Description: A Microchannel Sabatier Reactor System (MSRS) consisting of cross connected arrays of isothermal or graded temperature reactors is proposed. The reactor array enables nearly complete single pass carbon dioxide reduction using the Sabatier reaction, allowing efficient recovery of oxygen from in situ carbon dioxide resources on Mars or other Near Earth Objects. Arrays of microchannel reactors with decreasing temperatures and increasing residence times can be optimized to maximize reaction kinetics and overcome thermodynamic limits (85% conversion at 400 C)of the Sabatier reaction resulting in 99% conversion of carbon dioxide and hydrogen to water and methane. Alternatively, monolithic graded temperature reactors can be developed that will optimize reaction kinetics with respect to the thermodynamic limitations of the Sabatier reaction in a compact and efficient design. The Phase I efforts will focus on design and construction of the microchannel reactors. The Phase II effort will build upon the feasibility demonstration resulting in the development of a prototype MSRS consisting of a microchannel reactor array and a graded temperature microreactor capable of 99% single-pass, carbon dioxide conversion to methane and water capable of processing 1 kg hr-1.

Benefits: The NASA application for this technology will be as Flight Hardware for deployment in support of future, long duration exploration missions to Mars or other Near Earth Objects (NEOs) where reclamation of in situ resources and reduction of the logistics burden will be highly valued. The Microchannel Sabatier Reactor System will efficiently reclaim oxygen (as water) and produce a propellant (methane) from atmospheric or frozen deposits of carbon dioxide on Mars or other NEOs using only hydrogen. The Microchannel Sabatier Reactor System (MSRS)provides a fundamental starting point for planetary habitats where precursor robotic staging can prepare the road for subsequent human missions by reducing the logistics burden.

The MSRS technology can be used in the mitigation of carbon dioxide released into the atmosphere as a greenhouse gas. In a broader sense, in any situation where reaction kinetics and the thermodynamic driving force of a reaction are in thermal conflict, a graded temperature reactor or reactor array can be utilized to efficiently drive composition closer to the desired products. Additionally, a fully developed microchannel reactor technology will enable greater thermal control over highly exothermic/endothermic chemical reactions, which will improve selectivity and catalyst stability. A monolithic microchannel reactor with two parallel paths can also be used to mate exothermic and endothermic reactions eliminating costly and wasteful external heat transfer components.