Economic Analysis of Separation Unit of Methanol to Propylene Production Based on Optimization of Refrigeration Cycles Using Pinch and Exergy Analysis

•Light gas separation unit of MTP process and refrigeration cycles are simulated.•A new multi-objective optimization approach for minimizing TAC with achieving to the desired product specifications is applied.•Pinch and exergy methods are used for obtaining optimal results in columns and refrigeration cycles operating conditions.•Real costs of refrigeration cycles considering of their interactions with separation columns are calculated.•Operating parameter of the propylene and ethylene refrigeration cycles are optimized simultaneously with distillation columns.