Solid-Liquid Equilibrium Engineering Kit - Experiments


Why is SLE measurement important? Unlike Vapor Liquid Equilibrium (VLE) data, there are limited SLE data available in open literature. Very often the compound in question may even be a novel molecule that has no prior data at all. This is one of the most common setbacks in using SLE to design a crystallization-based separation system. SLE measurement is also important to gather information for process design and to develop an accurate model for crystallizer.

We combine the strength of modeling of SLEEKTM and the strength of experiments of SLEEK-EX in solving the above critical design issue. For example, using the SLE modeling, synthesis and simulation abilities in SLEEKTM, and optimum operability conditions for the crystallizer can be identified with minimum thermodynamic information of the system. SLEEKTM helps the user identify operating conditions that give maximum recovery of a desired compound with a certain solvent or solvent mixture. Focused experiments can then be performed in parallel using SLEEK-EX to validate the SLE model and improve its accuracy.

SLEEK-EX for Data Measurement 


There are two aspects of SLEEK-EX that are the key to its efficiency:

  • The ability to perform experiments in parallel, i.e. multiple data points in one measurement, and have the output relayed digitally to the computer (to SLEEKTM)
  • The accuracy of measurement using “turbidity analysis” with an electronic output rather than visual observation. 


Characterisations (upgraded model):

  • The standard model of SLEEK-EX contains 6 SLE cells.
  • The SLE experiment will take place in the SLE jacketed glass bottles. 
  • The temperature all 6 cells, that are connected in series, is needed to be controlled by external water/oil circulating system.
    • Suggested temperature range for SLE experiments : -20C to 100C.
  • Chemicals in the cells are mixed by magnetic stirrer.
  • Each cell will be equipped with a turbidity probe and a temperature sensor to monitor turbidity changes along temperature profile. 
  • Specially designed cap for each bottle can ensure air-tight system during the SLE experiments.
  • The turbidity changes along temperature profile and time could be logged and stored in the computer connected. The data can be called to SLEEKTM for analysis. 
  • Different cells configurations can be tailer-made upon request.


“Anyone looking to design crystallization unit operations should look seriously at the abilities of SLEEKTM to optimize overall plant design.”

Dr. Timothy Nordahl


Swenson Tecnology, USA


How to Order

To place an order, or for more information, please contact by email at This email address is being protected from spambots. You need JavaScript enabled to view it..

Reference Publications

  • S. M. Lai, M. Y. Yuen, L. K. S. Siu, K. M. Ng, and C. Wibowo, "Experimental Determination of Solid-Liquid-Liquid Equilibrium Phase Diagrams," AIChE J., 53, 1608-1619 (2007).
  • K. D. Samant, L. O'Young, M. Kwok, and K. M. Ng, "Workflow and Regression Methods for Determining Solid-Liquid Phase Diagrams," FOCAPD 2004 Proceedings, Princeton, New Jersey, USA (2004).
  • C. Wibowo, K.D. Samant, J.W. Schroer, and L. O’Young, "A Novel Software Tool for Crystallization Process Development," European Symposium on Computer Aided Process Engineering-14, Lisbon, Portugal, A. Barbosa-Povoa and H. Matos, eds, Elsevier, Amsterdam, pp.1153-1158 (2004).
  • C. Wibowo, L. O’Young, and K. M. Ng, "Streamlining Crystallization Process Design," Chem. Eng. Prog., 100, 30-42 (2004).
  • C. Wibowo, K. D. Samant and K. M. Ng, "High-Dimensional Solid-Liquid Phase Diagrams Involving Compounds and Polymorphs," AIChE J., 48, 2179-2192 (2002).
  • K. D. Samant and K. M. Ng, "Representation of High-Dimensional Solid-Liquid Phase Diagrams of Ionic Systems," AIChE J., 47, 861-879 (2001).
  • K. D. Samant, D. A. Berry, and K. M. Ng, "Representation of High-Dimensional, Molecular Solid-Liquid Phase Diagrams," AIChE J., 46, 2435-2455 (2000).

(The content of this page is originated from CWB Tech website.)