Abdelmottaleb ouederni - Academia.edu (original) (raw)
Papers by Abdelmottaleb ouederni
Journal of Chemical Engineering & Process Technology, 2013
Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4 . Batch ... more Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4 . Batch adsorption of phenol from aqueous solution was investigated. The adsorptive properties were studied in terms of pH, equilibrium time, initial concentration (C 0 : 25-300 mg/L) and particle sizes (0.125-1.6mm) effects. The experimental kinetic data fitted well the pseudo second order model and the equilibrium isotherm data the Langmuir model. The results indicate that chemical olive stones activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solution.
Comptes Rendus Chimie, Sep 1, 2022
Hydrogen production by methane decomposition over Ni-doped activated carbons: effect of the activ... more Hydrogen production by methane decomposition over Ni-doped activated carbons: effect of the activation method
Journal of Porous Materials, 2017
of the carbon we obtained is 2.1 × 10 −3 wt% m −2 g which is very close to the theoretical maximu... more of the carbon we obtained is 2.1 × 10 −3 wt% m −2 g which is very close to the theoretical maximum hydrogen uptake density on a single graphene sheet. CO 2 and H 3 PO 4 activations are more effective on the creation of ultramicropores (d ≤ 0.7 nm) in the carbon matrix. This order of pore size is useful when hydrogen adsorption is performed at subatmospheric pressures. Our study suggests that activated carbons with a homogenous pore size distribution centered at narrow range are not as efficient H 2 adsorbents as the ACs with a bimodal PSD.
International Journal of Innovation and Applied Studies, Aug 2, 2014
Advanced oxidation, is the main of research in ozone fields for many years. Ozone generations and... more Advanced oxidation, is the main of research in ozone fields for many years. Ozone generations and uses as an oxidant and also the use of heterogeneous reactor were improve the de development of catalytic ozonation axes. The object of our project is the application of catalytic ozonation for some refractor molecules. Oxalic acid was chosen as a model of refractor molecules. In fact, it is the final product of the degradation by ozone of many organic molecules in aqueous solution. Ozonation have a significant effect on the mineralization of water charged with oxalic acid. In our experiences, the dioxide of manganese and titan and the oxide of cobalt were used as homogenous catalysts. Experiences of ozonation have been done in ambient conditions in a gas-liquid reactor with a capacity of 2 liters. Studies of ozone concentration, type and mass of catalysts and oxalic acid concentration have been done. With 1mmol/l of oxalic acid solution and 43mg/l of ozone, we obtained 50% of maximal oxidation report after 20min. the addition of 1g of MnO2 to the solution in the reactor changed the same report to 85% after 5min. a comparison between MnO2, TiO2 and CoO was done and results prove that the oxide of cobalt is more efficient than the two other catalyst. However, with the same mass added to the reactor 500 mg for each catalyst, the rate of conversion obtained with MnO2 and CoO was nearly 95% and 90% with TiO2 but the kinetic of CoO is faster than the two other catalysts.
Journal of Chemical Engineering & Process Technology, 2013
In this work the ability of olive stone activated carbon (COSAC) to remove Pb(II), Cd(II), Ni(II)... more In this work the ability of olive stone activated carbon (COSAC) to remove Pb(II), Cd(II), Ni(II) and Cu(II) metal ions from aqueous solutions was evaluated. The effect of initial pH, contact time and initial concentration on metal ions adsorption was investigated. The results indicated that pH 5 is the optimum value for metal removal. Adsorption kinetic rates were found to be fast; total equilibrium was achieved after 4 hours. Kinetic experimental data fitted very well the pseudo-second order equation and the values of adsorption rate constants were calculated. The equilibrium isotherms were evaluated in terms of maximum adsorption capacity and adsorption affinity by the application of Langmuir and Freundlich equations. Results indicate that the Langmuir model fits adsorption isotherm data better than the Freundlich model. The removal efficiency of heavy metal ions by COSAC decreases in the order Pb(II) > Cd(II) > Ni(II) ≥ Cu(II).
Chinese Journal of Chemical Engineering, 2013
In this work we investigated the effect of nitric acid concentration on the pore structure, surfa... more In this work we investigated the effect of nitric acid concentration on the pore structure, surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents. Chemicals and textural characterization show that the increase of HNO 3 concentration increases considerably the total acidic groups but decreases specific surface area and pore volume. The study of adsorption in aqueous solutions of two organics, phenol and methylene blue, on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO 3 concentrations less or equal to 2 mol•L 1 , while it has a negative effect on phenol adsorption.
