| All of the previous missions to outer space were short-term missions that were manned by relatively small crews. For these expeditions, consumables such as food, air, and water have been supplied at launch and the waste generated on board the spacecraft has been returned to Earth at the end of the mission. If future long-term missions to the Moon or Mars are to be successful, NASA will have to revamp their current solid waste management strategy. This research project focuses on the use of incineration as a means of solid waste treatment aboard a space station. Combustion of wastes such as inedible biomass, human waste (urine and feces) and recyclable components of trash will produce carbon dioxide and water that can be supplied to plants grown as a regenerable source of nutrition. This dissertation addresses the treatment of pollutants (nitrogen oxides, sulfur oxides, CO, hydrocarbons, HCl, Cl2, and particulate matter) that are inevitably produced during incineration. The gas clean-up process faces the unique challenge of removing trace levels of pollutants from a low-flow flue gas stream without destroying carbon dioxide and water. In addition, the process must consume only small amounts of expendable reagents and must not rely on gravity to achieve the separation.; The copper oxide process was found to meet these requirements where CuO/gamma-Al2O3 pellets remove SO2 by reactive adsorption to form CuSO4, the latter acting as a catalyst for the selective reduction (SCR) of NO to N2 with added NH 3. The kinetics of sulfation and SCR were studied on the basis of fundamental data obtained from a laboratory scale fixed bed reactor at feed concentrations ranging from 500 to 1500 ppm SO2, 100 to 1200 ppm NO, and temperatures from 200 to 500°C.; The fundamental information was integrated into the design and construction of a fixed bed reactor housing commercially available CuO/gamma-Al 2O3 sorbent from ALCOA. The reactor was ultimately a part of an incineration system which was used in a prototype regenerative life-support system. The feasibility of incineration as a waste treatment technology for space was demonstrated. |
