Investigation of energy-saving azeotropic dividing wall column to achieve cleaner production via heat exchanger network and heat pump technique
Journal
Journal of Cleaner Production
Journal Volume
234
Pages
410-422
Date Issued
2019
Author(s)
Abstract
A thermally coupled azeotropic dividing wall column (ADWC) configuration is explored for the separation of industrial wastewater to recycle the organic solvent tert-butanol. Heat pump technology is used to the ADWC configuration to improve the released heat duty quality of the condenser achieving the energy-saving. A gas preheater before the compressor is installed in the heat pump assisted ADWC configuration in increasing the temperature of the inlet vapour stream of the compressor that achieves effectively reducing the power and compression ratio of the compressor. To fully utilize a large amount of superheat energy produced in heat pump system indicated by the temperature-enthalpy and Grand Composite Curve diagrams, a green and sustainable Heat Integrated ADWC (HI-ADWC) separation configuration is proposed by the combined use of heat exchange network and heat pump implementations. Three indexes involving total annual cost, CO2 emissions, and exergy loss are introduced to evaluate the economic, environmental and thermodynamic performances. The results illustrate that the TAC of the proposed green and sustainable HI-ADWC configuration is significantly reduced by 32.91% with a ten-year payback period compared to that of the existing configuration. CO2 emissions are reduced by 86.43% and exergy loss of the HI-ADWC configuration by 36.72%. The proposed method for the green and sustainable HI-ADWC configuration could be widely extended to other industrial processes reduce energy consumption and related CO2 emissions. © 2019
Subjects
CO2 emissions reduction; Distillation; Energy-saving; Heat exchanger network; Heat pump
Other Subjects
Carbon dioxide; Compressibility of gases; Compressors; Distillation; Emission control; Energy utilization; Exergy; Heat pump systems; Investments; Pumps; Wastewater reclamation; CO2 emissions; Grand composite curves; Heat exchanger network; Heat pumps; Heat-exchange networks; Industrial wastewaters; Reduce energy consumption; Thermodynamic performance; Energy conservation
Type
journal article