Co 2 mitigation system and method of use

Abstract

Herein discussed is a method of carbon capture comprising providing a reactor having an anode, a cathode, and an electrolyte between and in contact with the anode and the cathode, wherein the electrolyte conducts oxide ions and electrons; introducing a carbonaceous gas to the anode; introducing steam and hydrogen (H2) or carbon dioxide (CO2) and carbon monoxide (CO) to the cathode, wherein steam or CO2 is the dominant component; producing carbon dioxide (CO2) at the anode, wherein the CO2 partial pressure is greater than 18 kPa in the anode exhaust; and producing H2 or CO or both at the cathode. In an embodiment, the anode exhaust has a pressure of from 1 atm to 5 atm. In an embodiment, the CO2 content in the anode exhaust is from 20vol% to 100vol%.

Description

CO2 Mitigation System and Method of UseTECHNICAL FIELD[1] This invention generally relates to methods and systems for CO2 mitigation. More specifically, this invention relates to electrochemical reactors to reduce CO2 emissions while producing hydrogen (H2) or carbon monoxide (CO) or both.BACKGROUND[2] Carbon dioxide (CO2) has been identified as the main greenhouse gas that contributes to environmental concerns, such as global warming. According to “The State of Carbon Dioxide Removal, 1stEdition, 2023”, to get the atmosphere back to its composition before fossil fuels were burned en masse would mean capturing and storing more than 900 billion tons of CO2. Today’s technologies can only capture a small fraction, around 2 billion tons of CO2 per year. As such, carbon capture and storage (CCS) have become a focal point of many efforts, especially CCS at industrial and energy facilities. The global CCS Institute has issued a report in March 2021 on “Technology Readiness and Costs of CCS”. Figure 11 of this report shows that the cost of carbon capture decreases from $180-300 per ton of CO2 at IkPa of CO2 partial pressure in flue gas to around $50 per ton of CO2 at 18kPa of CO2 partial pressure in flue gas. Clearly, increasing CO2 partial pressure in a flue gas has a substantial impact in reducing the cost of carbon capture, especially in view of the tremendous amount of CO2 that needs to be captured and stored.[3] The system and method of this disclosure are developed to increase CO2 partial pressure in various flue gases while producing CO and / or H2 via efficient electrochemical pathways. When CO is produced from CO2, the system is simultaneously a carbon capture unit turning CO2 into valuable products.SUMMARY[4] Herein discussed is a method of carbon capture comprising providing a reactor having an anode, a cathode, and an electrolyte between and in contact with the anode and the cathode, wherein the electrolyte conducts oxide ions and electrons; introducing a carbonaceous gas to the anode; introducing steam and hydrogen (H2) or carbon dioxide (CO2) and carbon monoxide (CO) to the cathode, wherein steam or CO2 is the dominant component; producing carbon dioxide (CO2) at the anode, wherein the CO2 partial pressure is greater than 18 kPa in the anode exhaust; and producing H2 or CO or both at the cathode.[5] In an embodiment, the anode exhaust has a pressure of from 1 atm to 5 atm, or from 1 atm to 3 atm, or from 1 atm to 2 atm. In an embodiment, the CO2 content in the anode exhaust is from 20vol% to 100vol%, or from 30vol% to 90vol%, or from 40vol% to 70vol%. In an embodiment, the cathode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof.[6] In an embodiment, the anode consists of LST and CoCGO or consists of Cu-CoCGO, wherein the carbonaceous gas comprises CO or a hydrocarbon. In an embodiment, the anode comprises Cu-CoCGO and a material selected from the group consisting of LST, LSTM (Lao.4Sro.6Tio.4Mno.603-5), LSCM (Lao.vsSro^sCro.sMno.sOs-s), and Ba doped Ceria, wherein the carbonaceous gas comprises CO or a hydrocarbon. In an embodiment, the anode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof, wherein the carbonaceous gas comprises CO or reformed gases from hydrocarbons.[7] In an embodiment, the anode and the cathode have the same elements. In an embodiment, the anode and the cathode comprise Ni-YSZ or Ni-CGO or Ni-CoCGO or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ or LST-YSZ or LST-CGO or LST-CoCGO.[8] In an embodiment, the electrolyte comprises an electronically conducting phase and an ionically conducting phase; wherein the electronically conducting phase comprises doped lanthanum chromite or LST or an electronically conductive metal or combination thereof; and wherein the ionically conducting phase comprises a material selected from the group consisting of CGO, SDC, YSZ, LSGM, SSZ, SCZ, and combinations thereof.[9] In an embodiment, the electrolyte comprises CoCGO or LST -stabilized zirconia, wherein the stabilized zirconia comprises YSZ or SSZ or SCZ, and wherein the LST comprises LaSrCaTiOs. In an embodiment, the electrolyte comprises Nickel, Copper, Cobalt, Lanthanum, Strontium, Titanium, or Niobium -doped zirconia. In an embodiment, the electrolyte, the anode, and the cathode have the same elements. In an embodiment, the electrolyte, the anode, and the cathode comprise Ni-YSZ or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ.

