Systems and methods for co-treatment of no x, so x, and h 2s in FLUE gas streams

Abstract

Exemplary systems and methods may be configured to process flue gas containing streams. Exemplary systems may comprise a catalytic unit, one or more reactors, and a condenser unit. An input gas stream provided to the one or more reactors typically comprises NOx, SOx, H2S, and a first molar amount of CO2. Exemplary oxygen carriers in the one or more reactors comprise a support material and a metal. An output gas stream from the one or more reactors may comprise at least 70 mol% CO2, less than 0.01 mol% NOx, less than 0.01 mol% SOx, and less than 0.01 mol% H2S, where 95-99.99% of the first molar amount of CO2 is in the first output gas stream.

Description

SYSTEMS AND METHODS FOR CO-TREATMENT OF NOx, SOx, AND H2S IN FLUEGAS STREAMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 555,263, filed on February 19, 2024, the entire contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates to systems, methods, and operating strategies for the cotreatment of streams comprising nitrogen oxides (NOX), sulfur oxides (SOx), and hydrogen sulfide (H2S). Exemplary systems, methods and operating strategies may be particularly suited for processing flue gas streams.INTRODUCTION

[0003] The global energy demand is expected to triple in the next three decades, with nearly three-quarters of this demand currently being met by fossil-based fuels. Renewable and less carbon-intensive fuels, such as biomass and biogas, are also gaining traction. However, a common issue with these fuels is the formation of pollutants such as nitrogen oxides, sulfur oxides, and hydrogen sulfide during their conversion.

[0004] Nitrogen oxides (NOx) are harmful pollutants responsible for photochemical smog, acid rain, and depletion of the ozone layer. These oxides include NO, NO2, N2O, NO3, and N2O5, with NO or nitric oxide being the majority. The state-of-the-art process for NOx removal is Selective Catalytic Reduction (SCR), where N0xis reduced using a reducing agent, typically urea or ammonia.

[0005] Sulfur oxides (SOx), including SO, SO2, SO3, S7O2, S6O2, and others, with SO2 or sulfur dioxide being the predominant form, can severely impact human health and the environment. High levels of SO2 exposure can cause respiratory issues, lung disease, and other health complications. Environmentally, SOx contributes to acid rain, haze, and particulate matter pollution, adversely affecting crops, forests, and aquatic ecosystems. The industry commonly employs flue gas desulfurization to treat SO2 emissions, capturing them with calcium oxide(CaO) and converting them into gypsum (CaSO4).

[0006] Hydrogen sulfide (H2S), a highly flammable and corrosive gas, poses severe risks when its concentration exceeds permissible limits in the atmosphere or industrial processes. Its presence can lead to catalyst poisoning and material corrosion. Moreover, its direct release into the atmosphere can be fatal and may contribute to acid rain upon oxidation. Liquid solvent absorption methods using amines or alcohols, such as methyl diethanolamine, Selexol, and Rectisol, are widely used for H2S separation. This process produces a concentrated H2S stream during solvent regeneration, which is then processed through the Claus process to decompose H2S into steam (H2O) and elemental sulfur.

[0007] These pollutants often occur together, especially in oxy-combustion or chemical looping combustion systems. Operating separate units to tackle each pollutant is economically disadvantageous. Consequently, there have been numerous attempts to develop methods that can address these pollutants concurrently.SUMMARY

[0008] In some aspects, the techniques described herein relate to a method for operating a reactor system, the method including: providing a reactor input gas stream to an inlet of a reactor in the reactor system such that the reactor input gas stream contacts a plurality of oxygen carrier particles in a first oxidation state, the reactor input gas stream including NOx, SOx, H2S, and a first molar amount of CO2; and each of the plurality of oxygen carrier particles including: a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; collecting a first output gas stream from an outlet of the reactor, the first output gas stream including: at least 70 mol% CO2, less than 0.01 mol% NOX, less than 0.01 mol% SOx, and less than 0.01 mol% H2S, wherein 95-99.99% of the first molar amount of CO2 is in the first output gas stream; providing an oxidation gas stream to the reactor such that the oxidation gas stream contacts the plurality of oxygen carrier particles, the oxidation gas stream including oxygen (O2); collecting a second output gas stream from a second outlet of the reactor, the second output gas stream including SO2, N2, and O2; providing a regeneration gas stream to the reactor such that the regeneration gas stream contacts the plurality of oxygen carrier particles, the regeneration gas stream including hydrogen (H2); and collecting a third output gas stream from the first outlet or the second outlet of the reactor, the third output gas stream including steam (H2O).

[0009] Tn some aspects, the techniques described herein relate to a system for processing flue gas, the system including: a catalytic unit including: a catalyst bed including a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogen-containing gas source; and a catalytic unit outlet; a reactor including: a reactor gas inlet being selectively in fluid communication with: a flue gas containing stream; an oxidation gas stream; and a regeneration gas stream; a reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; the reactor including a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles include: a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; and a condenser unit configured to generate a first stream including sulfur (S) and a second stream including hydrogen sulfide (H2S), the condenser unit including: an inlet in fluid communication with the catalytic unit outlet; a first outlet configured to provide the first stream; and a second outlet configured to provide the second stream.

[0010] In some aspects, the techniques described herein relate to a system for processing flue gas, the system including: a catalytic unit including: a catalyst bed including a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogen-containing gas source; and a catalytic unit outlet; a first reactor including: a first reactor gas inlet; a first reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; a second reactor including: a second reactor gas inlet; a second reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; a third reactor including: a third reactor gas inlet; a third reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; and a condenser unit configured to generate a first stream including sulfur (S) and a second stream including hydrogen sulfide (H2S), the condenser unit including: an inlet in fluid communication with the catalytic unit outlet; a first condenser outlet configured to provide the first stream; and a second condenser outlet configured to provide the second stream.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. l is a schematic illustration of an exemplary reactor system.

[0012] FIG. 2 is a schematic illustration of another exemplary reactor system.

[0013] FIG. 3 schematically illustrates an exemplary operation for NOx, SOx, and H2S decomposition from flue gas in a single reactor configuration.

[0014] FIG. 4A schematically illustrates an exemplary operation of a multiple reactor configuration. FIG. 4B schematically illustrates an exemplary operation of a multiple reactor configuration where after a time interval, the input gases are switched such that the exhausted bed of reactor-1 is under oxidation, the oxidized bed of reactor-2 is under regeneration, and the regenerated bed in reactor-3 is used for the decomposition of NOx, SOx, and H2S. FIG. 4C schematically illustrates an exemplary operation of a multiple reactor configuration where after a time interval, the input gases are switched such that the oxidized bed of reactor- 1 is under regeneration, the regenerated bed in reactor-2 is used to for decomposition, and the exhausted bed in reactor-3 is under oxidation.

[0015] FIG. 5 schematically illustrates an exemplary operational configuration of a reactor system including catalytic bed and condenser units, where hydrogen (H2) is provided to the catalytic bed.

[0016] FIG. 6 schematically illustrates another exemplary operational configuration of a reactor system including catalytic bed and condenser units, where hydrogen sulfide (H2S) is provided to the catalytic bed.

[0017] FIG. 7 schematically illustrates an exemplary operational configuration of a reactor system including catalytic bed and condenser units, where hydrogen (H2) is provided to the catalytic bed, and including a recycle stream from the condenser unit.

[0018] FIG. 8 schematically illustrates an exemplary operational configuration of a reactor system including catalytic bed and condenser units, where hydrogen sulfide (H2S) is provided to the catalytic bed, and including a recycle stream from the condenser unit.

[0019] FIG. 9 shows exemplary material balance data for a computational exemplary system.DETAILED DESCRIPTION

[0020] The present disclosure relates to the systems, methods, reactor configurations, and operating strategies for processing streams comprising NOx, SOx, and H2S.I. Definitions

[0021] 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 presentdocument, 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.

[0022] 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.

[0023] For the recitation of numeric ranges herein, each intervening number there between 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.

[0024] 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 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.II. Exemplary Materials

[0025] Exemplary systems, methods and techniques disclosed and contemplated herein may use various materials, such as catalytic particles, oxygen carrier particles, reactor input gas streams (flue gas containing streams), oxidation gas streams, regeneration gas streams, catalytic bed input streams, reactor output streams, catalytic bed output streams, and condenser unit output streams. Various aspects of each are described below.A. Exemplary Particles

[0026] Exemplary particles used with systems, methods and techniques disclosed and contemplated herein include catalytic particles and oxygen carrier particles.

