NGL stands for natural gas liquids, a group of hydrocarbons that are extracted from raw natural gas during processing. They include ethane, propane, butane, isobutane, and natural gasoline (also called pentanes plus). These components are heavier than methane, the primary ingredient in natural gas, and they have enormous value on their own as fuels, petrochemical feedstocks, and blending agents. In 2024, NGL production accounted for about 9% of total U.S. energy production, reaching a record 4 trillion cubic feet.
What NGLs Actually Are
When natural gas comes out of a well, it isn’t pure methane. It contains a mix of heavier hydrocarbons that exist as gases underground but can be condensed into liquids at the surface under the right pressure and temperature conditions. These heavier hydrocarbons are the natural gas liquids. Each one is a slightly larger molecule than methane, and that size difference determines its boiling point, its value, and what it’s used for.
The five main NGLs, from lightest to heaviest:
- Ethane: Two carbon atoms. The lightest NGL and the one produced in the largest volume.
- Propane: Three carbon atoms. The most widely recognized NGL, commonly sold as LP gas for grills and home heating.
- Normal butane: Four carbon atoms. Used primarily in gasoline blending and as lighter fuel.
- Isobutane: Also four carbon atoms, but arranged differently. Mainly a refinery feedstock.
- Natural gasoline (pentanes plus): Five or more carbon atoms. The heaviest NGL, liquid at room temperature and atmospheric pressure.
How NGLs Are Separated From Natural Gas
Raw natural gas goes to a gas processing plant, where the goal is to strip out the heavier hydrocarbons and leave behind pipeline-quality methane. Two main methods handle this extraction.
The first is cryogenic expansion, where the gas stream is cooled to around negative 120°F. At that temperature, the heavier hydrocarbons condense into liquids and can be collected, while methane stays in gas form. This is the most common method for large-scale NGL recovery and captures a high percentage of the ethane in the stream.
The second is absorption, where the gas passes through a special oil that selectively soaks up hydrocarbons heavier than methane. The absorbed liquids are then separated from the oil through heating. This method is older and generally less efficient at capturing ethane, but it works well for propane and heavier components.
Fractionation: Splitting the Mix
After extraction, the NGLs come out as a mixed liquid stream sometimes called “y-grade” or “raw make.” This mix needs to be separated into individual products, each with its own market and price. That separation happens at a fractionation plant through a series of distillation towers, each one targeting a specific component based on its boiling point.
The process works from lightest to heaviest. A deethanizer removes ethane first. The remaining stream moves to a depropanizer, which pulls out propane. Then a debutanizer separates the butanes, leaving natural gasoline as the heaviest remaining product. Each tower heats the liquid to a temperature where only the target component boils off, allowing it to be captured as a purified product.
What Each NGL Is Used For
Ethane is the workhorse of the petrochemical industry. Most ethane goes to steam crackers, industrial facilities that break it down at extreme temperatures to produce ethylene. Ethylene is one of the most important building-block chemicals in the world, serving as the starting material for plastics, antifreeze, and detergents. Ethane can also be blended with natural gas and burned directly for power generation, though its petrochemical value typically makes that less attractive.
Propane wears two hats. In the consumer market, it’s a heating and cooking fuel, particularly in rural areas without natural gas pipelines. Farms use it to heat livestock housing, dry crops, and power irrigation pumps. It also fuels forklifts, school buses, and backup generators. On the industrial side, propane serves as a petrochemical feedstock alongside ethane, cracked to produce propylene and other chemicals used in plastics manufacturing.
Normal butane is blended into motor gasoline, especially during cooler months when its higher volatility isn’t a problem. (In summer, butane blending is restricted because heat can cause it to evaporate too readily in fuel tanks.) It also serves as a petrochemical feedstock. When cracked, butane yields butadiene, a key ingredient in synthetic rubber. Isobutane goes primarily to refineries, where it’s used in alkylation units to produce high-octane gasoline components.
Natural gasoline, the heaviest fraction, finds use as a gasoline blending component and as a diluent for heavy crude oil. Heavy crude from places like Canada’s oil sands is too thick to flow through pipelines on its own, so producers mix in natural gasoline to thin it out for transport. It also serves as a petrochemical feedstock and as a denaturant added to fuel-grade ethanol.
NGL vs. LNG vs. LPG
These three abbreviations cause constant confusion. They refer to different things.
NGL is the broad category of heavier hydrocarbons separated from natural gas: ethane, propane, butane, isobutane, and natural gasoline. It’s a product category, not a single substance.
LNG (liquefied natural gas) is predominantly methane that has been cooled to negative 260°F, converting it from a gas into a liquid. This shrinks its volume by about 600 times, making it practical to ship overseas in specialized cryogenic tankers. LNG is about transporting methane, not the heavier components.
LPG (liquefied petroleum gas) is a subset of NGLs, specifically propane and butane. Unlike LNG, LPG can be stored as a liquid in pressurized tanks at normal temperatures, with no extreme cooling required. The propane tank on a backyard grill is LPG. So LPG is a narrower term that sits inside the broader NGL category.
Why NGLs Matter Economically
NGL production has become a major revenue driver in the U.S. oil and gas industry. For natural gas producers, the value of the liquids extracted during processing can make or break the economics of a well. In some basins, the gas itself sells for relatively little, and the NGLs are what generate the profit. U.S. NGL production grew 7% from 2023 to 2024, reflecting both rising natural gas output and strong petrochemical demand.
The petrochemical connection is especially significant. Steam cracking of NGLs is the primary source of ethylene globally, and ethylene demand tracks closely with economic growth because it flows into so many consumer products. The U.S. has built substantial ethane cracking capacity along the Gulf Coast, driven by abundant and relatively cheap NGL supply from shale gas production in basins like the Permian and Appalachian.
NGL prices tend to move with crude oil rather than with natural gas, since many of their end uses compete with petroleum-derived products. When crude prices rise, NGLs become more valuable because gasoline blending components and petrochemical alternatives from oil refineries also become more expensive. This pricing dynamic means that NGL-rich gas wells can be profitable even when natural gas prices are low.