Lime salts: origin and control in beet processing

Abstract

Lime salts in the thin juice obtained after juice purification is one of the most important chemical KPI’s (Key Performance Indicator) in beet processing. Too high lime salts content will significantly affect processing costs – particularly energy – due to scaling of heat exchange surfaces thus decreasing heat transfer. In addition, high lime salts are at the origin of turbidity and insoluble solids in white sugar. Therefore, it is of the utmost importance to understand the chemistry behind lime salts in beet processing in order to be able preventing too high lime salts contents in thin juice. This paper will explain the details of the chemistry behind the presence of lime salts. Further, a trouble-shooting guide is included to elucidate the different causes for high lime salts contents and how these causes can be identified, as well as the process measures to reduce the lime salts content in thin juice.