NOVELTY - Ammonia is prepared by reacting a hydrocarbon stream, a compressed process air stream (7) from a gas turbine (1) and steam; converting carbon monoxide to carbon dioxide and hydrogen; and converting residual carbon monoxide and carbon dioxide to methane and water, in such a way that a synthesis gas containing nitrogen and hydrogen is obtained and converted to ammonia.    USE - Preparation of ammonia.    ADVANTAGE - The method is highly integrated as far as heat balance is concerned. It leads to a more energy efficient process per tonne of ammonia produced with its reduced energy requirement ( about 6.4 Gcal/tonne compared with 8-10 Gcal/tonne for a conventional process). It is also able to provide its own electricity requirement and to export electrical energy.    DETAILED DESCRIPTION - Preparation of ammonia comprises:    (a) a reforming step, in which a hydrocarbon stream, a process air stream and steam are reacted to obtain a discharge stream which contains carbon monoxide (CO), carbon dioxide (CO2), hydrogen (H2) and nitrogen (N2);    (b) a CO conversion step, in which CO in the discharge stream is converted to CO2 and H2;    (c) a CO2 removal step, in which CO2 is removed from the stream obtained in step (b); and    (d) a methanization step, in which the residual CO and CO2 are converted to methane (CH4) and water (H2O), in such a way that a synthesis gas that contains N2 and H2 is obtained and converted to ammonia in a synthesis cycle.    At least a portion of the process air stream that is reacted in the reforming step is compressed with the aid of a compressor (2), which is part of a gas turbine.    An INDEPENDENT CLAIM is also included for an installation for carrying out the method, comprising:    (a) a reformer section (16);    (b) a CO conversion section connected to the reformer section;    (c) a CO2 removal section connected to the CO conversion section;    (d) a methanization section connected to the CO2 removal section; and    (e) a gas turbine comprising a compressor, a combustion chamber and an expansion turbine (3).    The discharge for the compressed air from the compressor is connected by a pipe to the reformer section to provide at least a portion of the process air stream.    DESCRIPTION OF DRAWING(S) - The figure shows an installation for producing ammonia.    Gas turbine (1)    Compressor (2)    Expansion turbine (3)    Heat exchanger (11)    Reformer section (16)    Saturating unit (25)