Process for operating a compression ignition internal combustion engine in combination with a catalytic reformer

A process for operating a compression ignition internal combustion engine in combination with a catalytic partial oxidation reformer and a NOX abatement system as an exhaust gas aftertreater, wherein:

• (a) a mixture of a first fuel and air, wherein the first fuel comprises Fischer-Tropsch derived fuel, is introduced in the combustion chamber of the engine;
• (b) exhaust gas is discharged from the engine and partly recirculated to the combustion chamber of the engine;
• (c) a second fuel and oxygen and/or steam are supplied to the catalytic partial oxidation reformer to produce synthesis gas, wherein the second fuel comprises Fischer-Tropsch derived fuel;
• and
• (d) the non-recirculated part of the exhaust gas and at least part of the synthesis gas is supplied to the NOX abatement system and at least part of the synthesis gas is supplied to the combustion chamber of the engine.