Drying Kinetics of Maize Cob Using Mathematical Modelling

2021 ◽  
Vol 58 (1) ◽  
pp. 40-49
Author(s):  
Pankaj Kumar ◽  
Dhritiman Saha
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Temperature ◽  
Page Model ◽  
Maize Cob ◽  
Kinetics Of ◽  
Maize Cobs

Maize cobs (with husk and without husk) with initial moisture content of 78.38 % and 62.39 % (d.b.), respectively, were dried up to 20 % moisture content (d.b.) at three temperatures (45°C, 55°C and 65°C). Moisture ratios (MR) were calculated from moisture loss data and fitted to six (Newton’s, Page, Thompson, Modified Page, Henderson and Pabis, and Wang and Singh) drying mathematical models. Coefficient of determination (R2) and root mean square error (RMSE) were used for comparison of the models. From the analyses, Modified Page model showed the best fit to the experimental data with R2 varying from 0.9924 to 0.9968 for maize cob with husk and 0.9994 to 9989 for cobs without husk at given drying temperatures. The Modified Page model was found to be a superior model representing the drying kinetics of maize cob with and without husk at drying temperatures of 45, 55, and 65°C. The increase in drying temperature caused a reduction in drying time, and the drying took place in the falling rate period. Maize cobs with husk took more time for drying as compared to that without husk at the same temperature. The values of effective diffusivity lied between 1.079×10-8 m2.s-1 and 4.239×10-8 m2.s-1 for maize cob with husk, and between 1.194×10-8 m2.s-1 and 5.230×10-8 m2.s-1 for maize cob without husk. Effective diffusivity increased with an increase in drying temperature and was higher for maize cob without husk than that of with husk

Comparison of Drying Kinetics of Maize in Oven and in Pilot Silo Dryer: Influence on Moisture Content and Physical Characteristics

2016 ◽  
Vol 12 (6) ◽  
pp. 599-606 ◽  
Author(s):  
Flávia Daiana Montanuci ◽  
Raphaela Mulato Cavalcante ◽  
Camila Augusto Perussello ◽  
Luiz Mario de Matos Jorge
Keyword(s):  
Moisture Content ◽  
Temperature Increase ◽  
Drying Kinetics ◽  
Final Moisture Content ◽  
Drying Rate ◽  
Drying Time ◽  
Drying Temperature ◽  
Design And Optimization ◽  
Process Kinetics ◽  
Kinetics Of

Abstract The study of process kinetics may aid the design and optimization of drying systems. This paper evaluated the influence of drying temperature (40, 60 and 80 °C) on the moisture content, drying rate, density, shrinkage and breakage of maize dried in two different dryers: oven and silo dryer. In both dryers, the temperature increase reduced drying time, final moisture content and shrinkage of the grains, however increased breakage. Drying rate was higher in the oven (6.4×10−4±2.3×10−4s−1 versus 5.4×10−4±1.2×10−4s−1), while shrinkage (15.2±4.7 % versus 24.4±5.6 %) and density increase (16.6±5.9 % versus 33.4±5.8 %) were more intense in the silo. There was a large release of husk in the silo dryer and the moisture content was slightly smaller in the lower layers respective to the upper ones.

scholarly journals Drying kinetics and thin layer modeling of ogi produced from six maize varieties at varying soaking period and drying temperature

Food Research ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 431-440
Author(s):  
O.T. Bolaji ◽  
P.A. Adepoju ◽  
E.O. Adelana ◽  
B.S. Adesina
Keyword(s):  
Activation Energy ◽  
Moisture Content ◽  
Thin Layer ◽  
Research Work ◽  
Initial Moisture Content ◽  
Moisture Diffusivity ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Temperature ◽  
Maize Varieties

The drying kinetics of ogi produced from six varieties of maize at varying soaking period (12, 24 and 36 hrs) and drying temperature of 40, 50 and 60oC, respectively were studied. Seven common thin layer models were evaluated, and the best models were selected. The moisture content of ogi decreased with increased drying temperature and drying time while the drying rate increased with an increase in drying temperature and decreased with an increase in drying time. Logarithmic and two term models best fitted about 40.77% (22 samples each). However, where two term models were selected best, the R2 values ranged from 0.9858-0.99999999, χ 2 = 0.03715-0.000412, RMSE = 0.02206-0.0000677, unlike Logarithmic model that ranged from 0.8876-0.9964, χ 2 = 0.07045-0.001447, RMSE = 0.1084-0.01098. There was no definite pattern for effective moisture diffusivity (Deff) and Activation energy (Ea). This research work strongly suggests that the drying process was predominantly in the falling rate period (FRP) and was significantly affected by the change in temperature and moisture gradient. The activation energy obtained for ogi at varying soaking period and drying temperature ranged from 2.58-12.00 kJ/mol (A4Y), 7.72-44.95 kJ/mol (A4W), 14.53-35.88 kJ/mol (S7Y), 6.02-20.10 kJ/mol (D2Y), 14.024- 45.31 kJ/mol (DIY) and 19.34-64.22 kJ/mol (T3W). It was obviously indicated in this research that the soaking period had less or no impact on the drying behavior of ogi compared with the influence of drying temperature, drying time and initial moisture content.

