Helium is primarily collected by extracting it from underground natural gas reservoirs where it exists in trace amounts.
The Process of Obtaining Helium
Obtaining helium involves a multi-step process focused on separating the helium from other gases found underground.
Locating the Source
The journey to collect helium begins with locating underground reservoirs of natural gas that contain the element in trace amounts. Not all natural gas fields contain significant amounts of helium; finding those that do is the critical first step.
Extraction and Separation
Once a suitable reservoir is found, the natural gas is extracted. The core collection process then involves separating out the impurities from this natural gas, leaving behind only pure helium molecules. This separation is typically done through a process called cryogenic distillation, which utilizes the different liquefaction points of the various gases present (methane, nitrogen, helium, etc.). Helium has a very low liquefaction point, meaning it remains a gas while most other components of natural gas turn into liquid at extremely cold temperatures.
Key Steps:
- Identify natural gas fields containing helium.
- Extract the raw natural gas mixture.
- Cool the gas to very low temperatures.
- Separate the liquid components (mostly methane).
- Further process the remaining gas mixture (containing helium and nitrogen) through additional cooling and separation stages.
- Purify the raw helium to various grades depending on its intended use.
This process effectively "collects" the helium by isolating it from the much larger volume of natural gas.
Storage and Distribution
After purification, the helium is typically compressed and stored in cylinders or transported in bulk, often in specialized cryogenic containers if it is liquefied for efficiency.
This method of extraction from natural gas is currently the primary way commercial quantities of helium are obtained and collected globally.