Biosorption of Lead Heavy Metal on Prickly Pear Cactus Biomaterial: Kinetic, Thermodynamic and Regeneration Studies
Cellulose Chemistry and Technology
The potential of Tunisian prickly pear cactus as a low-cost adsorbent for Pb(II) ions from aqueou... more The potential of Tunisian prickly pear cactus as a low-cost adsorbent for Pb(II) ions from aqueous solution was investigated in batch mode. To determine the optimum adsorption conditions, experiments were conducted varying the operating parameters, as follows: pH of the solutions (2-10), initial concentration of metal ions (0.98-2.4 mmol/L) and temperature (30-60 °C). The adsorption isotherm data were analyzed by applying the Langmuir, Freundlich, Dubinin–Raduskevich, Temkin and Redlich–Peterson models. The experimental results were better fitted by the Freundlish model. The pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models were applied to the description of the kinetic data. The best fit was achieved for the pseudo-second order model, and the presence of both film and intraparticle diffusion mechanisms was demonstrated. Thermodynamic studies indicated that the biosorption on the cladode powder is an exothermic and chemical process. The desorption/r...
Effet de la teneur en oxygène des carbones activés sur leur capacité de stockage de l’hydrogène à température ambiante
Adsorption of dyes onto activated carbon prepared from olive stones
Journal of environmental sciences, 2005
Activated carbon was produced from olive stones(OSAC) by a physical process in two steps. The ads... more Activated carbon was produced from olive stones(OSAC) by a physical process in two steps. The adsorption character of this activated carbon was tested on three colour dyes molecules in aqueous solution: Methylene blue (MB), Rhodamine B (RB) and Congo Red(CR). The adsorption equilibrium was studied through isotherms construction at 30 degrees C, which were well described by Langmuir model. The adsorption capacity on the OSAC was estimated to be 303 mg/g, 217 mg/g and 167 mg/g respectively for MB, RB and CR. This activated carbon has a similar adsorption properties to that of commercial ones and show the same adsorption performances. The adsorption kinetics of the MB molecule in aqueous solution at different initial concentrations by OSAC was also studied. Kinetic experiments were well fitted by a simple intra-particle diffusion model. The measured kinetics constant was influenced by the initial concentration and we found the following correlation: Kid = 1.55 C0(0.51).
Received March 12, 2016; Accepted September 12, 2016 Abstract: Activated carbon based pomegranate... more Received March 12, 2016; Accepted September 12, 2016 Abstract: Activated carbon based pomegranate peels with potassium hydroxide as activating agent has been undertaken in the present study. Experiments were conducted to investigate the influence of different process parameters: the impregnation ratio, the temperature and the time of activation, followed by optimization. Activated carbon prepared in the optimum conditions with high specific surface area of 1403 mg and total pore volume of 0.7 cmg was evaluated for its ability to remove the 2-Nitrophenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 100-500 mg/L initial 2-Nitrophenol concentrations at temperature of 30°C. The experimental data were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The kinetic models studies were also conducted. The pseudo-second order equation was the best applicable model to describe the adsorption process of 2-Nitrophenol onto optimiz...
Thermal degradation of Tunisian olive stones using thermogravimetric analysis (TGA)
The aim of this paper is to study of the thermal degradation of Tunisian olive stones by non-isot... more The aim of this paper is to study of the thermal degradation of Tunisian olive stones by non-isothermal thermogravimetric analysis (TGA) device, under nitrogen atmosphere. Thermogravimetric analysis of different particles sizes (0.63-2.5mm) was evaluated. The effect of heating rates has been performed. Results showed that particles sizes don't have any effect on the pyrolysis of olive stones whereas the decomposition process is shifted to higher temperature zone with heating rate increasing. Three different kinetic models, the iso-conversional; kissinger-Akahira-Sunose, Ozawa-Flynn-Wall methods and Coats Redfern model were applied on TGA data of olive stones (OS) to calculate the kinetic parameters including activation energy, pre-exponential factor and reaction order. Simulation of olive stones pyrolysis using data obtained from TGA analysis showed good agreement with experimental data for all models. The dependence of the apparent activation energy determined using kissinger-A...
