Apparatus for fractionating the product stream of an alkane dehydrogenation

The invention relates to an apparatus for production of an input (1) for a dehydrogenation reactor (R) consisting largely of an alkane and hydrogen and separation of the dehydrogenation product (2) comprising hydrogen and an alkene generated in gaseous form in the dehydrogenation reactor (R), comprising at least a first heat exchanger (E1) and a second heat exchanger (E2) which are arranged in a thermally insulating housing (cold box) (K) for cooling the dehydrogenation product (2), wherein the first heat exchanger (E1) is assigned a first separator (D1) and the second heat exchanger (E2) is assigned a second separator (D2) and wherein separable in the first separator (D1) from a first biphasic material stream (3) obtainable by cooling of the dehydrogenation product (2) in the first heat exchanger (E1) is a first hydrogen-rich, alkene-containing gas mixture (5), from which is obtainable in the second heat exchanger (E2) by further cooling a second biphasic material stream (6), from which in the second separat