[0027] Exemplary catalytic particles may comprise various metal oxides and ores. For instance, exemplary catalytic particles may comprise AI2O3, bauxite, TiCh, V2O5, MmCh, La20s, CaO, MgO, ZrC>2, CnC , or SiCh.

[0028] Exemplary oxygen carrier particles may comprise support material and metals.

[0029] Various support materials may be used in exemplary oxygen carrier particles. For instance, exemplary support materials may comprise AI2O3, ZrCh, La2O3, TiCh, SiCh, MgO, MgAhO4, zeolites, SiC, carbon, mesoporous silica, mesoporous-AhCh, or mesoporous CeO2.

[0030] Various metals may be used in exemplary oxygen carrier particles. For instance, exemplary metals may comprise nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof. In some implementations, exemplary metals may comprise nickel (Ni), copper (Cu), or cobalt (Co).

[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, exemplaryoxygen 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 mm.

[0032] Exemplary oxygen carrier particles are designed to cycle between two or more oxidation states. Exemplary decomposition operations, discussed in greater detail below, may comprise oxidizing elemental metals of the oxygen carrier particles to sulfides and / or oxides. As non-limiting examples, when oxygen carrier particles comprise nickel (Ni), the Ni may be converted to NiO, NiS, NiS2, Ni?S6, NisS4, N13S2, or various non-stoichiometric phases NiSx. Exemplary oxidation operations, discussed in greater detail below, may comprise oxidizing residual elemental metal and metal sulfides of the oxygen carrier particles to metal oxide and sulfur dioxide. As a non-limiting example, Ni, NiS, and / or M3S2 may be converted to NiO and SO2. Exemplary regeneration operations, discussed in greater detail below, may comprise reducing metal oxide to elemental metal. As a non-limiting example, NiO may be converted to Ni.B. Exemplary Input Gas Streams

[0033] Exemplary systems and methods utilize various input gas streams, such as reactor input gas streams, oxidation gas streams, regeneration gas streams, and catalytic bed input streams.

[0034] Exemplary reactor input gas streams may comprise NOx, SOx, H2S, and / or CO2 gases in varying amounts and concentrations. In some instances, exemplary reactor input gas streams may comprise flue gas. Exemplary NOXgases may comprise NO or NO2. Exemplary SOXgases may comprise SO, SO2, or SO3.

[0035] Exemplary reactor input gas streams may comprise a majority CO2 gas and steam (H2O), with the remainder of constituents being one or more “pollutants,” such as NOx, SOX, and H2S.

[0036] In some implementations, exemplary reactor input gas streams may comprise at least 90 mol% CO2 and steam (H2O). In various instances, exemplary reactor input gas streams may comprise a total amount of CO2 and steam (H2O) 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%; or 99 mol% and 99.99 mol%. In various instances, exemplary reactor input gas streams may comprise a total amount of CO2 and steam (H2O) no less than 90 mol%; no less than 92 mol%; no less than 94 mol%; no less than 96 mol%; no less than 98 mol%; no less than 99 mol%; no less than 99.5 mol%; no less than 99.9 mol%; or no less than 99.99 mol%. In various instances, exemplary reactor input gas streams may comprise a total amount of CO2 and steam (H2O) no greater than 99.99 mol%; no greater than 99.9 mol%; no greater than 99.5 mol%; no greater than 99 mol%; no greater than 98 mol%; no greater than 96 mol%; no greater than 94 mol%; no greater than 92 mol%; or no greater than 90 mol%.

[0037] Exemplary oxidation gas streams may include gases that oxidize metal sulfides to create metal oxides and sulfur dioxide (SO2). Exemplary oxidation gas streams may comprise oxygen (O2), pure oxygen (O2), air, or enriched oxygen (O2).

[0038] Exemplary regeneration gas streams may include gases that reduce metal oxides to elemental metal. Exemplary regeneration gas streams may comprise hydrogen (H2), methane (CH4), and / or carbon monoxide (CO).

[0039] Exemplary catalytic bed input streams may comprise or consist of hydrogen (H2). Exemplary catalytic bed input streams may comprise or consist of hydrogen sulfide (H2S). In some instances, exemplary catalytic bed input streams may comprise hydrogen (H2) and hydrogen sulfide (H2S). In some instances, when exemplary catalytic bed input streams comprise hydrogen (H2) and hydrogen sulfide (H2S), a majority, in terms of mol%, of the catalytic bed input stream is hydrogen (H2).C. Exemplary Output Gas Streams

[0040] Exemplary systems and methods generate various output gas streams, such as reactor output gas streams, catalytic bed output streams, and condenser unit output streams. Various aspects of each are discussed below.

[0041] Exemplary reactor output gas streams may include a first output gas stream, a second output gas stream, or a third output gas stream.

[0042] Exemplary first output streams of a reactor typically comprise CO2 and H2O. In some instances, exemplary first output streams may comprise trace amounts of NOx, SOx, and / or H2S.Exemplary NOXgases may comprise NO or NO2. Exemplary SOXgases may comprise SO, SO2, or SO3.

[0043] In some implementations, exemplary first output gas streams of a reactor may comprise 95-99.99% of the first molar amount of CO2 in the reactor input gas stream. For instance, if the reactor input gas stream comprised 1 mole per unit of CO2, then the first output gas stream may comprise between 0.95 moles and 0.9999 moles per unit of CO2.

[0044] In various instances, exemplary first output gas streams of a reactor may comprise between 95% and 99.99%; 96% and 99.99%; 97% and 99.99%; 98% and 99.99%; or 99% and 99.99% of the first molar amount of CO2. In various instances, exemplary first output gas streams of a reactor may comprise no less than 95%; no less than 96%; no less than 97%; no less than 98%; no less than 99%; or no less than 99.99% of the first molar amount of CO2. In various instances, exemplary first output gas streams of a reactor may comprise no greater than 99.99%; no greater than 99%; no greater than 98%; no greater than 97%; no greater than 96%; or no greater than 95% of the first molar amount of CO2.

[0045] In some implementations, exemplary first output gas streams of a reactor may comprise more than 70 mol% CO2 of the total output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 70 mol% and 99.9 mol% CO2. In various instances, exemplary first output gas streams of a reactor may comprise CO2 at an amount between 70 mol% and 99.9 mol%; 79 mol% and 99.9 mol%; 80 mol% and 99.9 mol%;82 mol% and 99.9 mol%; 85 mol% and 99.9 mol%; 90 mol% and 99.9 mol%; 95 mol% and 99.9 mol%; 79 mol% and 95 mol%; 79 mol% and 90 mol%; 79 mol% and 85 mol%; 79 mol% and 82 mol%; or 79 mol% and 80 mol%. In various instances, exemplary first output gas streams of a reactor may comprise CO2 at an amount no less than 70 mol%; no less than 79 mol%; no less than 80 mol%; no less than 81 mol%; no less than 82 mol%; no less than 85 mol%; no less than 90 mol%; no less than 95 mol%; or no less than 99.9 mol%. In various instances, exemplary first output gas streams of a reactor may comprise CO2 at an amount no greater than 99.9 mol%; no greater than 95 mol%; no greater than 90 mol%; no greater than 85 mol%; no greater than 82 mol%; no greater than 81 mol%; no greater than 80 mol%; no greater than 79 mol%; or no greater than 70 mol%.

[0046] In some implementations, exemplary first output gas streams of a reactor may comprise more than 20 mol% H2O of the total output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 20 mol% and 40 mol% H2O. In various instances, exemplary first output gas streams of a reactor may comprise H2O at an amount between 20 mol% and 40 mol%; 20 mol% and 35 mol%; 20 mol% and 30 mol%; 20 mol% and 25 mol%; or 20 mol% and 40 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2O at an amount no less than 20 mol%; no less than 25 mol%; no less than 30 mol%; no less than 35 mol%; or no less than 40 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2O at an amount no greater than 40 mol%; no greater than 35 mol%; no greater than 30 mol%; no greater than 25 mol%; or no greater than 20 mol%.

[0047] In some implementations, exemplary first output gas streams of a reactor may comprise more than 99 mol% H2O and CO2 of the total amount of output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 99 mol% and 100 mol% H2O and CO2. In various instances, exemplary first output gas streams of a reactor may comprise H2O and CO2 at an amount between 99 mol% and 100 mol%; 99.2 mol% and 100 mol%; 99.4 mol% and 100 mol%; 99.6 mol% and 100 mol%; 99.8 mol% and 100 mol%; or 99.9 mol% and 100 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2O and CO2 at an amount no less than 99 mol%; no less than 99.2 mol%; no less than 99.4 mol%; no less than 99.6 mol%; no less than 99.8 mol%; no less than 99.9 mol%; or no less than 100 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2O and CO2 at an amount no greater than 100 mol%; no greater than 99.9 mol%; no greater than 99.8 mol%; no greater than 99.6 mol%; no greater than 99.4 mol%; no greater than 99.2 mol%; or no greater than 99 mol%.

