Abstract: A liquid fuel synthesis system includes a liquid fuel synthesis portion and a sweep gas supply unit. The liquid fuel synthesis portion is partitioned into a non-permeation side space and a permeation side space by the separation membrane. A temperature of the sweep gas flowing into the permeation side space is higher than at least one of a temperature of the raw material gas flowing into the non-permeation side space and a temperature of a first outflow gas flowing out of the non-permeation side space. A temperature of a second outflow gas flowing out of the permeation side space is higher than at least one of the temperature of the raw material gas flowing into the non-permeation side space and the temperature of the first outflow gas flowing out of the non-permeation side space.

Abstract: Described herein is a soda magcite composition, methods of manufacture of soda magcite compositions and use of soda magcite for carbon dioxide sequestration. The soda magcite composition comprises a mixture of magnesium hydroxide, metal hydroxide and water to create a composition that is highly effective at sequestering carbon dioxide.

Abstract: A flare gas recovery system includes a primary gas sweetening unit; and a liquid-driven ejector in continuous fluid communication with the primary gas sweetening unit. The ejector includes an inlet configured to receive a motive fluid including a regenerable amine solvent in a rich state from the primary gas sweetening unit; a gas inlet configured to receive a suction fluid including a gas; and a fluid outlet configured to either directly or indirectly discharge to the primary gas sweetening unit a two-phase fluid including a mixture of the suction fluid and the amine solvent in a rich state.

Abstract: Provided is a composition for removing a sulfur-containing compound contained in at least one of a liquid and gas, the sulfur-containing compound being at least one selected from the group consisting of hydrogen sulfide and an —SH group-containing compound, the composition containing an aldehyde and an amine whose conjugate acid has a pKa value of 11.3 or higher in water at 25° C.

Abstract: The invention relates to a process and plant for purifying a raw synthesis gas containing hydrogen and carbon monoxide as target components and carbon dioxide and sulfur components as disruptive components by gas scrubbing with a physically acting, liquid scrubbing medium selective for carbon dioxide and sulfur components. The process/the plant comprise an absorption apparatus, a hot regeneration apparatus, a preferably multistage flash regeneration apparatus and a reabsorber column supplied with the first portion of a stripping gas. According to the invention the flash regeneration apparatus is supplied with the second portion of the stripping gas.

Abstract: Provided herein are methods and systems to form calcium carbonate comprising vaterite, comprising dissolving limestone in an aqueous base solution under one or more precipitation conditions to produce a precipitation material comprising calcium carbonate and a supernatant solution, wherein the calcium carbonate comprises vaterite.

Abstract: The present disclosure provides systems and methods useful in capture of one more moieties (e.g., carbon dioxide) from a gas stream (i.e., direct air capture). In various embodiments, the systems and methods can utilize at least a scrubbing unit, a regeneration unit, and an electrolysis unit whereby an alkali solution can be used to strip the moiety (e.g., carbon dioxide) from the gas stream, the removed moiety can be regenerated and optionally purified for capture or other use, and a formed salt can be subjected to electrolysis to recycle the alkali solution back to the scrubber for re-use with simultaneous production of one or more further chemicals.

Abstract: In an embodiment, a method for recovering carbon dioxide comprises introducing a carbon dioxide rich stream to a scrubber comprising a metal hydroxide and allowing the carbon dioxide to react with the metal hydroxide to form a metal carbonate; directing a metal carbonate stream from the scrubber to an electrochemical concentrator and applying a potential to the electrochemical concentrator to form a metal hydroxide stream and a separated carbon dioxide stream; directing the metal hydroxide stream comprising a recovered metal hydroxide and hydrogen to an electrochemical separator and applying a potential to the electrochemical separator to separate the hydrogen forming a hydrogen recycle stream from the recovered metal hydroxide forming a metal hydroxide recycle stream; and directing the separated carbon dioxide stream to a gas liquid separator and separating the separated carbon dioxide stream into a recycled water stream and a concentrated carbon dioxide stream.

