Techno-economical evaluation of three methods for stripping gas recovery in gas dehydration by unit of  Khark petrochemical complex

Abstract

The presence of water vapor in natural gas poses several issues including corrosion, blockages, and reduced pipeline capacity. The gas dehydration is a crucial process to reduce the water content and mitigate these problems. In this paper, glycol dehydration unit of Khark Petrochemical Company (KPC) has been simulated using Aspen Hysys v11.0 process simulator. At first, the simulation results has been validated with the design data and affecting parameters on the dehydration unit performance were identified through sensitivity analysis and their effects on the produced dry gas was investigated. The results showed that increasing the solvent circulation rate, stripping gas flow rate and reboiler temperature leads to more water removal rate. Secondly, the several options are suggested for stripping gas recovery and capital and operating expenditure for each option has been estimated and techno-economical evaluation of stripping gas recovery was carried out. Our techno-economic analysis reveals that about 0.7 MMSCFD stripping gas can be recovered from regeneration towers by increasing the operating pressure of regenerator and separating water from stripping gas. In the optimum option (sending the stripping gas to low pressure feed gas compressor), this project requires about 80,000 $ capital cost and has 1.7 MM$ annual revenue.