Natural Gas Liquids - Extraction and Fractionation
In addition to being a major interstate natural gas pipeline, operating one of the nation's largest underground natural gas storage systems and being the largest gatherer of gas in West Virginia, Dominion Energy Transmission is a producer and supplier of natural gas liquids (NGLs).
Our products include propane, normal butane, isobutane and natural gasoline. We extract, fractionate, store, transport and market to various end-user markets including propane retailers, refineries, petrochemical facilities, and aerosol companies.
Our investment in the Hastings Extraction Plant was the largest in the history of the company's Gathering & Processing business. The $85 million modernization gives Dominion Energy an updated plant with low maintenance costs, increased efficiencies and high reliability. Capacity has increased by up to 33 percent, creating significant drilling opportunities for West Virginia producers.
Liquids Extraction & Fractionation Process
The gas feed from an inlet centrifugal compressor is first used to supply heat to the deethanizer in the reboiler. Because the gas must be chilled to -102° F, all traces of moisture are removed by molecular sieve bed driers. The extraction process then begins.
The inlet gas passes through heat exchangers to continue the cooling process. Some of the heavier components of the gas become liquid and drop out in the cold separator. The remaining cold gas is then fed to the Turbo-expander, where the expansion of the gas and resulting pressure drop causes more liquid to be produced.
This liquid is then fed to the absorber for even more heat exchange and final removal from the gas stream of all except the very lightest hydrocarbon components. The gas from the top of the absorber is warmed, the pressure boosted by the expander boost compressor and fed to the residue compressor for return to the pipeline system.
The liquid produced in the cryogenic area is processed in the fractionation section of the plant. The various fractionation towers distill the products using temperature and pressure control to cause the products to vaporize and leave the tops of the towers. This vaporized product is condensed to liquid by air coolers and then pumped to storage.
If there is an emergency involving a Dominion Energy Transmission pipeline, call the Dominion Energy Transmission 24-hour emergency telephone number: