Cryogenic processing plant

From Wikimarcellus

A cryogenic processing plant (aka striping plant) is a facility where natural gas flowing from wells is cooled to sub-zero temperatures in order to condense liquids or NGLs (natural gas liquids). These can include butane, ethane and propane. NGLs are shipped to market and often used in refineries and petrochemical plants for fuel or feedstock. The methane gas that remains after removing liquids is transported via pipeline to where it is needed.

As an example of how cryogenic processing works, gas in Butler Co., PA typically has a BTU level that runs around 1250. A higher BTU level signifies the presence of greater amounts of NGLs. A cryogenic plant reduces the BTU level of the gas flowing from the well to 1100 which is a suitable level for use as natural gas.

Typically a plant separates NGLs from natural gas by chilling the gas stream down to around -120 degrees Fahrenheit. This allows a blended liquid hydrocarbon feedstock to be collected which then is fed into a fractionation plant that finishes processing the liquid hydrocarbon or Y Grade into high purity propane, butane and natural gasoline.