Exploring water production dynamics in a Sabatier reactor: A comprehensive experimental investigation

• Sabatier reaction efficiently produces water and methane for space missions. • The temperature profile inside the reactor varies with distance in the flow direction. • Sabatier water has low electrical conductivity and low pH. • Increasing the molar ratio decreases the electrical conductivity of Sabatier water. • Increasing the molar ratio increases the pH of Sabatier water. In near space (e.g., the International Space Station), the Sabatier reaction is used to produce water and address shortages, while in deep space (e.g., Mars), it enables the production of methane as rocket propellant. This study focuses on the performance analysis of the Sabatier system for water generation, which converts carbon dioxide and hydrogen into water through a catalytic reaction. A catalyst-packed Sabatier reactor was designed, manufactured, and tested in water generation experiments under various operating conditions. For the first time, this experimental study analyzed the combined effects of total feed flow rate and molar flow rate ratio on water production and quality. A lower molar ratio (richer in carbon dioxide) increased the solubility of carbon dioxide in the produced water, leading to higher electrical conductivity and lower pH. Both the total feed flow rate and the molar ratio of reactants significantly affected conversion efficiency. Additionally, the study measured and analyzed temperature profiles within the Sabatier reactor over time and distance, as well as the concentration and flow rate of discharged gases. These results suggest that variations in reactant supply conditions, determined by available resources in the environment, would influence the quantity, quality, and conversion efficiency of the produced water. Consequently, Sabatier technology for water generation is poised to play a crucial role in expanding human activities in space and could become central to future space-related water technologies and businesses.