Kinetics of heat and mass transfer in moringa leaves drying in a cabinet dryer
Timothy A. Adekanye, Elijah A. Alhassan, Matthew Folorunsho Amodu, T.O. Olanrewaju, Murtala Iyanda
Abstract
• The findings indicated that the rate of drying increased as the temperature rose. • The Page model demonstrated excellent fit, having a large coefficient of determination (R²) and decreased error levels. • Drying at 1.5 m/s resulted in Deff values ranging from 4.06 × 10 −11 m 2 s -1 to 1.40 × 10 −10 m 2 s -1 , while drying at 1.7 m/s resulted in values ranging from 6.74 × 10 −11 m 2 s -1 to 6.48 × 10 −10 m 2 s -1 . • The study gives an insight into the drying characteristics of moringa leaves which will thus serve as a basis for the development of an ideal drying characteristics scale which can be used in the cabinet dryer to increase efficiency and the quality of dried moringa products. This research focuses on kinetic modeling and investigating heat and mass transport dynamics while drying moringa oleifera leaves in a cabinet dryer. Moringa leaves possess nutritional and pharmacological value, but maintaining these properties after drying has been challenging. An investigation was performed to evaluate the drying kinetics and maximize the quality. The trials were carried out at 40 °C, 50 °C, and 60 °C to examine the variation in moisture removal rates and drying timeframes. The moisture content was recorded periodically till an equilibrium occurred, and the collected data was incorporated into five drying kinetic models, including Midilli and Kucuk, Newton, Page, Henderson and Pabis, and Wang and Singh models, to determine the one with the most accurate representation of the drying behavior. The effective moisture diffusivity was determined using Fick's second law of diffusion. Moisture diffusion activation energy was calculated using the Arrhenius equation. The findings indicated that the rate of drying increased as the temperature rose. The Page model demonstrated an excellent fit, having a large coefficient of determination (R²) and decreased error levels. Drying at 1.5 m/s resulted in Deff values ranging from 4.06 × 10 −11 m 2 s -1 to 1.40 × 10 −10 m 2 s -1 , while drying at 1.7 m/s resulted in values ranging from 6.74 × 10 −11 m 2 s -1 to 6.48 × 10 −10 m 2 s -1 . The study gives an insight into the drying characteristics of moringa leaves, which will serve as a basis for developing ideal drying characteristics.