Abstract: A method of removing carbon dioxide from an atmosphere and generating hydrogen includes capturing carbon dioxide from the atmosphere in an alkaline capture solution, sending the alkaline capture solution to a series of electrolyzers in a CO2-rich path, wherein each electrolyzer cell raises the acidity of the input CO2-rich solution to produce an acidified CO2-rich solution, removing carbon dioxide from the acidified CO2-rich solution at a carbon dioxide removal unit operation to produce a CO2-poor solution, sending the CO2-poor solution to the series of electrolyzers in a return path, wherein each electrolyzer raises the alkalinity of the return CO2-poor solution to produce a basified CO2-poor solution, wherein a difference in pH between the CO2-rich solution and the CO2-poor solution within each electrolyzer is less than 3, and returning the basified CO2-poor solution to the carbon dioxide capture unit operation.

Abstract: A system and method for creating a useful carbon-enriched media in a reactor which will assimilate carbon into an algae biomass, requires measuring a respective carbon concentration of the media, C(measured), as it enters, and as it leaves the reactor. Operationally, desired carbon concentration values are preset, C(set), and are provided along with values obtained for C(measured) as input to a system controller. Respective differentials between C(measured) and C(set) at the reactor's input and output ports are determined by the controller and are used to control a volumetric fluid flow rate of the media through the reactor. Specifically, the controller establishes a volumetric fluid flow rate of the media as it is passed through an absorber where the media is carbon-enriched by interaction with combustion gases from an external source (e.g. a power plant).

Abstract: Provided is a facilitated CO2 transport membrane having improved CO2 permeance and improved CO2 selective permeability. The facilitated CO2 transport membrane includes a separation-functional membrane comprising a hydrophilic polymer gel membrane which contains a CO2 carrier and a CO2 hydration catalyst, wherein the hydrophilic polymer is a copolymer including a first structural unit derived from an acrylic acid cesium salt or an acrylic acid rubidium salt and a second structural unit derived from vinyl alcohol. More preferably, the CO2 hydration catalyst has catalytic activity at a temperature of 100° C. or higher.

Abstract: Provided herein are compositions, methods, and systems for a material containing metastable carbonate and stabilizer. Methods for making the compositions and using the compositions are also provided.

Abstract: A process for the removal of co2 from a gas comprising the steps of: (a) contacting the gas (1) in an absorber (2) with an aqueous solution of one or more carbonate compounds in the presence of an accelerator, thereby reacting at least part of the co2 to form a bicarbonate compound, under conditions such that at least a part of the bicarbonate compound formed precipitates, forming a bicarbonate slurry; (b) subjecting at least part of the bicarbonate slurry to a concentration step (5) to obtain an aqueous solution (6) and a concentrated bicarbonate slurry (7), wherein the concentrated bicarbonate slurry comprises from 20 to 80 wt % of bicarbonate compounds; (c) returning at least part of the aqueous solution to the absorber; (d) pressurising (8) the concentrated bicarbonate slurry, (e) transferring the pressurized concentrated bicarbonate slurry to a regenerator (12) and applying heat to obtain a co2-rich gas stream (13) and a regenerated carbonate stream (14).

Abstract: Process for the removal of CO2 from a gas comprising CO2, comprising the steps of: (a) contacting the gas in an absorber (102) with an aqueous solution of one or more carbonate compounds in the presence of an accelerator, thereby reacting at least part of the CO2 to form a bicarbonate compound, under conditions such that at least a part of the bicarbonate compound formed precipitates, forming a bicarbonate slurry; (b) subjecting at least part of the bicarbonate slurry to a concentration step (105) to obtain the aqueous solution and a concentrated bicarbonate slurry, wherein the concentrated bicarbonate slurry comprises in the range of from 10 to 60 wt % of bicarbonate compounds; (c) returning at least part of the aqueous solution to the absorber; (d) transferring a first part of the concentrated bicarbonate slurry to a first heat exchanger (110a), wherein the first part of the slurry is being heated against a hot lean solvent of a regenerator (112); (e) transferring a second part of the concentrated bicarbona

Abstract: The invention generally relates to a method for sequestration contaminates. More particularly, the invention relates to a significant performance enhancement over existing mineral carbonation processes through the use of a high mass transfer system and an efficient pH swing reaction. More particularly, aspects of the invention are directed to direct and indirect methods of sequestering contaminates.

Abstract: Hydraulic cement compositions that include a carbonate compound composition, e.g., a salt-water derived carbonate compound composition containing crystalline and/or amorphous carbonate compounds, are provided. Also provided are methods of making and using the hydraulic cements, as well as settable compositions, such as concretes and mortars, prepared therefrom. The cements and compositions produced therefrom find use in a variety of applications, including use in a variety of building materials and building applications.

