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Hydrocarbon gas liquids explained Where do hydrocarbon gas liquids come from?

Propane is produced from crude oil refining and natural gas processing

Propane production is generally consistent throughout the year because it results from natural gas processing and crude oil refining. Most U.S. propane production occurs during natural gas processing.

In natural gas processing plants, propane enters the plant as a component of the wet natural gas stream from natural gas and crude oil wells. When the raw, wet natural gas is cooled and pressurized in the plant, the heavier hydrocarbons (including ethane, propane, normal butane, isobutane, and natural gasoline) turn into liquids and separate from the natural gas stream. The mixed liquids, also referred to as Y-grade, are then refined and separated in a fractionator into purity products (products that are at least 90% of one type of hydrocarbon gas liquid [HGL]).

Oil refineries can produce propane in two stages of the crude oil refining process. The first refining process that yields propane is the atmospheric distillation column, where crude oil undergoes initial distillation. In modern, complex refineries, propane (and propylene) is also produced in fluid catalytic crackers (FCC). During this process, long-chain hydrocarbon molecules are cracked under high temperatures and pressures to break these molecules into lighter hydrocarbons that are more suitable for motor gasoline production. In addition to those gasoline blending products, the refinery crackers produce lighter molecules including propane, normal butane, isobutane, and their olefins.

Image of propane supply and disposition

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Propane is imported from other countries to supplement U.S. sources

The United States generally imports propane to supplement U.S. propane production, especially during the autumn and winter months to meet demand from farmers and for space heating in buildings. Most propane imports come by rail from Canada into the Midwest, East Coast, and Rocky Mountain regions of the United States. Some propane imports arrive by ship, usually at times of high demand and in regions where infrastructure constraints limit the ability to deliver domestic supplies, such as New England or Hawaii.

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Last updated: December 26, 2023.