Recovery of Sugars From Cane Molasses by Continuous Simulated Moving Bed Ion-Exclusion Chromatography.

Present investigation was undertaken to determine the feasibility of using a Simulated Moving Bed (SMB) Ion Exclusion Chromatographic system for the recovery of sugars from molasses. The recovery of sugars from molasses is complicated because of the presence of high concentration of salts of K, Ca, Mg, etc. The presence of these salts in the molasses prevents sucrose to crystallize. SMB Ion Exclusion Chromatography has been shown to be successful to recover sugars from beet molasses, and to separate sugars from each other in High Fructose Corn Syrup industry. The basis of the ion exclusion is that the sorbent used in the column prevents the salts from being adsorbed whereas the sugars are adsorbed on the resin. The adsorbed sugars in the resin are recovered by elution with water. The efficiency of the SMB Ion Exclusion system for separation of sugar and non-sugars is affected by variables such as concentration of ionic material in the molasses, flow rates in different zones of the system, concentration of the molasses etc. In the first phase, equilibria and kinetics of the system were studied for proper modelling and design of the SMB operation. In the second phase, properly treated cane molasses were used as feed for SMB pilot plant with parameters obtained from best simulation data. Two products, Extract (high sugars; low non-sugars) and Raffinate (high non-sugars; low sugars) were obtained. The quality of the extract is very promising for recovery of sucrose in crystalline form as it contained 81% sucrose, (96% total sugars) and only 4% non-sugars. The raffinate, with 36% total sugars, still has enough caloric value to be used as cattle feed. SMB recovery of 88% sucrose (80% in crystalline form) and 79% of total sugars achieved warrants a potential increase in total recovery of sucrose by 11%