Freeze concentration of sugarcane juice in a jaggery making process

Abstract

A heat pump based Freeze Concentration System (FCS) is proposed to concentrate sugarcane juice from 20 to 40 Brix in a jaggery making process. Further concentration of the juice is carried out in a boiling pan. Inclusion analysis is carried out to estimate sucrose loss in the ice formed in a layer freezing process. A mathematical model is developed taking in to consideration effect of time varying ice thickness on evaporator temperature, compressor capacity, Coefficient of Performance (COP) of the heat pump. Data on operating parameters for a jaggery unit located at Rahu Pimplgaon in Daund District, Maharashtra was collected through field visits. Using this data, energy consumption of this conventional jaggery making process is calculated. Energy balance has been carried out and Sankey diagram is drawn. Energy consumption of the FCS is calculated using results of the mathematical model. Total energy consumption of the FCS integrated jaggery making process is calculated. Comparison of the conventional process and FCS integrated process is presented. Bagasse saving of about 1338 kg per day can be achieved using heat pump based FCS along with bagasse fired pan boiling. Further, hot spots are eliminated thereby reducing caramelisation significantly resulting in improved jaggery color.