Study on an energy-saving process for separation ethylene elycol mixture through heat-pump, heat-integration and ORC driven by waste-heat

Energy-saving separation processes of Ethylene Glycol (EG) driven by waste heat were investigated. These are basic separation process (BSP) and separation process (SEP) with waste heat recovery (WHRSP). Electricity and heat from waste heat recovery (WHR) were generated for supplying separation system. The optimal operating parameters of each process were determined by the minimum total annual cost (TAC). The optimal process was studied by through multi-objective analysis-based exergy, environment and economy performance. The result of exergy analysis indicated that exergy loss of SEP was 1811.40 kW, which 26.38% lower than that of BSP. The environment analysis showed that compared with the benchmarked BSP process, the emissions and emission costs of WHRSP are significantly reduced by about 32.69%. The results of economic analysis showed that TAC of BSP and WHRSP are 2.05x10(6) $/y, 1.41x10(6) $/y. TAC of the WHRSP process was 31.54% lower than that of the benchmarked BSP. The WHRSP shows the high energy efficiency, low economy cost and low exergy loss with a great industrial application prospect when compared to the benchmarked process. (C) 2021 Elsevier Ltd. All rights reserved.