Partial oxidation of propane to acrolein in a dual bed inert membrane reactor

The partial oxidation of propane to acrolein is studied in a dual bed membrane reactor. A porous membrane tube is used to feed oxygen to the annular catalyst beds surrounding the porous section of the membrane tube. The distributed oxygen feed in the membrane tube lowers the partial pressure of oxygen in each bed increasing selectivity to the partially oxidized product over total oxidation. The first bed contained a V/MgO catalyst for the partial oxidation of propane to propene. The second bed consisted of a BiMo catalyst to convert propene to acrolein. Studied were conducted first in each bed separately to determine operating conditions in each bed and then in a dual bed configuration.The separate inert membrane reactors show improvement in selectivity of few % in comparison to fixed bed reactors. On the other hand when using both membrane reactors combined in a dual bed configuration a major improvement in acrolein selectivity of up to 21% was obtained. Catalysts characterization by surface area, X-ray diffraction, and X-ray photoelectron spectroscopy showed that the improvement was due to the distribution of the oxygen flow rate through the membrane in the second membrane reactor which prevented the deactivation of the BiMo catalyst.