SYNTHETIC FUEL WITH REDUCED PARTICULATE MATTER EMISSIONS AND A METHOD OF OPERATING A COMPRESSION IGNITION ENGINE USING SAID FUEL IN CONJUNCTION WITH OXIDATION CATALYSTS

摘要

The invention provides a compression ignition engine fuel derived from a Fischer-Tropsch process, which fuel has a generally increasing iso:n paraffins ratio with increasing paraffin carbon number at least between C9 to C18, less than 0.05 % m/m sulphur, and less than 10 % by mass aromatics. The fuel may have on average more than 0.9 alkyl branches per paraffinic molecule as measured by H+ NMR analysis. The invention also provides a method for operating a CI engine to produce low particulates emissions, which method comprises combusting the fuel with oxygen or an oxygen containing gas in the engine. Yet further the invention provides a method of improving the conversion efficiency of oxidation catalysts used in conjunction with CI engines, said method including combusting the fuel in the CI engine in the presence of said oxidation catalysts and in oxygen or an oxygen containing gas.