An Investigation of Dehydration Inefficiencies and Associated Design Challenges in a Gas Dehydration Unit: A Case Study of X Gas Plant

Abstract

The value and contribution of natural gas in both domestic and economic terrains are extensive. However, its contaminant limits direct application and hence must be treated. Water vapour existing in equilibrium with dry gas is the principal among contaminants. Most corrosion both with acid gases and carbonate salts are traceable to the presence of water. Also the formation of solid icy structures called hydrates constitutes a threat to flow assurance. Removal of water by TEG dehydration trains is not uncommon. Dehydration inefficiencies such as high water content of the outlet gas and glycol losses could impair operations and considerably reduce profit. Inefficiency in GDU was identified to be due to design factors and operational conditions/scenarios. In the case studied, laboratory analysis of TEG was combined with process simulation results to resolve inconsistencies in design and operational phases. Recommendations for further improvements were also presented.