1. Integrated Energy Production Using a Fuel Cell System for a Crewed Space Base Station

2. Outline Background System Description Compatibility Concerns –Size –Fuel, Water, Oxygen Availability –Extreme Environmental Conditions Fuel Source Options –Hydrogen from waste gases –Hydrogen from reforming Fuel Processing Concept –Steam Reforming –Autothermal Reforming –Catalytic Partial Oxidation Reforming –Current Concept Recommendations Fuel Cell Integration –Oxygen, Water Balance –Size Barrier –Efficiency concerns addressed Conclusions Recommendations –Other Options to a Fuel Cell

3. Background Fuel cell: an energy conversion tool which creates electric energy by separating out electrons from hydrogen and sending them on a path around the membrane to be combined with oxygen and the original hydrogen molecule creating water and electricity from hydrogen and oxygen. Reforming Fuel: reforming fuels such as ethanol or methane is necessary in order for the gases to be used in a fuel cell. Reforming converts these fuels into hydrogen though processes like steam reforming, catalytic partial oxidation, or autothermal reforming.

4. System Description Fuel will be supplied by grown sweet potatoes and waste gases off a sabatier in the waste system. The Sweet potatoes will be converted to ethanol Ethanol will be reformed into hydrogen though autothermal or catalytic partial oxidation reforming. The methane off the methane gas stream can be directly reformed on the anode of the Solid Oxide Fuel Cell. The hydrogen will then mix with the methane and pass through a Solid Oxide Fuel Cell (SOFC) producing electricity to power the station. Waste heat is produced from the SOFC Waste gas is burned from SOFC

7. Fuel Source Options Fuel can be taken from several different places, and can even be brought along. Sweet potatoes will be present on the station as well as soybeans. Both of these make excellent fuel sources. The sabatier process on the solid and liquid waste streams produces methane and water.

8. Fuel Processing Concept Reforming is necessary in order to get hydrogen out of the fuels. Steam reforming is a large process and may not be easily fit into the systems on the station. Catalytic Partial Oxidation (CPOx) reforming may work well because it produces less heat and has a smaller system size. Autothermal reforming would be the best bet when it comes to producing hydrogen. It uses slightly higher temperatures than the CPOx, but incorporates steam into the process.

9. Space Station Schematic/ Integration of Fuel Cell. Picture below is an steam reformer

10. Conclusions The fuel cell most suitable for this application would be the Solid Oxide Fuel Cell The best process for reforming the fuels would be Catalytic Partial Oxidation or Autothermal Reforming. There are other types of fuel cells that look attractive as well. Like a polymer electrolyte fuel cell operates at lower temperatures, but has a lower efficiency rate Other types of fuel processing that might be incorporated into the reforming process might be electrolysis by the way of photovoltaic cells or possibly wind energy. Nuclear, geothermal, and wind energy are also other possible ways to power the station.

11. Recommendations To use either a Solid Oxide Fuel Cell or a Polymer Electrolyte Fuel Cell Get fuel from crops and waste processes on the space station Reform the fuels into hydrogen through catalytic partial oxidation or autothermal reforming