Effect of combined acid – thermal treatment of charcoal on clarification efficiency of sugar crystals affined water

The objective of this research was to study the clarification of affined water of sugar crystals. The clarification was carried out by different combined acid-thermal treatments of charcoal. In this work we analyzed the colour, total soluble solids (T.S.S), pH, titratable acidity, total sugars, reduced sugars, ash content, purity coefficient and ash ratio. During subsequent heating of the acid treated charcoal at different levels, the surface as well as interlayer water are dehydrated progressively with high temperature and leads to a collapse of the layer that become less accessible to adsorption of coloring pigments. The clarification of sugar crystals affined water showed that adding acid-thermal charcoal at different levels (5%, 10%, 15%, w/w) led to higher clarified affined water than those to standard clarifying agent (Tonsil). Highly significance (P ≥ 0.05) was observed for total sugars, sucrose, reduced sugars and ash content in treatments; charcoal amounts, charcoal-acid ratios and heating temperature. Heating of the acid-treated charcoal leads to diminishing total sugars, sucrose, total ash, water soluble and insoluble ash as acid-thermal charcoal increased. On the other hand, both of total sugars, sucrose purity coefficient and ash ratios were increased with increasing charcoal-acid ratio. Meanwhile, total sugars and sucrose decreased with increasing the heating temperature degree of charcoal. The results illustrated that clarification greatly increased affined water purity and ash ratio. The clarified affined water of sugar crystals with Tonsil agent had slightly lower total sugars, sucrose and reduced sugars under the higher rates of acid-thermal charcoal. Also, the clarified affined water with Tonsil agent had slightly higher total ash, water soluble and insoluble ash. The colour, T.S.S, pH, total sugars, sucrose, reduced sugars, ash ratio and purity coefficient increased proportionally with increasing acid ratio to charcoal, with the reduced proportionally for T.A., total ash, water soluble and insoluble ash. With increased temperature degrees of acid –charcoal reduces comparatively of color, T.S.S., PH, total sugars, sucrose, ash ratio and purity coefficient, with relatively increase of T.A., reducing sugar, total ash, water soluble and insoluble ash. Additionally, the clarified affined water with clarifying agent had greatly lower purity coefficient and ash ratio. Our results suggest that affined water of sugar crystals treated with acid-thermal charcoal gave the best clarification process making it more suitable for reusing in raw sugar refining.