Modelling of Engine Emissions and After-Treatment Systems

Higher levels of air pollutants and greenhouse gas emissions from fossil fuel-based internal combustion engines have raised environmental concerns and it has resulted in stringent emission regulations. Recent emission norms have made it a mandatory requirement to adopt after-treatment emission control systems for controlling and reducing emission levels to meet the required emission standards. This chapter will discuss the recent research efforts in modelling engine emissions, and after-treatment systems like oxidation catalyst filters, particulate filters, and selective catalytic reduction systems. Detailed discussions on the mechanisms for soot emission modelling and NOx formation are covered in this chapter. Literature studies on one-dimensional, two-dimensional, and three-dimensional modelling of filters and catalysts coupled with CFD studies for application in three-way catalytic filters, NOx reduction catalysts, electrically heated catalysts, and particulate filters (soot accumulation and regeneration) are also discussed. Future directions for modelling advanced after-treatment systems to reduce regulated and unregulated emissions are also explored.