Solid nanoparticle and gaseous emissions of a diesel engine with a diesel particulate filter and use of a high-sulphur diesel fuel and a medium-sulphur diesel fuel

High-sulphur and medium-sulphur diesel fuels are still used in several countries. Although diesel particulate filter technology for on-road diesel engines has existed since 1989, the availability of high-sulphur and medium-sulphur diesel fuels in the market causes delays in the use of catalysed filter technologies. However, the situation in places such as Tehran is considered unhealthy because of particles and black carbon, and full distribution of ultra-low-sulphur diesel is awaited eagerly. The purpose of this study is to investigate the effect of the sulphur content in fuels on the gaseous and solid exhaust emissions of a 220 kW Euro II engine equipped with a sintered metal active-passive filter, focusing on the regeneration phenomenon. The results show that the efficiency for filtering the maximum number of particles was 99.9% and that the average was above 99% for steady-state operating conditions for both high-sulphur diesel (7700 ppm) and medium-sulphur diesel (229 ppm). The removal efficiency of the particle mass was low in the case of high-sulphur diesel owing to the sulphate condensate collection effect as the result of using a non-heated sample line. During regeneration, the number of particles increased in comparison with that in the filtration phase but the total number of emitted particles was less than the engine baseline value. The results for both fuels were the same, and the only measurable difference was the high sulphur dioxide production in the high-sulphur diesel during regeneration. This study demonstrates the potential of this type of filter technology for the effective removal of solid particles independent of the sulphur content of the fuel. With the exception of the decrease in the removal efficiency of the particle mass and the high sulphur dioxide production, no other notable difference was observed to be caused by the change in the sulphur content of the diesel fuel.