Making Sugar Upgrading Processes More Affordable

The ICUMSA (International Commission for Uniform Methods of Sugar Analysis) presents a method for measuring the purity of sugar in solution form. The lower the ICUMSA value in RBU (Reference Base Standard), the higher the purity of the sugar. Due to changes in the US/Mexico sugar trade agreement in 2018, liquid sugar providers are permitted to use Mexican Sugar as long as it has no higher purity than 99.2% sucrose, which means a higher RBU color value than the previously sourced Mexican sugar. To make Mexican sugar viable for use in food and beverage applications, the raw sugar must be refined to meet U.S. customer color requirements—but there is cost associated with the processing.

Carbon is often used as part of the decolorization treatment process, but treatment with carbon alone is not normally cost effective due to the amount of carbon needed. The use of resins, particularly high-performance decolorizing resins, helps increase sugar quality and reduce overall costs.

A supplier of sugar products for a major food producer in the USA provides liquid sucrose for use in breakfast cereal production. The previous process involved melting low color, high purity sugar and treating with carbon and diatomaceous earth (DE) to reduce the color to <50 RBU. This process produced very low margins. To be competitive, they would need to increase the performance of their system through more efficient media.

The new production process involved melting raw Mexican sugar with 1,200 –1,400 RBU color and then treating the melt syrup with powdered carbon and diatomaceous earth filtration to reduce the color to 600 – 700 RBU followed by decolorization resins to lower the color to <50 RBU.

The system required two upflow double-compartment decolorizers, one containing Puropack® PPA502PS macroporous strong base anion resin in the lower primary compartment and Puropack® PPA420S gel strong base anion resin in the upper polishing compartment and the second vessel containing Puropack® PPA502PS in the primary compartment and Shallow Shell™ SSTPPA64 gel strong base anion resin in the polishing compartment. 68˚ Brix syrup is pumped up-flow at 45 – 60 gpm through the Puropack® PPA502PS decolorization resin followed by either Puropack® PPA420S or Shallow Shell™ SSTPPA64 to produce color at ~35 RBU.

The customer color specification is 50 RBU, and their process will terminate service at ≤ 80 RBU to ensure the product tank averages the < 50 RBU tolerance level for color.

The company heard about Purolite through recommendations by other liquid sugar suppliers that we work with. Initially with this project, we supported the design prepared by the OEM, and then worked with the OEM to do a side-by-side plant comparison study using standard Puropack® PPA420S polishing decolorization resin versus Shallow Shell™ SSTPPA64 polishing decolorization resin. It was presumed that the Shallow Shell Technology resin would bring more efficient loading and lower color leakage.

Shallow Shell™ SSTPPA64 strong base anion decolorizer resin also has the highest regeneration efficiency of resins used for this application. The goal was to use Shallow Shell™ SSTPPA64 to maximize the color compound reduction within the liquid sugar, while also reducing the excessive product and water/waste expenses associated with powdered carbon. It was believed that the higher throughput would reduce the regeneration and waste discharge costs significantly enough to make the process cost effective.

Purolite was successful at making the process of upgrading less expensive raw Mexican sugar to liquid sugar specifications more affordable. The premium decolorization resin achieved the low color limit for a much longer service time. Comparisons between the standard resin and the Shallow Shell Technology™ resin showed that the company was able to run ~80,000 gallons of syrup through the standard resin, and ~120,000 gallons of syrup through the Shallow Shell Technology resin to the same service endpoint.

Thus, a 50% higher color loading was achieved on the Shallow Shell Technology resin, which significantly reduced the regeneration frequency and amount of alkaline brine solution used for regeneration and discharge into the sewer.

Why Purolite?

  • Innovative solutions
  • Unsurpassed implementation support
  • Timely follow-up to ensure system effectiveness