Why is helium usually obtained from natural gas rather than air?

Helium is primarily obtained from natural gas rather than air because of the significant difference in concentration. While ordinary air contains only about 5 parts per million of helium, certain natural gases found in the United States and other regions contain up to 7.6 percent helium.1

Extracting helium from air is a much less efficient process; for example, it takes 1,000 tons of air to obtain approximately 112 cubic feet of helium. In contrast, helium can be isolated from natural gas by liquefying the other components under high pressure and low temperatures, making it a far more practical and commercially viable source. Although some helium is supplied through the large-scale liquefaction of air, the high concentrations found in natural gas deposits—where helium accumulates as a product of radioactive disintegration—remain the primary source for industrial and scientific use.12