Process and reaction system for the preparation of methanol

A reaction system for use in a process for the preparation of methanol, the system comprises a first methanol reaction unit and a second methanol reaction unit, each containing a methanol catalyst;

• a process gas stream passageway for introducing a process gas stream of a fresh synthesis gas into the first methanol reaction unit and a circulation passageway for circulating unconverted synthesis gas to the second methanol reaction unit;
• a first effluent passageway for withdrawing and passing a first methanol containing effluent stream from the first reaction unit to a mixing point in a second effluent passageway for withdrawing a second methanol containing effluent from the second reaction unit;
• a separating means arranged downstream the mixing point in the second effluent passageway for separating methanol from the unconverted synthesis gas;
• and
• a circulator arranged in the circulation passageway between the separating means arranged upstream the second methanol reaction unit;
• and
• a purge gas line connected to the circulation passageway and arranged upstream the mixing point in the second effluent passageway.