Bjarne C Nielsen
Neltec Denmark A/S, Vestergade 35, 6500 Vojens, Denmark; bcn@neltec.dk
Efficient control of sugar processing and refining is vital for maintaining product quality while optimizing resource use. The role of real-time colorimeters in sugar process control is evaluated, emphasizing their validity for process control compared to ICUMSA® laboratory methods for solution colour determination. While traditional laboratory methods provide precise results, they are time-intensive. The adoption of real-time measurements enables timely and automatic corrections, enhancing process efficiency and product consistency. Five case studies illustrate the impact of real-time colour measurement. Saint Louis-Sucre Refinery, Marseille, France: Two ColourQ instruments were installed, demonstrating equivalent accuracy to laboratory methods. The refinery reported no added uncertainty from these instruments. RAR Refinery, Porto, Portugal: A ColourQ system installed in 1999, later upgraded with automatic wash water control in 2007, showed consistent calibration over decades. During a 6-week test, 911 wet crystal samples revealed minimal variability in sugar colour, with most values falling between 44 and 46 IU. Southern Minnesota Beet Sugar Coop, U.S.A.: The factory achieved a 5-second reduction in wash water application using a real-time colorimeter, saving over 10,000 t of sugar annually by reducing dissolution. The instrument operated successfully for 22 years, preventing the dissolution of over 220,000 t of sugar. Tereos Beet Factory, Czech Republic: Implementing automatic wash water control with a ColourQ system improved crystal yield by 3 percentage points. The system effectively adjusted wash water duration based on real-time measurements, compensating for massecuite variability. American Sugar Refining, Chalmette, U.S.A.: By controlling the crystal colour in continuous centrifugals in the recovery house, the refinery managed to control the ash content in the final white product. These case studies highlight the significant benefits of real-time colorimeters, including reduced energy and water consumption, lower CO2 emissions, increased sugar house capacity, and improved product quality. This technology enables sugar producers to meet stringent quality specifications while optimizing operational efficiency.