NOVELTY - An apparatus comprises reaction areas and components (e.g. static mixer/burner (4), monolithic reforming catalyser bed (6), plate-type heat exchangers (8, 12) and catalytic reactor (10)), that carry out reactions and/or single operations for reforming and desulphurisation of hydrocarbon fuels, integrated thermally and mechanically in a case/container (14). The apparatus is made of metal.    USE - For producing hydrogen and synthesis gas by autothermal reforming of liquid hydrocarbons (claimed) such as gasoline and methanol; useful in fuel cells such as melted-salt fuel cells.    ADVANTAGE - The apparatus provides integration of several unit operations and components into only one case; provides flexibility regarding the charges from liquid petroleum gas (LPG) to heavy diesel; is constructed without using conventional refractory materials that make the apparatus cumbersome and heavier; produces desulphurized gas with low loss of total load; controls the output gas temperature, even if the desulphurisation has been carried out at a lower temperature, thus reaching the requirements of the fuel cells without additional fuel consumption through the counter-current heat exchange between the gas to be desulphurized and already desulphurized gas; and provides final desulphurisation of the gases without adding hydrogen. The apparatus is a light-weight, compact, effective apparatus, that fully meets the requirements of the melted-salt fuel cells in terms of composition, pressure, temperature and size/weight of the conversion module.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for integrating an autothermal reformer and a synthesis gas desulphurisation device to be used in fuel cells.    DESCRIPTION OF DRAWING(S) - The figure shows an assembly of several components of an apparatus useful for producing hydrogen and synthesis gas by autothermal reforming of liquid hydrocarbon.    static mixer/burner (4)    monolithic reforming catalyser bed (6)    plate-type heat exchangers (8, 12)    catalytic reactor (10)    case. (14)