[0010] In an embodiment, the reactor comprises no interconnect and wherein the reactor receives no electricity and produces no electricity. In an embodiment, the carbonaceous gas comprises biogas, landfill gas, cement kiln plant flue gas, power plant flue gas, steelmaking off gas, smelter off gas, refinery fuel gases, refinery products, or combinations thereof.

[0011] In an embodiment, the reactor is operated at a temperature of no less than 550°C, or no less than 650°C, or no less than 700°C. In an embodiment, the anode and the cathode areexposed to reducing environments simultaneously during the entire time of operation. In an embodiment, the method comprises extracting H2 or CO or both from the cathode exhaust. In an embodiment, the method comprises utilizing the extracted H2 or CO or both to synthesize hydrocarbons, alcohols, polymers, or plastics.

[0012] Further aspects and embodiments are provided in the following drawings, detailed description, and claims. Unless specified otherwise, the features as described herein are combinable and all such combinations are within the scope of this disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following drawings are provided to illustrate certain embodiments described herein. The drawings are merely illustrative and are not intended to limit the scope of claimed inventions and are not intended to show every potential feature or embodiment of the claimed inventions. The drawings are not necessarily drawn to scale; in some instances, certain elements of the drawing may be enlarged with respect to other elements of the drawing for purposes of illustration.

[0014] Fig. 1 illustrates an electrochemical reactor, according to an embodiment of this disclosure.

[0015] Fig. 2A illustrates a tubular electrochemical reactor, according to an embodiment of this disclosure.

[0016] Fig. 2B illustrates a cross section of a tubular electrochemical reactor, according to an embodiment of this disclosure.DETAILED DESCRIPTIONOverview

[0017] The following terms and phrases have the meanings indicated below, unless otherwise provided herein. This disclosure may employ other terms and phrases not expressly defined herein. Such other terms and phrases shall have the meanings that they would possess within the context of this disclosure to those of ordinary skill in the art. In some instances, a term or phrase may be defined in the singular or plural. In such instances, it is understood that any term in the singular may include its plural counterpart and vice versa, unless expressly indicated to the contrary.

[0018] As used herein, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. For example, reference to “a substituent” encompasses a single substituent as well as two or more substituents, and the like. As used herein, “forexample,” “for instance,” “such as,” or “including” are meant to introduce examples that further clarify more general subject matter. Unless otherwise expressly indicated, such examples are provided only as an aid for understanding embodiments illustrated in the present disclosure and are not meant to be limiting in any fashion. Nor do these phrases indicate any kind of preference for the disclosed embodiment.

[0019] As used herein, compositions and materials are used interchangeably unless otherwise specified. Each composition / material may have multiple elements, phases, and components. Heating as used herein refers to actively adding energy to the compositions or materials.

[0020] As used herein, YSZ refers to yttria-stabilized zirconia; SDC refers to samaria-doped ceria; SSZ refers to scandia-stabilized zirconia; LSGM refers to lanthanum strontium gallate magnesite; LST refers to lanthanum-doped strontium titanate; SCZ refers to scandia-ceria- stabilized zirconia; CoCGO refers to cobalt doped CGO.

[0021] In this disclosure, no substantial amount of H2 means that the volume content of the hydrogen is no greater than 5%, or no greater than 3%, or no greater than 2%, or no greater than 1%, or no greater than 0.5%, or no greater than 0.1%, or no greater than 0.05%.

[0022] As used herein, CGO refers to Gadolinium-Doped Ceria, also known alternatively as gadolinia-doped ceria, gadolinium-doped cerium oxide, cerium(IV) oxide, gadolinium- doped, GDC, or GCO, (formula Gd:CeO2). CGO and GDC are used interchangeably unless otherwise specified. Syngas (i.e., synthesis gas) in this disclosure refers to a mixture consisting primarily of hydrogen and carbon monoxide.

[0023] A mixed conducting electrolyte is able to transport both electrons and ions. Ionic conductivity includes ionic species such as oxygen ions (or oxide ions), protons, halogenide anions, chalcogenide anions. In various embodiment, the mixed conducting electrolyte of this disclosure comprises an electronically conducting phase and an ionically conducting phase.

[0024] In this disclosure, the cross section of the tubulars is only illustrative and not limiting. The cross section of the tubulars is any suitable shape as known to one skilled in the art, such as circular, square, square with rounded corners, rectangle, rectangle with rounded corners, triangle, hexagon, pentagon, oval, irregular shape, etc. Axial direction is the direction along the length of the tubulars. Circumferential direction is the direction around the circumference of the cross section of the tubulars.

