Synthesis of ammonia with internal cooling circuit

The invention relates to a method for the synthesis of ammonia, in which a fresh gas consisting largely of hydrogen and nitrogen is compressed via a compressor and subsequently fed to an ammonia converter for conversion into a converter product containing ammonia and comprising hydrogen and nitrogen. Upstream of the compressor, ammonia is evaporated into the fresh gas in order to cool the fresh gas and to produce a cold substance mixture comprising ammonia and the fresh gas. The substance mixture is heated in a heat exchanger against at least one process stream to be cooled, and subsequently compressed via the compressor, to obtain a compressed substance mixture comprising ammonia and the fresh gas. Upstream of the circuit cooler, a gas mixture consisting largely of hydrogen and nitrogen is fed to a substance stream comprising the fresh gas. The constituents of the gas mixture are separated from the converter product and/or from the compressed substance mixture comprising ammonia and the fresh gas.