System and controls for near zero cold start tailpipe emissions in internal combustion engines

A method for operating an integrated fuel reformer-engine system comprising:

• producing a hydrogen-rich reformate fuel with an on-board catalytic partial oxidation fuel reformer;
• fueling an engine using said reformate, a liquid fuel, or a combination thereof, said engine having a reformate fuel intake, a liquid fuel intake, an air intake, and an exhaust;
• treating engine exhaust, reformate, or a combination thereof, in an exhaust catalyst having an intake for receiving said engine exhaust, said reformate, or a combination thereof, and an outlet for passing a treated stream;
• and
• controlling the supply to said engine and said exhaust catalyst of one or a combination of said reformate, said liquid fuel, and air to provide non-stoichiometric lean fueling of said engine and achieve low hydrocarbon and NOx emissions over a range of engine operating conditions from cold-start to high engine loads;
• wherein said controlling comprises controlling the supply of said reformate, said liquid fuel, or a combination thereof, to said engine so as to supply said engine with substantially 100% reformate fueling during starting, idling, and low engine load operating conditions and to supply said engine with a combination of said liquid fuel, said reformate, and recirculated exhaust gas fueling, as needed, during medium to high engine load conditions.