What is the purpose of a glycol-based dehydrator in gas processing?

• A. To remove water vapor from natural gas by contacting gas with a circulating glycol solution that absorbs water, then regeneration to release water.
• B. To remove sulfur compounds from gas using amine treatment.
• C. To cool the gas to condense liquids.
• D. To remove CO2 by chemical absorption.

Answer: (A)

The main idea is to remove water vapor from natural gas by using a circulating glycol solution that absorbs moisture and then regenerating that glycol to release the water and reuse the lean glycol. In operation, hot lean glycol is circulated to a contactor where natural gas passes through; water vapor from the gas is readily absorbed by the glycol, leaving dry gas and producing water-rich glycol. The rich glycol is then heated in a regeneration step to drive off the absorbed water, producing water vapor that exits and lean glycol that is cooled and returned to contact the gas again. This process lowers the gas dew point, preventing condensation and hydrates downstream and protecting equipment. It’s specifically aimed at moisture removal, unlike other options that target sulfur compounds, CO2, or general cooling, which are different treatment objectives.