Chemical Engineering Research & Design, Vol.108, 139-145, 2016
Process intensification by the use of micro devices for liquid fractionation with supercritical carbon dioxide
The present study is focused on the process intensification of extraction with supercritical fluids by using micro-devices. The main purpose is to investigate the efficiency and applicability of micro-mixers in supercritical fluid extraction processes. 'Itvo micro-devices with different mixing principles, multilamination and T-type lamination, were used and results were compared. The extraction experiments were carried out in a micro-device apparatus designed for high-pressure processes, in which the micro-device is the unit where the solvent and the liquid feed come into contact. Experiments on the continuous extraction of ethanol from aqueous solutions using supercritical CO2 as solvent were performed to study the feasibility of the extraction process in a micro-device apparatus. The separation of both liquid and vapour phases was achieved by changes of temperature and pressure. The experiments were carried out at 101 bar and 60 degrees C. Different ethanol concentrations in the feed and solvent-to-feed ratio values were considered. Results obtained with the two different micro-devices were compared. A phase equilibrium model using Peng Robinson equation of state was developed in ASPEN-Plus and calculations were performed to confirm that equilibrium was achieved through the extraction process and that one theoretical stage can be reached in a micro-device stage. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords:Supercritical fluid extraction;Micro-mixer;Multi-lamination principle;Supercritical CO2;Peng Robinson equation of state