Assessment of optimum energy demand for non-centrifugal sugar production through an alternate process

Abstract Non-centrifugal sugar (NCS), known conventionally as Jaggery, obtained by concentrating cane juice in large boiling pans using traditional furnaces. In the traditional process, cane juice at 20 Brix is heated in pan(s) to 70 Brix to evaporate the water in it. Traditional furnaces used for concentration of sugarcane juice have low heat utilization efficiency about 15%. In the quest of improving energy efficiency, freeze pre-concentrating operation could be done at the start to remove water in the form of ice and the remaining proportion of water could be removed by heating for production of NCS. A thermal model has been developed for assessing optimum energy demand for a prior freezing technique up to a certain intermediate Brix and further by a heating technique. The obtained analytical data indicate that 1880.83 KJ/kg of cane juice is required when the juice concentration is increasing from 20 to 70 Brix while heating. The energy demand is significantly low (i.e. 536.10 KJ/kg of cane juice) when prior juice concentration is done through freezing technique from 20 to 63 Brix and later the juice is concentrated through heating technique from 63 to 70 Brix . Since, the energy required for latent heat of fusion is quite low when compared with the latent heat of vaporization so; combination of freezing and heating technique for juice concentration seems to be a viable option for improving energy efficiency in NCS production.