[0025] In this disclosure, electrical resistance between two points is the ratio between the voltage applied to the current flowing between the two points. The unit of electrical resistance is, for example, ohms. Ionic resistance between two points is the ratio between the voltageapplied to the current flowing between the two points caused by ionic movement, such as oxide ions. The unit of ionic resistance is, for example, ohms.

[0026] As used herein, ceria refers to cerium oxide, also known as ceric oxide, ceric dioxide, or cerium dioxide, is an oxide of the rare-earth metal cerium. Doped ceria refers to ceria doped with other elements, such as samaria-doped ceria (SDC), or gadolinium-doped ceria (GDC or CGO). As used herein, chromite refers to chromium oxides, which includes all the oxidation states of chromium oxides.

[0027] A layer or substance being impermeable as used herein refers to it being impermeable to fluid flow. For example, an impermeable layer or substance has a permeability of less than 1 micro darcy, or less than 1 nano darcy.

[0028] In this disclosure, sintering refers to a process to form a solid mass of material by heat or pressure, or a combination thereof, without melting the material to the extent of liquefaction. For example, material particles are coalesced into a solid or porous mass by being heated, wherein atoms in the material particles diffuse across the boundaries of the particles, causing the particles to fuse together and form one solid piece.

[0029] The term “ / / / situ" in this disclosure refers to the treatment (e.g., heating or cracking) process being performed either at the same location or in the same reactor. For example, ammonia cracking taking place in the electrochemical reactor at the anode is considered in situ.

[0030] Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential, as a measurable and quantitative phenomenon, and identifiable chemical change, with either electrical potential as an outcome of a particular chemical change, or vice versa. These reactions involve electrons moving between electrodes via an electronically-conducting phase (typically, but not necessarily, an external electrical circuit), separated by an ionically-conducting and electronically insulating electrolyte (or ionic species in a solution). When a chemical reaction is effected by a potential difference, as in electrolysis, or if electrical potential results from a chemical reaction as in a battery or fuel cell, it is called an electrochemical reaction. Unlike chemical reactions, in electrochemical reactions electrons (and necessarily resulting ions), are not transferred directly between molecules, but via the aforementioned electronically conducting and ionically conducting circuits, respectively. This phenomenon is what distinguishes an electrochemical reaction from a chemical reaction.

[0031] Related to the electrochemical reactor and methods of use, various components of the reactor are described such as electrodes and electrolytes along with materials of constructionof the components. The following description recites various aspects and embodiments of the inventions disclosed herein. No particular embodiment is intended to define the scope of the invention. Rather, the embodiments provide non-limiting examples of various compositions and methods that are included within the scope of the claimed inventions. The description is to be read from the perspective of one of ordinary skill in the art. Therefore, information that is well-known to the ordinarily skilled artisan is not necessarily included.

[0032] An interconnect in an electrochemical reactor (e.g., a fuel cell) is often either metallic or ceramic that is placed between the individual cells or repeat units. Its purpose is to connect each cell or repeat unit so that electricity can be distributed or combined. An interconnect is also referred to as a bipolar plate in an electrochemical reactor. An interconnect being an impermeable layer as used herein refers to it being a layer that is impermeable to fluid flow.Electrochemical Reactor

[0033] Fig. 1 illustrates an electrochemical (EC) reactor 100, according to an embodiment of this disclosure. EC reactor 100 comprises first electrode 101, a second electrode 102, and a gas-tight electrolyte 103 therebetween. First electrode 101 (also referred to as an anode) is configured to receive a carbonaceous stream 104. Stream 104 contains no oxygen. Second electrode 102 (or a cathode) is configured to receive water (e.g., steam) or carbon dioxide as denoted by 105. In various embodiments, the carbonaceous gas comprises biogas, landfill gas, cement kiln plant flue gas, power plant flue gas, steelmaking off gas, smelter off gas, refinery fuel gases, refinery products, or combinations thereof.

[0034] In various embodiments, the reactor is operated at a temperature of no less than 550°C, or no less than 650°C, or no less than 700°C. In various embodiments, the anode exhaust (stream 106) has a pressure of from 1 atm to 5 atm, or from 1 atm to 3 atm, or from 1 atm to 2 atm. In various embodiments, the CO2 content in the anode exhaust (stream 106) is from 20vol% to 100vol%, or from 30vol% to 90vol%, or from 40vol% to 70vol%. As such, the CO2 partial pressure is greater than 18 kPa in the anode exhaust (stream 106).

[0035] In an embodiment, the cathode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof. In an embodiment, the anode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof, wherein the carbonaceous gas comprises CO or reformed gases from hydrocarbons.

