Process and plant for producing methanol

A process for producing methanol, comprising:

• a) providing an input gas comprising carbon oxides and hydrogen;
• b) introducing the input gas as a first fresh gas stream into a first compressor stage for precompression of the first fresh gas stream to obtain a second fresh gas stream;
• c) introducing a recycle gas stream and the second fresh gas stream into a second compressor stage for compression of the recycle gas stream and the second fresh gas stream to synthesis pressure to obtain a synthesis gas stream;
• d) catalytically converting the synthesis gas of the synthesis gas stream in a plurality of serially arranged reactor stages at synthesis pressure to obtain a product stream comprising methanol and unreacted synthesis gas per reactor stage;
• e) cooling the product stream obtained per reactor stage for condensation and separation of methanol from unreacted synthesis gas and introducing unreacted synthesis gas into a respective subsequent stage of the serially arranged reactor stages;
• f) withdrawing unreacted synthesis gas from at least one of the reactor stages as a recycle gas stream for introduction of the recycle gas stream into the second compressor stage according to step c).