Economic evaluation and optimization of liquefaction process of natural gas with mixed refrigerant
Volume Title: 1
1Department of Petroleum and Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
2Research Institute of Petroleum Industry (RIPI), Tehran, Iran
The mixed refrigerant in the liquefaction process of natural gas has been extensively used and considered as a subject for optimization of the effective parameters important in this process. In this research, the PRICO process with the mixed refrigerant has been optimized by genetic algorithm and considering the payback period as an objective function. Two various PRICO process including the ones with two compressors and three compressors were considered for optimization. Molar rates of mixed refrigerant compounds (methane, ethylene, propane, isopentane, and nitrogen, compressor outflow pressure of the first and second compressors (and third for the second configuration), outflow pressure of valve in refrigeration cycle, and temperature of the hot outflows from the heat exchanger were considered as the variables of optimization. The obtained optimization value for payback period in the first and second configurations is 2.2 and 2.57 years, respectively. According to the obtained numbers, the payback period for the first configuration reduced 14.39% than the second configuration. However, the liquefaction rate of the optimized process with the second configuration is 2.45% more than the liquefaction rate of the optimized process with the first one.