Improved lactic acid processing; methods; arrangements; and, products

摘要

Methods for processing lactic acid are provided. The methods generally include vaporizing an aqueous lactic acid solution, for purification. Preferred conditions for the vaporization include pressures within the range of 30-200 mm Hg and an inert (nitrogen) atmosphere. Preferably the process is conducted on an aqueous solution comprising 60-75 wt.% lactic acid. Preferred equipment and systems for conducting the process are also provided. The process is preferably integrated with downstream polylactic acid prepolymerization or oligomerization. A preferred vapor stream for direction into such a downstream process is defined.