Isotherm Adsorption Behavior and Drying Kinetics of Black Pepper

2012 ◽  
Vol 622-623 ◽  
pp. 1580-1585
Author(s):  
A. Sae-Khow ◽  
S. Tirawanichakul ◽  
Y. Tirawanichakul
Keyword(s):  
Energy Consumption ◽  
Relative Humidity ◽  
Moisture Content ◽  
Specific Energy ◽  
Specific Energy Consumption ◽  
Initial Moisture Content ◽  
Black Pepper ◽  
Drying Kinetics ◽  
Drying Temperature ◽  
Kinetics Of

The objective of this research were to evaulate equilibrium moisture contents (EMC) of black pepper using the gravimetric-static method and to study the drying kinetics of pepper using 1-stage hot air (HA) drying, 1-stage infrared (IR) drying, 2-stages drying with microwave (MW) and IR and 2-stages drying with MW and HA including to the specific energy consumption determination. For the first objective, the five saturated salt solutions were used for providing equlibrate state between pepper and surrounding at temperature ranging of 40-65°C correlated to relative humidity ranging of 10-90%. The results showed that EMC value decreased with increasing temperature at constant relative humidity. To evaluate the EMC value, the experimental data was simulated by four conventional EMC models and the criteria of the best fiiting models were determined by the determination of coefficient (R2) and the root mean square error (RMSE) value. The results showed that the calculated value using the Modified Oswin model was the most suitable for describing the relationship among equilibrium moisture content, relative humidity and temperature. To study effect of drying condition on drying kinetics, the initial moisture content and final moisture content after drying of papper sample was in ranges of 300-400% dry-basis and 12-16% dry-basis, respectively. The experimetal data were simulsted using empirical drying models and the results showed that the drying temperature relatively affected to drying rate of pepper while the evolution of moisture transfer was in the drying falling ratefor all drying strategies. The 1-stage IR drying and 2-stages drying with MW and IR provided low specific energy consumption (SEC) (0.11-0.15 MJ/kg of water evaporated) compared to the other drying strategies (0.87-1.52 MJ/kg of water evaporated). Moreover, the SEC of pepper drying decreased with increasing of drying temperature.

scholarly journals Drying kinetics of Hyola 430 hybrid canola (Brassica napus L.) seeds

2020 ◽  
pp. 1623-1629
Author(s):  
Lílian Moreira Costa ◽  
Osvaldo Resende ◽  
Daniel Emanoel Cabral de Oliveira ◽  
José Mauro Guimarães Carvalho ◽  
Sarah Gabrielle Sousa Bueno ◽  
...  
Keyword(s):  
Moisture Content ◽  
Mathematical Models ◽  
Effective Diffusion ◽  
Initial Moisture Content ◽  
Information Criteria ◽  
Drying Kinetics ◽  
Coefficient Of Determination ◽  
Statistical Parameters ◽  
Drying Time ◽  
Kinetics Of

This work aimed to study the drying kinetics of canola seeds, fit mathematical models and obtain the effective diffusion coefficient. Canola seeds with initial moisture content of 0.3653 (decimal, d.b.) were subjected to drying in a forced ventilation oven at temperatures of 40, 60, 80 and 100 °C and relative humidity of 37.15, 16.93, 8.35, 4.41 and 2.47%, respectively. The samples were dried on trays without perforations, containing approximately 77 g, in three replicates. A final moisture content of 0.080 ± 0.004 (decimal, d.b.) was established to determine the drying curves and fit the mathematical models. The mathematical models were selected considering the mean estimated error, chi-square, coefficient of determination, mean relative error, and Akaike (AIC) and Bayesian (BIC) information criteria. Drying time decreased with increasing temperature. Based on the best values of the statistical parameters and together with the Akaike and Bayesian information criteria, the Page model was selected to represent the drying kinetics of canola seeds. The effective diffusion coefficients showed magnitudes between 0.153x10-11 and 1.221x10-11 (m2 s-1), and their values increased with temperature increase, being described by the Arrhenius equation, with activation energy of 33.94 kJ mol-1, an important piece of information to consider when designing drying equipment

scholarly journals Mathematical modeling of pequi pulp drying and effective diffusivity determination