Abstract: A process for manufacturing a catalyst composition includes the steps of (i) combining one or more soluble metal compounds with a solution of an alkaline metal carbonate precipitant to form a precipitate of insoluble metal carbonates, (ii) processing the insoluble metal carbonates into a catalyst or catalyst precursor with the evolution of carbon dioxide, (iii) recovering at least a portion of the evolved carbon dioxide, and (iv) reacting the recovered carbon dioxide with a suitable alkaline metal compound in an absorber column to generate an alkaline metal carbonate, wherein at least a portion of the generated alkaline metal carbonate is used as a precipitant in step (i).

Abstract: The present invention relates to a method for capturing CO2 from exhaust gas in an absorber (A1), wherein the CO2 containing gas is passed through an aqueous absorbent slurry wherein said aqueous absorbent slurry comprises an inorganic alkali carbonate, bicarbonate and at least one of an absorption promoter and a catalyst, and wherein the CO2 is converted to solids by precipitation in the absorber, said slurry having the precipitated solids is conveyed to a separating device (F1), in which the solids are separated off, essentially all of at least one of the absorption promoter and catalyst is recycled together with the remaining aqueous phase to the absorber.

Abstract: Systems, methods, and compositions are provided related to utilizing gypsum for CO2 sequestration to form solid products containing calcium carbonate.

Abstract: A method for the reduction of corrosion in a treatment unit acid used for separating hydrogen sulfide from and acid gas stream using an alkaline absorption solution. Ions comprising the S2? and/or HS? ions formed by the absorption of the hydrogen sulfide in the absorbent solution are subjected to in situ electrochemical oxidization to form polysulfide ions which form a protective coating on the surfaces of the unit.

Abstract: A method of scrubbing flue gas includes introducing flue gas comprising an acidic gas through an inlet into a tower; spraying an acid-absorptive fluid into the tower such that the acid-absorptive fluid contacts the flue gas; accumulating the acid-absorptive fluid in a recycle tank portion of the tower; and introducing an oxygen-containing gas into the acid-absorptive fluid in the recycle tank portion of the tower, wherein the oxygen-containing gas is introduced through at least one opening of an aerator, each of the at least one openings are positioned to release the oxygen-containing gas at least at a distance greater than or equal to a predetermined radial distance from the flue gas inlet, the predetermined radial distance being equal to at least 10% of a diameter of the recycle tank portion of the tower.

Abstract: CO2-sequestering formed building materials are provided. The building materials of the invention include a composition comprising a carbonate/bicarbonate component. Additional aspects of the invention include methods of making and using the CO2-sequestering formed building material.

Abstract: An apparatus and method for removing contaminants from a gas stream is provided which includes (a) introducing the gas stream into a reaction chamber of a scrubber; (b) oxidizing first contaminants in a liquid phase with a reactive species in a sump of the scrubber for providing an oxidizing solution; (c) oxidizing second contaminants in a gas phase of the gas stream above the sump with excess reactive species disengaging from the oxidizing solution in the sump; (d) oxidizing and scrubbing third contaminants in a gas-liquid contact assembly disposed above the gas stream.

Abstract: The invention provides methods and apparatuses for removing carbon dioxide from a gas stream. In particular, the invention provides methods and apparatuses for absorbing carbon dioxide from a coal-fired boiler flue gas stream using an absorbing solution and for regeneration of an alkaline component used in the absorbing solution. In one embodiment, the invention provides a method for removing carbon dioxide from a gas stream by contacting a gas stream containing carbon dioxide with an alkaline liquid stream; absorbing at least a portion of the carbon dioxide into the alkaline liquid stream to produce absorbed carbon dioxide; and catalyzing a reaction of the absorbed carbon dioxide to a form of carbonate. In other embodiments, the invention provides a method for producing salable calcium carbonate, calcium chloride, and carbon dioxide gas.

Abstract: The present invention relates to a new process for removal of carbon dioxide from a feed gas, wherein the feed gas is fed to and concentrated in a stripper column (A) before condensation of the gaseous carbon dioxide. The present invention also relates to different uses of the removed carbon dioxide and to a plant for removal of carbon dioxide from the feed gas.