[0048] In some implementations, exemplary first output gas streams of a reactor may comprise less than 0.01 mol% NOx of the total output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 0 mol % and 0.01 mol% NOx. In various instances, exemplary first output gas streams of a reactor may comprise NOXat an amount between 0 mol% and 0.01 mol%; 0 mol% and 0.005 mol%; 0 mol% and 0.001 mol%; 0 mol% and 0.0005 mol%; 0 mol% and 0.0001 mol%; or 0.0001 mol% and 0.01 mol%. Invarious instances, exemplary first output gas streams of a reactor may comprise NOx at an amount no less than 0.0001 mol%; no less than 0.001 mol%; or no less than 0.01 mol%. In various instances, exemplary first output gas streams of a reactor may comprise NOx at an amount no greater than 0.01mol%; no greater than 0.001mol%; no greater than 0.0001mol%; or no greater than 0 mol%.

[0049] In some implementations, exemplary first output gas streams of a reactor may comprise less than 0.01 mol% SOXof the total output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 0 mol% and 0.01 mol% SOX. In various instances, exemplary first output gas streams of a reactor may comprise SOx at an amount between 0 mol% and 0.01 mol%; 0 mol% and 0.005 mol%; 0 mol% and 0.001 mol%; 0 mol% and 0.0005 mol%; 0 mol% and 0.0001 mol%; or 0.0001 mol% and 0.01 mol%. In various instances, exemplary first output gas streams of a reactor may comprise SOx at an amount no less than 0.0001 mol%; no less than 0.001 mol%; or no less than 0.01 mol%. In various instances, exemplary first output gas streams of a reactor may comprise SOx at an amount no greater than 0.01mol%; no greater than 0.001mol%; no greater than 0.0001mol%; or no greater than 0 mol%.

[0050] In some implementations, exemplary first output gas streams of a reactor may comprise less than 0.01 mol% H2S of the total output gas stream. In various instances, exemplary first output gas streams of a reactor may comprise between 0 mol% and 0.01 mol% H2S. In various instances, exemplary first output gas streams of a reactor may comprise H2S at an amount between 0 mol% and 0.01 mol%; 0.001 mol% and 0.01 mol%; 0.001 mol% and 0.005 mol%; or 0.005 mol% and 0.01 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2S at an amount no less than 0 mol%; no less than 0.001 mol%; no less than 0.002 mol%; no less than 0.003 mol%; no less than 0.004 mol%; no less than 0.005 mol%; no less than 0.006 mol%; no less than 0.007 mol%; no less than 0.008 mol%; no less than 0.009 mol%; or no less than 0.01 mol%. In various instances, exemplary first output gas streams of a reactor may comprise H2S at an amount no greater than 0.01 mol%; no greater than 0.009 mol%; no greater than 0.008 mol%; no greater than 0.007 mol%; no greater than 0.006 mol%; no greater than 0.005 mol%; no greater than 0.004 mol%; no greater than 0.003 mol%; no greater than 0.002 mol%; no greater than 0.001 mol%; or no greater than 0 mol%.

[0051] Exemplary second output gas streams of a reactor may comprise SO2, N2, and O2.

[0052] In some implementations, exemplary second output gas streams of a reactor may comprise more than 0 mol% SO2 of the total gas stream. In various instances, exemplary second output gas streams of a reactor may comprise between 0 mol% and 20 mol% SO2. In various instances, exemplary second output gas streams of a reactor may comprise SO2 at an amount between 0 mol% and 20 mol%; 0 mol% and 15 mol%; 0 mol% and 10 mol%; 0 mol% and 5 mol%; 5 mol% and 20 mol%; 10 mol% and 20 mol%; or 15 mol% and 20 mol%. In various instances, exemplary second output gas streams of a reactor may comprise SO2 at an amount between no less than 5 mol%; no less than 10 mol%; no less than 15 mol%; or no less than 20 mol%. In various instances, exemplary second output gas streams of a reactor may comprise SO2 at an amount between 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%.

[0053] In some implementations, exemplary second output gas streams of a reactor may comprise more than 79 mol% N2 of the total gas stream. In various instances, exemplary second output gas streams of a reactor may comprise between 79 mol% and 100 mol% N2. In various instances, exemplary second output gas streams of a reactor may comprise N2 at an amount between79 mol% and 100 mol%; 85 mol% and 100 mol%; 90 mol% and 100 mol%; 95 mol% and 100 mol%; 79 mol% and 95 mol%; 79 mol% and 90 mol%; or 79 mol% and 85 mol%. In various instances, exemplary second output gas streams of a reactor may comprise N2 at an amount no less than 79 mol%; no less than 85 mol%; no less than 90 mol%; no less than 95 mol%; or no less than 100 mol%. In various instances, exemplary second output gas streams of a reactor may comprise N2 at an amount no greater than 100 mol%; no greater than 95 mol%; no greater than 90 mol%; no greater than 85 mol%; or no greater than 79 mol%.

[0054] In some implementations, exemplary second output gas streams of a reactor may comprise less 21 than mol% O2 of the total gas stream. In various instances, exemplary second output gas streams of a reactor may comprise between 21 mol % and 0 mol% O2. In various instances, exemplary second output gas streams of a reactor may comprise O2 at an amount between 21 mol % and 0 mol%; 15 mol % and 0 mol%; 10 mol % and 0 mol%; or 5 mol % and 0 mol%. In various instances, exemplary second output gas streams of a reactor may comprise O2 at an amount no less than 5 mol%; no less than 10 mol%; no less than 15 mol%; or no less than 21 mol%. In various instances, exemplary second output gas streams of a reactor may compriseO2 at an amount no greater than 21 mol%; no greater than 15 mol%; no greater than 10 mol%; no greater than 5 mol%; or no greater than 0 mol%.

[0055] Exemplary third output gas streams of a reactor may comprise steam (H2O) and H2.

[0056] In some implementations, exemplary third output gas streams of a reactor may comprise more than 90 mol% steam (H2O) of the total gas stream. In various instances, exemplary third output gas streams of a reactor may comprise between 90 mol% and 100 mol% steam (H2O). In various instances, exemplary third output gas streams of a reactor may comprise steam (H2O) at an amount between 90 mol% and 100 mol%; 92 mol% and 100 mol%; 94 mol% and 100 mol%; 96 mol% and 100 mol%; or 98 mol% and 100 mol%. In various instances, exemplary third output gas streams of a reactor may comprise steam (H2O) at an amount no less than 90 mol%; no less than 92 mol%; no less than 94 mol%; no less than 96 mol%; no less than 98 mol%; or no less than 100 mol%. In various instances, exemplary third output gas streams of a reactor may comprise steam (H2O) at an amount no greater than 100 mol%; no greater than 98 mol%; no greater than 96 mol%; no greater than 94 mol%; no greater than 92 mol%; or no greater than 90 mol%.

[0057] In some implementations, exemplary third output gas streams of a reactor may comprise less than 10 mol% H2 of the total gas stream. In various instances, exemplary third output gas streams of a reactor may comprise between 0 mol% and 10 mol% H2. In various instances, exemplary third output gas streams of a reactor may comprise H2 at an amount between 0 mol% and 10 mol%; 0 mol% and 5 mol%; 0 mol% and 2 mol%; or 0 mol% and 1 mol%. In various instances, exemplary third output gas streams of a reactor may comprise H2 at an amount no less than 1 mol%; no less than 2 mol%; no less than 5 mol%; or no less than 10 mol%. In various instances, exemplary third output gas streams of a reactor may comprise H2 at an amount no greater than 10 mol%; no greater than 5 mol%; no greater than 2 mol%; no greater than 1 mol%; or no greater than 0 mol%.

[0058] Exemplary catalytic bed output streams may comprise sulfur (S), sulfur dioxide (SO2), hydrogen sulfide (H2S), and / or steam (H2O), with the remainder being nitrogen (N2).

[0059] In some implementations, exemplary catalytic bed output gas streams may comprise less than 2 mol% sulfur of the total gas stream. In various instances, exemplary catalytic bed output gas streams may comprise between 0 mol% and 2 mol% sulfur (S). In various instances,exemplary catalytic bed output gas streams may comprise sulfur (S) at an amount between 0 mol% and 2 mol%; 0.5 mol% and 2 mol%; 1 mol% and 2 mol%; 1.5 mol% and 2 mol%; 0 mol% and 1.5 mol%; 0 mol% and 1 mol%; or 0 mol% and 0.5 mol%. In various instances, exemplary catalytic bed output gas streams may comprise sulfur (S) at an amount no less than 0.5 mol%; no less than 1 mol%; no less than 1.5 mol%; or no less than 2 mol%. In various instances, exemplary catalytic bed output gas streams may comprise sulfur (S) at an amount no greater than 2 mol%; no greater than 1.5 mol%; no greater than 1 mol%; no greater than 0.5 mol%; or no greater than 0 mol%.

