Determination of Moisture Diffusivity and Activation Energy in Thin Layer Drying of Olive Pomace

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Smail Meziane ◽  
Naima Mesbahi
Keyword(s):  
Activation Energy ◽  
Thin Layer ◽  
Moisture Diffusivity ◽  
Olive Pomace ◽  
Air Velocity ◽  
Drying Time ◽  
Effective Moisture ◽  
Air Temperatures ◽  
Thin Layer Drying

Abstract The thin layer drying of olive pomace was experimentally studied in a laboratory convective dryer. Drying experiments were performed under five air temperatures of 60, 70, 80 and 90ºC, two air velocities of 1.0 and 1.8 m s-1 and three thickness of thin layer of 6, 9 and 12 mm. The results show that the drying time decreased with increased in drying temperature and air velocity but increased with the decreasing of thin layer thickness of olive pomace. Over the experimental range studied, the values of effective moisture diffusivity and activation energy ranged from 1.25 • 10-9 to 6.30 • 10-9 m2 s-1 and 26.30 to 37.63 kJ mol-1, respectively. The dependence of these parameters on thickness of thin layer, and temperature and velocity of drying air has been investigated.

Effect of Air Velocity and Temperature on the Drying Kinetics of Drumstick Leaves (Moringa Oleifera)

2012 ◽  
Vol 8 (4) ◽  
Author(s):  
Monica Premi ◽  
Harish Sharma ◽  
Ashutosh Upadhyay
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Moringa Oleifera ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Rate ◽  
Air Velocity ◽  
Drying Time ◽  
Effective Moisture ◽  
Kinetics Of

Abstract The present study examines the effect of air velocity on drying kinetics of the drumstick leaves in a forced convective dryer. The drumstick leaves were dried in the temperature range of 50–800 C, at different air velocity (Dv) of 0.5 and 1.3 m/s. The results indicated that drying temperature and air velocity are the factors in controlling the drying rate. Experimental data obtained for the samples for color, drying rate and drying time proved that air velocity of 1.3 m/s yielded the product superior in terms of both quality and energy efficiency as compared to the samples at 0.5 m/s. Activation energy for drumstick leaves dried with air velocity, 0.5 and 1.3 m/s was 12.50 and 32.74 kJ/mol respectively. The activation energy relates similarly with the effective moisture diffusivity which also increased with increase in air velocity and temperature.

scholarly journals Kinetics, energy efficiency and mathematical modeling of thin layer solar drying of figs (Ficus carica L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lahcen Hssaini ◽  
Rachida Ouaabou ◽  
Hafida Hanine ◽  
Rachid Razouk ◽  
Ali Idlimam
Keyword(s):  
Energy Efficiency ◽  
Thin Layer ◽  
Air Flow ◽  
Moisture Diffusivity ◽  
Energy Utilization ◽  
Ficus Carica ◽  
Effective Moisture Diffusivity ◽  
Drying Time ◽  
Effective Moisture ◽  
Thin Layer Drying

AbstractFirst convectional thin layer drying of two fig (Ficus carica L.) varieties growing in Moroccan, using partially indirect convective dryer, was performed. The experimental design combined three air temperatures levels (60, 70 and 80 °C) and two air-flow rates (150 and 300 m3/h). Fig drying curve was defined as a third-order polynomial equation linking the sample moisture content to the effective moisture diffusivity. The average activation energy was ranged between 4699.41 and 7502.37 kJ/kg. It raised proportionally with the air flow velocity, and the same pattern were observed for effective moisture diffusivity regarding drying time and velocity. High levels of temperature (80 °C) and velocity (300 m3/h) lead to shorten drying time (200 min) and improve the slices physical quality. Among the nine tested models, Modified Handerson and Pabis exhibited the highest correlation coefficient value with the lowest chi-square for both varieties, and then give the best prediction performance. Energetic investigation of the dryer prototype showed that the total use of energy alongside with the specific energy utilization (13.12 and 44.55 MWh/kg) were inversely proportional to the velocity and drying temperature. Likewise, the energy efficiency was greater (3.98%) higher in drying conditions.

Experimental Investigation to Evaluate the Effective Moisture Diffusivity and Activation Energy of Cassava (Manihot Esculenta) under Convective Drying

2021 ◽  
Author(s):  
Pathiwat Waramit ◽  
Bundit Krittakom ◽  
Ratinun Luampon
Keyword(s):  
Activation Energy ◽  
Type Equation ◽  
Moisture Diffusivity ◽  
Experimental Results ◽  
Effective Moisture Diffusivity ◽  
Convective Drying ◽  
Air Velocity ◽  
Drying Time ◽  
Hot Air ◽  
Effective Moisture

Investigation of effective moisture diffusivity (Deff) and activation energy (Ea) of cassava were conducted under convective drying at temperature and velocity of 60, 70 and 80 °C, and 1.0, 1.5 and 2.0 m/s, respectively. In the experiment, cassava was sliced into 3 mm-thickness and dried under given conditions until mass was saturated. Deff and Ea were described by Fick’s second law and Arrhenius-type equation, respectively. The experimental results indicated that the increase in Deff was significantly affected by increasing the hot air temperature and velocity. The slope method was used to calculate average Deff, and results were found to range from 3.83 × 10–9 – 9.86 × 10–9 m2/s. The Ea was found to decrease with an increase in hot air velocity, ranging from 21.23– 24.92 kJ/mol. Additionally, Moisture content (Mw) and Drying rate (DR) were also used to describe the drying kinetics. From the experimental results, Mw and DR decreased with an increase in drying time. DR increased with an increase in temperature and velocity causing Mw to rapidly decrease and drying time to reduce. The highest DR was found to be 0.55 gwater/min at temperature of 80 °C and velocity of 2.0 m/s.