Nickel and copper supported activated carbon (Ni/AC,Cu/AC) prepared by wetness impregnation proce... more Nickel and copper supported activated carbon (Ni/AC,Cu/AC) prepared by wetness impregnation process were used in the heterogeneous ozonation of nitrobenzene in water. The effect of the preparation conditions on catalysts characteristics was examined in order to optimize the metals content, the temperature and the calcination time. The two catalysts were characterized on the ground of Brunauer-Emmett-Teller adsorption isotherm application, through Fourier transform infrared spectroscopy, temperature programmed-desorption mass spectrometry, Boehm analysis and point of zero charge analysis. It was found that the catalyst properties and the functional surface groups were affected by the operating conditions. The maximum specific surface area of the catalysts was obtained when 12 % (w/w) of Cu or 4 % (w/w) of Ni were deposited on activated carbon and calcined at 550°C for 2 h. The effect of Cu and Ni addition to the activated carbon on nitrobenzene adsorption capacity was also examined. ...
Comptes Rendus. Chimie
This study aims to investigate the thermal behaviour of raw and phosphoric acid impregnated olive... more This study aims to investigate the thermal behaviour of raw and phosphoric acid impregnated olive stones via coupled thermogravimetric analysis-Mass spectrometry (TGA-MS) during pyrolysis. The impregnated material was prepared at three H 3 PO 4 /precursor weight ratio of 0.5; 1 and 1.5; for various impregnation time of 3, 6 and 9 h, which was then subjected for thermal analysis. TGA profiles were obtained under dynamic conditions in temperature range 25°C to 750°C with a heating rate of 10°C/min, using pure nitrogen as an inert gas. Thermal degradation of olive stones was observed in three stages namely dehydration, active and passive pyrolysis. Two-steps degradation of raw olive stone occurred, whereas the impregnated material displayed only one step. Addition of phosphoric acid sharply reduced the onset temperature of the main decomposition step. Onset temperatures decreased with increasing rate or time of impregnation. It could conclude that 3 h is sufficient as time of impregnation for activated carbon production. Examination of the main gas products were carried out using coupled TGA-MS. The principal permanent gases detected were H 2 , H 2 O, CO, CO 2 and the light hydrocarbons C 2 H 6 and CH 4. Different kinetic scenarios of raw and impregnated olive stones were observed. The above results should be useful to understand the pyrolysis mechanism of phosphoric acid impregnated olive stone for improving activated carbon production.
Hydrogen sulfide removal from the waste gas of phosphoric acid plant
Environmental Progress & Sustainable Energy
CO2 activation of olive bagasse for hydrogen storage
Environmental Progress & Sustainable Energy, 2016
Hydrogen is considered as the most promising future fuel, as its combustion generates only water ... more Hydrogen is considered as the most promising future fuel, as its combustion generates only water vapor besides energy. However, finding efficient, safe and low-cost storage methods is the basic impediment for the adoption of hydrogen as fuel. For this purpose, an ultramicroporous activated carbon was successfully synthesized from low-cost biomass residues; olive bagasse. The carbon material was prepared throw physical activation, using carbon dioxide as activating agent, under controlled thermal conditions. Then, it was tested as hydrogen storage material at cryogenic and room temperature conditions. The textural characterizations showed a highly tailored porous texture adequate for gas adsorption. The totality of the created microporosity is of narrow range (d < 0.7 nm). Interestingly, the measured median pore width was about 0.65 nm, likely the optimum pore size for hydrogen adsorption. This feature accorded the AC with exceptional H2 storage capacity, achieving 3.34 wt % at liquid nitrogen temperature. It has outperformed Zeolites and MOFs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 315–324, 2017
Optimization of biomass-based carbon materials for hydrogen storage
IREC2015 The Sixth International Renewable Energy Congress, 2015
Five biomass-based carbon samples have been successfully prepared through KOH activation procedur... more Five biomass-based carbon samples have been successfully prepared through KOH activation procedure. The microstructure of the prepared materials was tuned by varying KOH/precursor weight ratio from 1:1 to 5:1, in order to optimize their hydrogen storage behavior and to clarify the storage mechanism. A careful physic-chemical characterization of the prepared sample (N2 and CO2 adsorption, X-ray diffraction, electron microscopy observations) showed that by increasing the activation ratio the nature of the carbons changes from microporous to micro-mesoporous. Thus, an increase in the surface area was observed which enhanced H2 sorption capacity when high H2 pressures were adopted (25-200 bar). At subatmospheric pressure, the role of active sites for H2 adsorption, located in the oriented graphene sheets, was clearly elaborated. Finally, the optimal carbon sample has shown a capacity of 6wt% and 1.22 wt% at -196°C and 25°C respectively, and 200 bar. These results make biomass-based carbons promising materials for H2 storage application.
