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, a solvent, such as an alcohol, ketone, or acetate 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 solvent 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 solvent is then sent back to the absorption vessel, exchanging heat with the cold absorption column effluent as it goes. After the clean solvent 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 2, an operating protoflight LSP unit meeting the full-scale NASA CO2 acquisition requirement needed to support 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. Compared to roughing pumps or solid sorption beds, the LSP can reduce CO2 acquistion power requirements by an order of magnitude.
The LSP could be used to separate CO2 from flue gas and other exhaust streams on Earth. Once separated the CO2 could be used to enable enhanced oil recovery (EOR). The USA has hundreds of thousands of dormant oil wells that could be revived by using CO2 to pressurize them and lower their viscosity. This will allow for a dramatic expansion of US oil production while combating climate change.