| 摘要 |
PCT No. PCT/EP88/00441 Sec. 371 Date Nov. 17, 1989 Sec. 102(e) Date Nov. 17, 1989 PCT Filed May 19, 1988 PCT Pub. No. WO89/10810 PCT Pub. Date Nov. 16, 1989.A method is provided for extracting helium from a relatively helium poor gas mixture through a pressure swing adsorption process which adhieves an enriched product gas containing over 50% helium. The gas mixture to be enriched is fed cyclically to four adsorber vessels ranged in parallel which successively pass through a pressure build-up, an adsorptive and a pressure relief phase, with pressure build-up and relief being in part brought about by pressure compensation with any one of the other adsorbers. The pressure-build up and relief phases include a series of three and four, respectively, steps involving alternating pressure levels. As a preliminary treatment, the process may include an initial step wherein the unenriched gas mixture is first fed through a series of pre-filters filled with activated carbon for removing higher hydrocarbons. |
