Crude helium extraction from natural gas:Technology progress and prospects
Helium is a strategic resource crucial for national security and the development of high-tech industries.The content of helium in the air is only 5.2 mL/m3,while the helium content in natural gas ranges from 0.3%to 8%.Although industrial-scale helium can be produced by separating the non-condensable gases from large air liquefaction units,extracting helium from helium-rich natural gas is more feasible economically and is currently the primary source.The process of helium extraction from natural gas involves first removing the majority of methane,nitrogen,and other components to obtain crude helium,followed by further purification of the crude helium.In this paper,a variety of crude helium extraction technologies,such as cryogenic technology,membrane separation technology,combined membrane separation and cryogenic technology,as well as polygeneration technology are introduced.Additionally,it provides a perspective on the future development of cost-effective technology package for helium-extraction from natural gas with low helium content commonly found in China and domestic production of equipment.