“…A comparison of the natural gas liquefaction processes with different precooling cycles was performed by Castillo et al (2013) using Aspen HYSYS with the Peng-Robinson thermodynamic fluid package. Using the PR equation to calculate the thermodynamic properties, Khan and Lee (2013) optimized a single mixed refrigerant natural gas liquefaction process using Honeywell UniSim Design and the particle swarm paradigm. With the PR equation of state calculating the thermodynamic properties, a typical single mixed refrigerant with low energy consumption was analyzed to determine the optimum operating conditions (Moein et al, 2015).…”