Abstract: The present invention relates to systems and processes for reducing the amount of carbon dioxide in a carbon dioxide-containing gas. In particular, the carbon dioxide-containing gas is contacted with a carbonate-containing solution. At least a portion of carbon dioxide in the carbon dioxide-containing gas is absorbed in the carbonate-containing solution to produce a carbon dioxide-, carbonate-containing solution. A heat recovery mechanism is employed to recover heat from the carbon dioxide-, bicarbonate-, carbonate-containing solution exiting the chamber to maintain the temperature of the chamber within a range of from about 50° C. to about 90° C.

Abstract: The absorptive removal of carbon dioxide from biogas using a scrubbing liquid in which carbon dioxide is chemically bound proceeds by heating the loaded scrubbing liquid, occurring after the absorption, to a temperature at which liberation of CO2 begins. Immediately thereafter, the loaded scrubbing liquid is fed to at least one centrifugal separator for separating off the gas phase from the liquid phase, wherein methane and dissolved fractions of CO2 escape via the gas phase. After separation is complete, the gas phase is passed into the absorber unit and the liquid phase is further heated to the temperature required for desorption and fed to the desorption unit for regeneration.

Abstract: The present disclosure provides for a solvent composition for recovery of carbon dioxide from gaseous mixture, comprising diethanolamine, piperazine or its derivative, alkali salt, optionally along with cupric carbonate. The disclosure relates to improved solvent formulations that utilizes less energy and increased carbon capture efficiency. The disclosure also addresses the high CO2 loading capacity and energy requirement over the existing carbon dioxide capture solvent.

Abstract: Reduced-carbon footprint concrete compositions, and methods for making and using the same, are provided. Aspects of the reduced-carbon footprint concrete compositions include CO2-sequestering carbonate compounds, which may be present in the hydraulic cement and/or aggregate components of the concrete. The reduced-carbon footprint concrete compositions find use in a variety of applications, including use in a variety of building materials and building applications.

Abstract: An apparatus 100 for scrubbing flue gas 122, the apparatus 100 including a tower 140 having an inlet 120 receiving a flow of flue gas 122 and a recycle tank portion 142; a fluid 162 disposed in the recycle tank portion 142; and an aerator 150 having at least one opening 152 for introduction of an oxygen-containing gas 154 into the fluid 162, wherein the at least one opening 152 is positioned to release the oxygen-containing gas 154 at least at a distance greater than or equal to a predetermined radial distance F from the inlet 120, the predetermined radial distance F being equal to at least 10% of a diameter of the recycle tank portion 142.

Abstract: CO2-sequestering formed building materials are provided. The building materials of the invention include a composition comprising a carbonate/bicarbonate component. Additional aspects of the invention include methods of making and using the CO2-sequestering formed building material.

Abstract: A solvent based flue gas processing system for removing CO2 from a flue gas stream is described. A catalyst is provided to increase the efficiency of the solvent in capturing CO2 from the flue gas stream or in regenerating the solvent.

Abstract: The absorptive removal of carbon dioxide from biogas using a scrubbing liquid in which carbon dioxide is chemically bound proceeds by heating the loaded scrubbing liquid, occurring after the absorption, to a temperature at which liberation of CO2 begins. Immediately thereafter, the loaded scrubbing liquid is fed to at least one centrifugal separator for separating off the gas phase from the liquid phase, wherein methane and dissolved fractions of CO2 escape via the gas phase. After separation is complete, the gas phase is passed into the absorber unit and the liquid phase is further heated to the temperature required for desorption and fed to the desorption unit for regeneration.

Abstract: A gas separation process for treating an exhaust gas stream from a combustion processes. The invention involves routing a first portion of the exhaust stream to a carbon dioxide capture step, and flowing a second portion of the exhaust stream and at least a portion of an off-gas stream from the carbon dioxide capture step across the feed side of a membrane, while flowing a sweep gas stream, usually air, across the permeate side, and then passing the resulting permeate sweep stream back to the combustor.

Abstract: The present invention is based on the realization that the carbon dioxide component of industrial gas streams also containing steam can be processed so to utilize either as latent and/or sensible heat the heat available from the steam component to assist in separating carbon dioxide from the remainder of the gas stream. For example, flue gases produced by power stations burning brown coal, black coal or natural gas inherently contain a useful amount of energy that can be harnessed according to the present invention. According to particular preferred forms of the invention, nitrogen and sulphur constituent such as SOx and NOx, H2S and other nitrogen containing compounds may also be removed from the gas stream through direct contact with the absorbing medium and used to produce by-products such as fertilizer material.

