Chemical Engineering Journal, Vol.334, 479-486, 2018
Recycling oxygen from spaceflight solid waste for life support system: Potential of pyrolysis process
Recycling of solid waste for oxygen recovery in manned spacecraft is extremely important during long-term space missions. In the current study, pyrolysis process was evaluated to investigate the recovery potential of oxygen from spaceflight solid waste (SSW). A low fidelity waste surrogate (LFWS) was employed to simulate the solid waste produced during long-term space missions, and the oxygen distribution and oxygen-containing species in various pyrolysis products were investigated. In comparison with terrestrial municipal solid waste, SSW has higher content of oxygen, nitrogen and sulfur, but the content of carbon is much lower. The amount of oxygen recovered from SSW was higher than from terrestrial solid waste by pyrolysis treatment. Moreover, much more oxygen in SSW could be easily converted into the gaseous phase for oxygen recovery by adjusting treatment temperature. Nearly 50% of oxygen in SSW was recovered in the form of the gaseous product, and the optimal oxygen recovery efficiency was 29.54% at 700 degrees C. Recycling oxygen from SSW is a desirable approach to improve the closure level of oxygen cycle in the life support system. This work provides fundamental information for oxygen recycling from SSW during long-term space missions.
Keywords:Manned spaceflight;Solid waste recycling;Low fidelity waste surrogate;Pyrolysis;Oxygen recovery