Abstract: An oxygen transport membrane reactor having an oxygen transport membrane and a downstream fuel injector located within a chamber. The oxygen transport membrane and fuel injector are enclosed by a duct that constrains an incoming oxygen containing feed to flow along the outer surface of the duct and then reverse direction and flow within the duct and past the oxygen transport membrane and then the fuel injector. The oxygen transport membrane permeates part of the oxygen within the oxygen containing feed by ion transport to form a retentate. The retentate is used to support combustion of the fuel injected by the fuel injector. The resulting heat is used to heat the incoming oxygen containing feed by indirect heat exchange which in turn is used to heat the oxygen transport membrane.