Jerzy Petera Faculty of Process & Environmental Engineering Technical University of Łódź

1. Room Temperature Ionic Liquids Numerical modelling of extraction with the use of ionic liquids for separation of azeotropes in the presence of a high voltage electric field producing liquid-liquid emulsions Jerzy Petera Faculty of Process & Environmental Engineering Technical University of Łódź

2. Introduction - Ionic Liquids • Salts that are liquid at ambient temperatures. • Have stable liquid range of over 300 K. • Very low vapour pressure at room temperature. • Selective solubility of water and organics. • Potential to replace volatile organic solvents used in processes • Often associated with Green Chemistry. Has been a major driving force behind the intense interest in ionic liquids

3. Alternative Solvents for Process Intensification • There is a need to develop more environmentally benign solvents or use solventless systems • Such solvents should replace toxic and environmentally hazardous and/or volatile solvents • Necessary to develop and optimize reactions conditions to use these new solvents and at the same time maximize yield and minimize energy usage. • Examples include use of solids or involatile liquids rather than volatile, flammable and environmentally hazardous organic compounds (VOC).

4. Why Consider Ionic Liquids as Green Solvents • Low melting organic salts (-60 C) • Very low vapor pressure (good) • Non-flammable (good) • Wide liquid range (300 C) (good) • Moderate to high viscosity (bad) • Solvent properties different from molecular solvents (good and bad) • Solvent properties can be controlled by selection of anion and cation – hence often termed designer solvents (good).

5. Designer solvents - flexibility of choosing functional groups to make ionic liquids Halide-based (Cl-, Br-, F-) Halogeno-based (BF4-, PF6-) Halogenoaluminium(III) Alkylammonium Alkylphosphonium Alkylnitride N,N’-dialkylimidazolium N-alkylpyridinium NO3-, ClO4-,HSO4- SO3-, CF3SO3- (CF3SO2)2N- (CF3SO2)3C- anion Organic cation

6. + N N R R1 1-alkyl-3-methylimidazolium is the most common cation With R = C4 to C8. , R1 = C4

7. Biocatalysis in Ionic Liquids • In many enzyme catalyzed reactions in water the rate is limited by secondary hydrolysis • Many reactions go to completion when ionic liquid (mass fraction 30 %) added • Lipase catalyzed transesterification reactions occur in 99 % mass fraction ionic liquids with much improved sterioselectivity at higher temperatures – hence faster reactions

8. Industrial Processes with Ionic Liquids

9. Ionic Liquid Publications

10. Ionic Liquid Patents Total: 699

11. Extractive Distillation and Breaking Azeotropes • IL have greater affinity for some components in a mixture • Results in a change in the activity coefficients that usually enhances separation • No IL in distillate • Arlt claims that all virtually azeotropes can be broken by the correct selection of an ionic liquid - Gmehling and Krummen, DE10154052 - Arlt et al., DE10136614/WO2002074718

12. Influence of [EMIM][BF4] on ethanol + water VLE at 363.15 K W. Arlt, AIChE, 11/02

13. Influence of [EMIM][BF4] on the Tetrahydrofuran + water VLE at 337.15 K W. Arlt, AIChE, 11/02

14. Breaking Azeotrope with IL Pure A A + C + IL Pure C Pure IL C + IL

15. Use of Ionic Liquids in IL-Based Industrial Processes • Challenges in simulating IL processes: • Simulation packages such as AspenTech not equipped to deal with unique properties of ILs • Lack of physical and thermodynamic data on the vast array of ILs • Potential Solutions: • Creation of IL Database based on increasing literature experimental data • Development of correlative and predictive models for: • Physical properties of ILs and their mixtures • Phase equilibria of IL mixtures • Numerical simulation packages for modeling and design of mass contactors

16. Ionic liquid spray in electric field • Electric potential controls the dispersion: the bigger voltage, the smaller droplet diameter. • 1 kV • 2 kV • 4 kV • Emulsion offers the best interface area and best mass exchange rate. 3) 2) 1)

17. Experimental Reactor

18. A CFD simulation procedure

19. Computational mesh for the contactor and the boundary conditions

20. Preliminary simulation results • The electric potential field (range from 0 to −40 kV) in the experimental contactor presented in Fig. 2. • Equipotential surfaces in 3D geometry with examples ofdroplet trajectories, • (2) contours in the contactor centerline 2D section.

21. Preliminary Simulation results The droplet dispersion simulated by means of the cloud model. (1) 3D picture of clouds, (2) 2D section of the same clouds with the droplet concentration contours. Calculated extract concentration profiles in the contactor after 2 h.

22. Preliminary Simulation results • Calculated extract concentration profiles in the new contactor geometry (four electrodes and four dies situated as on the right, after 2 h at applied electrical potential −4 kV. • View from the bottom side and (3) view from the top. • Much better concentration distribution is evident!

23. Plan of actionDuring this project, students must accomplish following tasks: • Literature review on possible ionic liquid with the focus on separating azeotropic mixture of organic components and their environmental impact  • Economical assessment of ionic liquids usage versus the traditional organic solvents  • Learning some basics of numerical modeling e.g. model formulation • Building individual column geometry and boundary conditions using commercial software ANSYS™  • Computations for the column efficiency evaluation • Analysis of the results and formulating recommendations for real experiments

24. Summary • Industrial processes involving ionic liquids are in an early stage of development • Established as useful liquids for reactions, separations, and as electrolytes • Research is still immature and much more needs to be done • Great opportunities for new developments and applications

25. Ionic liquids offer great opportunities to be used in Green processes • Ionic liquids can provide radically new process solutions • Potential applications include: reactions with inorganic and bio catalysis, separations including distillations, extraction, liquid-liquid partitioning, gas separations, electrochemistry, liquid crystals, etc. • Ionic liquid behave favorably in electric field offering high interface area development • Numerical simulation tools offer powerful means for optimal contactor design.