scholarly journals Mathematical modelling of thin layer drying of pear

2016 ◽  
Vol 22 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Monika Lutovska ◽  
Vangelce Mitrevski ◽  
Ivan Pavkov ◽  
Vladimir Mijakovski ◽  
Milivoj Radojcin
Keyword(s):  
Experimental Data ◽  
Thin Layer ◽  
Moisture Diffusivity ◽  
Effective Moisture Diffusivity ◽  
Data Set ◽  
Effective Moisture ◽  
Air Temperatures ◽  
Thin Layer Drying ◽  
Drying Kinetic ◽  
Drying Conditions

In this study, a thin - layer drying of pear slices as a function of drying conditions were examined. The experimental data set of thin - layer drying kinetics at five drying air temperatures 30, 40, 50, 60 and 70?C, and three drying air velocities 1, 1.5 and 2 m s-1 were obtained on the experimental setup, designed to imitate industrial convective dryer. Five well known thin - layer drying models from scientific literature were used to approximate the experimental data in terms of moisture ratio. In order to find which model gives the best results, numerical experiments were made. For each model and data set, the statistical performance index, (?), and chi-squared, (?2), value were calculated and models were ranked afterwards. The performed statistical analysis shows that the model of Midilli gives the best statistical results. Because the effect of drying air temperature and drying air velocity on the empirical parameters was not included in the base Midilli model, in this study the generalized form of this model was developed. With this model, the drying kinetic data of pear slices can be approximated with high accuracy. The effective moisture diffusivity was determined by using Fick?s second laws. The obtained values of the effective moisture diffusivity, (Deff), during drying ranged between 6.49 x 10-9 and 3.29 x 10-8 m2 s-1, while the values of activation energy (E0) varied between 28.15 to 30.51 kJ mol-1.

scholarly journals Drying characteristics and kinetics of fluidized bed dried potato

2008 ◽  
Vol 19 (2) ◽  
pp. 127 ◽  
Author(s):  
S.B. BAKAL ◽  
K.H. GEDAM ◽  
G.P. SHARMA
Keyword(s):  
Activation Energy ◽  
Developed Countries ◽  
Moisture Diffusivity ◽  
Drying Characteristics ◽  
Effective Moisture ◽  
Air Temperatures ◽  
Processed Products ◽  
Drying Conditions ◽  
Kinetics Of ◽  
Good Agreement

In developed countries, more than 50% potatoes are consumed as processed products. As drying is the vital phenomenon in processing, it is necessary to investigate the drying characteristics and its kinetics. In this experimental study, drying kinetics of Potato in two different shape of cuboidal & cylindrical with three aspect ratio was investigated as a function of drying conditions. Experiments were conducted using air temperatures of 50, 60 and 70 ºC, at velocity of 7 ms-1. The experimental moisture data were fitted to Page and simple models available in the literature, and a good agreement was observed. The Page model gave better fit than simple model. In the ranges covered, the values of the effective moisture diffusivity, Deff were obtained between 2.278 × 10-9 to 3.314 × 10-8 m2s-1 from the Fick's diffusion model. Using Deff, the value of activation energy (Ea) was determined assuming the Arrhenius-type temperature relationship.

scholarly journals Drying Modelling, Moisture Diffusivity and Sensory quality of Thin Layer dried Beef

2018 ◽  
Vol 6 (2) ◽  
pp. 552-565 ◽  
Author(s):  
Eunice Akello Mewa ◽  
Michael Wandayi Okoth ◽  
Catherine Nkirote Kunyanga ◽  
Musa Njue Rugiri
Keyword(s):  
Thin Layer ◽  
Sensory Quality ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Effect Of Temperature ◽  
Slice Thickness ◽  
Drying Time ◽  
Drying Characteristics ◽  
Thin Layer Drying

The objective of the present study was to determine the drying kinetics, moisture diffusivity and sensory quality of convective air dried beef. The effect of temperature of drying (30-60°C) and thickness of samples (2.5-10 mm) on the convective thin-layer drying kinetics of beefdried in a cabinet dryer was evaluated. Five semi-theoretical models were fit to the drying experimentaldata with the aim of predicting drying characteristics of beef and fitting quality of models determined using the standard error of estimate (SEE)and coefficient of determination (R2). Determination ofeffective moisture diffusivity (Deff) from the experimental drying datawas done and sensory quality of the optimized dried cooked and uncookedbeef samplesevaluated. Drying time and rate of drying increased with an increasing temperature but decreased with increased slice thickness. However, there was overlapping of drying curves at 40-50°C. Among the selected models, Page model gave the best prediction of beef drying characteristics. Effective moisture diffusivity (Deff) ranged between 4.2337 x 10-11 and 5.5899 x 10-10 m2/s, increasing with an increase in air temperature and beef slice thickness.Of all the sensory parameters evaluated, texture was the only attribute that gave significantly different (P > 0.05) scores between the cooked and uncooked dried beef samples.

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