Lean gas is a type of natural gas that contains very few or no liquefiable liquid hydrocarbons. It is also commonly referred to as dry gas.
Understanding Lean Gas
Natural gas, when extracted, is typically a mixture of various hydrocarbons. The primary component is methane, which remains a gas at standard temperature and pressure. However, natural gas can also contain heavier hydrocarbons such as ethane, propane, butane, and pentanes, which can be liquefied under pressure or reduced temperature. These are known as liquefiable liquid hydrocarbons or natural gas liquids (NGLs).
Key Characteristics
Based on the definition, lean gas stands in contrast to "rich gas" or "wet gas," which contains significant amounts of these liquefiable hydrocarbons.
- Composition: Primarily methane (CHâ‚„).
- Liquefiable Hydrocarbons: Contains few or no liquefiable liquid hydrocarbons (like ethane, propane, butane, etc.).
- Alternative Name: Also known as dry gas.
This composition is significant in the processing and transportation of natural gas. Gas processing plants often extract NGLs from wet gas because they are valuable commodities used as fuels, heating sources, and petrochemical feedstocks. Lean gas, having minimal or no NGLs, requires less processing to meet pipeline specifications and can often be transported and used directly as fuel gas after basic purification steps (like removing water and impurities).
In summary, lean gas is essentially natural gas that has been naturally depleted of, or processed to remove, most of the heavier, liquefiable hydrocarbon components, leaving behind primarily methane.
