown inDegree of Reduction100 (1)

[0033] A higher degree of reduction indicates a more reduced state of oxygen carrier particles. For example, when the oxygen carrier particles comprise Fe2O3, a 0% degree of reduction corresponds to a fully oxidized state (Fe2O3), while a 100% degree of reduction corresponds to a fully reduced state (metallic Fe).

[0034] Without being bound by theory, limiting the degree of reduction to a maximum of 50% may improve recyclability of oxygen carrier particles.

[0035] In various implementations, exemplary oxygen carrier particles provided from a reducer reactor to an oxidizer reactor may have a degree of reduction between 11% and 50%. In various instances, exemplary oxygen carrier particles provided from a reducer reactor to an oxidizer reactor may have a degree of reduction between 11% and 50%; 15% and 50%; 20% and 50%; 25% and 50%; 30% and 50%; 35% and 50%; 40% and 50%; 45% and 50%; 11% and 45%; 11% and 40%; 11% and 35%; 11% and 30%; 11% and 25%; 11% and 20%; or 11% and 15%. In various instances, exemplary oxygen carrier particles provided from a reducer reactor to an oxidizer reactor may have a degree of reduction no less than 11%; no less than 15%; no less than 20%; no less than 25%; no less than 30%; no less than 35%; no less than 40%; no less than 45%; or no less than 50%. In various instances, exemplary oxygen carrier particles provided from a reducer reactor to an oxidizer reactor may have a degree of reduction no greater than 50%; no greater than 45%; no greater than 40%; no greater than 35%; no greater than 30%; no greater than 25%; no greater than 20%; no greater than 15%; or no greater than 11%.

[0036] At various locations throughout exemplary systems, oxygen carrier particles may be described as being “reduced oxygen carrier particles,” “partially oxidized oxygen carrier particles,” or “oxidized oxygen carrier particles.” In general, oxygen carrier particles possess more oxygen atoms when oxidized and fewer oxygen atoms when reduced. Further, reduced oxygen carrier particles, partially oxidized oxygen carrier particles, and oxidized oxygen carrier particles may be described by their degree of reduction as discussed in greater detail above. Exemplary MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 “partially oxidized oxygen carrier particles” may be construed as oxygen carrier particles that are not completely oxidized. Exemplary “partially oxidized oxygen carrier particles” may be construed as a plurality of particles where some oxygen carrier particles are oxidized, and some oxygen carrier particles are in a reduced state. B. Exemplary Input Gas Streams

[0037] Exemplary methods utilize various input gas streams, such as carbonaceous fuel streams, oxidizer reactor input streams, and air streams.

[0038] Exemplary carbonaceous fuel streams may comprise biomass, municipal solid waste, plastics, petroleum products, or methane.

[0039] Exemplary oxidizer reactor input streams comprise steam (H2O). In some instances, exemplary oxidizer reactor input streams may comprise air in addition to steam (H2O). In some instances, the air may be oxygen-depleted air. In some instances, exemplary oxidizer reactor input streams may comprise nitrogen (N2) in addition to steam (H2O).

[0040] Exemplary oxygen-depleted air may comprise nitrogen (N2) and less than 21 mol% oxygen (O2). In various instances, exemplary oxygen-depleted air may comprise oxygen (O2) at an amount between 0 mol% and 21 mol%; 5 mol% and 21 mol%; 10 mol% and 21 mol%; 15 mol% and 21 mol%; 20 mol% and 21 mol%; 0 mol% and 20 mol%; 0 mol% and 15 mol%; 0 mol% and 10 mol%; or 0 mol% and 5 mol%. In various instances, exemplary oxygen-depleted air may comprise oxygen (O2) at an amount no less than 0 mol%; no less than 5 mol%; no less than 10 mol%; no less than 15 mol%; no less than 20 mol%; or no less than 21 mol%. In various instances, exemplary oxygen-depleted air may comprise oxygen (O2) at an amount no greater than 21 mol%; no greater than 20 mol%; no greater than 15 mol%; no greater than 10 mol%; no greater than 5 mol%; or no greater than 0 mol%.

[0041] When used, exemplary air streams provided to a combustor reactor may comprisenitrogen (N2), oxygen (O2), and argon (Ar).C. Exemplary Output Gas Streams

[0042] Exemplary methods generate various output gas streams, such as reducer reactor output gas streams, oxidizer reactor output streams, and combustor reactor output streams. Various MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 aspects of each are discussed below.

[0043] Exemplary reducer reactor output gas streams may comprise carbon dioxide (CO2) and steam (H2O).

[0044] Exemplary reducer reactor output gas streams may comprise carbon dioxide (CO2) with a dry purity of at least 90 mol%. Dry purity is defined as the amount of carbon dioxide (CO2) in the stream, without including steam (H2O). In various instances, exemplary reducer reactor output gas streams may comprise CO2with a dry purity between 90 mol% and 99.99 mol%; 92 mol% and 99.99 mol%; 94 mol% and 99.99 mol%; 96 mol% and 99.99 mol%; 98 mol% and 99.99 mol%; 90 mol% and 98 mol%; 90 mol% and 96 mol%; 90 mol% and 94 mol%; or 90 mol% and 92 mol%. In various instances, exemplary reducer reactor output gas streams may comprise CO2with a dry purity of no less than 90 mol%; no less than 91 mol%; no less than 92 mol%; no less than 93 mol%; no less than 94 mol%; no less than 95 mol%; no less than 96 mol%; no less than 97 mol%; no less than 98 mol%; no less than 99 mol%; or no less than 99.99 mol%. In various instances, exemplary reducer reactor output gas streams may comprise CO2with a dry purity of no greater than 99.99 mol%; no greater than 99 mol%; no greater than 98 mol%; no greater than 97 mol%; no greater than 96 mol%; no greater than 95 mol%; no greater than 94 mol%; no greater than 93 mol%; no greater than 92 mol%; no greater than 91 mol%; or no greater than 90 mol%.

[0045] Exemplary oxidizer reactor output streams may comprise hydrogen (H2) and nitrogen (N2). In some implementations oxidizer reactor output streams may additionally comprise steam (H2O).

