An exhaust gas after-treatment system was developed to reduce oxides of nitrogen (NOx) emissions from a heavy duty diesel derived natural gas engine. The goal of the project was to reduce NOx emissions by 80% with a minimum ammonia slip and without negatively impacting other exhaust emissions.
This system utilized a stationary source, commercially available Selective Catalytic Reduction (SCR) catalyst and an ammonia (NH3) injection system developed during the course of this project to reduce the NOx emissions.
Preliminary results indicate that NOx emissions were reduced by over 80% during transient operation with an ammonia slip of less than 2 ppm. This system had little impact on other engine emissions and engine performance.