Thermodynamic Analysis of a Continuous Vacuum Pan in the Crystallization Process of Sugar Beet Syrup

Abstract

Due to the limitations of fossil resources, it is momentous to accurately assess the high-energy consumption systems that could be used to improve the performance of these systems. The crystallization process directly affects particle size, purity, and product yield in the sugar industry. In this study, a continuous vacuum pan in the crystallization line, located in the Urmia sugar plant, was evaluated by energy and exergy analyses and compared with syrup concentration line evaporators. Mass, energy, and exergy balances were conducted via coding in EES software, and energetic and exergetic functional parameters were obtained. The system’s heat loss and exergy destruction were calculated at 33.40 and 255.93 kW, respectively. The improvement potential was 114.70 kW, the sustainability index was 2.24, and the exergy efficiency of the vacuum pan was 58.46%, which indicates its poor performance compared to the evaporators of the concentration line. The vapor with energy and exergy of 12.66% and 18.44% of the total entering energy and exergy leaves the vacuum pan without any use and is considered a system loss. Therefore, as a solution, a thermocompressor is proposed as a solution to recompress the vapor and reduce the production costs and environmental impacts of the process in the Urmia sugar plant.