Journal of Chemical Engineering & Process Technology, 2013
This study consists on developing a model of internal diffusion with adsorption in a porous parti... more This study consists on developing a model of internal diffusion with adsorption in a porous particle in order to estimate its effective diffusivity. For this purpose, the particle is put in suspension in an isothermal perfectly agitated reactor in transient state (closed system). The adopted model is based on the adsorption equilibrium on the internal porous surface and assumes that the external concentration varies with time in the external transfer resistance absence. The proposed model equations are numerically solved using the finite differences technique. Experimental concentration profiles of adsorption of dyes either on a commercial activated carbon are smoothed to suit the proposed model. A good agreement between experimental theory profiles is obtained.
Removal of Color and Organic Matter in Industrial Phosphoric Acid by Ozone: Effect on Activated Carbon Treatment
Ozone: Science & Engineering, 1995
Abstract Industrial phosphoric acid at 42-45% P2O5 and containing organic matter (OM) in the rang... more Abstract Industrial phosphoric acid at 42-45% P2O5 and containing organic matter (OM) in the range of 220 mg/L to 300 mg/L is treated by combined ozonation and activated carbon. Ozonation alone removes the initial dark color of the acid and eliminates the organic content. Adsorption on activated carbon alone can reduce OM levels by 80% for more than 25 g/kg P2O5. We find that a preozonation noticeably enhances activated carbon efficiency and reduces its specific consumption. Isoconversion curves are plotted in specific ozone and activated carbon ratio space.
Activated carbon from olive stones by a two step process: influence of production parameters on textural characteristics
Annales de Chimie Science des Matériaux, 2006
Charbon actif produit a partir des grignons d'olive selon un procede en deux etapes: influenc... more Charbon actif produit a partir des grignons d'olive selon un procede en deux etapes: influence des parametres operatoires sur les caracteristiques texturales. Les noyaux des olives, sous- produit des huileries du Sud de la Tunisie, broyes pour avoir une granulometrie de 1,25 a 4,00 mm, sont utilises comme precurseur pour la fabrication d'un charbon actif. La matiere premiere est d'abord carbonisee dans un reacteur a lit fixe par effet thermique sous atmosphere d'azote. Le suivi de la surface specifique par la methode BET a l'azote montre qu'une carbonisation durant 2 heures a 600°C conduit a un intermediaire avec des caracteristiques optimales pour l'activation ulterieure soit une surface specifique de 240 m 2 / g et un volume des micropores de 0,12 cm 3 /g. L'analyse thermogravimetrique de l'etape de carbonisation fait apparaitre trois groupes de reactions avec des pics a 280°C et 320°C ainsi qu'une longue phase qui s'etend au dela de 400°C. Dans la seconde etape du procede, le solide intermediaire est active a haute temperature par un courant d'azote charge de vapeur d'eau. L'elevation de la teneur en vapeur d'eau est favorable au processus d'activation. Un accroissement de la temperature ou du temps de sejour se traduit par une augmentation de la surface specifique ainsi que du volume des micropores et du volume total des pores. Cependant, on note un developpement relativement important des mesopores. L'experience montre aussi l'existence de conditions optimales de temperature et de temps de sejour dans l'etape d'activation qui conduisent aux meilleures caracteristiques structurales. En effet, une temperature de 700°C, pour une duree d'activation de 8 heures sous un courant d'azote a 70% de vapeur, conduit a un charbon actif presentant une surface specifique de 789 m 2 /g et 1122 m 2 /g, calcules respectivement par les methodes BET et Langmuir. Dans ces conditions, le charbon actif produit a un volume des micropores de 0,34 cm 3 /g et un volume total des pores de 0,63 cm 3 /g. Le volume des micropores et le volume des mesopores augmentent avec le temps de sejour; cependant le developpement du volume des mesopores est plus important.
