Regenerable Adsorption-based Continuous CO2 Removal (RACCR) System for Continuously Eliminating CO2 from Closed Circuit Rebreathers

Precision Combustion, Inc. (PCI) proposes a novel approach based on a high-capacity Regenerable Adsorption-based Continuous CO2 Removal (RACCR) process architecture for self contained breathing apparatus (SCBA). Our approach combines a fast-cycling regenerable sorbent media comprising a non-toxic sorbent with high capacity and selectivity for CO2 supported on a unique rapid diffusion, heat and mass transfer substrate (Microlith® metal meshes) to efficiently eliminate CO2 from the breathing loop and maintain the input at comfort levels for the wearer. Our continuously operated scrubber will be developed as a drop-in replacement to the current soda-lime beds which are non-regenerable and can operate for thousands of cycles of CO2 sorption and venting with no loss of performance. The system weighs less than half of the current scrubber and can extend operation time to at least 10- hours based on battery pack size. The RACCR will be provided as a plug-in solution for existing rebreather systems in the form of a fully assembled cartridge containing the sorbent bed architecture inside a housing. Our system design avoids any bypass and eliminates human error which could occur in cartridges that have to be refilled manually.  A modular, compact, efficient, and durable Microlith-based integrated system approach will hence be identified in Phase I (design recommendations will be included in the final report) and will be developed and delivered to DoD for further evaluation and performance validation in Phase II. PCI will utilize its previous experience with CO2 adsorber and Trace Contaminant Control (TCC) development for NASA cabin air cleaning and spacesuit applications and for Direct Air Capture (DAC) of CO2  respectively, to develop, iterate, and optimize the sorbent materials and bed design. A follow-on Phase II work is expected to further optimize the system level integration solutions as well as prototype design, fabrication, and testing. In Phase II a prototype CO2 removal unit will be integrated with an off-the-shelf rebreather system for a full-scale system demo to DoD personnel.