the present invention is directed to a sparger system provided for appropriately feeding reactant streams to fluidized bed reactors of hydrocarbon partial oxidation processes that are retrofitted to selectively recover and recycle unreacted hydrocarbons . as a result of the sparger system , the reactor productivity and selectivity is enhanced while employing only two spargers . also , the capital cost required for retrofitting existing sparging equipment is minimized , while at the same time , the desired fluidization and catalyst oxidation characteristics are achieved without the formation of flammable mixtures within the sparging system .