Abstract:
Quick lime is commonly used additive in Sri Lanka during the period of Palmyrah (Borassus flabellifer)
sweet sap collection to delay sap fermentation by natural yeast and bacteria. There are several Palmyrah
sweet sap based products such as jaggery, treacle, sugar candy and sugar produced in northern Sri Lanka
which shows poor keeping qualities and large variation in physicochemical characteristics among batches.
Quality of the above products mainly connects with collection of raw material. Local tappers follow poor
quality control practices such as applying excess amount of quick lime with low purity that is adulterated
by impurities (sand and ash). In Jaffna two traditional kilns present in Pandaiththrippu and Anaikkoddai
produce quick lime from sea shells using coconut husk charcoal. Purity of quick lime expressed as CaO
(g/100g) produced from Anaikoddai kiln was 59.99±0.97 and Pandaitharippu kiln was 42.34±0.74. Quick
lime produced from both kilns were not in suitable condition to be used during processing of Palmyrah
sweet sap for the production of standardized Palmyrah sweet sap based products. Temperature (levels
750 °C, 850 °C, 950 °C and 1000 °C) and time period (10, 20 and 30 minutes) combinations of treatments
were carried out to produce high purity quick lime through furnacing of sea shells. The experiment was
arranged in two factor factorial design. Purity of quick lime obtained was statistically analyzed using SAS.
Significant differences were observed among all selected temperatures and time periods. Significantly
highest value for quick lime purity was obtained in 1000 °C and 30 minutes. Application of the treatments
1000 °C for 20 minutes, 1000 °C for 30 minutes, 950 °C for 30 minutes and 850 °C for 30 minutes were
produced significantly same and higher purity of quick lime compared to other of treatments. According
to high energy consumption 850 °C for 30 minutes treatment was selected to produce quick lime with
96.02+0.06 % of purity.
