VLE AUTOLAB Computer-Controlled Apparatus for
Vapor-Liquid Equilibrium Measurements

Fast Easy Accurate

Patent Pending



1. High accuracy VLE measurements.
2. Simple operation and high productivity.
3. Composition analysis are not required.
4. Wide operating range(0.1kPa-15MPa,40-150C).
5. Integration with DDB, the world's largest databank of physical properties.


1. Vapor-liquid equilibria.
2. Saturated vapor pressures.
3. Activity coefficients at infinite dilution.
4. Vapor-liquid-liquid equilibria.


VLE AUTOLAB was developed by a collaboration with Mitsubishi Chemical Corp. (MCC) and the university of Oldenburg, Germany.
Vapor-liquid equilibrium data(VLE) are essential for development and design of chemical processes. Traditional measurements of VLE are, however, very time-consuming and require highly skilled work.
VLE AUTOLAB is a fully automated system which allows measurement of VLE data simply, quickly, accurately and is also suitable for measurements of pure component vapor pressures, activity coefficients at infinite dilution, and 3-phase vapor-liquid-liquid equilibria.
VLE AUTOLAB is a fully computer-controlled apparatus featuring superior performance in terms of accuracy and time (see Table below). The VLE measurements are very cost efficient and require only minimal amounts of pure components and significantly reduced work.
VLE AUTOLAB is provided with an integrated system which uses the Dortmund Data Bank Software Package(DDBSP) for data processing and evaluation. VLE measurements can be readily compared with a large variety of literature data stored in the Dortmund Data Bank (DDB),the world's largest databank of physical properties. Similarly, new VLE data can be correlated by a variety of thermodynamic models and compared with results of established predictive methods, such as the UNIFAC(Do) group contribution method.

Time requirements and accuracy of VLE measurements
(Based on
VLE measurement
Time requirements (Actual manual operation)
Operation mode
Number of data
Rose-Williams still
Othmer-type still
32 data points
0.5 day
(1 hr)
12 days
(72 hrs)
16 days
(112 hrs)
5 isotherms
16 points/
3 days
(1 hr)
30 days
(180 hrs)
40 days
(280 hrs)
  0.03 K
  0.01 kPa
  0.01 %
   0.05 K
   0.02 kPa
   1 %
   1.0 K
   0.3 kPa
   5 %