A method for forming biodiesel, comprising: introducing a first stream comprising an alcohol proximate an upstream end of a plurality of fibers positioned longitudinally within a conduit reactor, wherein the end of the fibers opposite the upstream end thereof constitutes a downstream end thereof and is disposed proximate a collection vessel; introducing a second stream comprising vegetable oil into the conduit reactor proximate the upstream end of the plurality of fibers in the same direction of flow as the first stream, wherein the second stream is in contact with and is substantially immiscible with the first stream, at a flow rate, temperature, and pressure whereby the alcohol of the first stream interacts with the vegetable oil of the second stream to form biodiesel; receiving the biodiesel and residual amounts of the first and second streams in the collection vessel, wherein the biodiesel and the residual amounts of the second stream comprise a layer in a first portion of the collection vessel, and wherein the residual amounts of the first stream comprise a layer in a second portion of the collection vessel; and withdrawing separately from the collection vessel the different layers of the first and second portions of the collection vessel, wherein the first stream constitutes a phase substantially constrained to the surface of the fibers, and wherein the second stream constitutes a substantially continuous phase relative to the surface of the fibers, or wherein the second stream constitutes a phase substantially constrained to the surface of the fibers, wherein the first stream constitutes a substantially continuous phase relative to the surface of the fibers. introducing a first stream comprising an alcohol proximate an upstream end of a plurality of fibers positioned longitudinally within a conduit reactor, wherein the end of the fibers opposite the upstream end thereof constitutes a downstream end thereof and is disposed proximate a collection vessel; introducing a second stream comprising vegetable oil into the conduit reactor proximate the upstream end of the plurality of fibers in the same direction of flow as the first stream, wherein the second stream is in contact with and is substantially immiscible with the first stream, at a flow rate, temperature, and pressure whereby the alcohol of the first stream interacts with the vegetable oil of the second stream to form biodiesel; receiving the biodiesel and residual amounts of the first and second streams in the collection vessel, wherein the biodiesel and the residual amounts of the second stream comprise a layer in a first portion of the collection vessel, and wherein the residual amounts of the first stream comprise a layer in a second portion of the collection vessel; and withdrawing separately from the collection vessel the different layers of the first and second portions of the collection vessel, wherein the first stream constitutes a phase substantially constrained to the surface of the fibers, and wherein the second stream constitutes a substantially continuous phase relative to the surface of the fibers, or wherein the second stream constitutes a phase substantially constrained to the surface of the fibers, wherein the first stream constitutes a substantially continuous phase relative to the surface of the fibers.