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.
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.
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.
