Synergies between adsorption and energy conversion technologies

The analogy between heat uptake in a thermal regenerator and selective uptake of gas components in an adsorbent bed has inspired development of alternative architectures for adsorptive gas separation processes. An experimental laboratory sorption enhanced reaction approach for low pressure Haber-Bosch ammonia synthesis successfully used a Stirling engine mechanism to generate coordinated pressure swings and flow reversals of a thermally coupled PSA cycle. Attempts to apply similar mechanisms to air separation and hydrogen purification (rapid cycle PSA applications) motivated the development of very high surface area laminated parallel passage adsorbers for process intensification. Further efforts to develop compact PSA equipment for hydrogen purification and biogas upgrading led to practicable multiport rotary valves, enabling great simplification of PSA systems using multiple adsorbers. Higher degrees of simplicity and compactness for PSA and TSA processes were subsequently achieved using the laminated structured adsorbent in rotary adsorbers, now being used for post-combustion CO2 capture. Prospective applications in the energy conversion field include hydrogen recovery from SOFC anode tail gas, debottlenecking of MCFC carbon capture from flue gas, and recovery of tritium from fusion power plant breeder blanket helium purge gas. A major opportunity is identified for sorption-enhanced ammonia synthesis in the context of green hydrogen technologies.