A static analytical apparatus for vapour pressures and (vapour plus liquid) phase equilibrium measurements with an internal stirrer and view windows

A new static analytical apparatus for reliable vapour pressures and (vapour + liquid) equilibrium data of small-scale cell (approximate to 150 mL) with internal stirrer and view windows was designed. In this work, the compositions of the phases were analyzed by a gas chromatograph connected on-line with TCD detectors. The operating pressure ranges from (0 to 3000) kPa, and the operating temperature range from (293 to 400) K. Phase equilibrium data for previously reported systems were first measured to test the credibility of the newly developed apparatus. The test included vapour pressure of 1,1,1,3,3-pentafluoropropane (R245fa) and isobutane (R600a), VLE of the (R600a + R245fa) system from T = (293.150 to 343.880) K. The measured VLE data are regressed with thermodynamic models using Peng-Robinson EoS with two different models, viz. the van der Waals mixing rule, and the Huron-Vidal mixing rule utilising the non-random two-liquid activity coefficient model. Thermodynamic consistency testing is also performed for the newly measured experimental data. (C) 2014 Elsevier Ltd. All rights reserved.