(6ak) Conversion of Space Crew's Wastes into Biofuel Using Thermophiles

Authors: 
Wang, J., South Dakota School of Mines and Technology
Sani, R. K., South Dakota School of Mines & Technology
Salem, D. R., South Dakota School of Mines and Technology

The manned space exploration is a highly complex and challenging mission, and one of the difficulties is the logistic load which can be costly and limit for travelling time and distance.  Therefore for long term space flight, the reduction of logistical requirement is necessary and the related technologies are under investigation.  The Trash to Gas Fuel (TGF) is one of the promising processes in which crew’s waste generated during space mission can be converted into gaseous biofuels such as hydrogen.  Consolidated bioprocessing (CBP) has been applied for biohydrogen production from different kinds of wastes, and it offers promising alternatives over traditional multistep processes.  In the present research, CBP was used to convert untreated crew’s waste simulants into hydrogen through thermophilic microbial consortia and anaerobic fermentation processes.  Four consortia were developed using water/sediment/soil samples collected from hot springs, water treatment plant, and compost facility, and used for biohydrogen production from lignocellulosic substrate or food waste as a carbon source.  The results demonstrated that all of the consortia could produce biohydrogen (1.137 mmol) after 7 days culturing at 70.  The biohydrogen production from different kinds of human waste simulants as sole nutrient source by the same consortia using thermophilic CBP is currently being tested.  Optimization of various parameters including composition and concentration of simulants for better yields of biohydrogen will also be carried out.  The biohydrogen obtained could be used as propellants or energy source for power system during space missions.  Additionally, Trash to Gas Fuel process can diminish the volume requirement to store the waste generated by the crew members during long-term space missions.