Melt Decolourization Ion Exchange Process
To produce only sulphure free sugar with 45-50IU colour (with back end refinery) IER is not required. To produce refined sugar equivalent to EEC1 & EEC2 grade sugar IER is required.
Filtered melt from the melt filtration system (DBF) shall be fed to the Ion exchange columns for further colour removal up to 65-70% of input colour to the IER.
General Description of the Ion Exchange Process:
- The ion exchange process in the refinery is a continuous process whereby sugar liquor is passed through a resin bed & colour is trapped within the bed. However a bed of resin becomes saturated with colour after some time. At this time the current bed in production is terminated & a new bed is brought on line. The saturated bed must be regenerated.
- The liquor needs sufficient contact time with the resin for effective colour removal. Flow rate in relation to the amount of resin present is important.
- The lead resin bed obviously always takes the major colour impact. The trail bed always takes a lighter load.
- The beds are then washed with water to remove any traces of the caustic brine.
- The bed is sweetened on again in preparation for the next production run.
