| abstract |
The present invention relates generally to processes and systems for recovering helium from low helium-containing feed gases (i.e., containing less than about 10 volume % helium and more typically, less than about 5% helium by volume). The present invention more particularly relates to processes and systems for recovering helium from low helium-containing feed gases using temperature swing adsorption (TSA) systems and multiple (e.g. two) stage vacuum pressure swing adsorption (VPSA) systems. In preferred embodiments of the invention, the first stage VPSA system is configured to provide regeneration gas for the TSA system, and/or the VPSA second stage tail gas is recycled to the first stage VPSA system. |