Cartridge for separation of a gas mixture, comprising - a permeate collecting tube PSR which consists of one or more segments and has a front end PSRE1 and a rear end PSRE2, - a multitude of hollow-fibre membranes arranged around the permeate collecting tube PSR and having a front end HFE1 on the PSRE1 side and a rear end HFE2 on the PSRE2 side, - a first tube sheet VA1 at front ends HFE1 and PSRE1 and a second tube sheet VA2 at rear ends HFE2 and PSRE2, - a barrier which is impermeable to the fluid mixture to be separated and which surrounds the arrangement composed of the permeate collecting tube PSR and hollow-fibre membranes in the region between tube sheets VA1 and VA2, - a front end cap EK1 disposed above first tube sheet VA1 and optionally a rear end cap EK2 which, if present, is disposed above the second tube sheet VA2, characterized in that - the permeate collecting tube PSR or all the segments of the permeate collecting tube PSR in the region between tube sheets VA1 and VA2 are configured so as to be impermeable to the fluid mixture to be separated, - the impermeable barrier is configured, based on the longitudinal axis of the cartridge, in the first third, preferably in the first quarter, of the distance between tube sheets VA1 and VA2, more preferably at a distance of 0 to 10 cm beyond the inner end face of tube sheet VA1 and most preferably at a distance of 2 to 4 cm beyond the inner end face of tube sheet VA1 in such a way that one or more fluid entry orifice(s) or gap(s), into the interspace between the impermeable barrier and the permeate collecting tube PSR, are present, - the hollow fibre rear ends HFE2 are embedded in the second tube sheet VA2, with the cores of the hollow fibres closed at their rear ends HFE2, - the hollow fibre front ends HFE1 are embedded in first tube sheet VA1, with the cores of the hollow fibres open at their front ends HFE1, - the front end cap EK1 is configured and disposed above first tube sheet VA1 in such a way that a front end cap EK1 cavity is formed between the outer end face of the first tube sheet VA1 where the permeate flows out of the hollow-fibre cores and the inner surface of the end cap EK1, - in the region of the front end cap EK1 cavity, permeate exit orifices are present in the permeate collecting tube PSR or in a segment of the permeate collecting tube PSR, such that there is fluid communication between the fluid in the front end cap EK1 cavity and the interior of the permeate collecting tube PSR, - at least one exit orifice for the retentate is present in the last quarter of the distance between tube sheets VA1 and VA2 in the impermeable barrier or embedded into the second tube sheet VA2. - a permeate collecting tube PSR which consists of one or more segments and has a front end PSRE1 and a rear end PSRE2, - a multitude of hollow-fibre membranes arranged around the permeate collecting tube PSR and having a front end HFE1 on the PSRE1 side and a rear end HFE2 on the PSRE2 side, - a first tube sheet VA1 at front ends HFE1 and PSRE1 and a second tube sheet VA2 at rear ends HFE2 and PSRE2, - a barrier which is impermeable to the fluid mixture to be separated and which surrounds the arrangement composed of the permeate collecting tube PSR and hollow-fibre membranes in the region between tube sheets VA1 and VA2, - a front end cap EK1 disposed above first tube sheet VA1 and optionally a rear end cap EK2 which, if present, is disposed above the second tube sheet VA2, - the permeate collecting tube PSR or all the segments of the permeate collecting tube PSR in the region between tube sheets VA1 and VA2 are configured so as to be impermeable to the fluid mixture to be separated, - the impermeable barrier is configured, based on the longitudinal axis of the cartridge, in the first third, preferably in the first quarter, of the distance between tube sheets VA1 and VA2, more preferably at a distance of 0 to 10 cm beyond the inner end face of tube sheet VA1 and most preferably at a distance of 2 to 4 cm beyond the inner end face of tube sheet VA1 in such a way that one or more fluid entry orifice(s) or gap(s), into the interspace between the impermeable barrier and the permeate collecting tube PSR, are present, - the hollow fibre rear ends HFE2 are embedded in the second tube sheet VA2, with the cores of the hollow fibres closed at their rear ends HFE2, - the hollow fibre front ends HFE1 are embedded in first tube sheet VA1, with the cores of the hollow fibres open at their front ends HFE1, - the front end cap EK1 is configured and disposed above first tube sheet VA1 in such a way that a front end cap EK1 cavity is formed between the outer end face of the first tube sheet VA1 where the permeate flows out of the hollow-fibre cores and the inner surface of the end cap EK1, - in the region of the front end cap EK1 cavity, permeate exit orifices are present in the permeate collecting tube PSR or in a segment of the permeate collecting tube PSR, such that there is fluid communication between the fluid in the front end cap EK1 cavity and the interior of the permeate collecting tube PSR, - at least one exit orifice for the retentate is present in the last quarter of the distance between tube sheets VA1 and VA2 in the impermeable barrier or embedded into the second tube sheet VA2.