Optimizing supersaturation curves in various sugar crystallization processes

Poor crystal size distribution is a common issue in the sugar industry, leading to higher recirculation rates, increased energy and water consumption, lower yield, and problems with centrifuges. Achieving high-quality crystals with low CV and optimal MA requires carefully designed and controlled crystallization processes, with supersaturation being one of the most critical parameters. The author implemented supersaturation-based crystallization control systems in batch evaporating and cooling crystallizers of beet and cane sugar factories. All these cases focused on selecting and maintaining an optimal supersaturation setpoint that ensures superior crystal quality. Ideal supersaturation setpoint curves differ for high and low feed syrup purities. What works well in a refinery strike may not be suitable for beet white sugar A product and may be ineffective for C product in a cane sugar mill. This paper focuses on these differences and helps select the operating parameters for various crystallization scenarios.