[0046] Exemplary oxidizer reactor output streams may comprise a molar ratio of hydrogen (H2) to nitrogen (N2) between 1.5:1 and 4.0:1. In various instances, exemplary oxidizer reactor output streams may comprise a molar ratio of hydrogen (H2) to nitrogen (N2) between 1.5:1 and 4:1; 1.6:1 and 4:1; 1.8:1 and 4:1; 2.0:1 and 4:1; 2.2:1 and 4:1; 2.5:1 and 3.5:1; 2.6:1 and 4:1; 2.8:1 and 4:1; 3.0:1 and 4:1; 1.5:1 and 3.8:1; 1.5:1 and 3.6:1; 1.5:1 and 3.4:1; 1.5:1 and 3.2:1; 1.5:1 and 3.0:1; 2.6:1 and 3.4:1; 2.8:1 and 3.2:1; or 2.9:1 and 3.1:1. In various instances, exemplary oxidizer reactor output streams may comprise a molar ratio of hydrogen (H2) to nitrogen (N2) no less than 1.5:1; no less than 1.6:1; no less than 1.8:1; no less than 2.0:1; no less than 2.2:1; no less than 2.4:1; no less than 2.6:1; no less than 2.8:1; no less than 3.0:1; no less than 3.2:1; no less than 3.4:1; no less than 3.6:1; no less than 3.8:1; or no less than 4:1. In various instances, exemplary oxidizer reactor output streams may comprise a molar ratio of hydrogen (H2) to nitrogen (N2) no MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 greater than 4.0:1; no greater than 3.8:1; no greater than 3.6:1; no greater than 3.4:1; no greater than 3.2:1; no greater than 3.0:1; no greater than 2.8:1; no greater than 2.6:1; no greater than 2.4:1; no greater than 2.2:1; no greater than 2.0:1; no greater than 1.8:1; no greater than 1.6:1; or no greater than 1.5:1.

[0047] Exemplary combustor output streams may comprise oxygen-depleted air. Oxygen- depleted air is described in greater detail above. III. Exemplary Systems

[0048] Various systems for processing carbonaceous fuel and generating hydrogen (H2) and nitrogen (N2) may be used to perform exemplary methods and techniques described herein. Exemplary systems may be configured as reactor systems comprising a reducer reactor, an oxidizer reactor, and one or more combustor reactors. Various reactors in exemplary reactor systems may be configured for co-current and / or countercurrent operations. In various implementations, reactors shown as singular reactors in the figures may comprise two or more reactors of a given type operating in parallel. Various aspects of exemplary reactor systems are described below.

[0049] FIG. 1 schematically depicts an exemplary reactor system 100. System 100 may be particularly suited for processing carbonaceous fuel and generating H2and N2. As shown, exemplary system 100 comprises a hopper unit 110, an oxidized oxygen carrier particle stream 114, a reducer reactor 120, a carbonaceous fuel stream 122, a partially reduced oxygen carrier particle stream 124, a reducer reactor output stream 126, an oxidizer reactor 130, an oxidizer reactor input stream 132, a partially oxidized oxygen carrier particle stream 134, an oxidizer reactor output stream 136, a combustor reactor 140, an air stream 142, an oxidized oxygen carrier particle stream 144, and a combustor reactor output stream 146. Typically, system 100 does not include an air separation unit Optional components and connections are shown in dashed lines. Other embodiments may include more or fewer components.

[0050] Optional hopper unit 110 may receive oxidized oxygen carrier particle stream 144 from combustor reactor 140. Additional details regarding exemplary oxygen carrier particles are provided above. Hopper unit 110 may provide oxidized oxygen carrier particle stream 114 to reducer reactor 120. When used, hopper unit 110 is in communication with combustor reactor 140.

[0051] Exemplary reducer reactor 120 is configured to perform various reactions, such as reacting carbonaceous fuel with oxidized oxygen carrier particles to generate carbon dioxide MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 (CO2), steam (H2O), and reduced oxygen carrier particles. Reducer reactor 120 may be arranged as a fluidized bed reactor, fixed bed reactor, or a moving packed bed reactor. In some implementations, reducer reactor may be arranged as a moving packed bed reactor.

[0052] Reducer reactor 120 receives oxidized oxygen carrier particles from oxidized oxygen carrier particle stream 114 or oxidized oxygen carrier particle stream 144. Oxidized oxygen carrier particles are described in greater detail above. Reducer reactor 120 may include one or more inlets configured to receive solid oxygen carrier particles.

[0053] Reducer reactor 120 receives carbonaceous fuel stream 122. Exemplary carbonaceous fuels are described in greater detail above. Reducer reactor 120 may include one or more inlets configured to receive carbonaceous fuel. The inlets of reducer reactor 120 may be arranged such that the carbonaceous fuel moves counter-currently relative to the oxygen carrier particles.

[0054] Reducer reactor 120 provides reducer reactor output stream 126 comprising carbon dioxide (CO2). Exemplary reducer reactor output streams are described in greater detail above. Reducer reactor 120 may include one or more outlets configured to provide the reducer reactor output stream 126.

[0055] Reducer reactor 120 provides reduced oxygen carrier particle stream 124 to oxidizer reactor 130. Reduced oxygen carrier particles are described in greater detail above.

[0056] Exemplary oxidizer reactor 130 is configured to perform various reactions, such as reacting steam (H2O) with partially reduced oxygen carrier particles. Oxidizer reactor 130 receives partially reduced oxygen carrier particles stream 124 from reducer reactor 120. Oxidizer reactor 130 may be arranged as a fluidized bed reactor, fixed bed reactor, or a moving packed bed reactor. In some implementations, oxidizer reactor 130 may be arranged as a moving packed bed reactor.

[0057] Oxidizer reactor 130 receives oxidized oxygen carrier particles from reduced oxygen carrier particle stream 124. Oxidizer reactor 130 may include one or more inlets configured to receive solid oxygen carrier particles.

[0058] Oxidizer reactor 130 receives oxidizer reactor input stream 132. Oxidizer reactor input stream 132 comprises steam (H2O) and air or nitrogen (N2), and is described in greater detail above. Oxidizer reactor 130 may include one or more inlets configured to receive oxidizer reactor input streams 132. The inlets of oxidizer reactor 130 may be arranged such that oxidizer reactor input streams 132 move counter-currently relative to the oxygen carrier particles.

