Abstract
Helium is an extraordinary commodity. Its many remarkable properties, i.e., lightness, inertness, small atomic size, low liquefaction temperature, make this element play a crucial role in advanced technological sectors. Despite it is the second-most-abundant element in the universe, the only viable helium sources are certain natural gas fields, where helium accumulates because of a-decay of Uranium-238 and Thorium-232. Helium production from natural gas has long been discouraged by the marginal economic revenue compared with the required operating costs. However, the helium shortage we are experiencing today has revived the interest in its recovery. In this panorama, the development of efficient processes for helium separation from natural gas and its upgrading is of paramount importance. The aim of this work is to analyse the cryogenic helium recovery from natural gas. Single-column and double-column process configurations are discussed, to identify their applicability range depending on the feed compositions. To benefit from the high flexibility of the single column configuration, its application to CO2 containing mixtures is investigated, to lighten the upstream acid gas removal section, thus enabling significant energy savings in the overall gas-treatment chain.
