Method for producing highly pure anhydrosugar alcohols with improved yield by using recrystallite of waste generated from crystallization procedure

摘要

The present invention relates to a technique for producing anhydrosugar alcohol using hydrogenated sugar as a raw material, and more specifically, to a technique for producing high purity anhydrosugar alcohol at low costs and high efficiency. In a method for producing high purity anhydrosugar alcohol by adding an acid in hydrogenated sugar (i.e. hexitol) to be converted into an anhydrosugar alcohol, distilling a result liquid of the conversion reaction, and crystalizing a result liquid of the distillation reaction in a solvent, a crystallization solvent is removed from a mother crystallization liquid generated from the crystallization process; a result of the removal is processed to obtain a recrystallized product; and the recrystallized product is put with the resultant liquid of the distillation into the crystallization process, thereby raising total yield of the anhydrosugar alcohol, and further reducing the amount of waste generation and costs for processing.