2017 ◽  
Vol 21 (7) ◽  
pp. 493-498 ◽  
Author(s):  
Elisabete P. de Sousa ◽  
Rossana M. F. de Figueirêdo ◽  
Josivanda P. Gomes ◽  
Alexandre J. de M. Queiroz ◽  
Deise S. de Castro ◽  
...  
Keyword(s):  
Experimental Data ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Convective Drying ◽  
Drying Time ◽  
Air Speed ◽  
Drying Curves ◽  
Increasing Temperature ◽  
Kinetics Of ◽  
Best Fit

ABSTRACT The aim of this work was to study the drying kinetics of pequi pulp by convective drying at different conditions of temperature (50, 60, 70 and 80 °C) and thickness (0.5, 1.0 and 1.5 cm) at the air speed of 1.0 m s-1, with no addition of adjuvant. The experimental data of pequi pulp drying kinetics were used to plot drying curves and fitted to the models: Midilli, Page, Henderson & Pabis and Newton. Effective diffusivity was calculated using the Fick’s diffusion model for a flat plate. It was found that, with increasing thickness, the drying time increased and, with increasing temperature, the drying time was reduced. The Midilli model showed the best fit to the experimental data of pequi pulp drying at all temperatures and thicknesses, presenting higher coefficients of determination (R2), indicating that this model satisfactorily represents the pequi pulp drying phenomenon. There was a trend of increase in the effective diffusivity with the increase in pulp layer thickness and temperature.

scholarly journals Isotermas de adsorção de umidade e cinética de secagem de sementes de trevo persa (Trifolium resupinatum L.) e trevo vesiculoso (Trifolium vesiculosum) ¬¬¬¬

2020 ◽  
Vol 28 ◽  
pp. 535-548
Author(s):  
Gabriela Saldanha Soares ◽  
Scarlet Neves Tuchtenhagen ◽  
Luiz Antonio de Almeida Pinto ◽  
Carlos Alberto Severo Felipe
Keyword(s):  
Moisture Content ◽  
Adsorption Isotherms ◽  
Effective Diffusivity ◽  
Drying Kinetics ◽  
Peleg Model ◽  
Critical Moisture ◽  
Persian Clover ◽  
Trifolium Vesiculosum ◽  
Kinetics Of ◽  
Trifolium Resupinatum

The aim of this work was to obtain adsorption isotherms and to study the drying kinetics of persian clover (Trifolium resupinatum L.) and arrowleaf clover (Trifolium vesiculosum) seeds, in addition, fitting the experimental data by the predicted models of the literature. The equilibrium moisture content and the moisture adsorption behavior were found by isotherms curves at 40, 45 and 50 ºC, and the Peleg model was the most suitable. The drying kinetics was determined by thin layer assays in an air parallel flow dryer at all three temperatures. In addition, it was demonstrated the predominance of the falling drying rate period for the two species of seeds, and the critical moisture content values were approximately of 0.20 and 0.25 gwater gdry matter-1 for persian clover and arrowleaf clover seeds, respectively. The effective diffusivity values were estimated in ranges of values of 3.61×10-11 – 6.81×10-11 m² s-1 for persian clover and 6.76×10-11 – 1.15×10-10 m²s-1 for arrowleaf clover seeds and the temperature effect was expressed by an Arrhenius relation. Thus, drying kinetics confirmed the greater difficulty in moisture removal from the arrowleaf clover seeds, compared to the persian clover seeds drying, in agreement with the results obtained through adsorption isotherms.

scholarly journals The Experimental Research of Drying Kinetics of Nagpur Orange Fruit (Citrus Sinesis- L) by Hot Air Electrical Dryer

2019 ◽  
Vol 8 (6S4) ◽  
pp. 1131-1134
Keyword(s):  
Thin Layer ◽  
Drying Kinetics ◽  
Drying Time ◽  
Drying Characteristics ◽  
Drying Temperature ◽  
Hot Air ◽  
Thin Layer Drying ◽  
Drying Behavior ◽  
Orange Fruit ◽  
Kinetics Of