[0059] Oxidizer reactor 130 provides oxidizer reactor output stream 136 comprising hydrogen MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 (H2) and nitrogen (N2). Exemplary oxidizer reactor output streams 136 are described in greater detail above. Oxidizer reactor 130 may include one or more outlets configured to provide the oxidizer reactor output stream 136.

[0060] Oxidizer reactor 130 provides partially oxidized oxygen carrier particle stream 134 to combustor reactor 140. Partially oxidized oxygen carrier particles are described in greater detail above.

[0061] Exemplary combustor reactor 140 is configured to perform various reactions, such as reacting air with partially oxidized oxygen carrier particles. Combustor reactor 140 may be arranged as a fluidized bed reactor, moving bed reactor, or a moving packed bed reactor. In some implementations, combustor reactor 140 may be arranged as a moving packed bed reactor.

[0062] Combustor reactor 140 receives partially oxidized oxygen carrier particle stream 134 from oxidizer reactor 130. Combustor reactor 140 may include one or more inlets configured to receive solid oxygen carrier particles.

[0063] Combustor reactor 140 also receives air stream 142. Combustor reactor 140 may include one or more inlets configured to receive air streams 142. The inlets of combustor reactor 140 may be arranged such that combustor reactor air streams 142 move co-currently relative to the oxygen carrier particles.

[0064] Combustor reactor 140 provides combustor reactor output stream 146 comprising oxygen-depleted air. Exemplary combustor reactor output streams 146 are described in greater detail above. In some instances, a portion of combustor reactor output stream 146 is provided to oxidizer reactor 130. Combustor reactor 140 may include one or more outlets configured to provide the combustor reactor output stream 146.

[0065] Combustor reactor 140 provides oxidized oxygen carrier particle stream 144 to reducer reactor 120. In some implementations, a riser apparatus or other conveying means, not shown, may be used to convey oxygen carrier particles from combustor reactor 140 to hopper unit 110 or reducer reactor 120.

[0066] In some implementations, system 100 may comprise hopper unit 110. In those instances, combustor reactor 140 may provide oxidized oxygen carrier particle stream 144 to hopper unit 110. When used, hopper unit 110 provides oxidized oxygen carrier particle stream 114 to reducer reactor 120.

[0067] FIG. 2 schematically depicts an embodiment of exemplary system 100 shown in FIG. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 1. Unless otherwise indicated, the system of FIG. 2 includes the same components and configuration as shown in FIG.1.

[0068] The exemplary system of FIG. 2 includes a pot, i.e. hopper, which provides oxidized oxygen carrier particles to a reducer reactor. FIG. 2 schematically depicts providing oxygen- depleted air from the combustor reactor output stream to the oxidizer. In some instances, the oxygen-depleted air may be combined with the oxidizer reactor input stream. In some instances, the oxygen-depleted air may be provided separately to the oxidizer reactor.

[0069] FIG. 3 schematically depicts an embodiment of exemplary system 100 shown in FIG. 1. Unless otherwise indicated, the system of FIG. 3 includes the same components and configuration as shown in FIG.1.

[0070] The system in FIG. 3 uses nitrogen (N2) as a zone-sealing gas. Accordingly, the nitrogen (N2) is provided to the oxidizer reactor. Further, the nitrogen (N2) may be provided to the combustor reactor. Nitrogen (N2) may be selectively provided to the oxidizer reactor to achieve desired hydrogen (H2) to nitrogen (N2) ratios.

[0071] FIG. 4 schematically depicts an embodiment of exemplary system 100 shown in FIG. 1. Unless otherwise indicated, the system of FIG. 4 includes the same components and configuration as shown in FIG.1.

[0072] FIG.4 schematically depicts an additional oxidizer reactor input stream that comprises air. The air stream may react with reduced oxygen carrier particles in the oxidizer reactor, which in turn aids in modulating hydrogen (H2) to nitrogen (N2) ratios.

[0073] FIG. 5 schematically depicts an embodiment of exemplary system 100 shown in FIG. 1. Unless otherwise indicated, the system of FIG. 5 includes the same components and configuration as shown in FIG.1.

[0074] FIG. 5 schematically shows that air or oxygen-depleted air may be used as a zone- sealing gas. Air, or oxygen-depleted air from the combustor, may enter the oxidizer reactor and react with reduced oxygen carrier particles, which in turn aids in modulating hydrogen (H2) to nitrogen (N2) ratios.

[0075] FIG. 6 schematically depicts an embodiment of exemplary system 100 shown in FIG. 1. Unless otherwise indicated, the system of FIG. 6 includes the same components and configuration as shown in FIG.1.

[0076] In the exemplary system of FIG. 6, the oxidizer reactor input stream comprises steam MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 (H2O) and the oxidizer reactor output stream comprises hydrogen (H2). In the exemplary system of FIG. 6, a combustor reactor comprises a moving bed combustor reactor and a fluidized bed combustor reactor. Air and partially oxidized oxygen carrier particles from an oxidizer reactor are provided to a moving bed combustor reactor. A moving bed combustor reactor output stream comprises nitrogen (N2) and may be combined with the oxidizer reactor output stream to achieve various ratios of hydrogen (H2) to nitrogen (N2) as discussed in greater detail above.

[0077] Partially oxidized oxygen carrier particles are provided from the moving bed combustor reactor to the fluidized bed reactor. Air is also provided to the fluidized bed combustor reactor. Depleted air and oxidized oxygen carrier particles are generated in the fluidized bed combustor reactor. IV. Exemplary Methods of Operation

[0078] FIG. 7 schematically depicts exemplary method 200 of operating a reactor system. As shown, exemplary method 200 comprises: providing carbonaceous fuel and oxygen carrier particles to reducer reactor (operation 202), collecting reducer reactor output stream (operation 204), providing reduced oxygen carrier particles to oxidizer reactor (operation 206), providing oxidizer reactor input stream to oxidizer reactor (operation 208), collecting oxidizer reactor output stream (operation 210), providing partially oxidized oxygen carrier particles to combustor reactor (operation 212), providing air stream to combustor reactor (operation 214), collecting combustor out stream (operation 216), and providing oxidized oxygen carrier particles from combustor reactor to reducer reactor (operation 218). Various systems may be used to implement method 200, such as system 100 and the systems shown in FIGS. 2-6. Other embodiments may include more or fewer operations.