Abstract: A process for removing CO2 from a CO2 containing gas stream in which the CO2 containing gas stream is contacted with an aqueous ammonium solution. The aqueous ammonia solution comprises 0.1-40% w/v, v/v/ w/w ammonia, and a soluble salt at a concentration range of 0.01%-10% wt or v/v or w/v, the soluble salt having cations selected from the group of group IA, IIA, IIIA and IVA metals with counter anions selected from the group of anion of group VIIA elements, NO3?, SO42?, OH43?, PO43? and HCO3?. The invention also extends to a CO2 capture solvent comprising an aqueous ammonia solution and the above soluble salt.

Abstract: The invention relates to a method for removing gas components SOX, NOx, and CO2 from a flue gas, comprising the steps of: a) contacting the flue gas with a first liquid medium which provides a first plasma containing reactive electrons or ions in an amount such that the gas molecules SOX are subject to impingement of the electrons or ions in the first plasma to enable the dissociation of the gas molecules SOX so as to remove SOx from the flue gas; b) contacting the flue gas obtained from step a) with a second liquid medium which provides a second plasma containing reactive electrons or ions in an amount such that the gas molecules CO2 are subject to impingement of the electrons or ions in the second plasma to enable the dissociation of the gas molecules CO2 so as to remove CO2 from the flue gas; and c) contacting the flue gas obtained from step b) with a third liquid medium which provides a third plasma containing reactive electrons or ions in an amount such that the gas molecules NOx are subject to impingeme

Abstract: The gaseous effluent to be treated is contacted in column C1 with an absorbent solution selected for its property of forming two separable phases when it is heated. The regenerated absorbent solution is separated into two phases in drum B1; a fraction rich in water and a fraction rich in reactive compounds. Separation allows to optimize the operations performed on the regenerated absorbent solution. On the one hand, separation allows to carry out vaporization, through reboiler R1, of a fraction of the absorbent solution, preferably containing a limited reactive compound concentration in relation to the absorbent solution, thus limiting their degradation. On the other hand, separation of the phases allows to reduce the amount of solution to be treated in order to remove the non-regeneratable salts and thus to reduce the costs linked with their elimination. Finally, separation allows to eliminate the degradation products by carrying out a specific and suitable purification for each phase.

Abstract: CO2 capture from flue gas is a costly procedure, usually due to the energy required for regeneration of the capture medium. One potential medium which could reduce such an energy consumption, however, is Na2CO3. It has been well studied as a sorbent, and it is understood that the theoretical energy penalty of use of Na2CO3 for CO2 separation is low, due to the relatively low heat of reaction and low heat capacity of the material. While it offers some advantages over other methods, its primary downfall is the slow reaction with CO2 during adsorption and the slow Na2CO3 regeneration process. In an effort to reduce the energy penalty of post-combustion CO2 capture, the catalytic decomposition of NaHCO3 is studied. Nanoporous TiO(OH)2 is examined as a potential catalytic support for a cyclic Na2CO3/NaHCO3 based CO2 capture process.

Abstract: A method for the removal of CO2 from exhaust gases, e.g., exhaust gases from plants for pig-iron production or exhaust gases from synthesis-gas plants, includes removing CO2 using chemical and/or physical absorption, wherein the heat for regenerating the absorbent is obtained at least partially from an air separation plant. As a result, the CO2 can be separated from the exhaust gases to a greater extent than in the pressure-swing adsorption of other gases, but a lower-order energy carrier can additionally be used for this purpose.

Abstract: A process for the removal of CO2 and/or H2S from a gas comprising CO2 and/or H2S. The process comprises contacting the gas in an absorber with an absorbing solution wherein the absorbing solution absorbs at least part of the CO2 and/or H2S so as, to produce a CO2 and/or H2S lean gas and a CO2 and/or H2S rich absorbing solution. At least part of the CO2 and/or H2S rich absorbing solution is heated to produce a heated CO2 and/or H2S rich absorbing solution. At least part of the CO2 and/or H2S is removed from the heated CO2 and/or H2S rich absorbing solution in a regenerator to produce a CO2 and/or H2S rich gas and a CO2 and/or H2S lean absorbing solution. In the process, at least part of the heat for heating the CO2 and/or H2S rich absorbing solution in step b) is obtained in a sequence of multiple heat exchangers.

