Abstract: Systems and methods are provided for performing reforming in a manner where the flows for providing heat for the endothermic reforming reaction are counter-current to the flows for the reforming reaction. Although the flows are counter-current, the systems and methods also allow the heating profile of the reactor to have a temperature peak toward the middle of the reactor, as opposed to at the end of the reactor. This shift of the temperature peak toward the middle allows for improved heat utilization and recovery during operation of the reactor.

Abstract: The present disclosure relates to methods and systems for algae cultivation including the integration of electrochemical carbonate production for enhancing algae growth. More particularly, the present disclosure relates to methods and systems for producing a sodium hydroxide from brine using an electrochemical cell, contacting the sodium hydroxide stream with a CO2 gas sweep and producing a carbonate stream, and cultivating an algae slurry in a cultivation vessel comprising at least a portion of the carbonate stream.

Abstract: Catalyst systems are provided for reforming of hydrocarbons, along with methods for using such catalyst systems. The catalyst systems can be deposited or otherwise coated on a surface or structure, such as a monolith, to achieve improved activity and/or structural stability. The metal oxide support layer can correspond to a thermally stable metal oxide support layer, such as a metal oxide support layer that is thermally phase stable at temperatures of 800° C. to 1600° C. The catalyst systems can be beneficial for use in cyclical reaction environments, such as reverse flow reactors or other types of reactors that are operated using flows in opposing directions and different times within a reaction cycle.

Abstract: Systems and methods are provided for performing CO2 sorption and desorption using a sorbent structure with an integrated heat pump. The integrated heat pump can allow at least a portion of the heat generated during sorption to be recovered by forming steam from water. The steam raised during the sorption process can then be compressed and optionally heated to raise the temperature of the steam. The compressed and optionally heated steam can then be used as at least a portion of the steam for desorption of CO2 in the same sorbent bed or a different sorbent bed. By recovering the heat of sorption to raise steam, substantial energy savings can be achieved relative to a conventional process.

Abstract: A method includes containing an algae media within a contactor, introducing a stream of natural gas comprising up to 80 wt % carbon dioxide (CO2) into the contactor, contacting the natural gas on the algae media and thereby allowing the algae media to consume CO2 from the natural gas, and discharging a stream of natural gas comprising 2 wt % or less CO2 from the contactor.

Abstract: Systems and methods are provided for using size-reversing materials in vessels where direct heating is used to at least partially provide heat for reforming reactions under cyclic reforming conditions. An example of a size-reversing material is the combination of NiO and Al2O3. It has been discovered that size-reversing materials can undergo a phase transition that can assist with re-dispersion of metal at elevated temperatures. This can assist with maintaining catalytic activity for reforming over longer time periods in the presence of cyclic reforming conditions.

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 performing CO2 sorption and desorption using a sorbent structure with an integrated heat pump. The integrated heat pump can allow at least a portion of the heat generated during sorption to be recovered by forming steam from water. The steam raised during the sorption process can then be compressed and optionally heated to raise the temperature of the steam. The compressed and optionally heated steam can then be used as at least a portion of the steam for desorption of CO2 in the same sorbent bed or a different sorbent bed. By recovering the heat of sorption to raise steam, substantial energy savings can be achieved relative to a conventional process.

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: A reforming element for a molten carbonate fuel cell stack and corresponding methods are provided that can reduce or minimize temperature differences within the fuel cell stack when operating the fuel cell stack with enhanced CO2 utilization. The reforming element can include at least one surface with a reforming catalyst deposited on the surface. A difference between the minimum and maximum reforming catalyst density and/or activity on a first portion of the at least one surface can be 20% to 75%, with the highest catalyst densities and/or activities being in proximity to the side of the fuel cell stack corresponding to at least one of the anode inlet and the cathode inlet.

Abstract: A system includes a photobioreactor that provides a channel configured to contain an algae slurry, a duct positioned adjacent the channel and configured to convey a gas, and a barrier separating the duct from the channel and providing one or more apertures to allow a portion of the gas to be injected into the algae slurry from the duct.

Abstract: A system for growing algae includes a pivot arm pivotally coupled to a pivot connection positioned in a pond containing water and algae, and a mixing device coupled to the pivot arm and extending into the pond to mix the water and the algae as the pivot arm rotates.

Abstract: A reforming element for a molten carbonate fuel cell stack and corresponding methods are provided that can reduce or minimize temperature differences within the fuel cell stack when operating the fuel cell stack with enhanced CO2 utilization. The reforming element can include at least one surface with a reforming catalyst deposited on the surface. A difference between the minimum and maximum reforming catalyst density and/or activity on a first portion of the at least one surface can be 20% to 75%, with the highest catalyst densities and/or activities being in proximity to the side of the fuel cell stack corresponding to at least one of the anode inlet and the cathode inlet.

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: A system for growing and harvesting algae biomass includes a photo-bioreactor suitable for algae growth in water and a filter unit in fluid communication with the photo-bioreactor. An algae slurry, when at least partially contained within the photo-bioreactor, generates hydrostatic fluid pressure that exclusively drives the algae slurry to the filter unit and discharges a permeate.

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: Methods of the present disclosure may comprise: introducing a first effluent and a second effluent in a gasifier of a partial oxidation unit to produce a waste gas, wherein the first effluent comprises one or more hydrocarbon containing feeds and the second effluent comprises air, enriched air with oxygen or oxygen; selectively removing hydrogen sulfide (H2S) from the waste gas; combining the waste gas and steam in a water-gas shift unit to produce a shift gas comprising hydrogen and carbon dioxide; separating the carbon dioxide from the shift gas in a carbon capture unit to produce a carbon dioxide-enriched effluent and an effluent comprising a hydrogen- and nitrogen-enriched mixture; and recovering the carbon dioxide from the carbon dioxide-enriched effluent.