Entity

Time filter

Source Type


Touil A.,Institute Superieur Des Etudes Technologiques Of Zaghouan | Chemkhi S.,Center Recherches Et Technologies Of Lenergie | Zagrouba F.,Institute Superieur Des Science Et Technologies Of Lenvironnement
International Journal of Food Engineering | Year: 2010

The effect of the drying rates of fruit and cladode of Opuntia Ficus Indica was examined at different temperatures. The experimental drying curves show only a falling drying rate period. The values of drying rate of prickly pear (fruit and cladode) almost doubled when the drying temperature was increased from 40 to 60°C. The experimental drying data were applied to various drying equation (Logarithmic; Wang and Singh, Henderson and Pabis, MMF model and Midilli equation). Midilli equation was optimal for characterizing drying behaviour of prickly pear for the whole range of temperature with a correlation coefficient of 99.99% for the fruit and the cladode and a standard error of 0.0015 for the fruit and 0.0017 for the cladode. Copyright © 2010 The Berkeley Electronic Press. All rights reserved.


Attour A.,Institute Superieur Des Science Et Technologies Of Lenvironnement | Lapicque F.,CNRS Reactions and Process Engineering Laboratory | Leclerc J.-P.,CNRS Reactions and Process Engineering Laboratory
Desalination and Water Treatment | Year: 2015

This paper discusses two possible ways of intensifying the electrocoagulation treatment of water containing phosphate. The first one consists of controlling the chemical composition of the water by continuous adjustment of the pH. The second aspect focuses on electrode connection modes, and the four different modes were tested monopolar in series, in parallels and independents, and finally bipolar. Experiments were conducted in a small batch reactor containing water with 100 mg P/L using electrodes of aluminum. Several electrical connections were used for the water treatment under favorable operating conditions determined by a study and presented in a previous paper. The influence of pH adjustment was conducted using different adjustment step times (no adjustment, every 30, 10 and 5 min). The kinetics of the treatment was found to be accelerated by continuous adjustment of the pH. The choice of the electrode connection modes was found to strongly affect the efficiency of the treatment, the Faradic yield, and the consumption of energy. The monopolar in parallels connection mode was found to be the most economic, whereas bipolar in parallels was found to favor a higher kinetic rate of treatment. © 2015 Balaban Desalination Publications. All rights reserved.


Chouchene A.,Laboratoire Gestion des Risques et Environnement | Chouchene A.,Laboratoire dEnergetique et des Procedes Thermiques | Jeguirim M.,Laboratoire Gestion des Risques et Environnement | Khiari B.,Laboratoire dEnergetique et des Procedes Thermiques | And 2 more authors.
Resources, Conservation and Recycling | Year: 2010

The aim of this work is to study the effect of the particle size and the oxygen content on the thermal degradation of olive solid waste (OSW). Thermogravimetric analyses of different particles sizes (0.5-2.8 mm in diameter) were performed. Three different atmospheres were used: on the one hand, an inert atmosphere (N2) in order to study the pyrolysis of the olive solid waste and on the other hand two oxidative atmosphere (10% O2/N2; 20% O2/N2). Pyrolysis under oxidative conditions (10% O2/N2; 20% O2/N2) takes place according to three stages: drying, volatiles emission and char oxidation whereas in the case of pyrolysis under inert conditions only the two first stages occur. Loss of humidity and volatiles are independent of the oxygen concentration. However, the initial temperature of char oxidation is decreasing with the increase of oxygen concentration. Weight loss profiles as well as CO and CO2 emission rates during the oxidative pyrolysis are depending on the particle size of OSW. In fact, thermal degradation and emission rates of carbon oxides emissions proceed at lower temperatures for the smallest particle size. The temperature ranges of volatilization and char oxidation as well as the amount of remaining ash are also depending on the particle size. Reaction kinetic parameters are obtained under inert and oxidative conditions using global independent reactions model and compared with other biomass. Activation energy and preexponential factor of the devolatilization step increase with oxygen concentration. However, the reaction order was not affected by the variation of the oxygen concentration and the particle size with a value between 0.6 and 0.8. © 2009 Elsevier B.V. All rights reserved.


Chemkhi S.,Center Recherches Et Technologies Of Lenergie | Zagrouba F.,Institute Superieur Des Science Et Technologies Of Lenvironnement
International Journal of Food Engineering | Year: 2011

In this study, we are interested in a thermo-physic characterisation during hot air drying of one food product: the potato. The drying kinetics of potato slices are determined at three temperatures and three air velocities. The evolution of the density and the material shrinkage are determined and commented. We finish with the equilibrium moisture relations for the product. From experimental data, we have modeled the desorption isotherms using the GAB model. From the results, we notice that this model perfectly describes the measures with correlation factors superior to 97%. A thermodynamic analysis of isotherms has been made: the heat of sorption is calculated; the entropy of sorption has also been determined and has been commented. ©2011 Berkeley Electronic Press. All rights reserved.


Attour A.,Institute Superieur Des Science Et Technologies Of Lenvironnement | Lapicque F.,CNRS Reactions and Process Engineering Laboratory | Leclerc J.-P.,CNRS Reactions and Process Engineering Laboratory
Separation and Purification Technology | Year: 2014

Treatment of water containing phosphate by electrocoagulation has been studied in a laboratory batch reactor. The effect of operating parameters on both phosphate removal efficiency and pH evolution has been investigated. Influence of distance between electrodes, current density, initial pH, temperature and conductivity has been extensively studied in a wide range of values. The results show that the removal efficiency depends on the electrical charges; the same efficiency is obtained with low current density with long time of treatment, or higher current intensity with short treatment time. The time evolution of the pH during the treatment strongly depends on the operating conditions but the final pH is more or less the same due to the buffering effect of Al(OH)3/Al(OH)4- mixture. Effects of the temperature, often disregarded in the literature shows that treatment rate is strongly increased with temperature whereas conductivity near 1 mS/cm is enough to ensure reasonable treatment rate. The electrical energy consumption (around 4 Kw/m 3) is acceptable to achieve 90% of conversion but lower current density is preferable because of the lower voltage drop. © 2014 Elsevier Ltd. All rights reserved.

Discover hidden collaborations