The Liquid Sorption Pump (LSP) is a new technology for acquiring CO2 from the Martian atmosphere for use in In Situ Resource Utilization (ISRU) systems. In the LSP, propanol is cooled to temperatures below -100 C, where it becomes an effective solvent for Mars atmospheric CO2. After absorbing 5 percent or more by mole CO2, the propanol is pumped to another vessel where it is heated to 30 C, releasing the CO2 at pressures of more than 1 bar. The clean warm propanol is then sent back to the absorption vessel, exchanging heat with the cold absorption column effluent as it goes. After the clean propanol is cooled to near the design absorption temperature in this way, a mechanical refrigerator is used to achieve the final temperature reduction. Advantages of the LSP are that it can operate continuously day or night without the need for mechanical vacuum roughing pumps, solid freezers, or large sorption beds, requires less power than other options, is readily scalable to high outputs, and that it stops all sulfur, dust, or non-condensable gases from reaching the ISRU reactor system. In the proposed SBIR Phase 1, an operating LSP will be demonstrated and its performance assessed.
The primary initial application of the LSP is to provide a reliable, low cost, low mass technology to acquire CO2 on the surface of Mars out of the local atmosphere at low power. Such a system can be used to enable human exploration of Mars, as well as a Mars Sample Return mission. The LSP is dramatically superior to current alternative methods of collecting Mars CO2 because its power requirement is much less. The LSP could also be used by NASA to reduce its own CO2 emissions.
The LSP could be used to separate CO2 from flue gas. The US coal-fired electric power industry is in trouble because its CO2 emissions exceed government guidelines. The LSP can solve this by providing an economical method of collecting pure CO2 from flue gas. Once separated the CO2 could be used to enable enhanced oil recovery, expanding US oil production while combatting climate change.