Process for minimising the emission of particular matter from marine diesel engines

A process for minimizing the emission of particulate matter and precursors thereof from a flue gas stream of an engine, the flue gas stream comprising particulate matter and precursors thereof and at least one gaseous component, which process comprises the steps of:

• a. obtaining a flue gas stream of an engine comprising particulate matter and precursors thereof;
• b. increasing the moisture content of said stream by contacting the same with a first aqueous medium in an amount and at a temperature at which at least 50% of the water content of the first aqueous medium is evaporated;
• whereby a moisture laden gas stream, optionally containing suspension droplets, is formed;
• c. cooling said moisture laden gas stream, said cooling comprising contacting said moisture laden gas stream with a second aqueous medium, whereby suspension droplets are formed;
• and
• d. applying a centrifugal force to said moisture laden gas stream and to said suspension droplets to effect the swirling thereof;
• whereby a treated gaseous stream and an aqueous stream are formed;
• wherein the content of particulate matter in said treated gaseous stream is reduced by at least 50% compared with that in said flue gas stream, as measured by cooling to about 50° C. with no further treatment, and wherein said centrifugal force in step d is characterized in that the velocity of said moisture laden gas stream is between 20 m/sec and 120 m/sec.