The glycol dehydration process is an example of an absorption dehydration method, and it uses a liquid desiccant to absorb water from the gas stream. Since ethylene glycol has a very great affinity for water and comes into touch with a stream of naturally occurring water-wet gas, the gas stream's water is absorbed by the ethylene glycol, which was initially the main chemical agent in this process.

Glycol dehydration now uses an aqueous solution of a glycol derivative, usually diethylene glycol (DEG) or triethylene glycol (TEG), that is brought into contact with the water-wet gas stream in a contactor. Ethylene glycol was initially utilised in the procedure as the absorbent. However, with the advancement of technology, this step has been replaced. The natural gas will be transferred out of the dehydrator after being stripped of the majority of its water content and the glycol solution sinks to the bottom of the contactor after absorbing water from the wet gas.

The glycol solution, which contains all of the water removed from the natural gas, is put through a special boiler created to vaporise only the water out of the solution, where the difference in boiling points makes it relatively simple to remove the water. The glycol is then recycled to the contactor.

Some units have a flash tank separator-condenser that, in addition to removing water from the gas stream, also regenerates small amounts of methane and other compounds that the glycol solution occasionally picks up from the contactor stage after the contactor stage has also removed these components from the gas stream. Previously, this methane might have been released, lost to the product streams, and contributed to air pollution. The flash tank separator-condensers enable separation of the absorbed hydrocarbon ingredients before the glycol solution reaches the boiler, reducing the amount of methane and other compounds that are wasted.

Methane and other hydrocarbons can evaporate from the solution in the flash tank separator because of the lower boiling hydrocarbon constituents that are made possible by the reduced pressure. The residual hydrocarbons are then collected, mixed with other hydrocarbon streams, fractionated, and sent to the various product streams after the glycol solution is sent to the boiler, which may also be equipped with air- or water-cooled condensers. Due to the presence of hydrocarbon elements with larger molecular weights than methane in tight formation natural gas streams, the addition of a flash-separator-condenser system to the process is a valuable adaptation.