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Searching for green solvents is imperative for the sustainable development of liquid-liquid extraction. Liquid-liquid equilibrium data for two ternary systems of methyl tert-butyl ether (MTBE) + methanol + N-methylimidazolium hydrosulfate ([MIM][HSO4]) and MTBE + methanol + 1-butyl-3-methylimidazolium hydrosulfate ([BMIM][HSO4]) were measured at 278.15 K, 298.15 K and 318.15 K at 101.325 kPa for this study. The values of the distribution coefficient and the separation factor were calculated based on the experimental data, and then, the extraction ability was determined. Factors affecting the phase behavior such as the nature of the ionic liquid and the temperature were discussed. NRTL and UNIQUAC models were applied to correlate the experimental tie-line data.

The vapor liquid equilibrium data of diethylamine + acetone, acetone + N-methyl pyrrolidone and diethylamine + N-methyl pyrrolidone were measured at 101.3 kPa in this article. Van Ness and Herington test were used to check the experimental data. Three models of the NRTL, UNIQUAC and Wilson were selected to correlate the experimental data. Meanwhile, the binary interaction parameters were regressed with the three models. Root-Mean-Square Deviations and average absolute deviation of equilibrium temperature and mole fraction of vapor phase were calculated between measured value and calculated value. The result indicated that the three models were correlated well with vapor−liquid equilibrium data.

Vapor−liquid equilibrium (VLE) data for the binary systems of tetrahydrofuran (THF) + ethyl acetate (EtOAc), THF + N-methyl pyrrolidone (NMP) and EtOAc + NMP, and the ternary systems of THF + EtOAc + NMP were measured at 101.3 kPa. The modified Rose vapor recirculating type equilibrium still was utilized to obtain the experimental data. The Herington method, as well as the Van Ness test, was used to verify the thermodynamic consistency of the experimental data. The NRTL model, UNIQUAC model and Wilson model were adopted to correlate the vapor-liquid equilibrium data. Accordingly, the binary interaction parameter for each model was obtained by regressing the experimental data. The results show that the three models can accurately agreement with the experimental data.

Dynamic control structures are significant for liquid–liquid extraction combined with heterogeneous azeotropic distillation (LEHAD) and liquid–liquid extraction combined with extractive distillation (LEED) processes, which were proposed in our previous work for the separation of the azeotrope of propylene glycol methyl ether and water. However, there may be complications regarding the dynamic controllability of the two hybrid processes, and this work investigates the dynamic control structures. For the LEHAD process, an improved composition–temperature cascade control structure using the ratio of the reboiler duty to feed flow (QR/F) can realize effective control when feed disturbances are added. For the LEED process, the improved dual temperature control structure with QR/F was able to handle the disturbances well. Moreover, a comparison between the two hybrid processes was made according to the dynamic controllability, and the integral of the squared errors was calculated. The results show that the LEHA...

To solve the increasingly serious global energy problem, an innovative cascade absorption heat transformer system using industrial low-level waste heat is presented in this paper. Based on an accurate model and simulations, the cascade system is studied in terms of an energy, exergy, and economy analysis. To achieve a trade-off between the thermodynamic and economic performance, a multi-objective optimization method is used to optimize the system. The thermodynamic performance (total exergy destruction) of the multi-objective optimized design is 3.64% higher than its ideal minimum value, while the economic performance (total annual cost) is 2.74% higher than its ideal minimum value. This indicates that the multi-objective optimization scheme can provide better comprehensive performance than single optimization schemes for the cascade absorption heat transformer system. In addition, the results show that the exergy destruction rate is 74.30%. The exergy destruction of the NH3/H2O system accounts for 55.62% of the total input exergy; thus, improvements of this system should be prioritized.