A method permits concentration of a water-miscible organic liquid in a mixture of such liquid and water, with
recovery of a desired concentrate of the water-miscible organic liquid and water, and a relatively
clean water containing only a very low contest of the water-miscible organic liquid which enables disposal of the water in
sewage systems, the method thus enhancing the ability to satisfy environmental concerns; the method has particular application to the
recovery of a reusable glycol / water mixture from diluted spent aircraft deicer fluid (ADF). The diluted spent ADF is heated in a
plate heat exchanger with steam to form a hot frothing
mass of liquid and steam which is delivered to a
cyclone concentrator, the hot frothing
mass in the
plate heat exchanger and the
cyclone concentrator are maintained at a first pressure and a steam phase including steam bubbles in the hot frothing
mass is efficiently separated from and withdrawn from a hot
liquid phase which represents a more concentrated glycol / water mixture. The steam withdrawn from the hot frothing mass is compressed to a second pressure higher than the first pressure and cycled back to provide the steam input of the
plate heat exchanger. After start-up the operation proceeds, with maintenance of the pressure differential, exploiting the heat of the compressed steam with no requirement for external heating. The method may be applied to other aqueous fluid mixtures.