Simulated moving bed (SMB) chromatography is a well-established and widespread unit operation in the beet sugar industry and has been practiced commercially for more than thirty years. SMB chromatography has proven to be very efficient at removing inorganic ash components and colorants from sugar liquors, particularly those colorants with relatively high molecular masses. Recent optimization of the separation using raw sugar with a color ranging from 2000 IU up to 4000 IU has focused on minimizing the capital and operating costs of a chromatography system to replace the various purification and decolorization steps in conventional raw cane sugar refining. Decolorization levels exceeding 89% have been reliably achieved in the extract fraction from chromatography, along with ash removals ranging from 92% to 97%. As only water is added to purify the sugar, the application of this technology, in combination with modern industrial heat pumps and mechanical vapor recompression, allows for a powerful CO2-neutral process, with all the associated benefits regarding permits and marketability. The potential of this technology includes integration into new refinery projects (either standalone or back-end) by replacing affination, carbonatation and ion exchange decolorization (with raw sugar colors of up to 5000 IU), to expansion of existing refinery sites for slip stream processing of raw sugar syrups or refinery run-off syrups after clarification, and to the introduction of new process steps, such as direct liquid sugar production from cane raw sugar.
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