Optimization and economic performance improvement of processes using aspen HYSYS and streamlined life cycle assessment

Abstract

Due to the increase in population and demand for consumer products, chemical industries responsible for their production have grown rapidly year by year. Even if the positive effects are evident, they still threaten the environment due to their high energy consumption and harmful emissions. There is an urgent need to reduce the harmful environmental emissions and increase profitability at the same time. To address this problem, this study provided a method of process optimization wherein modifications may be quantified and compared in terms of economic and environmental performance. Life cycle assessment (LCA) of the process aids in the determination of the processes within the system with the most contribution to the environmental impact (EI). Characterization factors from ReCiPe2016 were used. Weighting of EI was applied with the use of the average weighting factors from EPA, BEES, and NOGEPA. Economic and environmental performance of the system was treated with equal weight with respect to the determination of the optimized process. Aspen HYSYS v8.8 was utilized in order to efficiently simulate the different modifications of the processes. This method of optimization was integrated in a program named ALCAPRO: Aspen HYSYS coupled with streamlined Life Cycle Assessment in Process Optimization. Three processes were studied: methylamine production from ammonia and methanol, methanol to olefins (MTO) process, and shell process. The study revealed that modifications of the processes and the process parameters within the system yielded optimized processes in terms of economic viability and environmental performance.