Sabatier Recycler

A Sabatier Recycler, also known as a Sabatier System, is an apparatus designed to aid in water production and air recycling aboard starships, orbital stations and other human-carrying structures in space, and is a component part of a vessel's greater life support system.

The key process behind the technology's function is the Sabatier reaction, discovered by French chemist Paul Sabatier in 1897, which involves the reaction of hydrogen and carbon dioxide at high temperatures (varying between 300°C to 1200°C for different applications) and pressures to produce water and methane. The water then, through electrolysis, is converted back into oxygen.

In ideal environments the recycling process can be maintained as a near-closed system, with the carbon dioxide required being exhaled by a ship's crew and passengers. As half of the input hydrogen is converted to methane during the reaction, additional hydrogen is required offhand to sustain it. On smaller ships this hydrogen is frequently drawn from VASIMR fuel tanks, which typically also use the lightweight gas as a propellant.

The methane byproduct, if not vented, can also be condensed and combined with liquid oxygen to be used as a chemical propellant.