Abstract: The present invention provides a method and apparatus for removing a contaminant, such as carbon dioxide, from a gas stream, such as ambient air. The contaminant is removed from the gas stream by a sorbent which may be regenerated using a humidity swing, a thermal swing, or a combination thereof. The sorbent may comprise a substrate having embedded positive ions and individually mobile negative ions wherein the positive ions are sufficiently spaced to prevent interactions between the negative ions. Where a thermal swing is used, heat may be conserved by employing a heat exchanger to transfer heat from the regenerated sorbent to an amount of sorbent that is loaded with the contaminant prior to regeneration.

Abstract: Carbon blacks, such as rubber blacks, having a low PAH concentration are described. Furthermore, elastomeric or rubber compositions containing the carbon black of the present invention are further described, as well as methods of making carbon black having a low PAH concentration.

Abstract: The present invention relates to a method for potassium or nitrogen based fertilizer production from the byproducts of flue gas processing. Further, the present invention relates to a method for isolating fertilizer precursors from a stream of flue gas. The method including a dry sorbent operation, wet scrubbing operation and an oxidization step to remove air pollutants, a carbon dioxide capture step and a sodium bicarbonate precipitation step. The steps involved in the removal of air pollutants are used to isolate precursors for the production of fertilizer. Additionally, the present invention relates to a method for the removal of carbon dioxide from a flue gas stream.

Abstract: The present invention is based on the realization that the carbon dioxide component of industrial gas streams also containing steam can be processed so to utilize either as latent and/or sensible heat the heat available from the steam component to assist in separating carbon dioxide from the remainder of the gas stream. For example, flue gases produced by power stations burning brown coal, black coal or natural gas inherently contain a useful amount of energy that can be harnessed according to the present invention. According to particular preferred forms of the invention, nitrogen and sulphur constituent such as SOx and NOx, H2S and other nitrogen containing compounds may also be removed from the gas stream through direct contact with the absorbing medium and used to produce by-products such as fertiliser material.

Abstract: A method for collecting combustion gases by (a) contacting a liquid phase with a gas flow containing said gases, where the liquid phase contains carbonate/bicarbonate buffer salts in a ratio of around 2:1, with a total inorganic carbon concentration no higher than 25 g/L and pH values between 8 and 12; and (b) recovering the CO2-rich liquid phase produced in step (a).

Abstract: There is provided a process for the capture and sequestration of carbon dioxide that would otherwise enter the atmosphere and contribute to global warming and other problems. CO2 capture is accomplished by reacting carbon dioxide in flue gas with an alkali metal carbonate, or a metal oxide, particularly containing an alkaline earth metal or iron, to form a carbonate salt. A preferred carbonate for CO2 capture is a dilute aqueous solution of additive-free (Na2CO3). Other carbonates include (K2CO3) or other metal ion that can produce both a carbonate and a bicarbonate salt. Examples of suitable metal oxides include several alkaline earths including CaO and MgO. The captured CO2 is preferably sequestered using any available mineral or industrial waste that contains calcium magnesium or iron in non-carbonate forms, or iron in the Fe+2 oxidation state.

Abstract: Processes are disclosed for managing the reduction of carbon dioxide emissions by a process of mining, acquiring water, capturing carbon and disposing of water containing bicarbonates. A number of process configurations of accelerated weathering of carbonate mineral-containing materials (AWC) reactors are disclosed.

Abstract: A method and an apparatus for removing carbon dioxide (CO2) from sulphur dioxide containing (SO2) flue gases, wherein the flue gases are washed with washing solution in a scrubber, which comprises at least two washing stages. In the first washing stage the flue gases are washed for removing the sulphur dioxide in the flue gases and after that in the second washing stage for removing carbon dioxide (CO2). Sodium carbonate solution (Na2CO3) is used as washing solution in both the first and the second washing stages.

Abstract: Mixing small amounts of an inorganic halide, such as NaCl, to basic copper carbonate followed by calcination at a temperature sufficient to decompose the carbonate results in a significant improvement in resistance to reduction of the resulting copper oxide. The introduction of the halide can be also achieved during the precipitation of the carbonate precursor. These reduction resistant copper oxides can be in the form of composites with alumina and are especially useful for purification of gas or liquid streams containing hydrogen or other reducing agents. These reduction resistant copper oxides can function at near ambient temperatures.