Method, tube bundle reactor and reactor system for carrying out catalytic gas phase reactions

A reactor system, comprising:

• a first reactor stage;
• a condenser;
• a heating zone;
• and
• a second reactor stage which are all arranged consecutively in a flow direction of a reaction gas flowing through the reactor system, wherein
• the first reactor stage is a tube bundle reactor comprising:
• a bundle of reaction tubes that are filled with a catalyst charge and through which the reaction gas flows during operation and which are cooled by a heat transfer medium;
• a metering tube is embedded at least partially in the catalyst charge in each reaction tube and arranged coaxially thereto,
• an interior of the metering tube is catalyst-free and extends from a gas-inlet-side end of the catalyst charge into the catalyst charge a predefined length, and the metering tube has at least one gas inflow point outside the catalyst charge and at least one gas outflow point in a region of the catalyst charge,
• wherein a first gas outflow point, of the at least one gas outflow point, in a flow direction of the reaction gas is arranged at a predefined distance from the gas-inlet-side end of the catalyst charge so that a partial flow of the reaction gas flowing into each reaction tube flows in a bypass to the catalyst charge there,
• wherein:
• a first catalyst charge of the catalyst charge has at least two catalyst layers of different activity,
• the at least two catalyst layers contain a same catalyst material,
• a first catalyst layer of the at least two catalyst layers in the flow direction of the reaction gas contains 5 vol. % to 90 vol. % of the catalyst material of a directly adjacent at least one second catalyst layer of the at least two catalyst layers, and
• the first gas outflow point in the flow direction of the reaction gas opens into the at least one second catalyst layer,
• wherein the reaction gas flowing into the reactor system is conveyed through the catalyst charge,
• wherein the condenser is configured to cool the reaction gas flowing out of the tube bundle reactor to a temperature below a dew point of at least a portion of components of the reaction gas and to divert the at least the portion of condensed components,
• wherein the heating zone is configured to heat the reaction gas from which a portion of the condensed components has been removed in the condenser;
• and
• wherein the second reactor stage is a reactor with a second catalyst charge, through which the reaction gas flowing out from the heating zone is conveyed,
• wherein the catalyst material is a methanation catalyst.