A comparative evaluation of energetic and exergetic performance parameters in syrup purification and evaporation lines

Abstract

Considering the global challenges of environmental destruction, limited fossil reserves, and the reduction of the share of energy in the final price of the product, a detailed evaluation of energy‐intensive systems is needed to improve performance. The syrup heating process is one of the basic processes in sugar factories. In this study, the syrup heating system in the purification and evaporation lines, located in the Urmia sugar plant, was evaluated, analyzed, and compared with energy and exergy analysis. Also, the subsystems of the syrup heating process were evaluated with thermodynamic analysis. Mass, energy, and exergy balances were carried out by coding in EES software, and energetic and exergetic operational parameters were extracted. The heat loss rate and exergy destruction rate in the syrup heating system of the purification line were calculated as 121.29 and 404.36 kW, respectively, and in the syrup heating system of the evaporation line as 112.70 and 238.62 kW, respectively. The recovery potential rate was 134.99 kW for the purification line and 37.70 kW for the evaporation line. The stability index and exergy efficiency for the purification line were calculated as 3.03% and 67.01% for the purification line and 6.54% and 84.71% for the evaporation line. The results of the thermodynamic analysis showed that the syrup heating process in the purification line has weaker performance from the energetic and exergetic point of view, is accompanied by large losses, and imposes a greater environmental burden. Accordingly, it is suggested that the improvement of the syrup heating performance in the purification line should be prioritized for engineering optimization and redesign in sugar processing plants.Practical applicationsMonitoring the operational state of the systems and determining system losses are critical steps in food thermal processing. A practical and accurate method to evaluate the purification and evaporation lines is required to improve the thermal efficiency. According to exergy analyses, the performance of the syrup heating process in the purification line is low due to large losses and imposes a greater environmental burden. Therefore, the improvement of the syrup heating performance in the purification line should be prioritized for engineering optimization and redesign in sugar processing plants.