NOVELTY - Process (P1) for converting wastes into gaseous fuels involves: subjecting the wastes to a pyrolysis process; subjecting the wastes to a gasification process, where the pyrolysis process and the gasification process are performed in series and in a loop.    USE - For converting wastes into gaseous fuels (claimed), preferably "fuel-from-wastes"-syngas (carbon dioxide reforming (CDR)).    ADVANTAGE - The process converts generic wastes into a gaseous fuel with low environmental impact; does not provide any emission to the atmosphere; and disposes wastes without additional energy consumptions, apart from the electric energy that is used for actuating the rotating oven of the pyrolyzer and its auxiliary components (e.g. fans and electrically-actuated valves). The process provides several inputs such as generic wastes, air, possible water, possible additives, possible auxiliary fuels, and the materials obtained from the process are syngas (CDR), that can be used as a normal fuel, inerts that can be used as base material in buildings, and metals, that can be recycled. The use of gasification in series and in a loop with pyrolysis this allows transforming a generic waste (solid urban and industrial wastes, biomasses as pruning wastes or biomasses as storage companies wastes) into a clean gaseous fuel, namely without potentially polluting substances (such as chlorine, fluorine, sulfur and heavy metals).    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for system (S1) for performing the process (P1), comprising at least one hopper; at least one chamber, connected to the hopper, for mixing wastes and hot gases for gasification; at least one rotating drum, connected to the chamber, adapted to perform a pyrolysis process; at least one pump adapted to operate the chamber; at least one centrifugating device connected to the rotating drum and adapted to separate syngas and tar from char in the wastes; at least one mechanical separator and one thermal separator for the char, connected to the centrifugating device; at least one gasifying device adapted to perform the gasification process of tar and char; at least one cleaning element, connected to the mechanical separator and the gasifying device and adapted to perform a chemical and electric washing of the char; and at least one hot gas duct coming from the gasifying device and connected to the chamber.