Hydrogen adsorption on HTC-Activated carbon
Journal of Chemical Engineering & Process Technology, 2013
Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4 . Batch ... more Activated carbon is prepared with chemical activation of olive stones, by using H 3 PO 4 . Batch adsorption of phenol from aqueous solution was investigated. The adsorptive properties were studied in terms of pH, equilibrium time, initial concentration (C 0 : 25-300 mg/L) and particle sizes (0.125-1.6mm) effects. The experimental kinetic data fitted well the pseudo second order model and the equilibrium isotherm data the Langmuir model. The results indicate that chemical olive stones activated carbon is suitable to be used as an adsorbent material for adsorption of phenol from aqueous solution.
Comptes Rendus Chimie, Sep 1, 2022
Hydrogen production by methane decomposition over Ni-doped activated carbons: effect of the activ... more Hydrogen production by methane decomposition over Ni-doped activated carbons: effect of the activation method
Journal of Porous Materials, 2017
of the carbon we obtained is 2.1 × 10 −3 wt% m −2 g which is very close to the theoretical maximu... more of the carbon we obtained is 2.1 × 10 −3 wt% m −2 g which is very close to the theoretical maximum hydrogen uptake density on a single graphene sheet. CO 2 and H 3 PO 4 activations are more effective on the creation of ultramicropores (d ≤ 0.7 nm) in the carbon matrix. This order of pore size is useful when hydrogen adsorption is performed at subatmospheric pressures. Our study suggests that activated carbons with a homogenous pore size distribution centered at narrow range are not as efficient H 2 adsorbents as the ACs with a bimodal PSD.
International Journal of Innovation and Applied Studies, Aug 2, 2014
Advanced oxidation, is the main of research in ozone fields for many years. Ozone generations and... more Advanced oxidation, is the main of research in ozone fields for many years. Ozone generations and uses as an oxidant and also the use of heterogeneous reactor were improve the de development of catalytic ozonation axes. The object of our project is the application of catalytic ozonation for some refractor molecules. Oxalic acid was chosen as a model of refractor molecules. In fact, it is the final product of the degradation by ozone of many organic molecules in aqueous solution. Ozonation have a significant effect on the mineralization of water charged with oxalic acid. In our experiences, the dioxide of manganese and titan and the oxide of cobalt were used as homogenous catalysts. Experiences of ozonation have been done in ambient conditions in a gas-liquid reactor with a capacity of 2 liters. Studies of ozone concentration, type and mass of catalysts and oxalic acid concentration have been done. With 1mmol/l of oxalic acid solution and 43mg/l of ozone, we obtained 50% of maximal oxidation report after 20min. the addition of 1g of MnO2 to the solution in the reactor changed the same report to 85% after 5min. a comparison between MnO2, TiO2 and CoO was done and results prove that the oxide of cobalt is more efficient than the two other catalyst. However, with the same mass added to the reactor 500 mg for each catalyst, the rate of conversion obtained with MnO2 and CoO was nearly 95% and 90% with TiO2 but the kinetic of CoO is faster than the two other catalysts.
Journal of Chemical Engineering & Process Technology, 2013
In this work the ability of olive stone activated carbon (COSAC) to remove Pb(II), Cd(II), Ni(II)... more In this work the ability of olive stone activated carbon (COSAC) to remove Pb(II), Cd(II), Ni(II) and Cu(II) metal ions from aqueous solutions was evaluated. The effect of initial pH, contact time and initial concentration on metal ions adsorption was investigated. The results indicated that pH 5 is the optimum value for metal removal. Adsorption kinetic rates were found to be fast; total equilibrium was achieved after 4 hours. Kinetic experimental data fitted very well the pseudo-second order equation and the values of adsorption rate constants were calculated. The equilibrium isotherms were evaluated in terms of maximum adsorption capacity and adsorption affinity by the application of Langmuir and Freundlich equations. Results indicate that the Langmuir model fits adsorption isotherm data better than the Freundlich model. The removal efficiency of heavy metal ions by COSAC decreases in the order Pb(II) > Cd(II) > Ni(II) ≥ Cu(II).
Chinese Journal of Chemical Engineering, 2013
In this work we investigated the effect of nitric acid concentration on the pore structure, surfa... more In this work we investigated the effect of nitric acid concentration on the pore structure, surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents. Chemicals and textural characterization show that the increase of HNO 3 concentration increases considerably the total acidic groups but decreases specific surface area and pore volume. The study of adsorption in aqueous solutions of two organics, phenol and methylene blue, on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO 3 concentrations less or equal to 2 mol•L 1 , while it has a negative effect on phenol adsorption.
