Use of organometallic additives for improving soot burning in diesel fuels

摘要

A diesel fuel containing an additive, which improves soot burning, for reducing the pollutant emissions of the combustion exhaust gases of diesel engines by discontinuous burning-off of soot which has been deposited on the exhaust gas filter is described. For this purpose, a lithium salt, sodium salt or potassium salt of an aliphatic or aromatic alcohol, of a phenol, of an aliphatic acid or a naphthoic acid, of phenylacetic acid or of cinnamic acid, individually or as a mixture, is added to the diesel fuel before the latter is burned in the internal combustion engine. As a result of the addition of the alkali metal salts, the ignition temperature of the soot deposited in the particle filter is reduced and the soot is oxidised at a temperature which is considerably lower than the normal ignition temperature. The regeneration range for the particle filter is thereby much more frequently reached in real driving practice. As a result, a critical filter loading with soot, which can cause filter damage on burning-off, is avoided. A further advantage of the process described is that, according to present knowledge, no additional substances injurious to health are emitted during running as a result of the addition of these alkali metal salts to the diesel fuel. IMAGE