Emissions and Exhaust Aftertreatment
Increasingly stringent air quality rules and laws have increased pressure on engine manufacturers to produce vehicles that can comply with federal and state laws. Argonne researchers work with a wide range of agencies and manufacturers to assess and advance technologies such as emission reduction using catalysts, filters and enrichment systems that can bring engines into compliance.
The reductions in emissions of nitrogen oxide (NOx) from stationary and moving sources have been substantiated by applying selective catalytic reduction (SCR) systems. Argonne researchers examine reaction mechanisms occurring in SCR catalysts. Exploring parameters include the evaporation and the thermolysis processes of urea-water droplets and effects of soot accumulated in the catalysts on catalytic performance.
As a multidisciplinary laboratory, Argonne provides unique capabilities to study the complex nature of particulate emissions using user facilities in Advanced Photon Source, Center for Nanoscale Materials and Electron Microscopy Center. Physico-chemical properties of particulate matter (PM) from internal combustion engines are accurately analyzed in terms of primary/aggregate sizes, fractal geometry, carbon crystalline structure and chemical compositions to help understand soot formation and oxidation processes in engine cylinder.
To achieve the ultimate goal of reducing PM emissions, researchers are exploring systems such as diesel particulate filters and gasoline particulate filters in order to better understand filtration/regeneration processes for diesel and gasoline-direct injection engines, respectively. Also, Argonne offers a sophisticated X-ray micro-tomography technique that analyzes detailed 3D images of porous filter materials. This technique enables Argonne researchers to propose ideal filter development by evaluating porosity, volumes of dead pores, pore size distributions and surface pore volumes, which provide accurate computation of permeability at micro-scale by using high performance workstation and simulating software.