Food Applications

An example is sugar decolourisation. Syrup enters the column through a surface distributor; the colour is adsorbed onto the resin and the decolourised syrup taken off by the bottom distributor. At the end of a loading cycle, rinse water is used to displace partially treated syrup from the resin bed; "sweetening off". Regenerant is then passed through the bed, initially displacing the water, to desorb the colour from the resin. Rinse water then displaces regenerant and is in turn displaced by syrup; "sweetening on", for the commencement of a new loading cycle. A number of factors determine the relative efficiency of this process, including the sweetening on/off time and volume, syrup dilution (evaporation costs), strength and volume of regenerant (chemical/running costs) and rinse water requirement (effluent). The resolution and sharpness obtained in the elution profiles shown in Graph 1 and Graph 2 during pilot trials highlight the efficiency of the system. This efficiency is guaranteed on main plant performance at all stages of the cycle, i.e., sweetening-on, loading, sweetening-off, regeneration and rinsing.