CONTINUOUS EUTECTIC FREEZE CRYSTALLISATION Report to the Water Research Commission by Jemitias Chivavava, Benita Aspeling, Debbie Jooste, Edward Peters, Dereck Ndoro, Hilton Heydenrych, Marcos Rodriguez Pascual and Alison Lewis Crystallisation and Precipitation Research Unit Department of Chemical Engineering University of Cape Town WRC Report No. 2229/1/18 ISBN 978-1-4312-0996-5 July 2018 Obtainable from Water Research Commission Private Bag X03 Gezina, 0031
[email protected] or download from www.wrc.org.za DISCLAIMER This report has been reviewed by the Water Research Commission (WRC) and approved for publication. Approval does not signify that the contents necessarily reflect the views and policies of the WRC nor does mention of trade names or commercial products constitute endorsement or recommendation for use. Printed in the Republic of South Africa © Water Research Commission ii Executive summary Eutectic Freeze Crystallisation (EFC) has shown great potential to treat industrial brines with the benefits of recovering potentially valuable salts and very pure water. So far, many studies that have been concerned with the development of EFC have all been carried out (1) in batch mode and (2) have not considered the effect of minor components that may affect the process efficiency and product quality. Brines generated in industrial operations often contain antiscalants that are dosed in cooling water and reverse osmosis feed streams to prevent scaling of heat exchangers and membrane fouling. These antiscalants may affect the EFC process, especially the formation of salts. The first aim of this work was to understand the effects of antiscalants on thermodynamics and crystallisation kinetics in EFC.