NOVELTY - Sweep membrane separator comprises membrane that is selectively permeable to selected gas; mixed gas stream including selected gas entering the sweep membrane separator and contacting retentate side of membrane, where part of selected gas separates from mixed gas stream and passes through permeate side of membrane; sweep gas at high pressure sweeping the gas from permeate side of membrane; and mixture of sweep gas and selected gas exiting the sweep membrane separator at high pressure, separating the selected gas from gas mixture and pressurizing the selected gas.    USE - For removing sulfur from liquid hydrocarbon feedstocks including hydrodesulfurization (HDS) and supplying hydrogen at high pressure for used in HDS system used in hydrocarbon fuel processing system, and also in fuel cell systems and fields such as automotive, chemical, and energy.    ADVANTAGE - The sweep membrane separator provides high purity hydrogen to desulfurization process at rate that can be adjusted by the rate of steam flow. The use of high purity hydrogen may enable the processing of more difficult fuels e.g. diesel and may beneficially change the composition of the fuel by hydrogenating and breaking some aromatic ring structures, beneficial to e.g. solid oxide fuel cell. By using sweep membrane separator in fuel processor, increases the hydrogen content of feedstock and also positively affects catalyst lifetime and performance prior to reforming reactor; also simplifies and reduces the size of the system. This approach has the potential to process heavy fuels in a small, compact configuration not achievable using other technologies.    DETAILED DESCRIPTION - Sweep membrane separator comprises membrane which is selectively permeable to selected gas (i.e. hydrogen); mixed gas stream including selected gas entering sweep membrane separator and contacting retentate side of membrane, where part of selected gas separates from mixed gas stream and passes through permeate side of membrane; mixed gas stream, minus the separated gas, exiting sweep membrane separator; sweep gas (i.e. steam) at high pressure entering sweep membrane separator and sweeping the gas from permeate side of membrane; mixture of sweep gas and selected gas exiting the sweep membrane separator at high pressure, where the sweep membrane separator separates the selected gas from gas mixture and pressurizing the selected gas. INDEPENDENT CLAIMS are included for the following:    (1) fuel pre-processing system comprising hydrodesulfurization (HDS) reactor operating at 200-500 psig and 200-500 degrees C; sulfur compound absorbing reactor operating at 200-500 psig and 200-400 degrees C; supply of hydrocarbon fuel containing sulfur bearing material; and supply of hydrogen at pressure greater than or equal to HDS operating pressure;    (2) fuel processor comprising fuel pre-processing system, where the clean fuel output is directed to reformer without being condensed; sweep separator to provide hydrogen to fuel pre-processing system; reforming reactor; primary water vaporizer to supply the reformer; and secondary water vaporizer to supply the sweep separator, where sweep membrane separator is used to increase hydrogen content of feedstock prior to reformation; and    (3) fuel processing system for solid oxide fuel cell comprising reformer for hydrocarbon fuel producing reformate, and including sweep membrane separator, and which routes reformate directly from sweep membrane separator to solid oxide fuel cell.    DESCRIPTION OF DRAWING(S) - The figure shows schematic diagram of fuel processing system for solid oxide fuel cell that includes sweep membrane separator.