[0036] In an embodiment, the anode consists of LST and CoCGO or consists of Cu-CoCGO, wherein the carbonaceous gas comprises CO or a hydrocarbon. In an embodiment, the anodecomprises Cu-CoCGO and a material selected from the group consisting of LST, LSTM (Lao.4Sro.6Tio.4Mno.603-5), LSCM (Lao^sSro^sCro.sMno.sCh-s), and Ba doped Ceria, wherein the carbonaceous gas comprises CO or a hydrocarbon.

[0037] In an embodiment, reactor 100 is configured to receive stream 104 containing CO and to generate CO2 (in stream 106 as anode exhaust) at the first electrode 101; reactor 100 is also configured to receive water or steam (in stream 105) and to generate a hydrogen-containing stream 107 (as the cathode exhaust) at the second electrode 102. In some cases, the second electrode receives a mixture of steam and hydrogen. Since water provides the oxide ion (which is transported through the electrolyte) needed to oxidize the CO at the opposite electrode, water is considered the oxidant in this scenario. As such, the first electrode 101 performs oxidation reactions in a reducing environment. In scenarios in which a mixture of steam and hydrogen is provided to the second electrode 102, the composition of the steam and hydrogen mixture may be such that the steam is the dominant component (i.e., there is a greater amount of steam than hydrogen) on any one of a volume, molar, or mass basis.

[0038] In some cases, the second electrode also or alternatively receives a mixture of carbon monoxide and carbon dioxide. The mixture of carbon monoxide and carbon dioxide may be included in the mixture of steam and hydrogen (as described previously), or may be provided as an alternative feed stream to the mixture of steam and hydrogen. In such a scenario, carbon dioxider provides the oxide ion (which is transported through the electrolyte) needed to oxidize the CO at the opposite electrode, and therefore the CO2 is considered the oxidant in this scenario. As above, the first electrode 101 performs oxidation reactions in a reducing environment. In scenarios in which a mixture of carbon monoxide and carbon dioxide is provided to the second electrode 102, the composition of the carbon monoxide and carbon dioxide mixture may be such that the carbon dioxide is the dominant component (i.e., there is a greater amount of carbon dioxide than carbon monoxide) on any one of a volume, molar, or mass basis.

[0039] In various embodiments, 103 represents an oxide ion conducting electrolyte. In an embodiment, the first electrode 101 and the second electrode 102 may comprise Ni-YSZ or NiO-YSZ. In an embodiment, the oxide ion conducting electrolyte 103 also conducts electrons.

[0040] In an embodiment, stream 104 contains methane and water or methane and carbon dioxide entering reactor 100. In other embodiments, 103 represents a mixed-conducting electrolyte. Stream 104 represents an influx of hydrocarbon and water or hydrocarbon and carbon dioxide. Stream 105 represents an influx of water and hydrogen or CO and CO2. Insome embodiments, electrode 101 comprises Cu-CGO, or further optionally comprises CuO or Cu2O or combination thereof. Electrode 102 comprises Ni-YSZ or NiO-YSZ. Stream 104 represents an influx of hydrocarbon with little to no water, with no carbon dioxide, and with no oxygen, and stream 105 represents an influx of water and hydrogen or CO and CO2. Since water or CO2 provides the oxide ion (which is transported through the electrolyte) needed to oxidize the hydrocarbon or CO at the opposite electrode, water or CO2 is considered the oxidant in this scenario. When CO2 is introduced to the cathode, CO is produced. When CO2 and H2O are introduced to the cathode, CO and H2 are produced simultaneously.

[0041] In this disclosure, no oxygen means there is no oxygen present at first electrode 101 or at least not enough oxygen that would interfere with the reaction. Also, in this disclosure, water only means that the intended feedstock is water and does not exclude trace elements or inherent components in water. For example, water containing salts or ions is considered to be within the scope of water only. Water only also does not require 100% pure water but includes this embodiment. In embodiments, the hydrogen produced from second electrode 102 is pure hydrogen, which means that in the produced gas phase from the second electrode, hydrogen is the main component. In some cases, the hydrogen content is no less than 99.5%. In some cases, the hydrogen content is no less than 99.9%. In some cases, the hydrogen produced from the second electrode is the same purity as that produced from electrolysis of water.

[0042] In an embodiment, first electrode 101 is configured to receive a fuel, optionally with water or carbon dioxide. In an embodiment, the fuel comprises a hydrocarbon having a carbon number in the range of 1-12, 1-10 or 1-8. Most preferably, the fuel is methane or natural gas, which is predominantly methane. In an embodiment, the reactor does not generate electricity and is not a fuel cell.