[0060] In some implementations, exemplary catalytic bed output gas streams may comprise less than 0.05 mol% sulfur dioxide (SO2) of the total gas stream. In various instances, exemplary catalytic bed output gas streams may comprise between 0 mol% and 0.05 mol% SO2. In various instances, exemplary catalytic bed output gas streams may comprise sulfur SO2 at an amount between 0 mol% and 0.05 mol%; 0.01 mol% and 0.05 mol%; 0.02 mol% and 0.05 mol%; 0.03 mol% and 0.05 mol%; 0.04 mol% and 0.05 mol%; 0 mol% and 0.04 mol%; 0 mol% and 0.03 mol%; 0 mol% and 0.02 mol%; or 0 mol% and 0.01 mol%. In various instances, exemplary catalytic bed output gas streams may comprise SO2 at an amount no less than 0.001 mol%; no less than 0.01 mol%; no less than 0.02 mol%; no less than 0.03 mol%; no less than 0.04 mol%; or no less than 0.05 mol%. In various instances, exemplary catalytic bed output gas streams may comprise SO2 at an amount no greater than 0.05 mol%; no greater than 0.04 mol%; no greater than 0.03 mol%; no greater than 0.02 mol%; or no greater than 0.01 mol%.

[0061] In some implementations, exemplary catalytic bed output gas streams may comprise less than 10 mol% hydrogen sulfide (H2S) of the total gas stream. In various instances, exemplary catalytic bed output gas streams may comprise between 0 mol% and 10 mol% H2S. In various instances, exemplary catalytic bed output gas streams may comprise H2S at an amount between 0 mol% and 10 mol%; 2 mol% and 10 mol%; 4 mol% and 10 mol%; 6 mol% and 10 mol%; 8 mol% and 10 mol%; 0 mol% and 8 mol%; 0 mol% and 6 mol%; 0 mol% and 4 mol%; or 0 mol% and 2 mol%. In various instances, exemplary catalytic bed output gas streams may comprise H2S at an amount no less than 2 mol%; no less than 4 mol%; no less than 6 mol%; no less than 8 mol%; or no less than 10 mol%. In various instances, exemplary catalytic bed output gas streams may comprise H2S at an amount no greater than 10 mol%; no greater than 8 mol%;no greater than 6 mol%; no greater than 4 mol%; no greater than 2 mol%; or no greater than 0 mol%.

[0062] In some implementations, exemplary catalytic bed output gas streams may comprise less than 23 mol% steam (H2O) of the total gas stream. In various instances, exemplary catalytic bed output gas streams may comprise between 0 mol% and 23 mol% steam (H2O). In various instances, exemplary catalytic bed output gas streams may comprise steam (H2O) at an amount between 0 mol% and 23 mol%; 5 mol% and 23 mol%; 10 mol% and 23 mol%; 15 mol% and 23 mol%; 20 mol% and 23 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 catalytic bed output gas streams may comprise steam (H2O) at an amount no less than 5 mol%; no less than 10 mol%; no less than 15 mol%; no less than 20 mol%; or no less than 23 mol%. In various instances, exemplary catalytic bed output gas streams may comprise steam (H2O) at an amount no greater than 23 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%.

[0063] Exemplary condenser unit output streams may include a first output stream and a second out stream.

[0064] Exemplary first condenser unit output streams comprise sulfur (S) and / or steam (H2O).

[0065] In some implementations, exemplary first condenser unit output streams may comprise less than 8 mol% sulfur (S) of the output stream. In various instances, exemplary first condenser unit output streams may comprise between 0 mol% and 6 mol% sulfur (S). In various instances, exemplary first condenser unit output streams may comprise sulfur (S) in an amount between 0 mol% and 6 mol%; 2 mol% and 6 mol%; 4 mol% and 6 mol%; 0 mol% and 4 mol%; or 0 mol% and 2 mol%. In various instances, exemplary first condenser unit output streams may comprise sulfur (S) in an amount no less than 2 mol%; no less than 4 mol%; no less than 6 mol%; or no less than 8 mol%. In various instances, exemplary first condenser unit output streams may comprise sulfur (S) in an amount no greater than 8 mol%; no greater than 6 mol%; no greater than 4 mol%; no greater than 2 mol%; or no greater than 0 mol%.

[0066] In some implementations, exemplary first condenser unit output streams may comprise more than 94 mol% steam (H2O) of the output stream. In various instances, exemplary first condenser unit output streams may comprise between 94 mol% and 100 mol% steam (H2O). Invarious instances, exemplary first condenser unit output streams may comprise steam (H2O) at an amount between 94 mol% and 100 mol%; 96 mol% and 100 mol%; 98 mol% and 100 mol%; 94 mol% and 98 mol%; or 94 mol% and 96 mol%. In various instances, exemplary first condenser unit output streams may comprise steam (H2O) at an amount no less than 94 mol%; no less than 96 mol%; no less than 98 mol%; or no less than 100 mol%. In various instances, exemplary first condenser unit output streams may comprise steam (H2O) at an amount no greater than 100 mol%; no greater than 98 mol%; no greater than 96 mol%; or no greater than 94 mol%.

[0067] Exemplary second condenser unit output streams comprise hydrogen sulfide (H2S), nitrogen (N2), and sulfur dioxide (SO2).

[0068] In some implementations, exemplary second condenser unit output streams may comprise less than 0.5 mol% H2S. In various instances, exemplary second condenser unit output streams may comprise between 0 mol% and 0.5 mol% H2S. In various instances, exemplary second condenser unit output streams may comprise H2S in an amount between 0 mol% and 0.5 mol%; 0.1 mol% and 0.4 mol%; 0.2 mol% and 0.4 mol%; 0 mol% and 0.2 mol%; or 0 mol% and 0.1 mol%. In various instances, exemplary second condenser unit output streams may comprise H2S in an amount no less than 0.05 mol%; no less than 0.1 mol%; no less than 0.15 mol%; no less than 0.2 mol%; no less than 0.25 mol%; no less than 0.3 mol%; or no less than 0.5 mol%. In various instances, exemplary second condenser unit output streams may comprise H2S in an amount no greater than 0.5 mol%; no greater than 0.3 mol%; no greater than 0.25 mol%; no greater than 0.2 mol%; no greater than 0.15 mol%; no greater than 0.1 mol%; no greater than 0.05 mol%; or no greater than 0 mol%.

[0069] In various instances, exemplary second condenser unit output streams may comprise N2 in an amount between 97 mol% and 99.9 mol%. In various instances, exemplary second condenser unit output streams may comprise N2 in an amount between 97 mol% and 99.9 mol%; 98.5 mol% and 99.9 mol%; 97 mol% and 98.5 mol%; 99.5 mol% and 99.9 mol%; 98.0 mol% and 99.5 mol%; 98.0 mol% and 98.5 mol%; or 98.3 mol% and 98.5 mol%. In various instances, exemplary second condenser unit output streams may comprise N2 in an amount no less than 97 mol%; no less than 98.3 mol%; no less than 98.5 mol%; no less than 99 mol%; no less than 99.5 mol%; or no less than 99.9 mol%. In various instances, exemplary second condenser unit output streams may comprise N2 in an amount no greater than 99.9 mol%; no greater than 99.5 mol%;no greater than 99 mol%; no greater than 98.5 mol%; no greater than 98.3 mol%; or no greater than 97 mol%.

