Process for conducting exothermic equilibrium reactions

A process for preparing methanol by converting a synthesis gas feed comprising hydrogen and carbon oxides, comprising the following process steps:

• (a) providing a reactor comprising at least two series-connected reaction cells that are in fluid connection with one another and are arranged in a common reactor shell, wherein each reaction cell comprises the following series-connected assemblies that are in fluid connection with one another:
• (aa) a preheating zone suitable for heating the feed mixture or the gaseous product stream from an upstream reaction cell, wherein the preheating zone can optionally be dispensed with in a first reaction cell in flow direction of the gaseous feed mixture;
• (ab) at least one reaction zone comprising a catalyst active in respect of the exothermic equilibrium reaction to be conducted and a cooling apparatus in a heat-exchanging relationship with the catalyst;
• (ac) at least one cooling zone comprising a cooling apparatus suitable for cooling the partly converted, gaseous product stream that has been laden with condensable reaction product and exits from the reaction zone to a temperature below the dew point of this gas;
• (ad) a deposition zone comprising a phase separation apparatus for separation of the product stream that exits from the cooling zone into a gaseous product stream that has been freed of condensate and a condensate stream comprising liquid reaction product;
• (ae) means of discharging the condensate stream comprising liquid reaction product and optionally means of feeding the condensate stream to a workup apparatus for the reaction product;
• (af) means of discharging the gaseous product stream that has been freed of condensate and means of feeding this gaseous product stream to a subsequent reaction cell arranged downstream or means of discharging the gaseous product stream from the process;
• (b) providing a synthesis gas feed comprising hydrogen and carbon oxides and introducing it into the reactor;
• (c) at least partly converting the synthesis gas feed in the reactor under methanol conversion conditions;
• (d) discharging a liquid reactor product stream comprising methanol and water from the reactor and optionally feeding the liquid reactor product stream to a further deposition apparatus and/or at least one further methanol workup apparatus;
• and
• (e) discharging a synthesis gas output stream and recycling this synthesis gas output stream to the reactor with a fixed recycle ratio and/or discharging the synthesis gas output stream from the process.