System for the Removal of NO
from Incinerator Effluents, Part 2
Incineration is a promising method for converting biomass and human waste into CO2 and H2O during extended planetary exploration. During incineration, however, small amounts of NOx and SO2 are produced and must be removed. TDA Research, Inc. (TDA) has developed a safe and effective process to remove NOx and SO2 from waste incinerator product gas streams. In our process, NO is oxidized into NO2 with high selectivity. The NO2 is then removed by wet scrubbing with a weak base to form an innocuous water solution of nitrates and nitrites. SO2 will be removed by a packed bed containing a basic sorbent developed at TDA.
As part of an SBIR Phase II project, TDA is to design and construct a pilot-scale effluent cleaning system to be coupled with an existing waste incinerator at NASA Ames Research Center. The effluent from this incinerator may contain fly ash, SO2, unburned hydrocarbons, CO, and NOx. These compounds are hazardous and their concentrations must be reduced to below spacecraft maximum allowable concentrations (SMAC), leaving an effluent consisting primarily of CO2, N2, O2 and H2O, which can be fed directly into plant growth chambers. The clean-up system will consist of a cyclone separator and filter for fly ash removal, a solid sorbent bed for SO2 control, two catalyst beds for oxidation of NO, CO, and unburned hydrocarbons, a wet scrubber to remove NOx, heat exchangers for thermal management, and instrumentation for process control. In this paper, we present a breakdown of the system design and discuss the performance of each component. We include results from the bench scale tests along with a preliminary design of the full-scale components which will be installed in the pilot scale system. Our process for NOx control is simpler than the competing technology and is therefore attractive for NOx control for natural gas fired turbines and other stationary NOx sources.