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A process to desulfurize a fuel gas, such as natural gas, for use as a feed fuel for a fuel cell is characterized by providing a feed stream (10) of sulfur containing gas, passing part of that as a stream (12) to a compressor (14), passing the compressed stream to a sulfur selective membrane (16) to

A process to desulfurize a fuel gas, such as natural gas, for use as a feed fuel for a fuel cell is characterized by providing a feed stream (10) of sulfur containing gas, passing part of that as a stream (12) to a compressor (14), passing the compressed stream to a sulfur selective membrane (16) to provide a sulfur rich stream (18) which is returned to the feed stream (10), and a sulfur lean stream (20) which can be passed to an optional gas meter (26) and then to a sulfur sorbent medium (28) before reforming the essentially sulfur free stream (34) in the reformer (40) of a fuel cell unit (36) also containing a fuel cell (38).

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1. A process to desulfurize sulfur containing fuel gas used as feed fuel for fuel cell system comprising the steps:(1) providing a main feed stream of sulfur containing fuel gas containing at least 0.30 ppm of odorous sulfur compounds; and then(2) passing part of that main feed stream of sulfur cont

1. A process to desulfurize sulfur containing fuel gas used as feed fuel for fuel cell system comprising the steps:(1) providing a main feed stream of sulfur containing fuel gas containing at least 0.30 ppm of odorous sulfur compounds; and then(2) passing part of that main feed stream of sulfur containing fuel gas and compressing it to a pressure over 304 kPa; and then(3) passing the compressed sulfur containing fuel gas to sulfur selective membrane, where the gas is separated into a sulfur concentrated stream, and a sulfur lean stream containing no more than 0.20 ppm of sulfur compounds; and then(4) passing the sulfur concentrated stream back to the main feed stream down stream from where the stream of step (2) was provided; and then(5) optionally measuring gas flow and reducing gas pressure; and then(6) passing the sulfur lean stream through a sulfur sorbent medium to collect sulfur, providing an essentially sulfur free stream containing no more than 0.10 ppm of sulfur compounds; and(7) optionally reforming the essentially sulfur free stream prior to passing it to contact a fuel cell.2. The method of claim 1, where the main feed stream is natural gas stream.3. The method of claim 1, where the main feed stream contains odorous sulfur compounds selected from the group consisting of mercaptans, sulfides, and thiophenes and mixtures thereof.4. The method of claim 1, where the main feed stream is a natural gas stream containing odorous sulfur compounds selected from the group consisting of tertiary butyl mercaptan, dimethyl sulfide, tetrahydrothiophene and mixtures thereof.5. The method of claim 1, where the sulfur free stream is reformed in step (7).6. The method of claim 1, where the fuel cell is an axially elongated solid oxide fuel cell.7. The method of claim 1, where the fuel cell is contacted with a pressurized, essentially sulfur free stream in step (7).8. The method of claim 1, where gas flow is measured between steps (4) and (6).9. The method of claim 1, where the sulfur containing fuel gas passed to the sulfur selective membrane is at a pressure between 304 kPa and 20670 kPa.10. The method of claim 1, where the essentially sulfur free stream provided in step (6) contains between about 0.025 ppm and 0.075 ppm of sulfur compounds.11. A method of reducing the sulfur concentration in a sulfur containing fuel gas used as feed fuel for a fuel cell system, comprising:providing a main fuel feed stream containing a sulfur containing fuel gas;pressurizing at least a portion of the sulfur containing fuel gas;passing at least a portion of the pressurized sulfur containing fuel gas through a sulfur selective membrane to separate the gas into a sulfur concentrated stream and a sulfur lean stream, the sulfur concentrated stream having a higher sulfur concentration than the sulfur lean stream;passing the sulfur concentrated stream back into the main fuel feed stream downstream from where the sulfur containing fuel gas is pressurized; andpassing the sulfur lean stream through a sulfur sorbent medium to reduce the sulfur concentration in the sulfur lean stream.12. The method of claim 11, wherein the sulfur containing fuel gas contains at least 0.30 ppm of odorous sulfur compounds.13. The method of claim 11, wherein the sulfur containing fuel gas is pressurized to a pressure greater than 304 kpa.14. The method of claim 11, wherein the sulfur lean stream contains no more than 0.20 ppm of sulfur compounds.15. The method of claim 11, wherein a gas flow is measured and a gas pressure is adjusted based upon the gas flow measurement.16. The method of claim 15, wherein the gas flow is measured prior to passing the sulfur lean stream through the sulfur sorbent medium.17. The method of claim 11, wherein the sulfur sorbent medium reduces the sulfur concentration in the sulfur lean stream to no more than 0.10 ppm of sulfur compounds.18. The method of claim 11, wherein the sulfur lean stream is reformed prior to contacting a fuel cell.19. A method of reducing the sulfur concentration in a sulfur containing fuel gas used as feed fuel for a fuel cell system, comprising:providing a main fuel feed stream containing a sulfur containing fuel gas;passing at least a portion of the sulfur containing fuel gas through a sulfur selective membrane to separate the gas into a sulfur concentrated stream and a sulfur lean stream, the sulfur concentrated stream having a higher sulfur concentration than the sulfur lean stream;passing the sulfur concentrated stream back into the main fuel feed stream such that the sulfur concentrated stream does not mix with the sulfur lean stream; andpassing the sulfur lean stream through a sulfur sorbent medium to reduce the sulfur concentration in the sulfur lean stream for use as the feed fuel for the fuel cell system.20. The method of claim 19, wherein at least a portion of the sulfur containing fuel gas is pressurized to over 304 kpa prior to passing the sulfur containing fuel gas through the sulfur selective membrane.