NOVELTY - Preparing synthesis gas in at least one chemical loop comprising at least three distinct reaction areas for oxidation, reduction and gasification, comprises: oxidation of reduced metal oxides (a) in an oxidation reaction area (R1) fed by the air; combustion of a solid, liquid and/or gaseous hydrocarbon charge by partially reducing the metal oxides (b) in a reduction reaction area (R2) to produce a carbon dioxide/water gas mixture; and catalytic gasification of a solid and/or liquid hydrocarbon charge by partially reduced metal oxides obtained from R2 in a gasification reaction area (R3).    USE - The process is useful for preparing synthesis gas (CO + H2), which is useful in fuel cell and in Fischer Tropsch hydrocarbon synthesis or a unit of methanol synthesis or dimethyl ether synthesis (all claimed).    ADVANTAGE - The process: is cost effective for the simultaneous production of synthesis gas and energy; enables the simultaneous production of synthesis gas and energy (in the form of heat and/or electricity) in the same chemical looping.    DETAILED DESCRIPTION - Preparing synthesis gas in at least one chemical loop comprising at least three distinct reaction areas for oxidation, reduction and gasification, comprises: oxidation of reduced metal oxides of formula (MeO1-x) (a) in an oxidation reaction area (R1) fed by the air; combustion of a solid and/or liquid and/or gaseous hydrocarbon charge by partially reducing metal oxides of formula (MeO) (b) in a reduction reaction area (R2) to produce a carbon dioxide (CO2)/water (H2O) gas mixture; and catalytic gasification of a solid and/or liquid hydrocarbon charge by partially reduced metal oxides obtained from (R2) in a gasification reaction area (R3) to produce a synthesis gas (carbon monoxide (CO) + hydrogen (H2)), in which the energy released by oxidation of metal oxides in the oxidation reaction area R1 allows the activation of gasification and reduction reactions.    Me = metal; and    x = not defined.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a process for preparing synthesis gas.    Air supply line (1)    Metal oxide circulation line (3)    Oxidation reaction area (R1)    Reduction reaction area (R2)    Gasification reaction area. (R3)