Method for producing hydrogen
First Claim
1. A method for producing hydrogen including the step of shift converting a hydrogen containing gas stream under a given set of conditions of length of time, flow rate, temperature, pressure, moles steam to moles carbon ratio, and inlet CO concentration using a chromia stabilized iron oxide shift catalyst, wherein the hydrogen sulfide content of the gas stream is maintained between 20 ppm and 520 ppm on a dry gas volume basis, but in no event more than that which would result in the conversion of the iron oxide to iron sulfide under said given conditions, and wherein the step of shift converting comprises reducing the carbon monoxide concentration of said gas stream to less than p% by volume using an amount "A" of said shift catalyst which is no greater than about two-thirds the minimum amount "B" which would be required under said given set of conditions if there were no hydrogen sulfide in said gas stream.
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Abstract
In a method for producing high quality hydrogen, the carbon monoxide level of a hydrogen stream which also contains hydrogen sulfide is shifted in a bed of iron oxide shift catalyst to a desired low level of carbon monoxide using less catalyst than the minimum amount of catalyst which would otherwise be required if there were no hydrogen sulfide in the gas stream. Under normal operating conditions the presence of even relatively small amounts of hydrogen sulfide can double the activity of the catalyst such that much less catalyst may be used to do the same job.
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Citations
8 Claims
- 1. A method for producing hydrogen including the step of shift converting a hydrogen containing gas stream under a given set of conditions of length of time, flow rate, temperature, pressure, moles steam to moles carbon ratio, and inlet CO concentration using a chromia stabilized iron oxide shift catalyst, wherein the hydrogen sulfide content of the gas stream is maintained between 20 ppm and 520 ppm on a dry gas volume basis, but in no event more than that which would result in the conversion of the iron oxide to iron sulfide under said given conditions, and wherein the step of shift converting comprises reducing the carbon monoxide concentration of said gas stream to less than p% by volume using an amount "A" of said shift catalyst which is no greater than about two-thirds the minimum amount "B" which would be required under said given set of conditions if there were no hydrogen sulfide in said gas stream.
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