Thermal integration analysis and improved configuration for multiple effect evaporator system based on pinch analysis

Pinch analysis for a sugar plant production capacity 4000 TCD has been carried out to reduce its energy consumptions. The plant has ten evaporators that can be configured to several multiple effect evaporators. It has been running with five-effect evaporator (quintuple) scheme. To maximize energy utilization within the plant, three multiple effect evaporator schemes were evaluated. They are triple effect evaporator, quadruple effect evaporator, and quintuple effect evaporator as the benchmark. The result shows that the quintuple effect evaporator yields the highest energy efficiency by about 10%. Options to achieve such target is to use low pressure steam only for the first effect and to use steam bleeding from the first effect to heat a tertiary juice heater. With this proposed scenario, sugar dryer, wash water RVF unit and wash water HGF unit no longer need external steam for its operation.

Performance analysis of basin-type vertical multiple-effect diffusion solar still integrated with solar pond: energy, exergy and economical analysis

An experimental analysis was carried out with basin-type vertical multiple-effect diffusion solar still coupled with solar pond (BVMEDS-SP) to evaluate 24 hours overall performance of still by varying feed flow rate and temperature in addition to other affecting parameters. A solar pond was utilized to harness solar energy diurnal and the same energy was provided to basin water nocturnal in batch mode to produce distillate throughout the day. It can be seen that the daily energy and exergy performance of BVMEDS-SP having four effects was improved by 21.74% and 16.83%, respectively, when the feed flow rate was reduced from 0.32 g/m2/s to 0.13 g/m2/s. As the temperature of feed water was enhanced from 25.65°C to 32.4°C, the daily energy and exergy efficiency of BVMEDS-SP correspondingly increased by 41.76% and 46.62%. In addition, increasing the number of effects from 2 to 5 improved the overall energy and exergy efficiency to 93.15% and 171.80%, respectively. The cost analysis revealed that cost of distillate for 2-effect still was Rs. 4.64/kg and it reduced to Rs. 3.11/kg for 7-effect still. A productivity correlation was furthermore developed and estimated that the experimental database of current research was in good agreement with the error band of −5% to +10%.