[0043] In various embodiments, the reactor does not contain a current collector. In an embodiment, the reactor comprises no interconnect. There is no need for electricity and such a reactor is not an electrolyser. The electrolyte 103 is configured to conduct electrons and as such is mixed conducting, i.e., both electronically conductive and ionically conductive. In an embodiment, the electrolyte 103 conducts oxide ions and electrons. In an embodiment, the electrodes 101, 102 and the electrolyte 103 are tubular (see, e.g., Fig. 2A and 2B). In an embodiment, the electrodes 101, 102 and the electrolyte 103 are planar. In these embodiments, the electrochemical reactions at the anode and the cathode are spontaneous without the need to apply potential / electricity to the reactor.

[0044] In an embodiment, the reactor comprises a first electrode, a second electrode, and an electrolyte between the electrodes, wherein the first electrode and the second electrode comprise a metallic phase that does not contain a platinum group metal when the reactor is in use, and wherein the electrolyte is oxide ion conducting. In an embodiment, wherein the first electrode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), LSGM, and combinations thereof. In an embodiment, the first electrode is configured to receive a fuel. In an embodiment, said fuel comprises a hydrocarbon or hydrogen or carbon monoxide or combinations thereof.

[0045] In an embodiment, the second electrode comprises Ni or NiO and a material selected from the group consisting of yttria-stabilized zirconia (YSZ), ceria gadolinium oxide (CGO), samaria-doped ceria (SDC), scandia-stabilized zirconia (SSZ), lanthanum strontium gallate magnesite (LSGM), and combinations thereof. In an embodiment, the second electrode is configured to receive water and hydrogen and configured to reduce the water to hydrogen. In an embodiment, the second electrode is configured to receive CO2 and CO and configured to reduce the CO2 to CO. In various embodiments, such reduction takes place electrochemically.

[0046] In an embodiment, the electrolyte comprises an electronically conducting phase containing doped lanthanum chromite or an electronically conductive metal or combination thereof; and wherein the electrolyte comprises an ionically conducting phase containing a material selected from the group consisting of gadolinium or samarium doped ceria, yttria- stabilized zirconia (YSZ), lanthanum strontium gallate magnesite (LSGM), scandia-stabilized zirconia (SSZ), Sc and Ce doped zirconia, and combinations thereof. In an embodiment, the doped lanthanum chromite comprises strontium doped lanthanum chromite, iron doped lanthanum chromite, strontium and iron doped lanthanum chromite, lanthanum calcium chromite, or combinations thereof; and wherein the conductive metal comprises Ni, Cu, Ag, Au, Pt, Rh, or combinations thereof.

[0047] In an embodiment, the electrolyte comprises gadolinium doped ceria, samarium doped ceria, a sintering aid, or combinations thereof. In various embodiments, the sintering aid comprises di-valent or tri-valent transition metal ions or combinations thereof. In an embodiment, the metal ions are oxides. In an embodiment, the transition metal comprises Co, Mn, Fe, Cu, or combinations thereof. In an embodiment, the electrolyte comprises CGO. In an embodiment, the electrolyte comprises cobalt doped CGO (CoCGO). In an embodiment, the electrolyte consists essentially of CGO. In an embodiment, the electrolyteconsists of CGO. In an embodiment, the electrolyte consists essentially of CoCGO. In an embodiment, the electrolyte consists of CoCGO.

[0048] Fig. 2A illustrates (not to scale) a tubular electrochemical (EC) reactor or an EC reactor 200, according to an embodiment of this disclosure, referred to herein as a tubular producer. Tubular producer 200 includes an inner tubular structure 202, an outer tubular structure 204, and an electrolyte 206 disposed between the inner and outer tubular structures 202, 204, respectively. Tubular producer 200 further includes a void space 208 for fluid passage. Fig. 2B illustrates (not to scale) a cross section of a tubular producer 200, according to an embodiment of this disclosure. Tubular producer 200 includes a first inner tubular structure 202, a second outer tubular structure 204, and an electrolyte 206 between the inner and outer tubular structures 202, 204. Tubular producer 200 further includes a void space 208 for fluid passage.

[0049] In an embodiment, the electrodes and the electrolyte are tubular with the first electrode being outermost and the second electrode being innermost, wherein the second electrode is configured to receive water and hydrogen or CO and CO2. In an embodiment, the electrodes and the electrolyte are tubular with the first electrode being innermost and the second electrode being outermost, wherein the second electrode is configured to receive water and hydrogen or CO and CO2.

[0050] In an embodiment, the cathode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof. In an embodiment, the anode and the cathode have the same elements. In an embodiment, the anode and the cathode comprise Ni-YSZ or Ni-CGO or Ni-CoCGO or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ or LST-YSZ or LST-CGO or LST-CoCGO. In an embodiment, the anode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof.

