Natural gas usually contains a large amount of water and is typically water-saturated. This water causes several problems for downstream processes and equipment, such as corrosion or freezing in pipelines at relatively high temperatures. Glycol-based gas dehydration is a liquid desiccant technology for the removal of both water and CO2 from natural gas. Glycols commonly used in the industry include diethylene glycol (DEG), triethylene glycol (TEG) and tetraethylene glycol (TREG), with TEG being the most popular variant. This technology is able to achieve the water content requirements that will help to prevent the challenges mentioned above.
Removal of the dissolved water (and hydrocarbons) takes place in adsorbers. The feed gas enters at the top and flows downwards passing a bed with the desiccant. Water and hydrocarbons remain behind in the desiccant and dry product gas exits below. In a two-vessel system, one adsorber is in service while the other is regenerated for re-use.