Quantum chemical calculation, molecular dynamics simulation and process design for separation of heptane - butanol using ionic liquids extraction

Zhu, Zhaoyou; Li, Huiyuan; Xu, Ying; Zhang, Wanxiang; Shen, Yuanyuan; Gao, Jun; Wang, Lei; Wang, Yinglong

doi:10.1016/j.molliq.2020.113851

Cited by 32 publications

(16 citation statements)

References 54 publications

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“…For this reason, research is needed to develop separation techniques such as extractive distillation, pressure-swing adsorption (PSA), and membrane processes for breaking the azeotropic compositions to produce pure refrigerants. Ionic liquids (ILs) are ideal entrainers for extractive distillation because ILs have essentially no measurable vapor pressure (i.e., <1 × 10 –3 to 1 × 10 –5 Pa) and will not contaminate the product streams. − This study is a continuation of research focused on experimental measurements and modeling to identify IL-based entrainers for the separation of R-410A. R-410A is a near azeotropic refrigerant mixture composed of 50 wt % HFC-32 and 50 wt % HFC-125.…”

Section: Introductionmentioning

confidence: 99%

Phase Equilibria and Diffusivities of HFC-32 and HFC-125 in Ionic Liquids for the Separation of R-410A

Baca

Olsen

Valenciano

et al. 2021

ACS Sustainable Chem. Eng.

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Current legislation calling for the phase out of hydrofluorocarbon (HFC) refrigerants is driving a global market shift that has prompted industry and research institutions to investigate new refrigerant mixtures and sustainable separation techniques for recycling refrigerants. The recent American Innovation and Manufacturing (AIM) Act of 2020 requires an 85% phase down of HFC production over the next 15 years. To achieve this goal, azeotropic refrigerant mixtures, such as R-410A composed of 50 wt % HFC-32 (difluoromethane, CH 2 F 2 ) and 50 wt % HFC-125 (pentafluoroethane, CHF 2 CF 3 ), will have to be separated to recycle the lower global warming HFC-32 component. The present work investigates the solubility of HFC-32 and HFC-125 in six ionic liquids (ILs) with halogen anions for the purpose of developing the thermophysical property data required for designing extractive distillation recycling processes and understanding the choice of cation and anion type. A gravimetric microbalance was used to collect isothermal vapor liquid equilibrium data for each of the ILs at 298.15 K and pressures from 0.05 to 1.0 MPa. The Peng−Robinson equation of state was used to model the solubility of the HFCs in the ILs. The solubility of HFC-32 in the ILs showed small differences, while the solubility of HFC-125 had significant variations with respect to the anion type and the cation alkyl chain length. Fick's law was applied to calculate diffusion coefficients for each HFC/IL system. HFC-32 has a greater diffusivity than HFC-125 based on smaller molecular size. The 1-n-hexyl-3-methylimidazolium chloride and the trihexyl(tetradecyl)phosphonium chloride ILs have the highest HFC-125/HFC-32 selectivity at 298.15 K. Based on both the mass uptake and selectivity ratio, these two ILs are potential entrainers for the separation of R-410A using extractive distillation.

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Section: Introductionmentioning

confidence: 99%

Phase Equilibria and Diffusivities of HFC-32 and HFC-125 in Ionic Liquids for the Separation of R-410A

Baca

Olsen

Valenciano

et al. 2021

ACS Sustainable Chem. Eng.

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“…For the NG dehydration process, the σ-profiles of the mixed system were calculated by the COSMO-RS model to qualitatively explore the microscopic interaction mechanism. , As shown in Figure a, the σ-profile of H 2 O has peaks in both the HB donor and receptor regions spanning a wide range, indicating that H 2 O easily forms HB with other molecules containing HB donors or receptors. CH 4 hardly forms HBs with other substances because all of its peaks of the σ-profile range from −0.006 to 0.005 e/Å 2 (nonpolar region).…”

Section: Resultsmentioning

confidence: 99%

Natural Gas Dehydration with Ionic-Liquid-Based Mixed Solvents

Gui

Zhu

et al. 2021

ACS Sustainable Chem. Eng.

