Energy efficient separation with freeze concentration

With the arrival of energy efficient compressors for water vapor and direct contact heat exchangers, where the generation of ice happens at evaporation temperatures close to the freezing point, freeze concentration can become a very efficient technology. It can also be highly relevant when converting thermal processes to electrically based technologies in our fossil free future society. In contrary to most of the thermal technologies this system would be incorporated in a flexible electric grid.

During freeze concentration the water part of the solution is lowered by crystallization with subsequent removal of the ice crystals.

This gentle and energy efficient method can compete with the best-optimized evaporation processes connected to heat pumps and MVR (mechanical vapor recompression). The removal of water takes place at much lower temperatures, which has an effect on the product quality and losses. Freeze concentration is a sublime method when product quality is the focus point and is widely used in the food industry exemplified with juice and coffee extracts. In this first part of the project the project partners will cover the possibilities related to technical and business issues. An optimized complete system will be suggested and basic tests will support the theory. In a second part we will develop a complete system based on Danish produced water vapor compressors and direct contact heat exchangers.