| abstract |
Disclosed is a shell-and-tube reactor for carrying out catalytic gas phase reactions, in particular methanization reactions, comprising a bundle (2) of catalyst-packed reaction tubes (3) through which reaction gas (15) flows and around which heat transfer medium (8) flows during operation, wherein in the region of the catalyst packing (16) the reaction tubes (3) run through at least two separate heat transfer medium zones (29, 30), the first of which extends over the starting region of the catalyst packing (16), and wherein during operation the heat transfer medium temperatures can be adjusted for each heat transfer medium zone (29, 30) such that they decrease in the flow direction of the reaction gas (15) from zone (29) to zone (30). Each reaction tube (3) comprises a first reaction tube section (21) having a first hydraulic diameter of the catalyst packing (16) and, downstream in the flow direction of the reaction gas (15), at least one second reaction tube section (22) having a second hydraulic diameter of the catalyst packing (16) which is greater than the first diameter, the first reaction tube section (21) extending over the starting region of the catalyst packing (16), and the first heat transfer medium zone (29) extending no more than to the end of the first reaction tube section (21). |