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In this work, a mixed absorbent of an ionic liquid (IL) and triethylene glycol (TEG) is first proposed for natural gas (NG) dehydration. The hydrophilic [EMIM][BF4] is selected as an appropriate IL composition from 240 potential candidates by calculating the thermodynamic separation factors (i.e., solubility and selectivity). The separation mechanism of NG dehydration with the mixed absorbent of [EMIM][BF4] + TEG at the microscopic molecular level is systematically unraveled by employing the COSMO-RS model and quantum chemical calculations. The solubility of CH4 in pure [EMIM][BF4] and TEG, as well as in binary mixtures of [EMIM][BF4] + H2O and [EMIM][BF4] + TEG, is experimentally measured and predicted by the modified (mod.) UNIFAC-Lei model. It is proved that the mod. UNIFAC-Lei model can well predict the gas–liquid equilibrium (GLE) and be successfully extended from binary to ternary systems. In the dehydration experiment, the mixed absorbent shows an excellent dehydration performance (i.e., the water content of the product gas is decreased to 172 ppm, in mole fraction). The equilibrium (EQ) stage model embedded with the mod. UNIFAC-Lei model parameters is built to carry out the process simulation of CH4 dehydration at the laboratory and industrial scales. The results show that the total annual cost (TAC) of the optimized process with mixed solvents is reduced by 33.63 and 15.98%, respectively, at the same separation conditions when compared to that of pure TEG and pure IL processes. This confirms that the IL-based mixed absorbent is a promising alternative to pure ILs or conventional solvents for applications in the field of gas separation and purification.

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“…The COSMO-SAC model has been proven to be an effective tool for selecting extractants. , The σ-profiles obtained by the COSMO-SAC model can predict various thermodynamic properties, and we can analyze the relationship between the hydrogen bond donor (HBD) and the hydrogen bond acceptor (HBA) through the σ-profiles and preliminarily predict the interaction between molecules. As we know, common ChCl-based DESs (ChCl-Malonic acid (MA), ChCl-Urea, ChCl-Glycerol (Gly), ChCl-Ethylene glycol (EG), ChCl-Thiourea, etc.)…”

Section: Extractant Selection Based On the Cosmo Modelmentioning

confidence: 99%

Liquid–Liquid Equilibrium Measurements and Interaction Explorations for Separation of Dimethyl Carbonate and Isopropyl Alcohol Using ChCl-Based Deep Eutectic Solvents

Sun

Xing

et al. 2023

Ind. Eng. Chem. Res.

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Deep eutectic solvents (DESs) were adopted to separate the azeotropes of dimethyl carbonate (DMC) and isopropyl alcohol (IPA). Liquid–liquid equilibrium (LLE) data plays a crucial role in designing the separation process. Three appropriate DESs (choline chloride (ChCl)-Urea, ChCl-Glycerol (Gly), ChCl-Ethylene glycol (EG)) were selected using the COMSO model. Then, the LLE data of DMC-IPA-(ChCl-Urea), DMC-IPA-(ChCl-EG), and DMC-IPA-(ChCl-Gly) were obtained through experiments at 298.15 K under 101.32 kPa, the binary interaction parameters were obtained by regressing the LLE data by the nonrandom two-liquid (NRTL) model, and the GUI-Matlab was adopted to verify the precision of the NRTL interaction parameters and the experimental data. Finally, the mechanism of formation of the combined structures (DES-IPA/DMC) was explored through ESP. To further explore the extraction capacities of the selected DESs, the extraction mechanism of three DESs was revealed. The interactions between DESs and IPA/DMC were explored through penetration distance and AIM analysis; the calculation results showed that (ChCl-EG) has the best extraction capacity, which is consistent with the experimental results. The results of experimental and theoretical calculations showed that the DES could effectively separate DMC and IPA.

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Quantum chemical calculation, molecular dynamics simulation and process design for separation of heptane - butanol using ionic liquids extraction

Cited by 32 publications

References 54 publications

Phase Equilibria and Diffusivities of HFC-32 and HFC-125 in Ionic Liquids for the Separation of R-410A

Phase Equilibria and Diffusivities of HFC-32 and HFC-125 in Ionic Liquids for the Separation of R-410A

Natural Gas Dehydration with Ionic-Liquid-Based Mixed Solvents

Liquid–Liquid Equilibrium Measurements and Interaction Explorations for Separation of Dimethyl Carbonate and Isopropyl Alcohol Using ChCl-Based Deep Eutectic Solvents

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