[0079] Method 200 may begin by providing a carbonaceous fuel stream to an inlet of a reducer reactor (operation 202). The carbonaceous fuel stream may be provided to a single inlet or multiple inlets of a reducer reactor. The one or more inlets may be physically located on a reactor at a top or upper portion of the reactor, at a side portion or a plurality of side locations, or near a bottom portion.

[0080] As discussed above in greater detail, the carbonaceous fuel stream may comprise biomass, municipal solid waste, plastics, petroleum products, or methane.

[0081] The carbonaceous fuel stream contacts a plurality of oxidized oxygen carrier particles. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 As explained in greater detail above, exemplary oxygen carrier particles comprise a support material and transition metal oxides. The plurality of oxygen carrier particles, after contacting the carbonaceous fuel stream, is partially reduced.

[0082] As discussed above, oxygen carrier particles comprise transition metal oxides. Exemplary weight ratios of transition metal oxide to carbonaceous fuel provided to the reducer reactor may be between 1:2 and 1:47. In various instances, exemplary weight ratios of transition metal oxide to carbonaceous fuel provided to the reducer reactor may be between 1:2 and 1:47; 1:10 and 1:47; 1:20 and 1:47; 1:30 and 1:47; 1:40 and 1:47; 1:2 and 1:40; 1:2 and 1:30; 1:2 and 1:20; or. 1:2 and 1:10. In various instances, exemplary weight ratios of transition metal oxide to carbonaceous fuel provided to the reducer reactor may be no less than 1:47; no less than 1:45; no less than 1:40; no less than 1:35; no less than 1:30; no less than 1:25; no less than 1:20; no less than 1:15; no less than 1:10; no less than 1:5; or no less than 1:2. In various instances, exemplary weight ratios of transition metal oxide to carbonaceous fuel provided to the reducer reactor may be no greater than 1:2; no greater than 1:5; no greater than 1:10; no greater than 1:15; no greater than 1:20; no greater than 1:25; no greater than 1:30; no greater than 1:35; no greater than 1:40; no greater than 1:45; or no greater than 1:47.

[0083] After the carbonaceous fuel stream contacts oxygen carrier particles, method 200 includes collecting a reducer reactor output stream from an outlet of the reducer reactor (operation 204). The reducer reactor output stream may comprise carbon dioxide (CO2) and steam (H2O). The carbon dioxide (CO2) may be collected for sequestration. Additional details regarding exemplary reducer reactor output streams are provided above.

[0084] An exemplary method may comprise providing reduced oxygen carrier particles to an oxidizer reactor (operation 206).

[0085] An exemplary method may comprise providing an oxidizer reactor input stream to an inlet of an oxidizer reactor (operation 208). The oxidizer reactor input stream may be provided to a single inlet or multiple inlets. The inlets may be physically located on a reactor at a top or upper portion of the reactor, at a side portion or a plurality of side locations, or near a bottom portion.

[0086] As discussed above in the Exemplary Materials section, the oxidizer reactor input stream may comprise steam (H2O). In some instances, the oxidizer reactor input stream may comprise nitrogen (N2) and steam (H2O). In some instances, the oxidizer reactor input stream may MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 comprise air and steam (H2O).

[0087] Exemplary weight ratios of transition metal oxide to steam (H2O) provided to the oxidizer reactor may be between 1:20 and 1:100. In various instances, exemplary weight ratios of transition metal oxide to steam (H2O) may be between 1:20 and 1:100; 1:40 and 1:100; 1:60 and 1:100; 1:80 and 1:100; 1:20 and 1:80; 1:20 and 1:60; or 1:20 and 1:40. In various instances, exemplary weight ratios of transition metal oxide to steam (H2O) may be no less than 1:100; no less than 1:90; no less than 1:80; no less than 1:70; no less than 1:60; no less than 1:50; no less than 1:40; no less than 1:30; or no less than 1:20. In various instances, exemplary weight ratios of transition metal oxide to steam (H2O) may be no greater than 1:20; no greater than 1:30; no greater than 1:40; no greater than 1:50; no greater than 1:60; no greater than 1:70; no greater than 1:80; no greater than 1:90; or no greater than 1:100.

[0088]

[0089] An exemplary method may use a zone-sealing gas input to modulate the output ratio for hydrogen (H2) to nitrogen (N2). An exemplary zone-sealing gas may be nitrogen (N2) or air.

[0090] Zone-sealing gas may be injected in the standpipe region between the oxidizer and the combustor reactors. The exemplary zone-sealing gas may be split into two streams, each entering one of the two reactors. By controlling the amount and the split of zone sealing gas, a gaseous mixture of nitrogen (N2) and hydrogen (H2) in a desired ratio may be produced. A split may be controlled by adjusting the length of the standpipe or by adjusting the location of the gas inlet based on the pressure balance across the reactor system.

[0091] The oxidizer reactor input stream contacts a plurality of partially reduced oxygen carrier particles to generate a plurality of partially oxidized oxygen carrier particles and an oxidizer reactor output stream.

[0092] An exemplary method includes collecting an oxidizer reactor output stream from an outlet of the oxidizer reactor (operation 210). The oxidizer reactor output stream may comprise hydrogen (H2), nitrogen (N2), and steam (H2O). The hydrogen (H2) and nitrogen (N2) may be collected for ammonia production. Additional details regarding exemplary oxidizer reactor output streams are provided above.

[0093] An exemplary method may continue by providing partially oxidized oxygen carrier particles to a combustor reactor (operation 212).

[0094] An exemplary method may continue by providing an air stream to an inlet of a MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 combustor reactor (operation 214). The air stream may be provided to a single inlet or multiple inlets. The inlets may be physically located on a reactor at a top or upper portion of the reactor, at a side portion or a plurality of side locations, or near a bottom portion.

[0095] As discussed above in the Exemplary Materials section, the air stream may comprise air, oxygen (O2), gaseous mixtures with oxygen (O2), or combinations thereof.