[0051] In an embodiment, the electrolyte is mixed-conducting. In an embodiment, the electrolyte comprises an electronically conducting phase and an ionically conducting phase; wherein the electronically conducting phase comprises doped lanthanum chromite or LST or an electronically conductive metal or combination thereof; and wherein the ionically conducting phase comprises a material selected from the group consisting of gadolinium or samarium doped ceria, yttria-stabilized zirconia (YSZ), lanthanum strontium gallate magnesite (LSGM), scandia-stabilized zirconia (SSZ), Sc and Ce doped zirconia (SCZ), and combinations thereof.

[0052] In an embodiment, the electrolyte comprises CoCGO or LST -stabilized zirconia. In an embodiment, the stabilized zirconia comprises YSZ or SSZ or SCZ (scandia-ceria- stabilized zirconia), and wherein the LST comprises LaSrCaTiO3. In an embodiment, the electrolyte comprises Nickel, Copper, Cobalt, Lanthanum, Strontium, Titanium, or Niobium -doped zirconia.

[0053] In an embodiment, the electrolyte, the anode, and the cathode have the same elements. In an embodiment, the electrolyte, the anode, and the cathode comprise Ni-YSZ or LaSrFeCr- SSZ or LaSrFeCr-SCZ or LST-SCZ.

[0054] In an embodiment, the electrolyte comprises cobalt-CGO (CoCGO), i.e., cobalt doped CGO. In an embodiment, the electrolyte consists essentially of CoCGO. In an embodiment, the electrolyte consists of CoCGO. In an embodiment, the electrolyte comprises LST (lanthanum-doped strontium titanate)-YSZ or LST-SSZ or LST-SCZ (scandia-ceria- stabilized zirconia). In an embodiment, the electrolyte consists essentially of LST-YSZ or LST-SSZ or LST-SCZ. In an embodiment, the electrolyte consists of LST-YSZ or LST-SSZ or LST-SCZ. In this disclosure, LST-YSZ refers to a composite of LST and YSZ. In various embodiments, the LST phase and the YSZ phase percolate each other. In this disclosure, LST- SSZ refers to a composite of LST and SSZ. In various embodiments, the LST phase and the SSZ phase percolate each other. In this disclosure, LST-SCZ refers to a composite of LST and SCZ. In various embodiments, the LST phase and the SCZ phase percolate each other. YSZ, SSZ, and SCZ are types of stabilized zirconia’s. In an embodiment, the LST comprises LaSrCaTiCh. In an embodiment, the electrolyte comprises Nickel, Copper, Cobalt, or Niobium -doped zirconia.

[0055] In an embodiment, the anode and the cathode are both exposed to reducing environments during the entire time of operation. In an embodiment, the anode is configured to come in contact with a fuel. In an embodiment, the fuel comprises ammonia, syngas, hydrogen, methanol, carbon monoxide, a hydrocarbon, or combinations thereof. In an embodiment, the cathode is configured to reduce water to hydrogen electrochemically or configured to reduce carbon dioxide to carbon monoxide electrochemically. In an embodiment, the cathode is configured to simultaneously reduce water and carbon dioxide to hydrogen and carbon monoxide electrochemically.Production of Valuable Products

[0056] In various embodiments, the produced CO and / or H2 is extracted from the cathode, optionally purified, and sent to a chemical producer selected from the group consisting of Fischer-Tropsch reactor, methanol producer, ethanol producer, hydrocarbon producer, plasticmonomer producer, and combinations thereof. The Fischer-Tropsch reactor is able to generate valuable products such as naphtha, gasoline, diesel, wax. The produced methanol may be further converted to gasoline, ethylene, acetic acid, formaldehyde, methyl acetate, polyolefins, dimethyl ether (DME), or combinations thereof. In various embodiments, the chemical producer is configured to receive carbon monoxide and hydrogen from a separator purified. Additionally, the system may comprise a polymerization unit to convert the plastic monomers to various types of plastics. In some embodiments, the methods provided in this disclosure includes utilizing the extracted H2 or CO or both to synthesize or produce hydrocarbons, alcohols, polymers, or plastics. The configurations and arrangements for utilizing the produced CO and H2 are known to one skilled in the art, and all such configurations and arrangements are within the scope of this disclosure.

[0057] This reactor for CO and H2 production according to this disclosure has various advantages. CO generation from CO2 is desirable because it reduces greenhouse gas emission. Making CO and H2 locally (on site) is inherently safer than transporting CO and H2 in pressurized containers or vessels. The process of this disclosure utilizes efficient electrochemical pathways but yet needs no electricity. The CO / CO2 and H2 / H2O separation from the cathode exhaust is easy and inexpensive. As such, the method and system of this disclosure are cost competitive both in capital equipment and in operational expenses.

