A process for producing ammonia (2) in an ammonia synthesis converter (19) with co-production of steam (40) from the recovery of process heat generated in the synthesis converter, the process includes producing power (44) from expansion of said steam (40) in a steam turbine (42) which is mechanically coupled to a reversible motor/generator (43) and to a compressor so to form an assembly which can be selectively operated in a first mode of operation and in a second mode of operation wherein: in said first mode, mechanical power (44) is transferred from said steam turbine (42) to said reversible motor/generator (43) and to said compressor whilst in said second mode, mechanical power (44) is transferred to said compressor from said steam turbine (42) and from said reversible motor/generator.