[0096] The air stream contacts a plurality of partially oxidized oxygen carrier particles in the combustor reactor. The plurality of oxygen carrier particles, after contacting the air stream, are further oxidized.

[0097] Exemplary weight ratios of transition metal oxide to air provided to the combustor reactor may be between 1:20 and 1:100. In various instances, exemplary weight ratios of transition metal oxide to air may be between 1:20 and 1:100; 1:40 and 1:100; 1:60 and 1:100; 1:80 and 1:100; 1:20 and 1:80; 1:20 and 1:60; or 1:20 and 1:40. In various instances, exemplary weight ratios of transition metal oxide to air may be no less than 1:100; no less than 1:90; no less than 1:80; no less than 1:70; no less than 1:60; no less than 1:50; no less than 1:40; no less than 1:30; or no less than 1:20. In various instances, exemplary weight ratios of transition metal oxide to air may be no greater than 1:20; no greater than 1:30; no greater than 1:40; no greater than 1:50; no greater than 1:60; no greater than 1:70; no greater than 1:80; no greater than 1:90; or no greater than 1:100.

[0098] After the air stream contacts oxygen carrier particles, an exemplary method includes collecting a combustor reactor output stream from an outlet of the combustor (operation 216). The combustor reactor output stream may comprise oxygen-depleted air. Additional details regarding exemplary combustor reactor output streams are provided above. The oxygen-depleted air may be recycled for use in the oxidizer reactor. The oxidized oxygen particles may be provided to the reducer reactor (operation 218).

[0099] An exemplary method for operating a system according to FIG.6 may include some or all operations discussed with reference to method 200 or variations of operations in method 200. For instance, a method may comprise providing an input stream to the oxidizer reactor comprising or consisting of steam. An example method may include collecting an oxidizer reactor output stream comprising mostly, or entirely, hydrogen (H2). Partially oxidized oxygen carrier particles are provided from the oxidizer reactor to a moving bed combustor. An air stream is provided to the moving bed combustor such that the oxygen carrier particles react with air in the moving bed combustor reactor. An example method includes collecting a moving bed combustor output stream MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 comprising mostly or entirely nitrogen (N2). An example method may include combining the oxidizer reactor output stream and the moving bed combustor output stream to obtain a desired H2:N2ratio.

[0100] An example method for operating a system such as shown in FIG.6 includes providing the oxygen carrier particles and an air stream to a fluidized bed combustor reactor. The oxygen carrier particles react with air in the fluidized bed combustor reactor and generate depleted air and oxidized oxygen carrier particles. An example method includes collecting a depleted air stream from the fluidized bed combustor reactor and providing oxidized oxygen carrier particles from the fluidized bed combustor to a reducer reactor or pot / hopper.

[0101] Reducer reactor operating temperatures may be between 700 °C and 1050 °C. In various instances, reducer reactor operating temperatures may be between 700 °C and 1050 °C; 800 °C and 1050 °C; 900 °C and 1050 °C; 1000 °C and 1050 °C; 700 °C and 950 °C; 700 °C and 850 °C; or 700 °C and 750 °C. In various instances, reducer reactor operating temperatures may be no less than 700 °C; no less than 750 °C; no less than 800 °C; no less than 850 °C; no less than 900 °C; no less than 950 °C; no less than 1000 °C; or no less than 1050 °C. In various instances, reducer reactor operating temperatures may be no greater than 1050 °C; no greater than 1000 °C; no greater than 950 °C; no greater than 900 °C; no greater than 850 °C; no greater than 800 °C; no greater than 750 °C; or no greater than 700 °C.

[0102] Oxidizer reactor operating temperatures may be between 700 °C and 1000 °C. In various instances, oxidizer reactor operating temperatures may be between 700 °C and 1000 °C; 800 °C and 1000 °C; 900 °C and 1000 °C; 700 °C and 900 °C; or 700 °C and 800 °C. In various instances, oxidizer reactor operating temperatures may be no less than 700 °C; no less than 750 °C; no less than 800 °C; no less than 850 °C; no less than 900 °C; no less than 950 °C; or no less than 1000 °C. In various instances, oxidizer reactor operating temperatures may be no greater than 1000 °C; no greater than 950 °C; no greater than 900 °C; no greater than 850 °C; no greater than 800 °C; no greater than 750 °C; or no greater than 700 °C.

[0103] Combustor reactor operating temperatures may be between 500 °C and 1100 °C. In various instances, combustor reactor operating temperatures may be between 500 °C and 1100 °C; 600 °C and 1100 °C; 700 °C and 1100 °C; 800 °C and 1100 °C; 900 °C and 1100 °C; 1000 °C and 1100 °C; 500 °C and 1000 °C; 500 °C and 900 °C; 500 °C and 800 °C; 500 °C and 700 °C; or 500 °C and 600 °C. In various instances, combustor reactor operating temperatures may be no less than MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 500 °C; no less than 600 °C; no less than 700 °C; no less than 800 °C; no less than 900 °C; no less than 1000 °C; or no less than 1100 °C. In various instances, combustor reactor operating temperatures may be no greater than 1100 °C; no greater than 1000 °C; no greater than 900 °C; no greater than 800 °C; no greater than 700 °C; no greater than 600 °C; or no greater than 500 °C.

[0104] Reducer reactor, oxidizer reactor, and combustor reactor operating pressures may be between 0.1 MPa and 5 MPa. In various instances, reducer reactor, oxidizer reactor, and combustor reactor operating pressures may be between 0.1 MPa and 5 MPa; 1 MPa and 5 MPa; 2 MPa and 5 MPa; 3 MPa and 5 MPa; 4 MPa and 5 MPa; 0.1 MPa and 4 MPa; 0.1 MPa and 3 MPa; 0.1 MPa and 2 MPa; or 0.1 MPa and 1 MPa. In various instances, reducer reactor, oxidizer reactor, and combustor reactor operating pressures may be no less than 0.1 MPa; no less than 0.2 MPa; no less than 0.3 MPa; no less than 0.4 MPa; no less than 0.5 MPa; no less than 0.6 MPa; no less than 0.7 MPa; no less than 0.8 MPa; no less than 0.9 MPa; no less than 1 MPa; no less than 2 MPa; no less than 3 MPa; no less than 4 MPa; or no less than 5 MPa. In various instances, reducer reactor, oxidizer reactor, and combustor reactor operating pressures may be no greater than 5 MPa; no greater than 4 MPa; no greater than 3 MPa; no greater than 2 MPa; no greater than 1 MPa; no greater than 0.9 MPa; no greater than 0.8 MPa; no greater than 0.7 MPa; no greater than 0.6 MPa; no greater than 0.5 MPa; no greater than 0.4 MPa; no greater than 0.3 MPa; no greater than 0.2 MPa; or no greater than 0.1 MPa.

