determination of moisture diffusivity and activation
Determination of effective moisture diffusivity and
The values of effective moisture diffusivity ranged from 9 6010-9 to 2 2610-8 m 2 /s and the activation energy was determined to be 21 2 kJ/mol Keywords: Effective moisture diffusivity Drying activation energy Isothermal condition Peanut shell TGA
Determination of the Bulk Moisture Diffusion Coefficient
Dec 14 2007The bulk moisture diffusion coefficient ( D b) is an important physical parameter of food ingredients and systems However the traditional method of measuring D b using saturated salt solutions is very time-consuming and cumbersome New automated water sorption instruments which can be used to conveniently and precisely control both relative humidity
Effective moisture diffusivity and activation energy of
The effects of two drying methods oven and microwave drying on the effective moisture diffusivity and activation energy of rambutan seed were studied Effective moisture diffusivity and activation energy are the main indicators used for moisture movement within the material Hence it is beneficial to determine an appropriate drying method to attain a final moisture
Lecture 5: Diffusion Coefficient (Diffusivity)
Diffusion coefficient also called Diffusivity is an important parameter indicative of the diffusion mobility Diffusion coefficient is not only encountered in Fick's law but also in numerous other equations of physics and chemistry Diffusion coefficient is generally prescribed for a given pair of species For a multi-component
DETERMINATION OF EFFECTIVE MOISTURE DIFFUSIVITY AND
The predicted values by the diffusion model based on Fick's second law were in good agreement with the experimental data obtained from the falling rate period The values of effective moisture diffusivity ranged from 9 60x10-9 to 2 26x10-8 m2/s and the activation energy was determined to be 21 2 kJ/mol
MODELING EFFECTIVE MOISTURE DIFFUSIVITY OF ORANGE
moisture diffusivity and activation energy of orange (Thompson variety) slices during drying process and its dependence on factors such as air temperature air velocity and determination R 2 were in the range of 0 9891–0 9935 Results show that the thin layer dry-
Kinetics and Temperature Dependent Moisture Diffusivities
The temperature dependence of the effective moisture diffusivity followed an Arrhenius relationship with the activation energies between 15 and 62 12 kJ/mol Keywords: drying effective moisture diffusivity fluidized bed drying pumpkin seed tray drying
Studies on Kinetics of Moisture Removal from Spinach Leaves
moisture diffusivity on drying air temperature was obtained by an Arrhenius-type relationship D = exp ? ( 6 7 5 9) A Where D 0 is the Arrhenius factor (m 2/s) E a is the activation energy for the moisture diffusion (kJ/mol) R is the universal gas constant (kJ/mol K) and T is drying air temperature (0C)
Effects of Drying Temperature on The Effective Coefficient
diffusion coefficient and activation energy were determined using the Arrhenius equation Drying occurred in the falling rate phase and different models fit at different temperatures Calculated values of effective moisture diffusivity varied from 1 17-3 51x10-8 to 1 25-3 13x10-8 and activation energy varied from a maximum of 52 61KJ/mol in treated
Determination of the liquid water diffusivity from
An inter-laboratory comparison for analyzing the reliability of the determination method showed that the inaccuracy in the liquid water diffusivity is caused by scatter in the transformed data and by uncertainty in the boundary conditions at the intake surface and ahead of the steep moisture
Determination of Moisture Diffusivity During Drying of
Determination of Moisture Diffusivity During Drying of Mortar Cement: Experimental and Modeling Study: Language : English: Author co-author : Bennamoun Lyes [Universit de Lige - ULige Dpartement de chimie applique Gnie chimique -
Moisture sorption and diffusion determination of Chinese
Furthermore the initial rate of moisture sorption of Zexie Decoction granules was lower than those of powders and dextrin The EMC and moisture diffusion coefficients were reduced significantly after granulation (p0 01) Critical relative humidity and diffusion activation energy of granules were higer than powders Conclusion
Determination of effective moisture diffusivity and drying
Mar 01 2012In addition the effect of temperature on effective diffusivity can be described by an Arrhenius-type equation (Vega-Glvez et al 2009): (7) D eff = D 0 exp-E a R (T + 273 15) where D 0 is the pre-exponential factor of the Arrhenius equation (m 2 /s) E a is the activation energy for the moisture diffusion (kJ/mol) R is the ideal gas constant (J/mol K) and
