NOVELTY - In a process to generate hydrogen gas for a fuel cell, non-polar hydrocarbons are reformed to supercritical water, in a first stage water is compressed in a compression zone to a pressure p1. The water is discharged to a heating zone and brought to a temperature t1. The water is in a supercritical state at pressure p1 and temperature t1.    USE - Process to generate hydrogen gas for a fuel cell on a small scale for e.g. remote site operation.    ADVANTAGE - The assembly is compact and suitable for use at remote sites.    DETAILED DESCRIPTION - Hydrocarbon fuel is compressed to pressure p1 and fed to the supercritical water to form a supercritical mixture of water and hydrocarbon. The mixture reacts in a supercritical reaction zone in the presence of a granular oxide catalyst, forming CO, CO2 and H2, and is allowed to cool to a sub-critical state at temperature t2 with pressure falling to p2 in the presence of hydrogen peroxide. Gas is separated from the liquid. Some or all of the residual liquid is returned to the compression zone and the cycle repeated.    INDEPENDENT CLAIMS are also included for:    (1) the use of hydrogen to reform non-polar hydrocarbons to supercritical water in the presence of hydrocarbons and a reforming assembly; and    (2) an assembly consisting of a high pressure water pump, a water heater, a high pressure hydrocarbon pump, a hydrocarbon injector unit, a heated regeneration reactor, a product chilling unit, a product expansion valve, a phase separator, and liquid feedback pipe.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart of the process. (Drawing includes non English-language text).    Separator (A1)    Water tank (B1)    Hydrocarbon tank (B2)    Rupture disc holder (BS)    Gas meter (GU)    Cooling (K)    Capillary reactor ((K1)    Tube reactor (K2)    HPLC pump (P1, P2)    Back-flow prevention fitting (R1, R2)    Shut-off valve (V1, V2, V3, V4)    Inlet pressure regulator (V5)    Overflow valve (V6)    High pressure valve (V7)    Aqueous phase (X1)    Flow meter (FQI1)    Pressure sensor (PI1, PI2)    Temperature sensor (TIC1, TIC2)    Temperature regulator (TIR1, TIR2, TIR3, TIR4)