This article presents an overview on oxygen permeation, oxidative activation of light hydrocarbons and splitting of various molecules (H(2)O, N(2)O, NO(x)) containing oxygen in a hollow fiber catalytic membrane reactor made of BaCo(x)Fe(y)Zr(z)O(3-delta) (BCFZ, x+y+z = 1) which is used to separate oxygen from oxygen containing gases. Innovative reactor concepts are introduced and performances for the various applications are discussed. A detailed view is also given on the thermodynamic and kinetic background with regard to the above mentioned reactions. The potentials in terms of product intensification and energy saving by usage of the BCFZ hollow fibers as reaction vessels are evaluated. However, there are still technological challenges that prevent the described processes from being practiced on commercial scale by now.