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• LTTMs were screened for ethyl acetate-isopropanol separation using COSMO-SAC. • VLE data LTTMs-ethyl acetate-isopropanol are measured. • The intermolecular mechanism was studied by using QC calculations. Ethyl acetate and isopropanol, as essential chemical ingredients and organic solvents, play an important role in the industry. At atmospheric pressure, ethyl acetate and isopropanol form an azeotrope, which can be separated by extractive distillation. The choice of extractant is critical in extractive distillation. Low transition temperature mixtures (LTTMs), which are emerging as efficient green solvents, are used as extractants in this work. The effect of type and structure on separation performance were studied, and three LTTMs were selected for the separation of the ethyl acetate-isopropanol system. The vapor–liquid equilibrium (VLE) data of ethyl acetate-isopropanol-LTTMs was measured by experiments, and the results showed that when the mole fraction of LTTMs was 0.1, all three LTTMs could break the azeotrope of ethyl acetate and isopropanol, especially LTTM1 (tetrabutylammonium bromide: ethanolamine = 1:2) having the best selectivity. To acquire the binary interaction parameters, the NRTL model was used to fit the experimental data, and the regression data was in good agreement with the experimental data. In addition, a quantum chemical method was used to investigate the interactions between molecules to gain insights into the microscopic mechanism. Results showed that the weak hydrogen bonding and van der Waals forces are formed between ethyl acetate and other systems, while moderate or weak hydrogen bonding are formed between isopropanol and other systems. [ABSTRACT FROM AUTHOR]

• The waste heat of extraction - extractive distillation is recovered by heat integration and organic Rankine cycles. • Compared with the heat-integrated process, organic Rankine cycle assisted process save 8.88% total annual cost. • The control scheme of organic Rankine cycle assisted extraction - extractive distillation process shows good robustness. The high-purity isopropanol butanol ethanol (IBE) mixture is a highly efficient gasoline additive that can be directly used without further separation. The product of isopropanol-butanol-ethanol fermentation contains a large amount of water, and a large amount of energy will be consumed in the purification process. In this paper, the separation IBE process is systematically studied from the aspects of process optimization, energy recovery and process control. The operation parameters of extraction combined with extractive distillation (E-ED) are optimized by a multi-objective genetic algorithm. Then, the pinch point technique is used to analyze the energy usage of the optimized process, and the maximum heat recovery heat integration scheme is obtained. Compared with the optimized process, the low pressure steam consumption of the heat integration process is reduced by 100%, the cooling water consumption is saved by 58.80%, and the TAC is reduced by 35.95%. In view of massive waste heat in the heat integration of the extraction combined with extractive distillation (E-ED-HI) process, a new configuration combining the E-ED-HI and organic Rankine cycle (E-ED-HI-ORC) is further proposed. The organic Rankine cycle using R600a can further reduce TAC by 8.88% based on the HI-E-ED process. Finally, the control scheme of E-ED process is proposed. The performance of the control scheme is examined with ±10% disturbance of the feed flow rate and composition change, and the results show that the process of extractive distillation and separation of IBE has good controllability. [ABSTRACT FROM AUTHOR]