Method for purifying sorbic acid

Abstract

The invention discloses a production technology for preparing high-purity sorbic acid by melt crystallization. The production technology comprises the following steps of firstly, sending freezing salt water into the bottom part of an outer jacket of a melt crystallization device, enabling the freezing salt water to uniformly flow along the outer wall of the crystallization device in a falling film way, feeding a crude sorbic acid solution into the melt crystallization device, enabling the sorbic acid solution to flow down along the inner wall of the crystallization device in the falling film way, gradually cooling and crystallizing, gradually growing a uniform crystal layer on the heat exchange surface, enabling the concentration of the crystal layer to be higher than the concentration of mixture solution, and enabling impurities to gradually enrich into the mixture solution; then, melting one part of crystal layer by adjusting the hot water temperature through a heat exchanger, and melting and removing the impurities with low melting point in the crystal layer, so as to further purify crystals. The production technology has the advantages that the method and technology are simple, the equipment structure is compact, the falling film type is adopted, the energy is decreased, and the cost and equipment investment are reduced at same time; the purity of a product produced by the melt crystallization device is high.

Description

technical field [0001] The invention relates to a method for purifying sorbic acid, in particular to a method for purifying sorbic acid with a melting crystallizer. Background technique [0002] Sorbic acid and its potassium salts can inhibit the growth of mold, and have been used as food preservatives for a long time, especially at low pH values, they can act as undissociated acids for preservatives. Sorbic acid has the characteristics that other preservatives do not have, that is, it has strong antiseptic selectivity. It can inhibit the growth of bacteria harmful to humans, but it is harmless to bacteria beneficial to humans. For example, it can inhibit the growth of cheese mold but does not Does not affect the growth of bacteria that help cheese ripen. Therefore, in the food industry, sorbic acid is widely used as a preservative for cheese, cakes and other pastries. Mainly used for mildew prevention of cheese, pickled vegetables, dried fruit, fruit juice, fruit syrup, b...

AI Technical Summary

Problems solved by technology

At present, the equipment for large-scale production of sorbic acid at home and abroad is a general enamel reaction kettle. The mature process of the process is as follows: that is, the condensation reaction of ketene and crotonaldehyde under the action of a catalyst, followed by hydrolysis, drying, packaging and other processes The finished product is obtained, but because the sorbic acid produced by this process has a poor appearance, many impurities and a pungent smell

Therefore existing technology and equipment of this sorbic acid need to be improved