[0070] In some implementations, exemplary second condenser unit output streams may comprise less than 0.05 mol% SO2. In various instances, exemplary second condenser unit output streams may comprise between 0 mol% and 0.05 mol% SO2. In various instances, exemplary second condenser unit output streams may comprise SO2 in an amount between 0 mol% and 0.05 mol%; 0.01 mol% and 0.04 mol%; 0.02 mol% and 0.04 mol%; 0 mol% and 0.02 mol%; or 0 mol% and 0.01 mol%. In various instances, exemplary second condenser unit output streams may comprise SO2 in an amount no less than 0.005 mol%; no less than 0.01 mol%; no less than 0.015 mol%; no less than 0.02 mol%; no less than 0.025 mol%; no less than 0.03 mol%; or no less than 0.05 mol%. In various instances, exemplary second condenser unit output streams may comprise SO2 in an amount no greater than 0.05 mol%; no greater than 0.03 mol%; no greater than 0.025 mol%; no greater than 0.02 mol%; no greater than 0.015 mol%; no greater than 0.01 mol%; no greater than 0.005 mol%; or no greater than 0 mol%.III. Exemplary Systems

[0071] Various systems for processing flue gas may be used to perform exemplary methods and techniques described herein. Exemplary systems may be configured as single reactor systems or as multiple reactor systems. Various aspects of single reactor systems and multiple reactor systems are described below.A. Exemplary Single Reactor Systems

[0072] FIG. 1 schematically depicts an exemplary reactor system 100. System 100 may be particularly suited for processing flue gas. As shown, exemplary system 100 comprises a flue gas source 102, an oxidation case source 104, a regeneration gas source 106, a reactor 110, a catalytic unit 120, and a condenser unit 130. Optional components and connections are shown in dashed lines. Other embodiments may include more or fewer components.

[0073] Exemplary reactor 110 is configured to perform various reactions, such as converting NOx, SOx, and FES in gas streams. Reactor 110 includes oxygen carrier particles. Additional details regarding exemplary oxygen carrier particles are provided above.

[0074] Exemplary reactor 110 may be configured as a fixed bed, bubbling bed, or fluidized bed. In some instances, reactor 110 may be arranged as a packed bed reactor.

[0075] Reactor 110 may include temperature control components, not shown in FIG. 1. Reactor 110 may include pressure control components, not shown in FIG. 1.

[0076] Reactor 110 comprises one or more outlets. As shown, reactor 110 may provide an output stream 111 in certain operational modes and configurations. In some instances, as discussed below, system 100 may further comprise a catalytic unit 120, and reactor 110 may have an outlet in fluid communication with catalytic unit 120. In some instances, an outlet of reactor 110 may be selectively in fluid communication with one or more downstream units, storage units, and / or catalytic unit 120.

[0077] Broadly, reactor 110 may be operated in three operational modes: a “decomposition” mode, an “oxidation” mode, and a “regeneration” mode. As shown, reactor 110 may be selectively in fluid communication with a flue gas source 102, an oxidation gas source 104, and a regeneration gas source 106.

[0078] During a “decomposition” mode, reactor 110 may receive a flue gas containing stream 103 from flue gas source 102. The flue gas containing stream 103 may be received at a reactor inlet. Although the reactor 110 inlet is shown schematically in FIG. 1 at the bottom of the reactor 110, various inlet positions may be used, such as at the top of reactor 110 or at one or more side injection positions.

[0079] During an “oxidation” mode, reactor 110 may receive an oxidation gas containing stream 105 from oxidation gas source 104. The oxidation gas containing stream 105 may be received at the reactor inlet.

[0080] During a “regeneration” mode, reactor 110 may receive a regeneration gas containing stream 107 from regeneration gas source 106. The regeneration gas containing stream 107 may be received at the reactor inlet.In some instances, reactor 110 may be in fluid communication with catalytic unit 120. Exemplary catalytic unit 120 converts SOx into steam (H2O), elemental sulfur (S), and hydrogen sulfide (H2S). Catalytic unit 120 may contain exemplary catalytic particles, details of which are provided above.

[0081] Catalytic unit 120 receives gas stream 1 12 from reactor 110. In some instances, catalytic unit 120 may be in communication with a hydrogen-containing gas source 114. In some instances, an output stream 124 of catalytic unit 120 may be in communication with condenser unit 130.

[0082] Exemplary condenser unit 130 generates a first stream 132 comprising sulfur (S) and a second stream 134 comprising hydrogen sulfide (H2S). As shown, condenser unit 130 may receive gas stream 124 from catalytic unit 120. In some instances, reactor 110 may be in fluid communication with condenser unit 130 and configured to receive material from condenser unit 130.

[0083] In some instances, condenser unit 130 may be configured to recycle hydrogen sulfide (H2S) back to reactor 110. In some instances, the recycle stream may comprise SO2 and / or H2 in addition to hydrogen sulfide (H2S). In some instances, reactor 110 may include a reactor gas inlet that receives condenser unit second stream 134 comprising hydrogen sulfide (H2S). In some instances, the second stream 134 may be mixed with the flue gas containing stream 103.B. Exemplary Multiple Reactor Systems

[0084] FIG. 2 schematically depicts an exemplary system 200 comprising multiple reactors. System 200 may be particularly suited for processing flue gas. As shown, exemplary system 200 comprises a reactor 210, a reactor 250, a reactor 270, a catalytic unit 220, a condenser unit 230, a flue gas source 204, an oxidation gas source 244, and a regeneration gas source 264. Optional components are shown in dashed lines. Other embodiments may include more or fewer components.

[0085] Broadly, reactor 210, reactor 250, and reactor 270 are arranged and configured similar to reactor 110 discussed above with reference to FIG. 1. Exemplary reactor 210, reactor 250, and reactor 270 are configured to each operate in three operational modes: a “decomposition” mode, an “oxidation” mode, and a “regeneration” mode. Typically, each reactor 210, reactor 250, and reactor 270 operate in a different mode than the other two reactors at a given time.

[0086] Reactor 210, reactor 250, and reactor 270 each contain exemplary oxygen carrier particles. Reactor 210, reactor 250, and reactor 270 are typically arranged as packed bed reactors.

[0087] Each of reactor 210, reactor 250, and reactor 270 has reactor outlets that provide output streams 211, 251, and 271, respectively, from each reactor outlet.

[0088] When system 200 includes catalytic unit 220, reactor 210, reactor 250, and reactor 270 are in fluid communication with catalytic unit 220.

[0089] When system 200 includes condenser unit 230, reactor 210, reactor 250, and reactor 270 are in fluid communication with condenser unit 230.

[0090] Each of reactor 210, reactor 250, and reactor 270 are in communication with a flue gas source 204, an oxidation gas source 244, and a regeneration gas source 264. One or more control units may selectively provide a flue gas containing stream 205, an oxidation gas stream 245, and a regeneration gas stream 265 to reactor 210, reactor 250, and reactor 270.

[0091] In some instances, reactor 210 may have a reactor gas inlet in communication with a flue gas containing stream 205, an oxidation gas stream 245, and a regeneration gas stream 265. In some instances, reactor 250 may have a reactor gas inlet in communication with a flue gas containing stream 205, an oxidation gas stream 245, and a regeneration gas stream 265. In some instances, reactor 270 may have a reactor gas inlet in communication with a flue gas containing stream 205, an oxidation gas stream 245, and a regeneration gas stream 265.

[0092] In some instances, reactor 210 may have a reactor gas inlet that receives condenser unit second stream 234 comprising hydrogen sulfide (H2S). In some instances, reactor 250 may have a reactor gas inlet that receives condenser unit second stream 234 comprising hydrogen sulfide (H2S). In some instances, reactor 270 may have a reactor gas inlet that receives condenser unit second stream 234 comprising hydrogen sulfide (H2S).

[0093] Exemplary catalytic unit 220 is arranged and configured similarly to condenser unit 120 discussed above with reference to FIG. 1. Catalytic unit 220 converts SOx into steam (H2O) and elemental sulfur. Catalytic unit 220 includes exemplary catalytic particles. In some instances, catalytic unit 220 may receive gas stream 212 from reactor 210, gas stream 252 from reactor 250, and / or gas stream 272 from reactor 270. In some instances, catalytic unit 220 may be in communication with a hydrogen-containing gas source 214. In some instances, catalytic unit 220 may be in communication with condenser unit 230.

[0094] Exemplary condenser unit 230 is arranged and configured similarly to condenser unit 130 described above with reference to FIG. 1. Condenser unit 230 generates a first stream 232 comprising sulfur (S) and a second stream 234 comprising hydrogen sulfide (FES). In some instances, condenser unit 230 may be in communication with catalytic unit 220. In some instances,condenser unit 230 may receive gas stream 224 from catalytic unit 220. In some instances, condenser unit 230 may be in communication with reactor 210. In some instances, condenser unit 230 may be in communication with reactor 250. In some instances, condenser unit 230 may be in communication with reactor 270.IV. Exemplary Methods of Operation

[0095] Various methods of operation may be used with exemplary systems described above. FIG. 3 schematically shows operation of a single reactor system. FIG. 4A, FIG. 4B, and FIG. 4C schematically show various stages during operation of a multiple reactor system. FIG. 5 schematically shows operation of a single reactor system with a catalytic unit receiving a first type of input. FIG. 6 schematically shows operation of a single reactor system with a catalytic unit receiving a second type of input. FIG. 7 schematically shows operation of a single reactor system with a catalytic unit receiving a first type of input and a recycle stream back to the reactor. FIG. 8 schematically shows operation of a single reactor system with a catalytic unit receiving a second type of input and a recycle stream back to the reactor. It should be noted that the operational strategies shown in FIG. 5-FIG. 8 may be applied to multiple reactor systems.A. Exemplary Methods of Operating Single Reactor Systems

[0096] FIG. 3 schematically illustrates an exemplary operation of a one-reactor configuration where the stages, or operations, are represented in order of operation by stage 1 (decomposition), stage 2 (oxidation), and stage 3 (regeneration). The inputs and outputs for each stage are shown in FIG. 3.

