CONICET | Buscador de Institutos y Recursos Humanos

Industrial-scale ethylene production is proposed by using a novel membrane multitubular reactor for the ethane oxidative dehydrogenation process over a Ni-Nb-O catalyst. The theoretical study is performed by means of a pseudo-homogeneous model of the tubes and the shell sides. The feasibility and convenience of using this novel design, as well as the influence of the main operating variables on the reactor performance, is analyzed through the manuscript. The introduction of the membrane conducts to lower oxygen partial pressures inside the catalyst tubes when compared with a conventional multitubular reactor. This leads to very good ethylene selectivities, good temperature control due to lower heat generation rates, and reasonable production rates. The reactor performance appears to be highly affected by the balance between the oxygen consumption rate by chemical reaction and its rate of permeation through the membrane. Under certain operating conditions leading to lower reaction rates, a non-desired oxygen accumulation inside the tubes is observed. A minimum amount of O2 injected at the tube mouth appears beneficial to overcome this accumulation phenomenon. The membrane reactor shows a non-conventional inverse parametric sensitivity with respect to the inlet temperature. When the reactor is operated at conditions where the reaction is controlled by the permeation flow of O2 through the membrane, it is possible to reach high selectivity to ethylene, significant ethane conversions and mild temperature profiles.