Total Sugar


Kroyer Index:

Flowchart illustrating the process of making Total Sugar.
Total Sugar. The Kroyer organization developed a method for turning high DE syrup into a crystalline product - Total Sugar - by instant crystallization. Two methods were developed:

1. Spray cooling
2. Airless crystallization (The pot process)

 << Picture: Solidifying of high dextrose syrup by the "pot" process. Early bench scale test.

Spray Cooling. Spray cooling or spray crystallization is carried out on huge spray towers and a high ration of back-mixing. The ratio of dry powder to fresh liquid is in the range of 2:1 to 3:1. The first full scale unit was 1965 supplied to Duintjer Wilkens Meihuizen, Veendam, Holland - later acquired by AVEBE. Next plant was supplied to Tunnel Refineries, UK.

The Pot Process. The patent is based on the observation, that the finest sugar always is at the bottom of the sugar bowl. Excess water is removed by evaporation of the all-enzyme converted high dextrose syrup and the hot concentrated liquid is pumped into the bottom of an agitated dextrose seed bed and the solidified microcrystalline dextrose is continuously pouring off at the top of the "pot". A production capacity of 1 t/h requires only 200 l of volume of the crystallizing vessel due to the fast solidification. A high DE is important. Polysaccharides act as crystallization inhibitors and therefore a DE of minimum 96 is used. The dried product will be in the β-form.

Nizo Total Sucrose. W.R. Grace & Co. USA contracted Karl Kroyer to develop the total sugar process for crude table sugar. Grace had two sugar mills in Peru and they wished to turn the crude sugar syrup into a dry product to save transport cost to refineries in Rotterdam.

We succeeded and proved, that the types of sucrose syrup in question can be solidified in an industrial plant in a continuously labour saving process.
<< Picture: Pilot plant tests 1968 at Nizo, Holland