Biosorption of Lead Heavy Metal on Prickly Pear Cactus Biomaterial: Kinetic, Thermodynamic and Regeneration Studies
Cellulose Chemistry and Technology
The potential of Tunisian prickly pear cactus as a low-cost adsorbent for Pb(II) ions from aqueou... more The potential of Tunisian prickly pear cactus as a low-cost adsorbent for Pb(II) ions from aqueous solution was investigated in batch mode. To determine the optimum adsorption conditions, experiments were conducted varying the operating parameters, as follows: pH of the solutions (2-10), initial concentration of metal ions (0.98-2.4 mmol/L) and temperature (30-60 °C). The adsorption isotherm data were analyzed by applying the Langmuir, Freundlich, Dubinin–Raduskevich, Temkin and Redlich–Peterson models. The experimental results were better fitted by the Freundlish model. The pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models were applied to the description of the kinetic data. The best fit was achieved for the pseudo-second order model, and the presence of both film and intraparticle diffusion mechanisms was demonstrated. Thermodynamic studies indicated that the biosorption on the cladode powder is an exothermic and chemical process. The desorption/r...
Effet de la teneur en oxygène des carbones activés sur leur capacité de stockage de l’hydrogène à température ambiante
Adsorption of dyes onto activated carbon prepared from olive stones
Journal of environmental sciences, 2005
Activated carbon was produced from olive stones(OSAC) by a physical process in two steps. The ads... more Activated carbon was produced from olive stones(OSAC) by a physical process in two steps. The adsorption character of this activated carbon was tested on three colour dyes molecules in aqueous solution: Methylene blue (MB), Rhodamine B (RB) and Congo Red(CR). The adsorption equilibrium was studied through isotherms construction at 30 degrees C, which were well described by Langmuir model. The adsorption capacity on the OSAC was estimated to be 303 mg/g, 217 mg/g and 167 mg/g respectively for MB, RB and CR. This activated carbon has a similar adsorption properties to that of commercial ones and show the same adsorption performances. The adsorption kinetics of the MB molecule in aqueous solution at different initial concentrations by OSAC was also studied. Kinetic experiments were well fitted by a simple intra-particle diffusion model. The measured kinetics constant was influenced by the initial concentration and we found the following correlation: Kid = 1.55 C0(0.51).
Received March 12, 2016; Accepted September 12, 2016 Abstract: Activated carbon based pomegranate... more Received March 12, 2016; Accepted September 12, 2016 Abstract: Activated carbon based pomegranate peels with potassium hydroxide as activating agent has been undertaken in the present study. Experiments were conducted to investigate the influence of different process parameters: the impregnation ratio, the temperature and the time of activation, followed by optimization. Activated carbon prepared in the optimum conditions with high specific surface area of 1403 mg and total pore volume of 0.7 cmg was evaluated for its ability to remove the 2-Nitrophenol from an aqueous solution in a batch process. Equilibrium studies were conducted in the range of 100-500 mg/L initial 2-Nitrophenol concentrations at temperature of 30°C. The experimental data were analyzed by the Langmuir, Freundlich and Temkin isotherm models. The kinetic models studies were also conducted. The pseudo-second order equation was the best applicable model to describe the adsorption process of 2-Nitrophenol onto optimiz...
Thermal degradation of Tunisian olive stones using thermogravimetric analysis (TGA)
The aim of this paper is to study of the thermal degradation of Tunisian olive stones by non-isot... more The aim of this paper is to study of the thermal degradation of Tunisian olive stones by non-isothermal thermogravimetric analysis (TGA) device, under nitrogen atmosphere. Thermogravimetric analysis of different particles sizes (0.63-2.5mm) was evaluated. The effect of heating rates has been performed. Results showed that particles sizes don't have any effect on the pyrolysis of olive stones whereas the decomposition process is shifted to higher temperature zone with heating rate increasing. Three different kinetic models, the iso-conversional; kissinger-Akahira-Sunose, Ozawa-Flynn-Wall methods and Coats Redfern model were applied on TGA data of olive stones (OS) to calculate the kinetic parameters including activation energy, pre-exponential factor and reaction order. Simulation of olive stones pyrolysis using data obtained from TGA analysis showed good agreement with experimental data for all models. The dependence of the apparent activation energy determined using kissinger-A...
