An Ambient NOx Reduction Reactor System with and without Forced Air

Ambient nitrogen oxide (NOX) is one of the main ingredients involved in the formation of ground-level ozone (smog), which contributes to global warming and the formation of particulates in the atmosphere and causes respiratory illnesses, especially in children, older adults, and people with lung diseases. Investigations on adding titanium dioxide (TiO2) nanoparticles to the paint used on concrete surfaces such as buildings and its potential in reducing ambient NOX concentration have provided opportunities for the research and development of methods for passive control and filtration of the ambient NOX. The present research used numerical geometrical optimization to identify an optimized surface geometry of half-stepped cylinders for increasing air recirculation and residence time for maximum ambient NOX reduction. The optimized surface was painted with titanium-infused paint and tested for NOX reduction according to ISO 22197-1 standard. Results showed a maximum of 11.5% increase in NO2 formation for an optimized surface compared with the result for the untextured smooth surface, with an estimated NOX reduction of approximately 15%. The results provided guidelines for developing a catalyst system for reducing ambient NOX when UV light is present. These results demonstrate potential of using paint infused with titanium to help reduce NOX and thus reduce smog, which harms people and the environment.