A system for reacting fuel and air into reformate, with a reformer (10) which has a reaction space (12), a nozzle (14) which at least in part is formed as a Venturi nozzle for supply of a fuel/air mixture to the reaction space (12), the Venturi nozzle part has a small diameter area (16) from which a diffuser extends to the reaction space. A first gas supply means (20) is provided on the side of the small diameter area which side faces away from the diffuser, and second gas supply means (26, 28) are provide at the small diameter area. A fuel supply (22) is also provided for supplying fuel to the nozzle and it preferably extends along the longitudinal axis of the nozzle.