The oxidative dehydrogenation (ODH) of n-butane (butane) produces three isomers of butene (1-butene, trans2-butene, and cis-2-butene) which in turn are oxidized to form butadiene. Butane also is oxidized directly to butadiene. In this simulation study, the authors have analyzed the operating conditions required to produce the maximum amount of butenes, i.e., all three isomers, and butadiene in a fixed-bed reactor (FBR) and in an inert porous membrane reactor (IMR). The theoretical maximum yields of butenes and butadiene were found to be 0.119 and 0.800 carbon mass fractions, respectively. The reactor configuration in both instances was a large IMR operating at a low constant partial pressure of oxygen in the stream of reactants and products. It was found that 99.7% and 83% of the theoretical maximum yields of butenes and butadiene, respectively, can be achieved in an IMR with a constant oxygen partial pressure of 0.25 kPa. The corresponding residence times are 75 and 322 s. Candidate attainable regions have been identified for the system subspaces butane-butenes and butane-butadiene.