(364b) Energy Efficiency Improvement in LNG Liquefaction Processes

This paper focuses on the efficiency comparison of various LNG liquefaction processes and suggests a better process which requires less power and handles larger MTPA using simulation and optimization techniques. Our team analyzed steady-state processes such as Single-Mixed Refrigerant processes and Cascade Single-Mixed Refrigerant processes case by case. Recent studies forecast the market demand of the global LNG will increase approximately 10% in next 10 years. And the global LNG plant market will increase as LNG consumption increases.

Major simulation variables in SMR refrigerant systems are the selection of equipment and compositions of feed gases. Another important variable is the compressor ratio changed for decreasing required power at the same capacity. Many other variables are considered to decrease the power consumption. The cascade SMR processes are also analyzed. The capacity of LNG production increases with low power consumption. Peng-Robinson like equations are used to solve thermodynamic properties. To improve its accuracy, our team measured various properties under some critical conditions. These experimental data are imbedded in commercial physical property routines and they improve the accuracy of the simulation. Taken some operating parameters as key parameters, influences of these compressor ratios on shaft power and compositions of mixed refrigerant are analyzed. A new efficient LNG liquefaction process is developed in this research.