Abstract: A tube bundle reactor for carrying out catalytic gas phase reactions, particularly methanation reactions, has a bundle of catalyst-filled reaction tubes through which reaction gas flows and around which heat carrier flows during operation. In the region of the catalyst filling, the reaction tubes run through at least two heat carrier zones which are separated from one another, the first of which heat carrier zones extends over the starting region of the catalyst filling. The reaction tubes each have a first reaction tube portion with a first hydraulic diameter of the catalyst filling and, downstream thereof in flow direction of the reaction gas, at least a second reaction tube portion with a second hydraulic diameter of the catalyst filling that is greater than the first hydraulic diameter of the catalyst filling.

Abstract: A tube bundle reactor for carrying out catalytic gas phase reactions, particularly methanation reactions, has a bundle of catalyst-filled reaction tubes through which reaction gas flows and around which heat carrier flows during operation. In the region of the catalyst filling, the reaction tubes run through at least two heat carrier zones which are separated from one another, the first of which heat carrier zones extends over the starting region of the catalyst filling. The reaction tubes each have a first reaction tube portion with a first hydraulic diameter of the catalyst filling and, downstream thereof in flow direction of the reaction gas, at least a second reaction tube portion with a second hydraulic diameter of the catalyst filling that is greater than the first hydraulic diameter of the catalyst filling.

Abstract: A method of varying the temperature of a tube bundle reactor for catalytic gas phase reactions upon start-up and shut-down, the tube bundle reactor comprising a major reactor portion which includes a bundle of vertically disposed reactor tubes, upper and lower tubesheets tightly connected to the upper and lower ends, respectively, of the reactor tubes, and a reactor shell enclosing the tube bundle, a heat transfer medium having a melting temperature in the range of from 100° C. to 450° C. flowing around the outer surfaces of the reactor tubes during normal operation and being circulated in at least one circuit through the major reactor portion, comprising the steps: (a) varying the heat transfer medium temperature during circulation of the heat transfer medium; and (b) passing a temperature gas through the reactor tubes at least when the heat transfer medium is not yet or no longer circulated.

Abstract: A method of varying the temperature of a tube bundle reactor for catalytic gas phase reactions upon start-up and shut-down, the tube bundle reactor comprising a major reactor portion which includes a bundle of vertically disposed reactor tubes, upper and lower tubesheets tightly connected to the upper and lower ends, respectively, of the reactor tubes, and a reactor shell enclosing the tube bundle, a heat transfer medium having a melting temperature in the range of from 100° C. to 450° C. flowing around the outer surfaces of the reactor tubes during normal operation and being circulated in at least one circuit through the major reactor portion, comprising the steps: (a) varying the heat transfer medium temperature during circulation of the heat transfer medium; and (b) passing a temperature gas through the reactor tubes at least when the heat transfer medium is not yet or no longer circulated.

Abstract: With a method for operating a tube bundle reactor for exothermic gas phase reactions having a tube bundle with catalyst-filled reaction tubes (2), wherein the one ends of the reaction tubes are spanned by a gas inlet hood and the other ends are spanned by a gas outlet hood and wherein around the outside of the reaction tubes a heat transfer medium flows to carry off reaction heat. An explosive gas mixture (G) is introduced into the reaction tubes (2) via the gas inlet hood and after reaction the gas mixture (G), that may still be explosive, it is led off from the reaction tubes via the gas outlet hood.