L. Zavodsky;

The interaction of sucrose – water – calcium oxide was observed in simulated systems and it was stated1 that :

1. In the system sucrose – water – CaO compounds of several types are formed, whereby the formation of these compounds is characterized by exothermicity of the reaction. The interaction is characterized by two reactions :

– the first one coursing quickly, nearly immediately,

– the second reaction is slow and is significant especialy at higher temperature.

2. The optimum of coagulation, filtration and sedimentation is connected with minimum of heat of reaction. At this point the concentration of these compounds is the lowest and the concentration of free calcium oxide, which is able to coagulize non-sugars is the highest.

3. In the compounds sucrose – CaO the ratio of sucrose to CaO is of constant value. It follows from this fact that the optimum of coagulation and sedimentation depends on concentration of sucrose.

4. It follows from the heat of the reaction sucrose – CaO and the reaction CaO – CO2 that the formation of hydrocarbonats is influenced also by compounds of sucrose and calcium oxide and in accordance with that there were found several optimums of 2-nd carbonation.

5. The favourable effect of CaC03 lies mainly on the fact that in the presence of CaCOs calcium oxide reacts with sucrose in lower rate according to the equilibrium state so that finaly the effect of coagulation rises and the structure of mud improves.

6. The second reaction coursing favourably at higher temperature is for the sugar technology not desirable, e.g. pre- and main liming at higher temperature, long- lasting decantation or recirculation of juice, because at these conditions stable bounds between sucrose and CaO are formed. These compounds are important for the further formation of undesirable scale.

Summarizing these facts and considering the two parts of reaction between sucrose and CaO it occurs possible to optimalize the technological process by small adjustment of technological conditions e.g. by changes of time and temperature values.

 

Proceedings: CITS 1971
Page: 351–360

Language: GER

pdf download: CITS1971-351-360.pdf