A reformer such as a CPO (18) receives a mix of fuel, moisture and oxygen from a mixing region (21) having an igniter (26, 66), which may include an inert ceramic foam (19), the fuel being provided by an atomizing nozzle (22), thereby avoiding the need for a vaporizer before use. The oxygen and moisture may comprise engine exhaust (11, 12). Fuel from a vehicle fuel tank (9), may be gasoline, diesel fuel, kerosene, jet fuel, or JP-8. The atomizing nozzle may be a gas-assist nozzle (22a), receiving the assisting gas from (a) engine exhaust (10), (b) a turbocharger (33), (c) an air pump (50) or (d) a steam generator (57). The oxygen and moisture may comprise moisturized air, which may be achieved by an ejector (41) which ingests water from a tank (43) in response to the flow of air from a pump (50) through a conduit (47). The air may be regeneratively heated (48) with the CPO exhaust. The igniter may be a glow plug (26) or a heater wire (66) coated with catalyst.