Exergoeconomic analysis and multi-objective Pareto optimization of the C3MR liquefaction process

Over the past decades, increasing attention is paid to optimal design and operation of energy intensive industries. A HYSYS simulated model is developed for a propane mixed refrigerant process. Synthesis of pinch and exergy analysis is employed to find the high value of exergetic efficiency. Exergoeconomic analysis also is carried out using the total revenue requirement method. Then a coded genetic algorithm from Matlab software is linked to HYSYS software to optimize the propane mixed refrigerant process. Optimization of the aforementioned system is performed for two singular objective functions. One of the objective functions can minimize the unit cost of exergy, and the other one can maximize exergetic efficiency of the system. In addition, a multi objective function is employed for finding the optimum point in terms of both high exergy efficiency and low total product cost. Results of exergy and exergoeconomic analyses for all the main streams and equipment are presented, and optimization results are compared with corresponding features of the base case design. In the end, sensitivity analysis is employed to examine variation of compressor pressure ratio in terms of total product cost of the system.