Control of Effluent Gases from Solid Waste Processing Using Impregnated Carbon Nanotubes

One of the major problems associated with solid waste processing technologies is effluent contaminants that are released in gaseous forms from the processes. This is a concern in both biological as well as physicochemical solid waste processing. Carbon dioxide (CO₂), the major gas released, does not present a serious problem and there are currently in place a number of flight-qualified technologies for CO₂ removal. However, a number of other gases, in particular NO_x, SO₂, NH₃, and various hydrocarbons (e.g. CH₄) do present health hazards to the crew members in space habitats.

In the present configuration of solid waste processing in the International Space Station (ISS), some of these gases are removed by the Trace Contaminant Control System (TCCS), demands a major resupply. Reduction of the resupply can be effective by using catalyst impregnated carbon nanotubes. For example, NO decomposition to N₂ and O₂ is thermodynamically favored. Data showing decomposition of NO on metal impregnated carbon nanotubes is presented.