| 摘要 |
A process for extracting helium from a feedstock containing helium at moderate levels together with trace amounts of hydrogen is disclosed. Helium is separated from the feedstock by pressure swing adsorption (PSA) and the hydrogen impurity is removed by chemisorption in a nickelbased catalytic bed. Where the feedstock contains significant amounts of nitrogen, less than 5% methane, and less than 1000 ppm carbon dioxide, the catalytic step preferably precedes the PSA step. Regeneration of the catalytic bed is preferred by passing over the spent bed an inert gas with controlled amounts of an oxidizing agent, preferably oxygen, to react with adsorbed hydrogen to form water. This method substantially increases the catalyst's capacity to adsorb hydrogen when the catalytic unit is placed back in service and eliminates the conventional step of thermally regenerating the bed by heating with an inert gas for an extended period of time. |
