Multiphase Equilibrium in A Novel Batch Dynamic VL-Cell Unit with High Mixing: Apparatus Design and Process Simulation
Abstract
The availability of vapor pressure data is essential to validate thermodynamic models and enhance the thermodynamic correlations. Despite its importance, there is limited vapor pressure data of the multicomponent mixtures in open literature. This is the case for hydrocarbon/water blends as they are found in the naphtha recovery unit in the oil sand process.
This thesis uses a CREC-VL-Cell, a batch apparatus to measure the vapor pressures of n-octane/water, synthetic naphtha (SN)/water and solids/n-octane/water. The CREC-VL-Cell operates at thermal equilibrium with less than 1.6 % error using a 1080 rpm impeller speed and various optimized operational factors. This apparatus saves at least 8 hours of the degassing procedures using an air contained correction.
Aspen Hysys process simulator with the Peng Robinson Equation of State package is valuable to emulate CREC-VL-Cell dynamic data of the air-contained hydrocarbon/water by adjusting the volumetric flow of all the phases exiting a continuous separator unit. On this basis, vapor pressure data from the CREC-VL-Cell and Aspen Hysys-Peng Robinson Equation of State simulations are shown to compare well for both n-octane/water and synthetic naphtha (SN)/water blends.
On the other hand, mass balances derived CREC-VL-Cell data allows one to establish liquid and vapor molar fractions boundaries for n-octane/water blends. With these boundaries, additional discrimination of thermodynamic models is allowed. For instance, this shows significant discrepancies of the derived Aspen Hysys-Peng Robinson Equation of State molar fractions, with the anticipated molar fractions boundaries calculated via mass balances in the CREC-VL-Cell.