[0105] V. Experimental and Computational Data

[0106] Exemplary experimental and computational examples were generated, and the results are discussed below. A. Experimental Setup

[0107] Experiments were conducted using a moving bed reducer reactor which can be modified for co-current and countercurrent operations. The fuel injection port was configured to achieve a middle injection configuration. The reducer reactor housed eight type-K thermocouples and an equal number of sampling ports spaced 10 cm apart. The sampling ports were positioned 180 degrees opposite the thermocouple ports. The reducer reactor’s external surface was equipped with clamshell heaters, allowing for an operating temperature range of 700 °C to 1050 °C with a MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 setpoint tolerance of ± 5 °C. A hopper at the upper section of the unit was used to introduce oxygen carrier particles, and a quartz window above the heated zone ensured that the reaction zone remained completely filled during operation. To regulate solids velocity, a screw feeder connected to a DC motor, which maintained a linear relationship between voltage and flow rate, was located at the bottom of the moving bed reducer reactor.

[0108] The degree of reduction in the reducer reactor was set at 45% for the oxygen carrier particles. The relative mass flow rate of biomass to oxygen carrier particles to the reducer reactor was 1:38.

[0109] Experiments were conducted using a moving bed oxidizer reactor which can be modified for co-current and countercurrent operations. The oxidizer reactor housed eight type-K thermocouples and an equal number of sampling ports spaced 10 cm apart. The sampling ports were positioned 180 degrees opposite the thermocouple ports. The oxidizer reactor’s external surface was equipped with clamshell heaters, allowing for an operating temperature range of 700 °C to 1050 °C with a setpoint tolerance of ± 5 °C. A hopper at the upper section of the unit was used to introduce oxygen carrier particles, and a quartz window above the heated zone ensured that the reaction zone remained completely filled during operation. To regulate solids velocity, a screw feeder connected to a DC motor, which maintained a linear relationship between voltage and flow rate, was located at the bottom of the moving bed reducer reactor.

[0110] B. Experimental Results

[0111] An experiment provided biomass to a moving bed reducer reactor. The carbon dioxide (CO2) purity of the reducer output stream was monitored, and the results over time are shown in FIG. 8. From this experiment, FIG.8 shows greater than 90% dry purity of carbon dioxide (CO2) in the reducer output stream.

[0112] An experiment monitored hydrogen (H2) and oxygen (O2) of an oxidizer output stream. The oxygen carriers from the reducer reactor were collected in a pot attached to the bottom of the reducer reactor. These oxygen carriers were then filled in the oxidizer reactor in a separate experiment, where steam and air were injected into the reactor with a moving bed configuration. FIG.9 shows the hydrogen (H2) and oxygen (O2) profiles from the oxidizer reactor output stream. The balance of wt% of the output stream shown in FIG.9 was nitrogen (N2).

[0113] FIG. 9 shows that a stable hydrogen concentration was achieved. As shown in FIG. 9, MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 the amount of oxygen in the oxidizer reactor output stream was close to zero, indicating that the oxidizer reactor outlet stream can have H2:N2in a desired ratio as well as some unconverted steam (H2O). These experimental results agreed with the simulations discussed in greater detail below, exemplifying the operability of such a system. C. Process Simulations

[0114] A computational version of the reactor system represented in FIG. 2 was simulated using Aspen Plus software. FIG. 10 shows the system for the computational simulations. Tables MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 1-4 show the stream tables from simulations and are broken up for ease of display. Table 1. Reducer Reactor Simulation Inputs

[0115] Table 2 shows the stream table from reducer reactor simulation outputs. As shown, the product gas stream from the reducer outlet predominantly includes CO2and water, with a dry MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 purity of CO2close to 100%. Table 2. Reducer Reactor Simulation OutputsMBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01

[0116] Table 3 shows the stream table from oxidizer reactor simulation outputs. The product gas stream from the oxidizer reactor shows the flow of H2and N2gas in the ratio of 3:1 with water as the by product. Table 3. Oxidizer Reactor Simulation OutputsMBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01

[0117] Table 4 shows the stream table from combustor reactor simulation outputs. The product gas stream from the combustor reactor shows the mixture of O2(3% by volume) and N2(97% by volume) Table 4. Combustor Reactor Simulation Outputs

