Abstract
In India, small commercial vehicles (SCV’s) with small engines < 1 liter, with one or two cylinders), are effectively utilized for various applications such as load delivery within city and in rural areas with narrow roads. After-treatment systems designed for these vehicles usually don’t have any active regeneration capability, but need to continuously achieve >50% particulate matter (PM) reduction to meet BS IV regulation requirements. Current solutions include metallic diesel oxidation catalyst (DOC) and metallic particulate oxidation catalyst (POC) filters, which usually require large system volume and incur high pressure drop penalties. There are also other design challenges, such as ensuring adequate passive regeneration under typical Indian driving conditions. This paper shows application of a novel, robust, ceramic-based system to meet the above challenges. Compared to existing metallic systems (DOC + POC) systems, the ceramic system (DOC + partial filter (PF)) delivers lower pressure drop, higher PM filtration efficiency, and excellent robustness, at significantly lower system volumes. The compact packaging also enables better temperature utilization for passive regeneration. Combined with advanced washcoat technologies, the ceramic system can effectively regenerate soot passively and maintain PM filtration efficiency. In this paper, detailed discussion carried on the application development to enable compact packaging, PGM savings, and lower system cost. Also demonstrated in this paper, robust systems design to deliver up to 75% filtration efficiencies for meeting emission regulations with good margin, along with continuous passive regeneration. These are possible solutions to meet current & future legislative requirements for HDD on-road BSIV (2017), off-road BSIV (2020) & 3-wheeler BSVI (2020) applications.