Design of an Industrial Heat Exchanger Unit at the TEG Inlet of a Natural Gas Dehydration Plant

Abstract

Gas processing industries globally grapple with water vapor in natural gas, causing issues like methane hydrate formation, caking, corrosion, and flow problems. Due to natural gas's pivotal role in energy and petrochemical production, the triethylene glycol (TEG) dehydration process proves vital for efficient water removal. Within this process, the heat exchanger at the TEG inlet to the contactor is crucial. It maintains optimal lean TEG absorption temperature and regulates sales gas temperature for pipeline transmission. Employing simulation tools like HYSYS, the analysis determined specific parameters such as an overall heat transfer coefficient of 140.4 kJ/h-m²-C, shell and tube side pressure drops of 34.47 kPa and 68.95 kPa respectively, a 5.027 m² heat exchanger area, shell volumes of 0.1955 m³ and 0.0608 m³ for the shell and tube sides respectively, and a positive heat duty of 1.727 x 10^4 kJ/hr. This positive duty signifies successful gas heating for standard transmission and maintaining lean TEG absorption temperature. Remarkably, the water composition in natural gas reduced from 0.005 mol% to 0.0002 mol% after the process simulation.