[0118] For reasons of completeness, various aspects of the technology are set out in the MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 following numbered embodiments. Embodiment 1. A method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, and a combustor reactor, the method comprising: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O) and air or nitrogen (N2); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O); providing the partially oxidized oxygen carrier particles to the combustor reactor; providing an air stream to the combustor reactor, thereby generating the oxidized oxygen carrier particles and oxygen-depleted air; collecting a combustor output stream from the combustor reactor, the combustor output stream comprising oxygen-depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the combustor reactor to the reducer reactor. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 Embodiment 2. The method according to Embodiment 1, further comprising operating the reducer reactor at a temperature between 700 °C and 1050 °C. Embodiment 3. The method, according to Embodiment 1 or Embodiment 2, wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 1.5:1 and 4:1. Embodiment 4. The method according to Embodiment 3, wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 2.8:1 and 3.2:1. Embodiment 5. The method according to any one of Embodiments 1-4, wherein the carbonaceous fuel stream and oxidized oxygen carrier particles are provided to the reducer reactor in counter-current flow. Embodiment 6. The method according to any one of Embodiments 1-5, further comprising mixing the oxygen-depleted air with steam to generate the oxidizer reactor input stream. Embodiment 7. The method according to any one of Embodiments 1-6, wherein the oxidizer reactor input stream further comprises oxygen-depleted air. Embodiment 8. The method according to any one of Embodiments 1-7, wherein the oxidizer reactor input stream further comprises oxygen (O2) and argon (Ar). Embodiment 9. The method according to any one of Embodiments 1-8, wherein oxygen carrier particles comprise a support material and a transition metal oxide, where the oxygen carrier comprises iron oxide (Fe2O3), copper oxide (CuO), manganese oxide (Mn2O3), cobalt oxide (Co3O4), calcium iron oxides (Ca2Fe2O5), or combinations thereof. Embodiment 10. The method according to Embodiment 9, wherein the support material of oxygen carrier particles comprises SiO2, MgO, Al2O3, TiO2, SiC, or a combination that comprises two or more of the support materials. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 Embodiment 11. The method according to Embodiment 9, wherein the oxygen carrier particles further comprise a dopant, where the dopant comprises nickel (Ni), cobalt (Co), copper (Cu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), or combinations thereof. Embodiment 12. The method according to any one of Embodiments 1-11, wherein a weight ratio of transition metal oxide to carbonaceous fuel provided to the reducer reactor is between 1:2 and 1:47. Embodiment 13. The method according to any one of Embodiments 1-12, wherein a weight ratio of transition metal oxide to steam (H2O) provided to the oxidizer reactor is between 1:20 and 1:100. Embodiment 14. The method according to any one of Embodiments 1-13, wherein a weight ratio of transition metal oxide to air provided to the combustor reactor is between 1:20 and 1:100. Embodiment 15. The method according to any one of Embodiments 1-14, further comprising operating the oxidizer reactor at a temperature between 700 °C and 1000 °C. Embodiment 16. The method according to any one of Embodiments 1-15, wherein the reduced oxygen carrier particles have a degree of reduction between 40% and 50%. Embodiment 17. The method according to any one of Embodiments 1-16, wherein the combustor reactor is operated as a moving bed reactor, and further comprising: providing the oxygen carrier particles from the combustor reactor to a fluidized bed combustor; MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 providing an air input stream to the fluidized bed combustor; and providing the oxygen carrier particles from the fluidized bed combustor to the reducer reactor. Embodiment 18. A reactor system, comprising: a reducer reactor comprising: a reducer reactor fuel inlet in fluid communication with a carbonaceous fuel source; a reducer reactor solids inlet configured to receive oxidized oxygen carrier particles, whereby oxidized oxygen carrier particles react with the carbonaceous fuel in the reducer reactor and generate carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles; a reducer reactor solids outlet configured to discharge reduced oxygen carrier particles; a reducer reactor gas outlet configured to provide a reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O), the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; an oxidizer reactor comprising: an oxidizer reactor gas inlet in fluid communication with a steam source and either a depleted air source or a nitrogen (N2) source; an oxidizer reactor solids inlet in fluid communication with the reducer reactor solids outlet and configured to receive reduced oxygen carrier particles, whereby the reduced oxygen carrier particles react with material received via the oxidizer reactor gas inlet and generate hydrogen (H2) and partially oxidized oxygen carrier particles; a oxidizer reactor gas outlet configured to discharge an oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O), wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 2.5:1 and 3.5:1; an oxidizer reactor solids outlet configured to provide partially oxidized oxygen carrier particles; MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 a combustor reactor configured to generate oxidized oxygen carrier particles and oxygen- depleted air, the combustor reactor comprising: a combustor reactor solids inlet in fluid communication with the oxidizer reactor solids outlet; a combustor reactor gas inlet in fluid communication with an air source; a combustor reactor gas outlet configured to provide a depleted air stream; and a combustor reactor solids outlet configured to provide oxidized oxygen carrier particles. Embodiment 19. The reactor system according to Embodiment 18, further comprising: a hopper unit; a riser apparatus in communication with the combustor reactor and the hopper unit, the riser unit being configured to convey the oxidized oxygen carrier particles to the hopper unit; and the hopper unit being configured to selectively provide oxidized oxygen carrier particles to the reducer reactor. Embodiment 20. A method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, a moving bed combustor reactor, and a fluidized bed combustor reactor, the method comprising: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2); providing the partially oxidized oxygen carrier particles to the moving bed combustor reactor; providing an air stream to the moving bed combustor reactor, thereby generating nitrogen (N2); collecting nitrogen (N2) from the moving bed combustor reactor; combining the nitrogen (N2) from the moving bed combustor reactor with the hydrogen (H2)from the oxidizer reactor output stream such that a molar ratio of hydrogen (H2) to nitrogen (N2) is between 2.5:1 and 3.5:1; providing partially oxidized oxygen carrier particles from the moving bed combustor to the fluidized bed combustor; providing an air stream to the fluidized bed combustor reactor, thereby generating oxygen-depleted air and the oxidized oxygen carrier particles; collecting a fluidized bed combustor output stream from the fluidized bed combustor reactor, the fluidized bed combustor output stream comprising oxygen-depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the fluidized bed combustor reactor to the reducer reactor. MBF\029784\0010\40065261.v9-3 / 21 / 25

Claims

Attorney Docket No. 029784-0010-WO01 CLAIMS 1. A method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, and a combustor reactor, the method comprising: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O) and air or nitrogen (N2); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O); providing the partially oxidized oxygen carrier particles to the combustor reactor; providing an air stream to the combustor reactor, thereby generating the oxidized oxygen carrier particles and oxygen-depleted air; collecting a combustor output stream from the combustor reactor, the combustor output stream comprising oxygen-depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the combustor reactor to the reducer reactor. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 2. The method according to claim 1, further comprising operating the reducer reactor at a temperature between 700 °C and 1050 °C.

3. The method, according to claim 1, wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 1.5:1 and 4:

1.

4. The method according to claim 3, wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 2.8:1 and 3.2:

1.

5. The method according to claim 1, wherein the carbonaceous fuel stream and oxidized oxygen carrier particles are provided to the reducer reactor in counter-current flow.

6. The method according to claim 1, further comprising mixing the oxygen-depleted air with steam to generate the oxidizer reactor input stream.

7. The method according to claim 1, wherein the oxidizer reactor input stream further comprises oxygen-depleted air.

8. The method according to claim 1, wherein the oxidizer reactor input stream further comprises oxygen (O2) and argon (Ar).

