Investigation on ammonia removal efficiency of selective catalytic reduction based emission control system

Abstract

Increasing concern about rising pollution levels and stringent emission regulations have led to the development of selective catalytic reduction (SCR) based after-treatment systems for reducing NOx emissions. SCR system has a complicated working principle involving chemical reactions and under certain operating conditions, side reactions take place, resulting in ammonia/urea slip from the exhaust outlet. In this article, a three-dimensional model of the SCR system is developed using CATIA v5 software and geometric design validation is conducted to ensure continuous flow without any backpressure rise. CFD study is conducted by considering chemical reactions and discrete phase modeling for determining variation mass fraction of various exhaust gas components related to SCR system along with the emission control system. The results of the study showed that the developed SCR system has average ammonia removal efficiency of 95% ensuring the effective working of the SCR system to meet emission norms.