Singapore-based start-up Memsift Innovations Pte Ltd has received an order from the Danish Aerospace Company A/S to deliver the new Water Recovery Subsystem (WRSS) prototype for space application. The company had previously signed a Product Testing Agreement (PTA) with Aquaporin Space Alliance ApS, a joint venture between Aquaporin A/S and Danish Aerospace Company A/S.
The contract will enable the company to design and develop an innovative WRSS prototype based on the TS-30™ Improved Membrane Distillation (IMD) process by using the proprietary STOMATE® membranes. The WRSS prototype is scheduled to be delivered to DAC by March 2020.
Concept design of the WRSS prototype SUNAI
According to the space agencies, each astronaut uses around four to six litres of water a day for drinking, washing and so on, and launch of supplies from ground to Earth orbit is usually valued from $18,000 to $50,000 per kilo, so any considerable amount of water which can be reused from condensate from the humidity in the cabin, urine from astronauts, wastewater from the toilet and cleaning processes, with a simplified and reliable system, will provide a direct significant cost saving in human exploration.
Process diagram of the WRSS prototype
The prototype WRSS will recover at least four litres of water per day from the draw solute of the primary Forward Osmosis (FO) loop that uses biomimetic water filtration membranes from Aquaporin. The subsystem will be operated in the principle of simple thermodynamic (heat and mass transfer) and the driving force is the partial vapor pressure gradient across the membrane. It operates at a relatively low temperature and pressure when compared to the conventional thermal and pressure driven membrane process and handle high salinity wastewater. The overall dimensions of the new WRSS are expected to be roughly 0.26m (L) x 0.25m (W) x 0.35m (H), and the dry weight will be less than eight kilogrammes. Memsift has named the WRSS as “SUNAI”, after a Tamil word that translates to “spring”.
According to Dr J Anthony Prince, founder and CEO of Memsift Innovations Pte Ltd, the overall size and weight required for the WRSS is almost 10 times lesser than the system on the earth treating the same volume of water.
