The recycling is made possible thanks to the environmental control and life support system installed in the space station, which consists of 6 corresponding subsystems for oxygen production by water electrolysis, carbon dioxide removal, removal of harmful gases, urine treatment, water treatment and water production with carbon dioxide and hydrogen.
According to the China Manned Space Administration (CMSA), the system can collect astronauts’ sweat and urine, then filter them into drinking water, while generating oxygen by electrolyzing recycled water.
A subsystem that produces water from carbon dioxide and hydrogen – the most improved version – was also installed in the Tiangong station and tested by the Shenzhou-14 crew with the support of the ground crew.
It can help recycle an extra kilogram of water per day, raising the percentage of drinking water produced by recycling from 80% to more than 90%.