[0097] Broadly, an exemplary method of operating a reactor system may include: providing a reactor input gas stream to an inlet of a reactor, collecting a first output gas stream from an outlet of the reactor, providing an oxidation gas stream to the reactor, collecting a second output gas stream from a second outlet of the reactor, providing a regeneration gas stream to the reactor, and collecting a third output gas stream from the first outlet or the second outlet of the reactor. Other embodiments may include more or fewer operations.

[0098] An exemplary method may begin by providing a reactor input gas stream to an inlet of a reactor. The reactor input gas stream may be provided to a single inlet or multiple inlets. Theinlets may be physically located on a reactor in a manner different from what is schematically represented in the Drawings, e.g. FIG. 1.

[0099] Broadly, the reactor input gas stream may comprise NOx, SOX, H2S, and CO2. For ease of reference, an amount of CO2 in the reactor input gas stream is referred to as a “first molar amount.” Additional details of exemplary reactor input gas streams are provided above in the Exemplary Materials section.

[0100] The reactor input gas stream contacts a plurality of oxygen carrier particles in a first oxidation state. As explained in greater detail above, exemplary oxygen carrier particles comprise a support material and metal. The plurality of oxygen carrier particles, after contacting the reactor input gas stream, are in a second oxidation state.

[0101] After the first input gas stream contacts oxygen carrier particles, an exemplary method includes collecting a first output gas stream from an outlet of the reactor. The first output gas stream may comprise nearly all of the first molar amount of CO2. Put another way, under typical operation, nearly all CO2 in the first input gas stream passes through the reactor. The first output gas stream may comprise CO2 and trace amounts of NOx, SOx, FES. Additional details and possible amounts of various constituents in exemplary first output gas streams are provided above.

[0102] An exemplary method may comprise providing an oxidation gas stream to the reactor. An oxidation gas stream may comprise oxygen (O2). The oxidation gas stream contacts oxygen carrier particles in the reactor and generates oxygen carrier particles in a second oxidation state. Additional details regarding exemplary oxidation gas streams are provided above.

[0103] An exemplary method may comprise collecting a second output gas stream from a second outlet of the reactor. The second output gas stream may comprise SO2, N2, and O2. Additional details regarding exemplary second output gas streams are provided above.

[0104] An exemplary method may comprise providing the second output gas stream to a flue gas desulfurization system. An exemplary method may comprise collecting a sulfur salt-containing species from the flue gas desulfurization system.

[0105] An exemplary method may comprise providing a regeneration gas stream to the reactor. Regeneration gas streams may include gases that reduce metal oxides to elemental metal. A regeneration gas stream may comprise hydrogen (H2), methane (CH4), and / or carbon monoxide (CO). Additional details regarding exemplary regeneration gas streams are provided above. Theregeneration gas stream contacts the oxygen carrier particles in the reactor and returns oxygen carrier particles to the first oxidation state.

[0106] An exemplary method may comprise collecting a third output stream from the first outlet or the second outlet of the reactor. The third output stream may comprise steam (H2O). Additional details regarding exemplary third output gas streams are provided above.

[0107] An exemplary method may comprise providing a second output gas stream to a catalytic bed reactor. A catalytic bed input stream may comprise hydrogen (H2) or hydrogen sulfide (H2S). An exemplary method may comprise collecting a catalytic bed output stream. The catalytic bed output stream may comprise hydrogen sulfide (H2S) and steam (H2O).

[0108] An exemplary method may comprise providing the catalytic bed output stream to a condenser unit. An exemplary method may comprise collecting a first condenser unit output stream. The first condenser unit output stream may comprise sulfur (S) and / or steam (H2O). An exemplary method may comprise collecting a second condenser unit output stream. The second condenser unit output stream may comprise hydrogen sulfide (H2S).

[0109] An exemplary method may comprise providing a portion of the second condenser unit output stream to the gas stream of the inlet of the reactor.

[0110] During the three operational reactor stages, decomposition, oxidation, and regeneration, reactor operating temperatures may be between 300 °C and 1000 °C. In various instances, reactor operating temperatures may be between 300 °C and 1000 °C; 400 °C and 1000 °C; 500 °C and 1000 °C; 600 °C and 1000 °C; 700 °C and 1000 °C; 800 °C and 1000 °C; 900 °C and 1000 °C; 300 °C and 900 °C; 300 °C and 800 °C; 300 °C and 700 °C; 300 °C and 600 °C; 300 °C and 500 °C; or 300 °C and 400 °C. In various instances, reactor operating temperatures may be no less than 300 °C; no less than 400 °C; no less than 500 °C; no less than 600 °C; no less than 700 °C; no less than 800 °C; no less than 900 °C; or no less than 1000 °C. In various instances, reactor operating temperatures may be 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; no greater than 500 °C; no greater than 400 °C; or no greater than 300 °C.

[0111] During the three operational reactor stages, decomposition, oxidation, and regeneration, reactor operating pressures may be between 0.1 MPa and 5 MPa. In various instances, reactor operating pressures may be between 0.1 MPa and 5 MPa; 1 MPa and 5 MPa; 2 MPa and 5 MPa; 3MPa 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, 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, 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.B. Exemplary Methods of Operating Multiple Reactor Systems

[0112] Generally, exemplary methods of operating multiple reactor systems include the operations discussed above with reference to operating single reactor systems. Exemplary methods of operating multiple reactor systems may comprise additional operations as discussed below.

[0113] FIGS. 4A-C schematically illustrate an exemplary operation of a multiple reactor system, where reactors can be operated in parallel performing decomposition, oxidation, and regeneration operations. As shown, in other embodiments, there may be n additional reactors operating in parallel with the three reactors shown.

[0114] FIG. 4A schematically illustrates a first operational configuration. As shown, an exemplary method may include providing a flue gas containing stream to a first reactor and collecting a first output gas stream during decomposition operations. During a same period of time, an oxygen gas containing stream is provided to a second reactor and a second output gas stream is collected during oxidation operations. During the same period of time, a hydrogen gas containing stream is provided to the third reactor and a third output gas stream is collected during regeneration operations.

[0115] FIG. 4B schematically illustrates a second operational configuration. As shown, an oxygen containing stream is provided to the first reactor and a second output gas stream is collected during oxidation operations. During the same period of time, a hydrogen containing stream is provided to the second reactor a third output gas stream is collected during regeneration operations.During the same period of time, a flue gas containing stream is provided to a third reactor and a first output gas stream is collected during decomposition operations.

[0116] FIG. 4C schematically illustrates a third operational configuration. As shown, a hydrogen-containing stream is provided to a first reactor a third output gas stream is collected during regeneration operations. During the same period of time, a flue gas containing stream is provided to the second reactor and a first output gas stream is collected during decomposition operations. During the same period of time, an oxygen containing stream is provided to the third reactor and a second output gas stream is collected during oxidation operations.C. Exemplary Methods of Operating Reactor Systems Including a Catalytic Unit and a Condenser Unit

[0117] FIGS. 5-8 schematically illustrate exemplary operations of reactor configurations with an oxidation operation providing a stream to a catalytic unit and the catalytic unit providing a stream to a condenser unit. FIG. 6 and FIG. 7 show recycling all or a portion of an H2S stream back to decomposition operational stage. For ease of reference, FIGS. 5-8 show a single reactor configuration. However, multiple reactor configurations, such as those shown in FIG. 2, may be used to implement the operations and / or principles shown in FIGS. 5-8.

[0118] FIG. 5 schematically illustrates an exemplary operation of a reactor configuration with a catalytic unit and a condenser unit where H2 is an input gas for the catalytic unit. FIG. 5 schematically illustrates an exemplary operation of a reactor configuration with a condenser unit providing an output stream with sulfur (S) and an output stream with steam (H2O) and H2S.

