Simulation &Improvement of Single Stage Refrigeration Cycle for Production of LNG

Liquefied natural gas is obtained by reducing the temperature of natural gas to a temperature of -160, in this study, by using ASPEN HYSYS software, the PRICO liquefaction cycle, which includes two compressors and a heat exchanger, was simulated. The simulations were performed in two modes of high pressure (7945 Kpa) and low pressure of natural gas (2861 Kpa). The objective function was to minimize the specific energy consumption of the process. The energy consumption was 0.316 kWh / kgLNG, which showed a decrease of 22% compared to the reference value.
From Sensitivity analysis, it was concluded that the higher the molar flow rate of methane, ethane, propane and nitrogen in the refrigerant composition, the higher the specific energy consumption. In addition, it is better to have a high percentage of isopentane in the refrigerant to achieve the lowest specific energy consumption. In addition, the coefficient of performance was examined, which in the high pressure reached 3.12.