Improvement of Energy Efficiency in Gas Condensate Stabilization Unit: Process Optimization Through Exergy Analysis

Abstract

Gas condensate stabilization is a common process in gas refineries and petrochemical industries. This process is energy-consuming since it uses distillation columns and furnaces to separate different cuts from the condensate feed. This study aims to improve the performance of the gas condensate stabilization unit in a large petrochemical company in terms of energy efficiency and loss prevention. The case under investigation is the gas condensate stabilization unit in the Nouri Petrochemical Company, treating 568 t/h of raw condensate feed. This plant includes two distillation columns, two furnaces, pumps, heat exchangers, and air coolers. A hybrid energy and exergy analysis is conducted in this study. First, the validation of the simulation phase is performed, and a parametric sensitivity analysis is conducted to explore the effects of various parameters, such as operating temperature and pressure, on the process performance. After that, the most influential variables are identified using thermodynamic analyses for optimization and design purposes. An optimization method is employed to attain the maximum production improvement and exergy efficiency. The exergy analysis shows 187.4 MW total exergy destruction in the plant; furnaces account for 79% of the total exergy destruction. According to the sensitivity analysis results, the energy consumption of the process could be reduced by 33.7 MW; this is an 18% reduction in the plant's energy consumption. The optimal process conditions outperform the current and design states (4.6% improvement in exergy efficiency). The fuel gas consumption is reduced by 2.1 t/h, leading to a reduction of 128 t/d CO2 emissions.