Continuous thin juice decalcification with weakly acidic cation exchangersin Pfeifer & Langen's Appeldorn factory

In the 1997/98 campaign, Pfeifer & Langen's Appeldorn factory installed a c ontinuous ISEP ion exchanger for thin juice softening, supplied by the Amer ican firm AMC. A modified Tasco process, using the weakly acidic IMAC HP 33 6 F cation exchanger from Rohm and Haas, was chosen as the exchange method. The exchanger is regenerated with 0.25% sulfuric acid. To avoid the format ion of invert sugar during ion exchange, the resin is transformed with soda lye from the H+ into the Na+ form. The installation produces little efflue nt as the regeneration runoff can be used in combination with the wash and rinse waters as extraction water. Solely the eluate of the reloading column in the amount of 2 m(3)/h (ca. 0.6 kg/100 kg beets) is to be regarded as w aste water. However, this effluent is mainly organically loaded and its tre atment does not present a problem. Some start-up difficulties having been overcome, it became possible to redu ce the lime salt content in thin juice to less than 1 degrees dH (10 mg CaO /l). At an acquisition price of DM2.5mn ($1.2mn), the capital cost of thin juice softening is of the same order of magnitude as that of precoat filtra tion (Schenk system). The operating costs of thin juice softening are also roughly equivalent to those of precoat filtration of stored thick juice, bu t the former has technological advantages, particularly by doing away with the need for anti-scaling agents in the evaporator station.