Development and Field Test of Ceramic-based Diesel Particulate Filter (DPF) for Urban Transport Vehicle

Particulate matter in the diesel exhaust is the dominant mobile source of cancer in the urban transport system. Diesel particulate filter (DPF) using a ceramic wall flow filter is the promising technology for abating particulate matter pollution. The mechanical durability of ceramic filter due to vehicle vibration, thermal durability during regeneration and efficient and economical regeneration systems are the major concerns for making this system viable. A novel system of DPF with simple and viable regeneration method suitable to Indian urban transport was developed and evaluated for performance by field testing. DPF was designed using wall flow filter made from highly thermal shock resistant cordierite honeycombs after optimizing the back pressure and engine power loss. The mechanical durability was measured after fitting DPF in a transport bus and running it for several cycles, accumulating with periodic regeneration more than 20,000 km and observed no deterioration of performance. An electrical regeneration system was designed with a practical regeneration interval of about a day using stationary power and pressurized air source. The back pressure, smoke density, temperature, fuel consumption were measured at each cycle of field test before and after regeneration to evaluate the thermal durability, filtration efficiency and regeneration performance. The developed DPF system showed an average 0.4 g/km collection of particulate matter without any appreciable loss of power and no significant increase in fuel consumption. The results obtained during the field test and, engine performance and emission data collected on engine test bed are discussed.