ECONOMIC STUDY OF CONVENTIONAL AND IMPROVED EXTRACTIVE DISTILLATION SYSTEM USING ASPEN ECONOMIC ANALYSER
Simulation and the economic analysis of a conventional and an improved extractive distillation system has been carried out. Aspen plus and the Aspen Economic Analyser were used to simulate and generate data tables and charts while the non-random two liquid physical property was selected for the process. The case study adopted is the separation of Isopropyl alcohol (IPA) – water (H2O) azeotrope mixture using dimethyl sulfoxide (DMSO) as the entrainer. Maintaining the optimum parameters, an improved configuration was designed to improve economic efficiency by reducing the amount and cost of utility requirements. The modification involved the addition of heat exchangers to make use of the available sensible heat from the entrainer stream to be recycled. The heat exchangers serve as preheaters for both column feed streams by using the excess sensible heat from the entrainer recovered as heat source. Results showed that the utility cost requirement for the extractive distillation column and the entrainer recovery column decreased from 49.4 $/hr to 41.9 $/h and from 57.7 $/hr to 47.2 $/h respectively. The total system utility cost requirement also decreased by 167,589 $/year in the proposed modification.
Keywords: economic analysis; extractive distillation; heat integration; process simulation.