SMART: Selective Membrane Air Revitalization Technology

Determine if Gas Permeable Membrane Modules remove Carbon Dioxide (CO2) in a Closed-Circuit Breathing Apparatus (CCBA). These modules do not produce unwanted heat and have an essentially unlimited lifetime compared to traditional CO2 scrubbers. Determining the optimal circuit configuration to remove sufficient CO2 from the breathing circuit while retaining oxygen is a major challenge. Determine the optimal module capacities, flow rates, and pressures. Test a breadboard breathing circuit using membrane-based separation to determine whether it has sufficient performance and reliability for operational use in a CCBA. Designed and developed an air revitalizing system using semi-permeable membranes. CO2 passes through the membrane much more rapidly than O2 and N2 allowing the gases to be separated. Assemble a bench testing apparatus which simulates a closed circuit breathing system. Flow compressed gas through the membrane with a similar composition of exhaled air (~4-5% CO2). Pressure, flow, and gas composition will be continuously monitored. Test a variety of membrane module configurations (series, parallel, etc.) at a wide range of pressures and flows, with the goal of reducing CO2 level to <2%, which is considered safe for breathing air. When an optimal configuration with adequate flow and output composition is identified, it will be integrated into a CCBA and breathing machine tests will be performed. At a larger scale the same design will be applicable to a spacecraft or habitation module. More »