METHOD OF CITRIC ACID PURIFICATION AND CONCENTRATION

摘要

Citric-liquors representing a solution of citric acid after fermentation undergo two stage nanofiltration on polymeric membranes. In the first stage, nanofiltration is performed on polymeric membranes with the nominal molecular weight cut-off 10,000 to 20,000 daltons and in the second stage on polymeric membranes with nominal molecular weight cut-off 200 to 400 daltons. The resulting concentrate from the second stage undergoes appropriate crystallisation and permeate is recycled into particular stages of technological process.