NOVELTY - Oxidative conversion of a gaseous alkane, preferably methane, in a fluidized bed membrane reactor comprising a first inlet pipe, a second inlet pipe (3), which is present, within the reactor, at least partially in the form of a membrane (5) having at least one active membrane surface, and a catalyst bed (4), comprises: introducing at least one first stream comprising the gaseous alkane (1) into the catalyst bed in the reactor through the first inlet pipe; and introducing at least one second stream comprising oxygen or oxygen containing gas (2) into the reactor through the second inlet pipe.    USE - The process is useful for the oxidative conversion of a gaseous alkane, preferably methane.    ADVANTAGE - The oxidative conversion of gaseous alkane can be carried out in a selective and in an inexpensive manner.    DETAILED DESCRIPTION - Oxidative conversion of at least one gaseous alkane, preferably methane, in at least one fluidized bed membrane reactor comprising at least one first inlet pipe, at least one second inlet pipe (3), which is present, within the reactor, at least partially in the form of a membrane (5) having at least one active membrane surface, and at least one catalyst bed (4), comprises: introducing at least one first stream comprising the gaseous alkane (1) into the catalyst bed in the reactor through the first inlet pipe; and introducing at least one second stream comprising oxygen or an oxygen containing gas (2) into the reactor through the second inlet pipe, where the second stream is introduced through the active membrane area in the catalyst bed of the reactor. INDEPENDENT CLAIMS are included for:    (1) the fluidized bed membrane reactor for performing the process, comprising the catalyst bed, the first inlet pipe for introducing the first stream comprising a first gas, preferably the gaseous alkane, in the catalyst bed arranged in the reactor, and the second inlet pipe for introducing the second stream comprising a second gas, preferably oxygen-containing gas, through the active membrane area of the second inlet line in the catalyst bed of the reactor; and    (2) a control device for moving the membrane portion of the inlet pipe for a gas stream within the reactor.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a fluidized-bed reactor.    First stream comprising gaseous alkane (1)    Second stream comprising oxygen or an oxygen containing gas (2)    Second inlet pipe (3)    Catalyst bed (4)    Membrane. (5)