The study is aimed experimentally and compared with the theoretical results of drying kinetics of Nagpur orange fruit dried in a hot air electrical dryer. Orange fruit is highly perishable and needs to be consumed or processed immediately after harvest. Drying or dehydration is one of the most practical methods of preserving food products. Therefore, thin layer drying characteristics of falling rate of Nagpur orange are determined experimentally under different conditions of drying air temperatures, relative humidity and air velocities for different moisture contents. Thin layer models like Wang and Singh, Page and Henderson have been compared with Experimental results. The knowledge of drying kinetics helps for identification of exact drying time and air flow velocity for different moisture content. Here drying operation is carried out at a velocity of 1m/sec and 1.25 m/sec for different temperature of 55°C, 65°C and 75°C. This analysis reveals that drying temperature has a more significant effect on moisture removal while velocity has the least effect. Drying rate is found to increase with the increase in drying temperature and reduce with drying time. Experimental data is statistically correlated by plotting the drying characteristics curve. The analysis reveals that Wang and Singh's model is a better model to explain the drying behavior of Nagpur Orange fruit (R2=0.9888).

scholarly journals Effect of Drying Temperatures on Chemical compounds and Antioxidant properties of Vitex negundo leaves

2020 ◽  
Vol 13 (2) ◽  
pp. 94-102
Author(s):  
Hada Masayu I ◽  
A Fauziah ◽  
K Y Pin ◽  
Safwan K Ihsan ◽  
M Shalini ◽  
...  
Keyword(s):  
Moisture Content ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Initial Moisture Content ◽  
Total Phenolic ◽  
Slight Reduction ◽  
Vitex Negundo ◽  
Drying Time ◽  
Drying Temperature ◽  
Time Required

The effect of drying temperature on the leaves of Vitex negundo was determined. Three levels of temperatures (40, 50 and 60°C) were used in the presented study. The initial moisture content of the leaves was 69.98%. Continuous drying at the above mentioned temperature levels was conducted to determine the drying time required to achieve equilibrium moisture content. The quality of dried leaves was evaluated based on the quantity of agnuside, a major compound in V. negundo using HPLC analysis. The fastest drying of the leaves was achieved at 60°C, followed by at 50°C, but HPLC results showed that dried V. negundo suffered at 40% reduction in agnuside content when drying at 60°C as compared to at 40°C. Slight reduction of agnuside was found in the sample dried at 50°C as compared to at 40°C. Whereas, antioxidant results showed that V. negundo leaves have significant level of phenolic content and the effect of drying at higher temperature has significantly reduce the amount of phenolics in V. negundo leaves. Total phenolic content of V. negundo leaves was highest at 50 °C drying temperature. Based on the findings of this work, the best convection oven drying condition for V. negundo leaves was at 50°C with the highest agnuside concentration of 502.224 mg/L and phenolic content of 286.7 ± 11.0 mg GAE/100g.

Drying Kinetics Evaluation of Solid Red Bricks

2015 ◽  
Vol 3 ◽  
pp. 119-134
Author(s):  
E. Barreira ◽  
J.M.P.Q. Delgado ◽  
V.P. de Freitas
Keyword(s):  
Moisture Content ◽  
Molecular Diffusion ◽  
Moisture Transfer ◽  
Drying Kinetics ◽  
Drying Process ◽  
Drying Time ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetics Of ◽  
Best Fit

Moisture is one of the most deteriorating factors of buildings. The moisture content depends on hygroscopic equilibrium between buildings materials and environment, which is determined by the drying and wetting rate of masonry. So, the moisture content is not only determined by the water that is absorbed by the material, but also by the amount of water that is evaporated under favourable conditions, which is described by the drying process.This work presents the results of an experimental evaluation of the drying kinetics of solid red brick, considering the bulk moisture transfer. The drying kinetics was assessed considering different environment conditions (air temperature and humidity). The experimental results showed that the drying flux is extremely dependent of temperature and relative humidity in the first stage of the drying process. The values obtained were between 0.025 kg/m2h (T=15oC and RH=80%) and 0.135 kg/m2h (T=30oC and RH=50%), for the worst and better drying ambient conditions.Different first-order kinetics models, available in the literature, were adjusted to describe the drying process and estimate the equilibrium moisture content of the samples. The results point that Midilli et al. model allows the best fit and that the drying time constant is strongly affected by the drying air conditions. It was also estimated the apparent molecular diffusion coefficient for solid red brick samples and its variation with temperature.

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