Experimental Study of the Linear Diffusion of Water in
For wood water diffusivity is an important factor that influences its mechanical and physical properties In this experimental study the water absorption and desorption were investigated in linear directions for woods of two Eucalyptus clones Eucalyptus grandis and Eucalyptus camaldulensis The diffusion model based on Fick's second law was applied to assess both
Determination of moisture content of crude drugs
Moisture content determination is important not only to know excess water but also in conjunction with suitable temperature moisture will lead to the activation of enzymes Various methods for determination of moisture content are measurement of moisture chemical methods and spectroscopic methods as per IP
Modeling and Evaluation of Thermal Diffusivity and
Effective diffusivity was found to vary from 1 17exp (-7) to 10 0889exp(-7)m2/sec and activation energy was found to vary from 0 0525KJ/mole to 4 524742 KJ/mole These findings are being presented in this paper Keywords: moisture diffusivity activation energy moisture ratio drying time Cite This Article:
1 Introduction
In order to describe the effect of temperature on the effective moisture diffusivity the following Arrhenius-type equation was used [8 13]: (8) D e = D 0 e-E a / R T where D 0 is the preexponential factor or the diffusivity at infinite temperature (m 2 /s) E a is the activation energy (kJ mol −1) R is the universal gas constant (0 008314
Modeling moisture diffusivity activation energy and
May 28 2011Moisture diffusivity values decreased as the input air temperature decreased Activation energy values were found to be between 31 94 and 34 49 kJ/mol for 50 C to 80 C respectively The specific energy consumption for squash seeds was calculated at the boundary of 0 783 106and 2 303 106 kJ/kg
Determination of moisture diffusivity and activation
The moisture diffusivity and activation energy of three tilapia fish varieties were determined under convective drying process (CDP) A locally fabricated drying system was used for the experiment at 60 90/60 and 90 o C drying air temperatures The drying rate showed falling rate period for all the drying processes with no sign of constant rate period
Determination of the Bulk Moisture Diffusion Coefficient
The bulk moisture diffusion coefficient ( D b) is an important physical parameter of food ingredients and systems However the traditional method of measuring D b using saturated salt solutions is very time-consuming and cumbersome New automated water sorption instruments which can be used to conveniently and precisely control both relative humidity and
Determination of Concentration
One of the major mechanisms associated with gas injection to recover heavy oil is the molecular diffusion of gas which reduces the viscosity of heavy oil Numerous efforts have been made to estimate the diffusivity of such gas in heavy oil by assuming the gas diffusivity as a constant Meanwhile only limited attempts have been made to determine the concentration-dependent diffusivity
Energy efficiency and moisture diffusivity of apple slices
2 2 Determination of effective diffusivity (Deff) and activation energy (Ea) One dimensional diffusion is considered and Fick's diffusion equation is used for the simple analysis of the only diffusion-based thin layer drying equation (Demiray Tulek 2012)
DETERMINATION OF EFFECTIVE MOISTURE DIFFUSIVITY AND
The predicted values by the diffusion model based on Fick's second law were in good agreement with the experimental data obtained from the falling rate period The values of effective moisture diffusivity ranged from 9 60x10-9 to 2 26x10-8 m2/s and the activation energy was determined to be 21 2 kJ/mol
Determination of effective moisture diffusivity and
Determination of effective moisture diffusivity and activation energy for DRYING OF powdered peanut shell under isothermal conditions Dengyu Chen Kai Li and Xifeng Zhu * In this study the effect of drying temperature from 50 C to 90 C on the drying characteristics of powdered peanut shell was investigated and an isothermal procedure
An Inverse Moisture Diffusion Algorithm for the
moisture diffusion are the same it is only natural to use the same procedure to investigate the diffusion coefficient in a moisture sorption or desorption process of wood The only condition for such an application is that moisture variations with time and space in wood be known over the entire domain of