[0058] In various embodiments, the ratio of H2 / CO co-production is controlled by varying the input ratio of H2O / CO2, by varying the operation temperature, by varying the fuel composition, or combinations thereof. As such, the produced H2 / CO is suitable for various downstream chemical productions without the need for further purification or modification. This is another major advantage of the process and system of this disclosure.

[0059] It is to be understood that this disclosure describes exemplary embodiments for implementing different features, structures, or functions of the invention. Exemplary embodiments of components, arrangements, and configurations are described to simplify the present disclosure; however, these exemplary embodiments are provided merely as examples and are not intended to limit the scope of the invention. The embodiments as presented herein may be combined unless otherwise specified. Such combinations do not depart from the scope of the disclosure.

[0060] Additionally, certain terms are used throughout the description and claims to refer to particular components or steps. As one skilled in the art appreciates, various entities may refer to the same component or process step by different names, and as such, the namingconvention for the elements described herein is not intended to limit the scope of the invention. Further, the terms and naming convention used herein are not intended to distinguish between components, features, and / or steps that differ in name but not in function.

[0061] While the disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and description. It should be understood, however, that the drawings and detailed description are not intended to limit the disclosure to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of this disclosure.

[0062] A. A method of carbon capture comprising providing a reactor having an anode, a cathode, and an electrolyte between and in contact with the anode and the cathode, wherein the electrolyte conducts oxide ions and electrons; introducing a carbonaceous gas to the anode; introducing steam and hydrogen (H2) or carbon dioxide (CO2) and carbon monoxide (CO) to the cathode, wherein steam or CO2 is the dominant component; producing carbon dioxide (CO2) at the anode, wherein a CO2 partial pressure is greater than 18 kPa in an anode exhaust; and producing H2 or CO or both at the cathode.

[0063] B. The method of Paragraph A, wherein the anode exhaust has a pressure of from 1 atm to 5 atm, or from 1 atm to 3 atm, or from 1 atm to 2 atm.

[0064] C. The method of either one of Paragraphs A and B, wherein a CO2 content in the anode exhaust is from 20vol% to 100vol%, or from 30vol% to 90vol%, or from 40vol% to 70vol%.

[0065] D. The method of any one of Paragraphs A-C, wherein the cathode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof.

[0066] E. The method of any one of Paragraphs A-D, wherein the anode consists of LST and CoCGO or consists of Cu-CoCGO, wherein the carbonaceous gas comprises CO or a hydrocarbon.

[0067] F. The method of any one of Paragraphs A-E, wherein the anode comprises Cu- CoCGO and a material selected from the group consisting of LST, LSTM (Lao.4Sro.6Tio.4Mno.603-5), LSCM (Lao.TsS sCro.sMno.sOs-s), and Ba doped Ceria, wherein the carbonaceous gas comprises CO or a hydrocarbon.

[0068] G. The method of any one of Paragraphs A-F, wherein the anode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ,LSGM, CoCGO, LST, and combinations thereof, wherein the carbonaceous gas comprises CO or reformed gases from hydrocarbons.

[0069] H. The method of Paragraph G, wherein the anode and the cathode have the same elements.

[0070] I. The method of Paragraph H, wherein the anode and the cathode comprise Ni-YSZ or Ni-CGO or Ni-CoCGO or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ or LST-YSZ or LST-CGO or LST-CoCGO.

[0071] J. The method of any one of Paragraphs A-I, wherein the electrolyte comprises an electronically conducting phase and an ionically conducting phase; wherein the electronically conducting phase comprises doped lanthanum chromite or LST or an electronically conductive metal or combination thereof; and wherein the ionically conducting phase comprises a material selected from the group consisting of CGO, SDC, YSZ, LSGM, SSZ, SCZ, and combinations thereof.

[0072] K. The method of any one of Paragraphs A- J, wherein the electrolyte comprises CoCGO or LST -stabilized zirconia, wherein the stabilized zirconia comprises YSZ or SSZ or SCZ, and wherein the LST comprises LaSrCaTiO3.

[0073] L. The method of any one of Paragraphs A-K, wherein the electrolyte comprises Nickel, Copper, Cobalt, Lanthanum, Strontium, Titanium, or Niobium -doped zirconia.

[0074] M. The method of any one of Paragraphs A-L, wherein the electrolyte, the anode, and the cathode have the same elements.

[0075] N. The method of Paragraph M, wherein the electrolyte, the anode, and the cathode comprise Ni-YSZ or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ.

[0076] O. The method of any one of Paragraphs A-N, wherein the reactor comprises no interconnect and wherein the reactor receives no electricity and produces no electricity.

[0077] P. The method of any one of Paragraphs A-O, wherein the carbonaceous gas comprises biogas, landfill gas, cement kiln plant flue gas, power plant flue gas, steelmaking off gas, smelter off gas, refinery fuel gases, refinery products, or combinations thereof.