[0119] FIG. 6 schematically illustrates an exemplary operation of a reactor configuration with a catalytic unit and a condenser unit where H2S is an input gas for the catalytic unit. FIG. 6 schematically illustrates an exemplary operation of a reactor configuration with a condenser unit providing an output stream with sulfur (S) and an output stream with steam (H2O) and H2S.

[0120] FIG. 7 schematically illustrates an exemplary operation of a reactor configuration with a catalytic unit and a condenser unit where H2 is an input gas for the catalytic unit. FIG. 7 schematically illustrates an exemplary operation of a reactor configuration with a condenser unit providing an output stream with sulfur (S) and steam (H2O) and another output stream with H2S,where the H2S is recycled. In some instances, the recycle stream may comprise SO2 and / or H2 in addition to hydrogen sulfide (H2S).

[0121] FIG. 8 schematically illustrates an exemplary operation of a reactor configuration with a catalytic unit and a condenser unit where H2S is an input gas for the catalytic unit. FIG. 8 schematically illustrates an exemplary operation of a reactor configuration with a condenser unit providing an output stream with sulfur (S) and steam (H2O) and another output stream with H2S, where the H2S is recycled.V. Computational Experimental Data[00122J Exemplary experimental examples were computationally generated and the results are discussed below.A. Computational Example 1

[0123] Process calculations were performed in Aspen V.11. A flue gas feed with a material flow rate of 6.52 kmol / hr containing 1500 ppmv NO, 1000 ppmv SO2, 1500 ppmv H2S, 79.5% CO2, and 20.2% H2O, typical of the stream from a reducer reactor of a chemical looping combustion (CLC) system, was fed into the decomposition reactor containing metallic Ni. The operating pressure and temperature were maintained at 0. 10 MPa and 700 °C, respectively. The outlet gases contained -79% CO2, 20% FEO, and less than 1% trace gases, including N2, EE, and CO. The bed in the reactor contained a mixture of NiO, M3S2, and a small amount of unconverted Ni at the end of the decomposition step.

[0124] In the oxidation step, operating at 700 °C and 0.10 MPa , a stoichiometric amount of air was added to completely convert Ni and NisS2 to NiO. A stochiometric amount of oxygen (O) in air was determined by subtracting the moles of Ni in NiO from the total number of moles of Ni in the bed. Adding a stoichiometric amount of air was necessary to prevent any sulfate formation due to excess oxygen (O2). However, the oxidation step can be operated above 800°C to avoid any sulfate formation, even in excess air, as NiSO4 decomposes to NiO above 790 °C. The outlet gas stream from the oxidation step contained -13% SO2 and 87% N2. This concentrated SO2 stream can be converted into manageable salt species using caustic wash. The solid bed was completely converted into NiO (100% conversion). This solid bed was thenregenerated using a stoichiometric amount of H2 to obtain metallic Ni. The outlet gases contain -100% H2O. The material balance for this exemplary case was summarized in (FIG. 9).B. Computational Example 2

[0125] FactSage 8.3 thermodynamic simulations were used with the following inputs: a temperature of 700 °C, a pressure of 0.10 MPa, inlet gases CO2 (mole faction, 0.7945), H2O (mole faction, 0.2015), H2S (mole faction, 0.0015), SO2 (mole faction, 0.0010), and NO (mole faction, 0.0015), and 0.01 mol / time flow of each metal for a total of 1 mol / time of inlet flue gas. The following output gas stream compositions were observed for different metals.Table 1. Exemplary Output Gas Stream Compositions.

[0126] For reasons of completeness, the following Clauses are provided.Clause 1. A method for operating a reactor system, the method comprising: providing a reactor input gas stream to an inlet of a reactor in the reactor system such that the reactor input gas stream contacts a plurality of oxygen carrier particles in a first oxidation state, the reactor input gas stream comprising NOx, SOx, H2S, and a first molar amount of CO2; and each of the plurality of oxygen carrier particles comprising: a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; collecting a first output gas stream from an outlet of the reactor, the first output gas stream comprising: at least 70 mol% CO2, less than 0.01 mol% NOx, less than 0.01 mol% SOx, and less than 0.01 mol% H2S,wherein 95-99.99% of the first molar amount of CO2 is in the first output gas stream; providing an oxidation gas stream to the reactor such that the oxidation gas stream contacts the plurality of oxygen carrier particles, the oxidation gas stream comprising oxygen (O2); collecting a second output gas stream from a second outlet of the reactor, the second output gas stream comprising SO2, N2, and O2; providing a regeneration gas stream to the reactor such that the regeneration gas stream contacts the plurality of oxygen carrier particles, the regeneration gas stream comprising hydrogen (H2); and collecting a third output gas stream from the first outlet or the second outlet of the reactor, the third output gas stream comprising steam (H2O).Clause 2. The method according to clause 1, wherein the support material comprises AI2O3, ZrCh, La2Os, TiCh, SiCh, MgO, MgAhCh, zeolites, SiC, carbon, mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and wherein metal is Ni, Zn, Co, or combinations thereof.Clause 3. The method according to clause 1 or clause 2, the third output gas stream further comprising hydrogen (H2).Clause 4. The method according to any one of clauses 1-3, further comprising: providing the second output gas stream to a catalytic bed reactor; providing a catalytic bed input stream to the catalytic bed reactor, the catalytic bed input stream comprising hydrogen (H2) or hydrogen sulfide (H2S); and collecting a catalytic bed output stream from the catalytic bed reactor, the catalytic bed output stream comprising hydrogen sulfide (H2S) and steam (H2O).Clause 5. The method according to clause 4, further comprising: providing the catalytic bed output stream to a condenser unit; collecting a first condenser unit output stream comprising sulfur (S); and collecting a second condenser unit output stream comprising hydrogen sulfide (H2S).Clause 6. The method according to clause 5, further comprising: recycling a portion of the second condenser unit output stream to the gas stream provided to the inlet of the reactor, wherein the first condenser unit output stream further comprises steam (H2O).Clause 7. The method according to clause 6, wherein the catalytic bed input stream consists of hydrogen (H2).Clause 8. The method according to clause 6, wherein the catalytic bed input stream consists of hydrogen sulfide (H2S).Clause 9. The method according to any one of clauses 1-8, where the reactor system further comprises a second reactor and a third reactor, the method further comprising: after providing the reactor input gas stream to an inlet of the second reactor: providing the oxidation gas stream to the inlet of the second reactor; collecting the second output gas stream from an outlet of the second reactor; after providing the reactor input gas stream to an inlet of the third reactor: providing the oxidation gas stream to the inlet of the third reactor; and collecting the second output gas stream from an outlet of the third reactor.Clause 10. The method according to any one of clauses 1-9, further comprising: providing the second output stream to a flue gas desulfurization system; and collecting a sulfur salt-containing species from the flue gas desulfurization system.Clause 11. The method according to any one of clauses 1-10, wherein a temperature of the reactor while collecting the first output gas stream is between 300° C to 1000° C; wherein a temperature of the reactor while collecting the second output gas stream is between 300° C to 1000° C; wherein a temperature of the reactor while collecting the third output gas stream is between 300° C to 1000° C.Clause 12. The method according to clause 11, wherein the temperature of the reactor while collecting the first output gas stream is between 575° C to 700° C; wherein the temperature of the reactor while collecting the second output gas stream is between 575° C to 700° C; wherein the temperature of the reactor while collecting the third output gas stream is between 575° C to 700° C.Clause 13. The method according to any one of clauses 1-12, wherein the regeneration gas stream further comprises methane (CH4) and / or carbon monoxide (CO); and wherein the oxidizing gas consists of one of the following: pure oxygen (O2), air, or enriched oxygen (O2).Clause 14. The method according to any one of clauses 1-13, wherein the reactor is operated as a packed bed reactor.Clause 15. The method according to any one of clauses 1-14, wherein a pressure of the reactor while collecting the first output gas stream is between 0.1 MPa and 5 MPa; wherein a pressure of the reactor while collecting the second output gas stream is between 0.1 MPa and 5 MPa; wherein a pressure of the reactor while collecting the third output gas stream is between 0.5 MPa and 5 MPa.Clause 16. A system for processing flue gas, the system comprising: a catalytic unit comprising: a catalyst bed comprising a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogen-containing gas source; and a catalytic unit outlet; a reactor comprising: a reactor gas inlet being selectively in fluid communication with: a flue gas containing stream; an oxidation gas stream; and a regeneration gas stream; a reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; the reactor comprising a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise: a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; and a condenser unit configured to generate a first stream comprising sulfur (S) and a second stream comprising hydrogen sulfide (H2S), the condenser unit comprising: an inlet in fluid communication with the catalytic unit outlet; a first outlet configured to provide the first stream; and a second outlet configured to provide the second stream.Clause 17. The system according to clause 16, wherein either the first outlet or the second outlet is in fluid communication with the reactor gas inlet; wherein the support material comprises AI2O3, ZrO2, La20.3, TiCh, SiCh, MgO, MgAhCh, zeolites, SiC, carbon, mesoporous silica, mesoporous-AhCh, or mesoporous CeCh; and wherein metal is Ni, Zn, Co, or combinations thereof.Clause 18. A system for processing flue gas, the system comprising: a catalytic unit comprising: a catalyst bed comprising a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogen-containing gas source; and a catalytic unit outlet; a first reactor comprising: a first reactor gas inlet; a first reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; a second reactor comprising: a second reactor gas inlet; a second reactor outlet being selectively in fluid communication withthe catalytic unit gas inlet; a third reactor comprising: a third reactor gas inlet; a third reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; and a condenser unit configured to generate a first stream comprising sulfur (S) and a second stream comprising hydrogen sulfide (H2S), the condenser unit comprising: an inlet in fluid communication with the catalytic unit outlet; a first condenser outlet configured to provide the first stream; and a second condenser outlet configured to provide the second stream.Clause 19. The system according to clause 18, wherein the first condenser outlet is in fluid communication with the first reactor gas inlet; wherein each of the first reactor, the second reactor, and the third reactor comprise a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise: a support material comprising mesoporous silica, mesoporous-AhCh, or mesoporous CeCh; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof.Clause 20. The system according to clause 18 or clause 19, wherein the second condenser outlet is in fluid communication with the first reactor gas inlet; wherein each of the first reactor, the second reactor, and the third reactor comprise a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise: a support material comprising mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof.

