Research for efficient separation

The Separation Technology group at VTT Energy, which is one of the nine business units of Technical Research Centre of Finland (VTT), develops equipment and methods to separate the valuable substances from industrial processes and side streams efficiently and with optimised energy use.Special attention is focused on filtration, power ultrasound applications and handling of forest industry side streams.The municipal sewage sludge and the sludge from wastewater plants in the forest industry, process recycling water and mining industry slurries are the typical substances studied.R&D work is carried out with laboratory and pilot scale devices.A pressure filter, two different sizes of membrane filtration units, and a disc filter simulator are available for the studies.Most of these devices are versatile and well instrumented having programmable data acquisition and operational control. Besides, typical analytical devices such as particle size analysers for size range of 3 nm - 2 mm, zeta-potential and conductivity meters and CST-device are available for the studies.The separation technology group also develops different power ultrasound applications for filtration, mixing and cleaning. New field is the utilisation of ultrasound in different chemical processes. Scanning laser vibrometer, hydrophone measurements, impedance measurements and PiezoCad design are examples of the resources used in the ultrasonic transducer system design.Ultrasound assisted reactors can be built for different applications.Concepts consisting of different unit operations are studied and developed to recycle useful substances from process side streams originating especially from the pulp and paper industry, and to make other beneficial products from the sate streams.For example fly ash and biosludge are processed for fertiliser and NaOH is produced from fly ash originating from a recovery boiler.The versatile PDU is useful equipment for side stream studies.