[0078] Q. The method of any one of Paragraphs A-P, wherein the reactor is operated at a temperature of no less than 550°C, or no less than 650°C, or no less than 700°C.

[0079] R. The method of any one of Paragraphs A-Q, wherein the anode and the cathode are exposed to reducing environments simultaneously during the entire time of operation.

[0080] S. The method of any one of Paragraphs A-R, further comprising extracting H2 or CO or both from the cathode exhaust.

[0081] T. The method of Paragraph S, further comprising utilizing the extracted H2 or CO or both to synthesize hydrocarbons, alcohols, polymers, or plastics.

Claims

WHAT IS CLAIMED IS:

1. A method of carbon capture comprising: providing a reactor having an anode, a cathode, and an electrolyte between and in contact with the anode and the cathode, wherein the electrolyte conducts oxide ions and electrons; introducing a carbonaceous gas to the anode; introducing steam and hydrogen (H2) or carbon dioxide (CO2) and carbon monoxide (CO) to the cathode, wherein steam or CO2 is the dominant component; producing carbon dioxide (CO2) at the anode, wherein a CO2 partial pressure is greater than 18 kPa in an anode exhaust; and producing H2 or CO or both at the cathode.

2. The method of claim 1, wherein the anode exhaust has a pressure of from 1 atm to 5 atm, or from 1 atm to 3 atm, or from 1 atm to 2 atm.

3. The method of claim 1, wherein a CO2 content in the anode exhaust is from 20vol% to 100vol%, or from 30vol% to 90vol%, or from 40vol% to 70vol%.

4. The method of claim 1, wherein the cathode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, and combinations thereof.

5. The method of claim 1, wherein the anode consists of LST and CoCGO or consists of Cu-CoCGO, wherein the carbonaceous gas comprises CO or a hydrocarbon.

6. The method of claim 1, wherein the anode comprises Cu-CoCGO and a material selected from the group consisting of LST, LSTM (Lao.4Sro.6Tio.4Mno.603-5), LSCM (Lao.75Sro.25Cro.5Mno.503-5), and Ba doped Ceria, wherein the carbonaceous gas comprises CO or a hydrocarbon.

7. The method of claim 1, wherein the anode comprises Ni or NiO and a material selected from the group consisting of YSZ, CGO, SDC, SSZ, SCZ, LSGM, CoCGO, LST, andcombinations thereof, wherein the carbonaceous gas comprises CO or reformed gases from hydrocarbons.

8. The method of claim 7, wherein the anode and the cathode have the same elements.

9. The method of claim 8, wherein the anode and the cathode comprise Ni-YSZ or Ni-CGO or Ni-CoCGO or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ or LST-YSZ or LST-CGO or LST-CoCGO.

10. The method of claim 1, wherein the electrolyte comprises an electronically conducting phase and an ionically conducting phase; wherein the electronically conducting phase comprises doped lanthanum chromite or LST or an electronically conductive metal or combination thereof; and wherein the ionically conducting phase comprises a material selected from the group consisting of CGO, SDC, YSZ, LSGM, SSZ, SCZ, and combinations thereof.

11. The method of claim 1, wherein the electrolyte comprises CoCGO or LST -stabilized zirconia, wherein the stabilized zirconia comprises YSZ or SSZ or SCZ, and wherein the LST comprises LaSrCaTiCh.

12. The method of claim 1, wherein the electrolyte comprises Nickel, Copper, Cobalt, Lanthanum, Strontium, Titanium, or Niobium -doped zirconia.

13. The method of claim 1, wherein the electrolyte, the anode, and the cathode have the same elements.

14. The method of claim 13, wherein the electrolyte, the anode, and the cathode comprise Ni-YSZ or LaSrFeCr-SSZ or LaSrFeCr-SCZ or LST-SCZ.

15. The method of claim 1, wherein the reactor comprises no interconnect and wherein the reactor receives no electricity and produces no electricity.

16. The method of claim 1, wherein the carbonaceous gas comprises biogas, landfill gas, cement kiln plant flue gas, power plant flue gas, steelmaking off gas, smelter off gas, refinery fuel gases, refinery products, or combinations thereof.

17. The method of claim 1, wherein the reactor is operated at a temperature of no less than 550°C, or no less than 650°C, or no less than 700°C.

18. The method of claim 1, wherein the anode and the cathode are exposed to reducing environments simultaneously during the entire time of operation.

19. The method of claim 1 comprising extracting H2 or CO or both from the cathode exhaust.

20. The method of claim 19 comprising utilizing the extracted H2 or CO or both to synthesize hydrocarbons, alcohols, polymers, or plastics.

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