9. The method according to claim 1, wherein oxygen carrier particles comprise a support material and a transition metal oxide, where the oxygen carrier comprises iron oxide (Fe2O3), copper oxide (CuO), manganese oxide (Mn2O3), cobalt oxide (Co3O4), calcium iron oxides (Ca2Fe2O5), or combinations thereof.

10. The method according to claim 9, wherein the support material of oxygen carrier particles comprises SiO2, MgO, Al2O3, TiO2, SiC, or a combination that comprises two or more of the support materials. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 11. The method according to claim 9, wherein the oxygen carrier particles further comprise a dopant, where the dopant comprises nickel (Ni), cobalt (Co), copper (Cu), scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), cadmium (Cd), lutetium (Lu), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), gold (Au), or combinations thereof.

12. The method according to claim 1, wherein a weight ratio of transition metal oxide to carbonaceous fuel provided to the reducer reactor is between 1:2 and 1:

47.

13. The method according to claim 1, wherein a weight ratio of transition metal oxide to steam (H2O) provided to the oxidizer reactor is between 1:20 and 1:

100.

14. The method according to claim 1, wherein a weight ratio of transition metal oxide to air provided to the combustor reactor is between 1:20 and 1:

100.

15. The method according to claim 1, further comprising operating the oxidizer reactor at a temperature between 700 °C and 1000 °C.

16. The method according to claim 1, wherein the reduced oxygen carrier particles have a degree of reduction between 40% and 50%.

17. The method according to claim 1, wherein the combustor reactor is operated as a moving bed reactor, and further comprising: providing the oxygen carrier particles from the combustor reactor to a fluidized bed combustor; providing an air input stream to the fluidized bed combustor; and providing the oxygen carrier particles from the fluidized bed combustor to the reducer reactor. MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 18. A reactor system, comprising: a reducer reactor comprising: a reducer reactor fuel inlet in fluid communication with a carbonaceous fuel source; a reducer reactor solids inlet configured to receive oxidized oxygen carrier particles, whereby oxidized oxygen carrier particles react with the carbonaceous fuel in the reducer reactor and generate carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles; a reducer reactor solids outlet configured to discharge reduced oxygen carrier particles; a reducer reactor gas outlet configured to provide a reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O), the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; an oxidizer reactor comprising: an oxidizer reactor gas inlet in fluid communication with a steam source and either a depleted air source or a nitrogen (N2) source; an oxidizer reactor solids inlet in fluid communication with the reducer reactor solids outlet and configured to receive reduced oxygen carrier particles, whereby the reduced oxygen carrier particles react with material received via the oxidizer reactor gas inlet and generate hydrogen (H2) and partially oxidized oxygen carrier particles; a oxidizer reactor gas outlet configured to discharge an oxidizer reactor output stream comprising hydrogen (H2), nitrogen (N2) and steam (H2O), wherein a molar ratio of hydrogen (H2) to nitrogen (N2) in the oxidizer reactor output stream is between 2.5:1 and 3.5:1; an oxidizer reactor solids outlet configured to provide partially oxidized oxygen carrier particles; a combustor reactor configured to generate oxidized oxygen carrier particles and oxygen- depleted air, the combustor reactor comprising: a combustor reactor solids inlet in fluid communication with the oxidizer reactor solids outlet; a combustor reactor gas inlet in fluid communication with an air source; MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 a combustor reactor gas outlet configured to provide a depleted air stream; and a combustor reactor solids outlet configured to provide oxidized oxygen carrier particles.

19. The reactor system according to claim 18, further comprising: a hopper unit; a riser apparatus in communication with the combustor reactor and the hopper unit, the riser unit being configured to convey the oxidized oxygen carrier particles to the hopper unit; and the hopper unit being configured to selectively provide oxidized oxygen carrier particles to the reducer reactor.

20. A method for operating a reactor system comprising a reducer reactor, an oxidizer reactor, a moving bed combustor reactor, and a fluidized bed combustor reactor, the method comprising: providing a carbonaceous fuel stream and oxidized oxygen carrier particles to the reducer reactor, thereby generating carbon dioxide (CO2), steam (H2O), and reduced oxygen carrier particles in the reducer reactor, wherein the reduced oxygen carrier particles have a degree of reduction between 11% and 50%; collecting a reducer reactor output stream from a reducer reactor outlet, the reducer reactor output stream comprising carbon dioxide (CO2) and steam (H2O); and the reducer reactor output stream comprising at least 90 mol% dry purity of CO2; providing the reduced oxygen carrier particles to the oxidizer reactor; providing an oxidizer reactor input stream to the oxidizer reactor, whereby the reduced oxygen carrier particles react with the oxidizer reactor input stream and generate hydrogen (H2) and partially oxidized oxygen carrier particles, wherein the oxidizer reactor input stream comprises steam (H2O); collecting an oxidizer reactor output stream from an oxidizer reactor outlet, the oxidizer reactor output stream comprising hydrogen (H2); MBF\029784\0010\40065261.v9-3 / 21 / 25Attorney Docket No. 029784-0010-WO01 providing the partially oxidized oxygen carrier particles to the moving bed combustor reactor; providing an air stream to the moving bed combustor reactor, thereby generating nitrogen (N2); collecting nitrogen (N2) from the moving bed combustor reactor; combining the nitrogen (N2) from the moving bed combustor reactor with the hydrogen (H2)from the oxidizer reactor output stream such that a molar ratio of hydrogen (H2) to nitrogen (N2) is between 2.5:1 and 3.5:1; providing partially oxidized oxygen carrier particles from the moving bed combustor to the fluidized bed combustor; providing an air stream to the fluidized bed combustor reactor, thereby generating oxygen-depleted air and the oxidized oxygen carrier particles; collecting a fluidized bed combustor output stream from the fluidized bed combustor reactor, the fluidized bed combustor output stream comprising oxygen-depleted air, wherein oxygen-depleted air comprises nitrogen (N2) and less than 21 mol% oxygen (O2); providing the oxidized oxygen carrier particles from the fluidized bed combustor reactor to the reducer reactor. MBF\029784\0010\40065261.v9-3 / 21 / 25

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