Increasing the efficiency of liquefied natural gas production plant with considering appropriate refrigerant components

Abstract

AbstractIn liquefied natural gas (LNG) production, the total efficiency of the system increased by using mixed refrigerants for the liquefaction process. In this study, the mixing of the effective refrigerants is considered as one of the most important factors in the optimization of liquefaction process of natural gas. In this regard, three mixed refrigerants with different compositions and conditions were selected. The refrigerants were selected based on optimization of power and electrical efficiency, overall thermal efficiency, heat exchanged with refrigeration cycle, and mass flow rate of Refrigerants in cycle. The optimized chemical process with related energy integrations were simulated and evaluated by Aspen HYSYS and Aspen energy analyzer (HX‐Net), respectively. Furthermore, the Aspen Capital Cost Estimator (Icarus) was employed for the economic analysis of these processes. The investment and operating costs of the optimized process (in the process with considering the MR3 refrigerant) are less than other processes. The calculated capital, operating, and equipment costs are about 22.6, 20.1, and 10.3 million US Dollars in the process with MR3 refrigerant. The mixed refrigerant 3 (MR3) contains the CH4, C2H6, C3H8, and N2with the mole fraction of 0.1316, 0.1317, 0.0299, and 0.7098, respectively. Modeling and cost estimation techniques can be used as a useful tool for the design and optimization of appropriate gas liquefaction and refrigeration processes with an effective performance for various industrial applications.