What is the main purpose of glycol in a gas dehydration system?

The main purpose of glycol in a gas dehydration system is to remove water vapor from natural gas to prevent hydrate formation and corrosion in pipelines and processing equipment. Natural gas often contains water vapor when it comes from the well. Water vapor can cause several problems, including the formation of hydrates, which are ice-like solids that can plug pipelines and restrict gas flow. Hydrates form under conditions of high pressure and low temperature, which are common in offshore pipelines. Water vapor can also lead to corrosion of pipelines and equipment, especially in the presence of carbon dioxide or hydrogen sulfide. Glycol dehydration systems use glycol, typically triethylene glycol (TEG), to absorb water vapor from the natural gas. The wet gas is contacted with liquid glycol in an absorber tower, where the glycol absorbs the water vapor. The dry gas exits the top of the absorber tower, while the rich glycol (glycol containing water) is sent to a regenerator, where the water is removed by heating the glycol. The regenerated lean glycol is then recycled back to the absorber tower. For example, offshore gas pipelines often use glycol dehydration to prevent hydrate formation, ensuring continuous gas flow and preventing costly blockages.