Method for preparing high-purity anhydrosugar alcohol using sequential combination of thin film distillation and short path distillation

Abstract

The present invention relates to a technique for preparing an anhydrosugar alcohol using hydrogenated sugar as a raw material and, more specifically, to a technique for preparing a high-purity anhydrosugar alcohol (in particular, isosorbide, isomannide, isoidide, and the like) having a purity of 98% or higher and containing less than 0.1% of sorbitol and a sorbitan isomer, which are impurities, in a high total distillation yield of 94% or higher (more preferably, 95% or higher) by adding an acid to hydrogenated sugar (for example, hexitol) to convert same to an anhydrosugar alcohol, and then distilling the converted liquid over two or more stages by sequentially using a combination of an external condenser type wiped film evaporator and an internal condenser type short path evaporator.

Dependencies are inferred from the claim text.