Purification of glycerin obtained as a bioproduct from the transesterification of triglycerides in the synthesis of biofuel

摘要

Methods for purifying glycerin contaminated with one or more lower boiling alcohols such as methanol, ethanol, straight, branched or cyclic C3-C6 alcohols, and the like. The methods are particularly useful for purifying crude glycerin phases recovered from the synthesis of biofuels. The present invention uses distillation techniques to strip alcohol contaminants from glycerin. In contrast to conventional methods that carry out distillation either under substantially anhydrous or very wet conditions, the present invention carries out distillation in the presence of a limited amount of water, e.g., from about 0.8 to about 5 parts by weight of water per 100 parts by weight of contaminated glycerin to be purified.