This paper aims to describe the state of the art of particulate emissions from compression ignition engines, and indicate some possible ways of reducing these emissions. It shows that the engine design characteristics and operating conditions and fuel properties all play an important part in generating and emitting particulates. Some experimental tests are discussed, which were conducted to seek some possible relationships between particulate emission levels and the following engine operating parameters: injection advance, engine speed, and load factor. Two fuels were tested, with notable differences between their aromatics content, sulphur content, cetane number, density, and distillation temperature. A 10l direct injection turbo intercooler diesel engine, with maximum power of 250kWh at 2000rpm, was used in the experimental analyses. The measuring equipment included a sampling probe used to collect particulate in stable engine conditions. Quantitative emission levels of particulates were obtained, together with qualitative levels of the particulates' insoluble and soluble organic fractions. Seven conclusions from the study are presented.
Abstract