Exergoeconomic analysis and multi-objective optimization using NSGA-II in a novel dual-stage Selexol process of integrated gasification combined cycle

Abstract

To alleviate the problem of global climate change and provide a new perspective of carbon recovery, a novel configuration of H2S concentrator adopting pressure drop method and self-stripping method in dual-stage Selexol process of integrated gasification combined cycle is developed in this study. A comprehensive thermodynamic and exergoeconomic analysis of the novel Selexol process is carried out. The total product specific cost and total exergoeconomic factor of the process are 48.54 $/hr and 7.84 %. The ideal condition of components in the context of exergoeconomic analysis is defined, and the concrete improvement directions and methods of components which are not in ideal condition are given. Towards the exergoeconomic analysis, the multi-objective optimization of the model is carried out by using the Non-dominant Sorting Genetic Algorithm-II (NSGA-II) in conjunction with Aspen Plus. Besides, the ideal optimal point method is applied to the Pareto frontier in this study to get the optimal operating conditions according to the three targets for actual operation. The multi-objective optimization results reveal that the optimal point between CO2 capture efficiency and total exergy efficiency is that CO2 capture efficiency is 93.13 % and the total exergy efficiency is 26.09 %. This study provides a reference for academic research and engineering design of novel CO2 capture systems.