Purification Performance and Deterioration Rule of Catalyzed Diesel Particulate Filter

Abstract:

The purification performance and deterioration rule of catalyzed diesel particulate filter (CDPF) with different precious metal loads (25, 20, 10 g?ft-3) on the exhaust emissions of bus was studied and analyzed based on portable emission measurement system(PEMS). The results show that the more the precious metal load on CDPF, the better the purification performance on CO, total hydrocarbon (THC), PN (particle number) and PM (particle mass) is. With the increase of the use time, the purification efficiency of CDPF decreases in the form of logarithmic and the more the precious metal load, the slower the purification efficiency decrease is. After using for 50 thousand kilometers, CDPF with 25 g?ft-3 precious metal load can still keep purification efficiency about 74% and 70% for CO and THC respectively, and more than 90% for PN and PM. The precious metal loads and using mileage has no effects on the NOx emission of buses. CDPF with 20 g?ft-3 precious metal load is the best choice considering both the cost and the performance.

Key words:diesel bus; catalyzed diesel particulate filter (CDPF); precious metal load; purification performance; deterioration rule