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Aouad A. Bilali L. Benchanâa M. Mokhlisse A. 《Journal of Thermal Analysis and Calorimetry》2002,67(3):733-743
The natural phosphate and its demineralization products from Moroccan deposit were pyrolysed in a thermogravimetric analyser
(TG) to examine the influence of the heating rate and mineral matter on their thermal decomposition. The heating rates investigated
in the TG were 5–100°C min−1 to final temperature of 1200°C. The integral method was used in the analysis of the TG to determine the kinetic parameters.
It has been found that for the natural phosphate and corresponding kerogen analysed in the TG, the increase of the heating
rate shifts the maximum rate loss to higher temperature. A first order reaction was found to be adequate for pyrolysis in
the range 150–600°C which was attributed to kerogen decomposition. In addition, the results indicate that the removal of mineral
matter affected the kinetic parameters found for kerogen in the natural phosphate.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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K. El harfi C. Bennouna A. Mokhlisse M. Ben chana L. Leme J. Joffre A. Ambls 《Journal of Analytical and Applied Pyrolysis》1999,50(2):163-174
Timahdit oil shale was subjected to supercritical water extraction. The results reveal significant difference in oil yields and composition when compared with those obtained from conventional pyrolysis. In addition, the effect of temperature and residence time on the supercritical water extraction of oil was investigated in a set of three experiments. The results revealed that the yield and the fraction of paraffins and aromatics increase while the percentage of asphaltenes decreases as the temperature is increased from 380 to 400°C. The residence time was found to affect the yield and the fraction of asphaltenes and polar compounds. 相似文献
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A. Aboulkas K. El Harfi A. El Bouadili M. Ben Chanâa A. Mokhlisse 《Journal of Thermal Analysis and Calorimetry》2007,89(1):203-209
The pyrolysis of oil shale and plastic wastes is being presently considered as an alternative means of partial substitution
of fossil fuels to generate the necessary energy to supply the increasing energy demand and as well as new technology to reduce
the negative environment of plastic wastes. However, Knowledge of pyrolysis kinetics is of great imponrtance for the design
and simulation of the reactor and in order to establish the optimum process conditions.
In this study, the thermal decomposition of polypropylene, oil shale and their mixture was studied by TG under a nitrogen
atmosphere. Experiments were carried out for various heating rates (2, 10, 20, 50 K min−1) in the temperature range 300–1273 K. The values of the obtained activation energies are 207 kJ mol−1 for polyethylene, 57 kJ mol−1 for the organic matter contained in the oil shale and 174 kJ mol−1 for the mixture. The results indicate that the decomposition of these materials depends on the heating rate, and that polypropylene
acts as catalyst in the degradation of the oil shale in the mixture. 相似文献
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Aouad A. Benchanâa M. Mokhlisse A. Arafan A. 《Journal of Thermal Analysis and Calorimetry》2002,70(2):593-603
Thermogravimetry (TG), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) were used
to study the thermal behaviour of the organic matter in the natural phosphate and its concentrate kerogen from the Moroccan
deposit. The TG analysis showed that both the investigated samples exhibited a one-step thermal oxidation in the main mass
loss area, between 160 and 540°C, attributed to the hydrocarbon material. When DSC analyses of oxidation as well as pyrolysis
yielded two evolutionary stages of the hydrocarbon in this temperature range : the first one at 160-360°C and the second one
above 360°C. Pyrolytic kerogen decomposition was monitored by measuring changes in the principal FTIR organic bands. The results
showed, in the first stage, the progressive decrease of signals due to CH2 and CH3 vibrations as well as the carbonyl and carboxylic bands, and their subsequent disappearance at 300°C. In the second stage
above 400°C, the signal due to the aromatic components (1600 cm-1) appeared but decreased with increasing temperature up to 540°C.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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R. Mokhlisse M. Couzi N.B. Chanh Y. Haget C. Hauw A. Meresse 《Journal of Physics and Chemistry of Solids》1985,46(2):187-195
The structural phase transitions of (C3H7NH3)2CdCl4 (PACC) have been studied by means of Raman scattering. X-ray diffraction and DSC measurements It is shown that the order-disorder phase transition Abma ? Pbca occurs at 156 K and not at 183 K as previously proposed by Chapuis (Acta CrystB34, 1506 (1978)) Apparently, the transition at 183 K does not change the Abma space group; it is suggested that it could be related to the occurrence of an incommensurate phase Another structural transformation of PACC is detected at 114 K, but no conclusion can be given as far as the structure of the low-temperature phase is not determined. 相似文献
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The effect of steam adsorption-desorption on hydrophilic polymer processes is studied under controlled pressure and temperature. Experiments were performed using a relatively high mass of polymer (2 to 20 g), to examine the influence of different parameters on the adsorption-desorption mechanisms, such as the polymeric adsorbant mass, the steam pressure, the temperature and the number of adsorption-desorption cycles.
The limiting step of these processes varies from a pseudo-first-order step type for the low adsorbant mass (< 1 g), to a diffusive step for the mass range 2 to 20 g. In this last range, the process does not depend upon the adsorbant mass; only the adsorption and desorption rates change due to the modification of the space scale of the solid. The adsorption kinetics was not modified by the number of cycles, even for the first cycle; this is the opposite result as compared to when the experiment was performed with a low mass of polymer. 相似文献
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Aouad A. Benchanâa M. Mokhlisse A. Ounas A. 《Journal of Thermal Analysis and Calorimetry》2004,75(3):887-900
A non-isothermal experimental study using thermogravimetry (TG) and differential scanning calorimetry (DSC) was conducted
for investigation the oxidation reactivity of natural phosphate and its demineralised products. The analyses were carried
out in oxygen atmosphere and at different heating rate (5, 10, 20, 30, 50, 60°C min-1) up to 1000°C. The results indicated
that the material washed with HCl from the original phosphate, mainly apatite and carbonates of calcium and magnesium, as
well as with HCl/HF, silicates minreals, had an inhibition effect during oxidation reactions of organic material. The increase
of the heating rate shifted the reactions to higher temperatures. In addition, kinetic parameters were determined by assuming
a single first-order kinetic model, using the Coats-Redfern method. The influences of demineralization process of natural
phosphate and the heating rate were examined and discussed.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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