Claims

CLAIMS1. A method for operating a reactor system, the method comprising: providing a reactor input gas stream to an inlet of a reactor in the reactor system such that the reactor input gas stream contacts a plurality of oxygen carrier particles in a first oxidation state, the reactor input gas stream comprising NOx, SOx, H2S, and a first molar amount of CO2; and each of the plurality of oxygen carrier particles comprising: a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; collecting a first output gas stream from an outlet of the reactor, the first output gas stream comprising: at least 70 mol% CO2, less than 0.01 mol% NOx, less than 0.01 mol% SOx, and less than 0.01 mol% H2S, wherein 95-99.99% of the first molar amount of CO2 is in the first output gas stream; providing an oxidation gas stream to the reactor such that the oxidation gas stream contacts the plurality of oxygen carrier particles, the oxidation gas stream comprising oxygen (O2); collecting a second output gas stream from a second outlet of the reactor, the second output gas stream comprising SO2, N2, and O2; providing a regeneration gas stream to the reactor such that the regeneration gas stream contacts the plurality of oxygen carrier particles, the regeneration gas stream comprising hydrogen (H2); and collecting a third output gas stream from the first outlet or the second outlet of the reactor, the third output gas stream comprising steam (H2O).

2. The method according to claim 1 , wherein the support material comprises AI2O3, Z1O2, La2Oa, TiCh, SiCh, MgO, MgAhC , zeolites, SiC, carbon, mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and wherein metal is Ni, Zn, Co, or combinations thereof.

3. The method according to claim 1, the third output gas stream further comprising hydrogen (H2).

4. The method according to claim 1, further comprising: providing the second output gas stream to a catalytic bed reactor; providing a catalytic bed input stream to the catalytic bed reactor, the catalytic bed input stream comprising hydrogen (H2) or hydrogen sulfide (H2S); and collecting a catalytic bed output stream from the catalytic bed reactor, the catalytic bed output stream comprising hydrogen sulfide (H2S) and steam (H2O).

5. The method according to claim 4, further comprising: providing the catalytic bed output stream to a condenser unit; collecting a first condenser unit output stream comprising sulfur (S); and collecting a second condenser unit output stream comprising hydrogen sulfide (H2S).

6. The method according to claim 5, further comprising: recycling a portion of the second condenser unit output stream to the gas stream provided to the inlet of the reactor, wherein the first condenser unit output stream further comprises steam (H2O).

7. The method according to claim 6, wherein the catalytic bed input stream consists of hydrogen (H2).

8. The method according to claim 6, wherein the catalytic bed input stream consists of hydrogen sulfide (H2S).

9. The method according to claim 1, where the reactor system further comprises a second reactor and a third reactor, the method further comprising: after providing the reactor input gas stream to an inlet of the second reactor: providing the oxidation gas stream to the inlet of the second reactor; collecting the second output gas stream from an outlet of the second reactor; after providing the reactor input gas stream to an inlet of the third reactor: providing the oxidation gas stream to the inlet of the third reactor; and collecting the second output gas stream from an outlet of the third reactor.

10. The method according to claim 1, further comprising: providing the second output stream to a flue gas desulfurization system; and collecting a sulfur salt-containing species from the flue gas desulfurization system.

11. The method according to claim 1, wherein a temperature of the reactor while collecting the first output gas stream is between 300° C to 1000° C; wherein a temperature of the reactor while collecting the second output gas stream is between 300° C to 1000° C; wherein a temperature of the reactor while collecting the third output gas stream is between 300° C to 1000° C.

12. The method according to claim 11, wherein the temperature of the reactor while collecting the first output gas stream is between 575° C to 700° C; wherein the temperature of the reactor while collecting the second output gas stream is between 575° C to 700° C; wherein the temperature of the reactor while collecting the third output gas stream is between 575° C to 700° C.

13. The method according to claim 1 , wherein the regeneration gas stream further comprises methane (CH4) and / or carbon monoxide (CO); and wherein the oxidizing gas consists of one of the following: pure oxygen (O2), air, or enriched oxygen (O2).

14. The method according to claim 1, wherein the reactor is operated as a packed bed reactor.

15. The method according to claim 1, wherein a pressure of the reactor while collecting the first output gas stream is between 0.1 MPa and 5 MPa; wherein a pressure of the reactor while collecting the second output gas stream is between 0.1 MPa and 5 MPa; wherein a pressure of the reactor while collecting the third output gas stream is between 0.5 MPa and 5 MPa.

16. A system for processing flue gas, the system comprising: a catalytic unit comprising: a catalyst bed comprising a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogencontaining gas source; and a catalytic unit outlet; a reactor comprising: a reactor gas inlet being selectively in fluid communication with: a flue gas containing stream; an oxidation gas stream; and a regeneration gas stream; a reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; the reactor comprising a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise:a support material; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof; and a condenser unit configured to generate a first stream comprising sulfur (S) and a second stream comprising hydrogen sulfide (H2S), the condenser unit comprising: an inlet in fluid communication with the catalytic unit outlet; a first outlet configured to provide the first stream; and a second outlet configured to provide the second stream.

17. The system according to claim 16, wherein either the first outlet or the second outlet is in fluid communication with the reactor gas inlet; wherein the support material comprises AI2O3, ZrCh, La2Os, TiCh, SiCh, MgO, MgAhC , zeolites, SiC, carbon, mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and wherein metal is Ni, Zn, Co, or combinations thereof.

18. A system for processing flue gas, the system comprising: a catalytic unit comprising: a catalyst bed comprising a plurality of catalytic particles; a catalytic unit gas inlet; a second catalytic unit gas inlet in fluid communication with a hydrogencontaining gas source; and a catalytic unit outlet; a first reactor comprising: a first reactor gas inlet; a first reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; a second reactor comprising: a second reactor gas inlet; a second reactor outlet being selectively in fluid communication with the catalytic unit gas inlet;a third reactor comprising: a third reactor gas inlet; a third reactor outlet being selectively in fluid communication with the catalytic unit gas inlet; and a condenser unit configured to generate a first stream comprising sulfur (S) and a second stream comprising hydrogen sulfide (H2S), the condenser unit comprising: an inlet in fluid communication with the catalytic unit outlet; a first condenser outlet configured to provide the first stream; and a second condenser outlet configured to provide the second stream.

19. The system according to claim 18, wherein the first condenser outlet is in fluid communication with the first reactor gas inlet; wherein each of the first reactor, the second reactor, and the third reactor comprise a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise: a support material comprising mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof.

20. The system according to claim 18, wherein the second condenser outlet is in fluid communication with the first reactor gas inlet; wherein each of the first reactor, the second reactor, and the third reactor comprise a plurality of oxygen carrier particles, where each of the plurality of oxygen carrier particles comprise: a support material comprising mesoporous silica, mesoporous- AI2O3, or mesoporous CeCh; and a metal selected from: nickel (Ni), copper (Cu), cobalt (Co), zinc (Zn), or combinations thereof.

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