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: 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: A system includes an algae bioreactor that contains an algae slurry, a heat exchanger in fluid communication with the algae bioreactor to receive the algae slurry from the algae bioreactor and heat and increase a pressure of the algae slurry, and one or more valves and a flash vessel in fluid communication with a discharge of the heat exchanger to flash the algae slurry and create steam and algae biomass. A separator receives the algae biomass from the flash vessel and separates oils from the algae biomass to generate a biofuel.

Abstract: Scale-up evaluation methods for algal biomass cultivation are provided, and more particularly, simultaneous scale-up evaluation methods for outdoor algal biomass cultivation are provided. The methods control various process variables to isolate the impact of scaling algal biomass cultivation, thereby permitting enhanced scale-up operation design to optimize the quality and quantity of algal biomass.

Abstract: Methods for autoflocculation of algae cells in an algae water slurry to facilitate harvesting. Algae cells are cultivated in the algae water slurry to produce an algal biomass and thereafter autoflocculated to allow for an enhanced dewatering harvesting process. Autoflocculation provides a cost-effective and efficient harvesting method compared to traditional dewatering processes.

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 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.

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: This invention relates to methods and apparatus for harvesting by-product oxygen from algae ponds or bioreactors (collectively, “algal biofuel production”) for use in an oxygen-requiring process that requires oxygen as a reactant such as syngas, hydrogen, or power production processes, which optionally can be integrated with the algal biofuel production. In some embodiments, the invention provides methods that include a method comprising: collecting oxygen from an algal biofuel production process; and using the collected oxygen in an oxygen-requiring process that requires oxygen as a reactant. In some embodiments, the invention provides systems that include an integrated system comprising: an algal bioreactor that produces biodiesel and oxygen, a pipeline for transporting oxygen to an oxygen-requiring process unit so that the oxygen can be used as reactant in the oxygen-requiring process unit, and the oxygen-requiring process unit.

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: High temperature metal monoliths for use in reverse flow reactors and methods of preparing said monoliths are provided.