Scientists from the University of Florida have developed a method that can process human waste into fuel in order to be used on space missions.
The process can produce around 750 liters of non-potable water every year. By using electrolysis, the water can be split into oxygen and hydrogen. Astronauts can then breathe the resulting oxygen and the carbon dioxide they exhale along with the remaining hydrogen can be transformed to water and methane once again.
The newly developed method that can process human waste into fuel resulted in the creation of a digestion system capable of anaerobic digestion which gets rid of pathogens in human waste and creates biogas. Biogas is a blend of carbon dioxide and methane achieved by breaking up the organic matter found in waste.
The team of scientists from the University of Florida were supplied by NASA with a range of human wastes produced chemically which included towels, packaging materials, cloths, clothing and food waste.
The team then analyzed the amount of waste that can be produced and how quickly it can be produced by running a series of laboratory tests. The method that can process human waste into fuel can in one week produce as much as 290 liters of methane per crew member out of human waste.
The methane resulted from the process could be used for transportation, electricity generation or heating as well as being able to be used to fuel the space ship.
Human waste is usually stored by NASA in containers loaded in space cargo vehicles that incinerate upon entering back into Earth’s atmosphere. It would be impractical, however, to carry enormous amounts of human waste in order to burn them upon re-entering the Earth’s atmosphere in missions that are long termed. A long-term mission would be the one to Mars planned as soon as 2021. The mission to Mars is a manned one.
Engineered and natural organisms have also been considered before to convert fuel from waste.
Earth applications include the newly launched A4 Bio-bus service from Bath to Bristol in the UK. It uses food and human waste as fuel and generates 30 percent less emissions than its other versions.
The yearly waste from just one person could be used to fuel a bus for more than 50 km.