Abstract: Systems and methods are provided for improving control of the temperature profile in a cyclic flow reactor, such as a reverse flow reactor, during operation. The improved temperature control is achieved in part based on inclusion of regions having reduced or minimized catalyst density with increased volumetric heat capacity within the reaction zone of the reactor. This improved control over the temperature profile is achieved while reducing or minimizing any loss of reaction capacity due to lowering the amount of catalyst in the reaction zone.

Abstract: Systems and methods are provided for performing both reforming and partial oxidation as part of the reaction step of a reaction cycle in a cyclic reaction environment such as a reverse flow reaction environment, where heat is provided by direct heating during a regeneration step. In some aspects, performing a combination of reforming and partial oxidation can allow for higher conversion of hydrocarbons than reforming alone while reducing or minimizing the peak temperatures within the cyclic reaction environment. In some aspects, performing both reforming and partial oxidation can also allow for an improved molar ratio of H2 to CO in the resulting effluent from the conversion reaction (relative to partial oxidation) while still maintaining high total conversion.

Abstract: Systems and methods are provided for using a high heat capacity gas as at least a portion of the diluent during the regeneration step of a reverse flow reactor process. Instead of using nitrogen or air as the primary diluent gas, CO2 and/or H2O can be added as diluent gas for the regeneration step in the reaction cycle. Increasing the heat capacity of the diluent gas provides a reduction in the peak temperature within the reactor relative to the amount of fuel combusted during regeneration. This can allow for a reduction in the volume of diluent used during regeneration and/or an increase in the amount of fuel used. Reducing the volume of diluent can reduce the pressure drop during regeneration, which can provide a corresponding reduction in the amount of compression required for recycle of the diluent. Increasing the amount of fuel can allow for a corresponding increase in the amount of endothermic reaction performed during the reaction step.

Abstract: Systems and methods are provided for using a reverse-flew reactor (or another reactor with flows in opposing directions at different parts of a process cycle) as part of a reaction system for production of ammonia and/or urea. Using a reverse flow reactor as part of an ammonia production process can provide a variety of advantages, including direct heating of the reaction environment, and simplified generation of multiple high-purity reagent streams for ammonia and/or urea synthesis.

Abstract: Systems and methods are provided for improving the operation of groups of reverse flow reactors by operating reactors in a regeneration portion of the reaction cycle to have improved flue gas management. The flue gas from reactor(s) at a later portion of the regeneration step can be selectively used for recycle back to the reactors as a diluent/heat transport fluid. The flue gas from a reactor earlier in a regeneration step can be preferentially used as the gas vented from the system to maintain the desired volume of gas within the system. This results in preferential use of higher temperature flue gas for recycle and lower temperature flue gas for venting from the system. This improved use of flue gas within a reaction system including reverse flow reactors can allow for improved reaction performance while reducing or minimizing heat losses during the regeneration portion of the reaction cycle.

Abstract: Systems and methods are provided for improving the operation of groups of reverse flow reactors by operating reactors in a regeneration portion of the reaction cycle to have improved flue gas management. The flue gas from reactor(s) at a later portion of the regeneration step can be selectively used for recycle back to the reactors as a diluent/heat transport fluid. The flue gas from a reactor earlier in a regeneration step can be preferentially used as the gas vented from the system to maintain the desired volume of gas within the system. This results in preferential use of higher temperature flue gas for recycle and lower temperature flue gas for venting from the system. This improved use of flue gas within a reaction system including reverse flow reactors can allow for improved reaction performance while reducing or minimizing heat losses during the regeneration portion of the reaction cycle.

Abstract: Systems and methods are provided for hydrogenation of CO2 in a reverse flow reactor environment via a reverse water gas shift reaction. A reverse flow reactor environment is suitable for performing endothermic reactions at high temperatures, where a reactant flow is passed into the reactor in a first portion of the cycle in a first flow direction while a combustion or heating flow is passed into the reactor during a second portion of the reaction cycle from the opposite direction. This can allow for efficient heating of surfaces within the reactor to provide heat for the endothermic reverse water gas shift reaction while reducing or minimizing incorporation of combustion products into the desired reaction products.

Abstract: Systems and methods are provided for performing hydrocarbon reforming within a reverse flow reactor environment (or another reactor environment with flows in opposing directions) while improving management of CO2 generated during operation of the reactor. The improved management of CO2 is achieved by making one or more changes to the operation of the reverse flow reactor. The changes can include using an air separation unit to provide an oxygen source with a reduced or minimized content of nitrogen and/or operating the reactor at elevated pressure during the regeneration stage. By operating the regeneration at elevated pressure, a regeneration flue gas can be generated that is enriched in CO2 at elevated pressure. The CO2-enriched stream can include primarily water as a contaminant, which can be removed by cooling while substantially maintaining the pressure of the stream. This can facilitate subsequent recovery and use of the CO2.

Abstract: Systems and methods are provided for using oxycombustion to provide heat within a reverse flow reactor environment. The oxygen for the oxycombustion can be provided by oxygen stored in an oxygen storage component in the reactor. By using an oxygen storage component to provide the oxygen for combustion during the regeneration step, heat can be added to a reverse flow reactor while reducing or minimizing addition of diluents and while avoiding the need for an air separation unit. As a result, a regeneration flue gas can be formed that is substantially composed of CO2 and/or H2O without requiring the additional cost of creating a substantially pure oxygen-containing gas flow.

Abstract: Ceramic compositions with catalytic activity are provided, along with methods for using such catalytic ceramic compositions. The ceramic compositions correspond to compositions that can acquire increased catalytic activity by cyclic exposure of the ceramic composition to reducing and oxidizing environments at a sufficiently elevated temperature. The ceramic compositions can be beneficial for use as catalysts in reaction environments involving swings of temperature and/or pressure conditions, such as a reverse flow reaction environment. Based on cyclic exposure to oxidizing and reducing conditions, the surface of the ceramic composition can be converted from a substantially fully oxidized state to various states including at least some dopant metal particles supported on a structural oxide surface.

