Cane Sugar Decolorization Ion Exchange Resin Configurations
PuropackTM Packed Bed Up-Flow System
A typical configuration for an ion exchange decolorization system is an up-flow packed bed system such as our PuroliteTM Puropack System. Since the specific gravity of 68 °Brix syrup is 1.3325 (at standard conditions) and the specific gravity of strong base anion resin is 1.09, the flow of syrup during a decolorization service often runs up-flow to ensure the bed is undisturbed throughout the service flow interruption. Advantages of the Puropack system are lower color released, higher operational capacity, lower chemical consumption and lower water consumption.
Service
The typical service flow rate is 2-4 BV/h (0.25-0.50 gpm/ft3) (i.e., syrup flowing through a bed containing 10 m3 (353 ft3) of resin operating at 2 BV/h (0.25 gpm/ft3) would be flowing at 20 m3/h (88.1 gpm).
Upflow Service Options
The following diagrams illustrate the configuration and performance achieved by decolorization resins.
Taste and Odor Removal
Cation resin is often used in conjunction with the decolorization anion resin because it is regenerated with the same NaCl regenerant that passes through the anion. It is used ahead of the anion resins when softening of the juice is desired. This is done to reduce the hardness scale formation on evaporators and crystallizers, which ultimately lowers the heat transfer rate. It is also used after the styrenic anion resins to remove amine odor which can occur from the use of the NaOH for anion regeneration. The cation resin will readily exchange Na+ for amine and since it is regenerated with the same NaCl regenerant that passes through the anion, no additional brine is required for cation regeneration.
Macronet™ MN102 adsorbent can be used as a final color, taste and odor polishing adsorbent to achieve the highest decolorizer product quality. By virtue of its lighter density, the Macronet will layer on the top of an up-flow anion decolorization resin so a small volume of it can replace some of the decolorizer resin and no separate vessel is required. The alkaline brine regeneration of the decolorizer resin is first preceded by NaOH only to regenerate the Macronet.
