Process and system for improving combustion and exhaust aftertreatment of motor vehicle engines

A process for improving fuel combustion and exhaust aftertreatment in a diesel engine, said process comprising:

• producing a hydrogen-rich reformate from hydrogen-containing liquid diesel fuel supplied to an on-board catalytic partial oxidation fuel reformer from a liquid diesel fuel source in fluid communication with said reformer and with a diesel combustion engine having a liquid fuel intake, an air intake, a reformate intake, and an exhaust outlet;
• supplying, under conditions of low engine load, reformate or a combination of liquid diesel fuel and reformate to said engine;
• supplying, under conditions of medium engine load, a combination of liquid diesel fuel and reformate to said engine;
• and
• supplying, under conditions of high engine load, liquid diesel fuel only to said engine and reformate only to an exhaust conduit in fluid communication with said exhaust outlet and with said reformer, said exhaust conduit comprising a reformate conduit upstream from exhaust aftertreatment components selected from the group consisting of oxidation catalysts, NOx adsorbers, particulate filters, and combinations thereof;
• wherein fuel combustion is improved under conditions of low engine load and medium engine load, and exhaust aftertreatment is improved under conditions of high engine load.