Abstract: Processes for transforming an inert metal component into an active metal catalyst are provided. Apparatus and methods using active metal catalyst prepared according the process described herein are also provided.

Abstract: Ceramic compositions with catalytic activity are provided, along with methods for using such catalytic ceramic compositions. The ceramic compositions correspond to compositions that can acquire increased catalytic activity by cyclic exposure of the ceramic composition to reducing and oxidizing environments at a sufficiently elevated temperature. The ceramic compositions can be beneficial for use as catalysts in reaction environments involving swings of temperature and/or pressure conditions, such as a reverse flow reaction environment. Based on cyclic exposure to oxidizing and reducing conditions, the surface of the ceramic composition can be converted from a substantially fully oxidized state to various states including at least some dopant metal particles supported on a structural oxide surface.

Abstract: Processes for transforming an inert metal component into an active metal catalyst are provided. Apparatus and methods using active metal catalyst prepared according the process described herein are also provided.

Abstract: Systems and methods are provided for improving thermal management and/or efficiency of reaction systems including a reverse flow reactor for performance of at least one endothermic reaction and at least one supplemental exothermic reaction. The supplemental exothermic reaction can be performed in the recuperation zone of the reverse flow reactor system. By integrating the supplemental exothermic reaction into the recuperation zone, the heat generated from the supplemental exothermic reaction can be absorbed by heat transfer surfaces in the recuperation zone. The adsorbed heat can then be used to heat at least one of the fuel and the oxidant for the combustion reaction performed during regeneration, thus reducing the amount of combustion that is needed to achieve a desired temperature profile at the end of the regeneration step.

Abstract: Systems and methods are provided for improving thermal management and/or efficiency of reaction systems including a reverse flow reactor for performance of at least one endothermic reaction and at least one supplemental exothermic reaction. The supplemental exothermic reaction can be performed in the recuperation zone of the reverse flow reactor system. By integrating the supplemental exothermic reaction into the recuperation zone, the heat generated from the supplemental exothermic reaction can be absorbed by heat transfer surfaces in the recuperation zone. The adsorbed heat can then be used to heat at least one of the fuel and the oxidant for the combustion reaction performed during regeneration, thus reducing the amount of combustion that is needed to achieve a desired temperature profile at the end of the regeneration step.

Abstract: Systems and methods are provided for hydrogenation of CO2 in a reverse flow reactor environment via a reverse water gas shift reaction. A reverse flow reactor environment is suitable for performing endothermic reactions at high temperatures, where a reactant flow is passed into the reactor in a first portion of the cycle in a first flow direction while a combustion or heating flow is passed into the reactor during a second portion of the reaction cycle from the opposite direction. This can allow for efficient heating of surfaces within the reactor to provide heat for the endothermic reverse water gas shift reaction while reducing or minimizing incorporation of combustion products into the desired reaction products.

Abstract: Systems and methods are provided for using oxycombustion to provide heat within a reverse flow reactor environment. The oxygen for the oxycombustion can be provided by oxygen stored in an oxygen storage component in the reactor. By using an oxygen storage component to provide the oxygen for combustion during the regeneration step, heat can be added to a reverse flow reactor while reducing or minimizing addition of diluents and while avoiding the need for an air separation unit. As a result, a regeneration flue gas can be formed that is substantially composed of CO2 and/or H2O without requiring the additional cost of creating a substantially pure oxygen-containing gas flow.

Abstract: Systems and methods are provided for improving the operation of groups of reverse flow reactors by operating reactors in a regeneration portion of the reaction cycle to have improved flue gas management. The flue gas from reactor(s) at a later portion of the regeneration step can be selectively used for recycle back to the reactors as a diluent/heat transport fluid. The flue gas from a reactor earlier in a regeneration step can be preferentially used as the gas vented from the system to maintain the desired volume of gas within the system. This results in preferential use of higher temperature flue gas for recycle and lower temperature flue gas for venting from the system. This improved use of flue gas within a reaction system including reverse flow reactors can allow for improved reaction performance while reducing or minimizing heat losses during the regeneration portion of the reaction cycle.

Abstract: Systems and methods are provided for improving the operation of groups of reverse flow reactors by operating reactors in a regeneration portion of the reaction cycle to have improved flue gas management. The flue gas from reactor(s) at a later portion of the regeneration step can be selectively used for recycle back to the reactors as a diluent/heat transport fluid. The flue gas from a reactor earlier in a regeneration step can be preferentially used as the gas vented from the system to maintain the desired volume of gas within the system. This results in preferential use of higher temperature flue gas for recycle and lower temperature flue gas for venting from the system. This improved use of flue gas within a reaction system including reverse flow reactors can allow for improved reaction performance while reducing or minimizing heat losses during the regeneration portion of the reaction cycle.

Abstract: Systems and methods are provided for performing hydrocarbon reforming within a reverse flow reactor environment (or another reactor environment with flows in opposing directions) while improving management of CO2 generated during operation of the reactor. The improved management of CO2 is achieved by making one or more changes to the operation of the reverse flow reactor. The changes can include using an air separation unit to provide an oxygen source with a reduced or minimized content of nitrogen and/or operating the reactor at elevated pressure during the regeneration stage. By operating the regeneration at elevated pressure, a regeneration flue gas can be generated that is enriched in CO2 at elevated pressure. The CO2-enriched stream can include primarily water as a contaminant, which can be removed by cooling while substantially maintaining the pressure of the stream. This can facilitate subsequent recovery and use of the CO2.