Effect of a non-metallic combustion enhancer diesel additive on mass and number particulate emissions from light duty vehicles and heavy duty engines

摘要

Tests were conducted at independent laboratories on a patented ashless additive technology designed generically for Fuel Charter I, II and III diesel fuels as defined by, AAMA (American Automobile Manufacturers Association), ACEA (European Automobile Manufacturers Association), EMA (Engine Manufacturers Association) & JAMA (Japan Automobile Manufacturers Association). The instantaneous effect of these additives in 6 light and 2 heavy duty engines in reducing particle number and particle mass emissions were measured as were mileage accumulation effects. Emission tests confirmed PM reduction of up to 19% from both light duty vehicles tested under ECE15+EUDC or MVEG cycles and heavy-duty engines tested under the R49 or FiGE cycle. The results also indicated that such reduction had negligible or possibly a beneficial effect on NO{sub}x emissions. Fleet testing of the additives in excess of 13 million km in a cross-section of European heavy-duty vehicles showed no detrimental effects but did measure a statistically significant improvement in fuel economy and reduction in smoke and PM emissions. A scanning mobility particle sizer instrument was used in the comparative study of two of the diesel fuels, (a) EN590 diesel and (b) ultra low sulphur 'city diesel' with and without the ChemEcol ashless additives to determine the effect of these fuel and additive mixtures on fine particle number emissions in two heavy duty and one light duty engine. The two fuels provided significantly different particle number emissions but similar size distributions under steady state testing. A formulation containing the non-metallic additive provided reductions of between 45% - 80% in particle number emissions for both test fuels with no significant shift in the particle size distribution. FiGE cycle tests showed a particle number reduction at the chosen 50 nm size range of approximately 20%. Analysis of PAH (poly-aromatic hydrocarbons) emissions based on particulate collected on filter papers revealed a large reduction in the sixteen US priority PAHs with the additised fuels. Results from these PAH, PM and ultra fine particle number emission results indicate a probable reaction mechanism for the additive and this is also reported.