Nickel and copper supported activated carbon (Ni/AC,Cu/AC) prepared by wetness impregnation proce... more Nickel and copper supported activated carbon (Ni/AC,Cu/AC) prepared by wetness impregnation process were used in the heterogeneous ozonation of nitrobenzene in water. The effect of the preparation conditions on catalysts characteristics was examined in order to optimize the metals content, the temperature and the calcination time. The two catalysts were characterized on the ground of Brunauer-Emmett-Teller adsorption isotherm application, through Fourier transform infrared spectroscopy, temperature programmed-desorption mass spectrometry, Boehm analysis and point of zero charge analysis. It was found that the catalyst properties and the functional surface groups were affected by the operating conditions. The maximum specific surface area of the catalysts was obtained when 12 % (w/w) of Cu or 4 % (w/w) of Ni were deposited on activated carbon and calcined at 550°C for 2 h. The effect of Cu and Ni addition to the activated carbon on nitrobenzene adsorption capacity was also examined. ...
Comptes Rendus. Chimie
This study aims to investigate the thermal behaviour of raw and phosphoric acid impregnated olive... more This study aims to investigate the thermal behaviour of raw and phosphoric acid impregnated olive stones via coupled thermogravimetric analysis-Mass spectrometry (TGA-MS) during pyrolysis. The impregnated material was prepared at three H 3 PO 4 /precursor weight ratio of 0.5; 1 and 1.5; for various impregnation time of 3, 6 and 9 h, which was then subjected for thermal analysis. TGA profiles were obtained under dynamic conditions in temperature range 25°C to 750°C with a heating rate of 10°C/min, using pure nitrogen as an inert gas. Thermal degradation of olive stones was observed in three stages namely dehydration, active and passive pyrolysis. Two-steps degradation of raw olive stone occurred, whereas the impregnated material displayed only one step. Addition of phosphoric acid sharply reduced the onset temperature of the main decomposition step. Onset temperatures decreased with increasing rate or time of impregnation. It could conclude that 3 h is sufficient as time of impregnation for activated carbon production. Examination of the main gas products were carried out using coupled TGA-MS. The principal permanent gases detected were H 2 , H 2 O, CO, CO 2 and the light hydrocarbons C 2 H 6 and CH 4. Different kinetic scenarios of raw and impregnated olive stones were observed. The above results should be useful to understand the pyrolysis mechanism of phosphoric acid impregnated olive stone for improving activated carbon production.
Hydrogen sulfide removal from the waste gas of phosphoric acid plant
Environmental Progress & Sustainable Energy
CO2 activation of olive bagasse for hydrogen storage
Environmental Progress & Sustainable Energy, 2016
Hydrogen is considered as the most promising future fuel, as its combustion generates only water ... more Hydrogen is considered as the most promising future fuel, as its combustion generates only water vapor besides energy. However, finding efficient, safe and low-cost storage methods is the basic impediment for the adoption of hydrogen as fuel. For this purpose, an ultramicroporous activated carbon was successfully synthesized from low-cost biomass residues; olive bagasse. The carbon material was prepared throw physical activation, using carbon dioxide as activating agent, under controlled thermal conditions. Then, it was tested as hydrogen storage material at cryogenic and room temperature conditions. The textural characterizations showed a highly tailored porous texture adequate for gas adsorption. The totality of the created microporosity is of narrow range (d < 0.7 nm). Interestingly, the measured median pore width was about 0.65 nm, likely the optimum pore size for hydrogen adsorption. This feature accorded the AC with exceptional H2 storage capacity, achieving 3.34 wt % at liquid nitrogen temperature. It has outperformed Zeolites and MOFs. © 2016 American Institute of Chemical Engineers Environ Prog, 36: 315–324, 2017
Optimization of biomass-based carbon materials for hydrogen storage
IREC2015 The Sixth International Renewable Energy Congress, 2015
Five biomass-based carbon samples have been successfully prepared through KOH activation procedur... more Five biomass-based carbon samples have been successfully prepared through KOH activation procedure. The microstructure of the prepared materials was tuned by varying KOH/precursor weight ratio from 1:1 to 5:1, in order to optimize their hydrogen storage behavior and to clarify the storage mechanism. A careful physic-chemical characterization of the prepared sample (N2 and CO2 adsorption, X-ray diffraction, electron microscopy observations) showed that by increasing the activation ratio the nature of the carbons changes from microporous to micro-mesoporous. Thus, an increase in the surface area was observed which enhanced H2 sorption capacity when high H2 pressures were adopted (25-200 bar). At subatmospheric pressure, the role of active sites for H2 adsorption, located in the oriented graphene sheets, was clearly elaborated. Finally, the optimal carbon sample has shown a capacity of 6wt% and 1.22 wt% at -196°C and 25°C respectively, and 200 bar. These results make biomass-based carbons promising materials for H2 storage application.
