Investigating the Performance of Dryers Equipped with MOF and Closed Air Circulation

One of the most common methods of drying is the use of heat. Therefore, high energy consumption has always been of concern in the drying process, and various methods have been tried to reduce high energy consumption. This research evaluated the performance of a thermal dryer with a closed air circulation system using porous metal-organic framework (MOF) nano sorbents. Dryer sections consisted of a crop drying chamber, connecting air pipes, air blowers, a chamber containing MOF nano sorbents, an electric air heater, and measurement and control systems. The performance of the dryer on the mint plant was compared at three temperature levels (40, 50, and 60 °C) and in two open and closed-air circulation methods. Finally, the energy consumption and efficiency were measured and evaluated for the dryer. The results showed that the closed air circulation system reduced energy consumption by 35% and therefore increased dryer efficiency, significantly affecting dryer efficiency and energy consumption. There was no obvious difference in the total color index between the two methods of use and without using nano sorbents. Antioxidant activity increased with increasing temperature. The study results indicated that a closed air circulation system significantly affects the dryer’s energy consumption and output. The highest output of the dryer was achieved at 50 °C when the dryer had been equipped with a closed air circulation system. No significant difference was evidenced in the total color index between the two applied methods when not using nano absorbents. The antioxidant activity was found to increase with the increase in temperature.