Process for the Solution Crystallization of Mixtures

Mr. Holpe, Dr. Kerschbaum, Dr. Rinke

Abstract

Process for the solution crystallization of mixtures. The object is to propose a process which, without additives, is suitable for improving the winter stability of, in particular, biodiesel fuels even in the case of large quantities. The object is achieved by a process which comprises providing a liquid mixture comprising at least one subcomponent having an elevated melting point, taking a substream from the mixture, feeding the substream to a heat exchanger, with the substream flowing through the heat exchanger, cooling the substream in the heat exchanger to a temperature below a crystal formation temperature of only the subcomponents of the mixture, with the temperature being set so that crystals of the subcomponents form in the substream directly at the outlet from the heat exchanger, mixing the substream comprising the crystals into the mixture, with the crystals selectively binding further substances in the mixture by crystal growth, and sedimenting and separating off the crystals in the mixture.