Journal of Chemical Engineering & Process Technology, 2013
This study consists on developing a model of internal diffusion with adsorption in a porous parti... more This study consists on developing a model of internal diffusion with adsorption in a porous particle in order to estimate its effective diffusivity. For this purpose, the particle is put in suspension in an isothermal perfectly agitated reactor in transient state (closed system). The adopted model is based on the adsorption equilibrium on the internal porous surface and assumes that the external concentration varies with time in the external transfer resistance absence. The proposed model equations are numerically solved using the finite differences technique. Experimental concentration profiles of adsorption of dyes either on a commercial activated carbon are smoothed to suit the proposed model. A good agreement between experimental theory profiles is obtained.
Removal of Color and Organic Matter in Industrial Phosphoric Acid by Ozone: Effect on Activated Carbon Treatment
Ozone: Science & Engineering, 1995
Abstract Industrial phosphoric acid at 42-45% P2O5 and containing organic matter (OM) in the rang... more Abstract Industrial phosphoric acid at 42-45% P2O5 and containing organic matter (OM) in the range of 220 mg/L to 300 mg/L is treated by combined ozonation and activated carbon. Ozonation alone removes the initial dark color of the acid and eliminates the organic content. Adsorption on activated carbon alone can reduce OM levels by 80% for more than 25 g/kg P2O5. We find that a preozonation noticeably enhances activated carbon efficiency and reduces its specific consumption. Isoconversion curves are plotted in specific ozone and activated carbon ratio space.
Activated carbon from olive stones by a two step process: influence of production parameters on textural characteristics
Annales de Chimie Science des Matériaux, 2006
Charbon actif produit a partir des grignons d'olive selon un procede en deux etapes: influenc... more Charbon actif produit a partir des grignons d'olive selon un procede en deux etapes: influence des parametres operatoires sur les caracteristiques texturales. Les noyaux des olives, sous- produit des huileries du Sud de la Tunisie, broyes pour avoir une granulometrie de 1,25 a 4,00 mm, sont utilises comme precurseur pour la fabrication d'un charbon actif. La matiere premiere est d'abord carbonisee dans un reacteur a lit fixe par effet thermique sous atmosphere d'azote. Le suivi de la surface specifique par la methode BET a l'azote montre qu'une carbonisation durant 2 heures a 600°C conduit a un intermediaire avec des caracteristiques optimales pour l'activation ulterieure soit une surface specifique de 240 m 2 / g et un volume des micropores de 0,12 cm 3 /g. L'analyse thermogravimetrique de l'etape de carbonisation fait apparaitre trois groupes de reactions avec des pics a 280°C et 320°C ainsi qu'une longue phase qui s'etend au dela de 400°C. Dans la seconde etape du procede, le solide intermediaire est active a haute temperature par un courant d'azote charge de vapeur d'eau. L'elevation de la teneur en vapeur d'eau est favorable au processus d'activation. Un accroissement de la temperature ou du temps de sejour se traduit par une augmentation de la surface specifique ainsi que du volume des micropores et du volume total des pores. Cependant, on note un developpement relativement important des mesopores. L'experience montre aussi l'existence de conditions optimales de temperature et de temps de sejour dans l'etape d'activation qui conduisent aux meilleures caracteristiques structurales. En effet, une temperature de 700°C, pour une duree d'activation de 8 heures sous un courant d'azote a 70% de vapeur, conduit a un charbon actif presentant une surface specifique de 789 m 2 /g et 1122 m 2 /g, calcules respectivement par les methodes BET et Langmuir. Dans ces conditions, le charbon actif produit a un volume des micropores de 0,34 cm 3 /g et un volume total des pores de 0,63 cm 3 /g. Le volume des micropores et le volume des mesopores augmentent avec le temps de sejour; cependant le developpement du volume des mesopores est plus important.
Hydrogen adsorption on HTC-Activated carbon