@article {1803,
	title = { Determination and modeling of the isotherms of adsorption/desorption and thermodynamic properties of obeche and lotofa using nelson{\textquoteright}s sorption model },
	journal = { HEAT AND MASS TRANSFER },
	volume = {55},
	year = {2019},
	pages = {2185-2197},
	abstract = {<p>Equilibrium moisture content (EMC), net isosteric heat of sorption (NIHS), net entropy of sorption (NES) and standard free energy of Gibbs (SFEG) of Triplochiton scleroxylon (obeche) and Sterculia rhinopetala (lotofa) are modeled using Nelson\&$\#$39;s sorption isotherm model. Experimental data are determined using a dynamic vapor sorption apparatus. Air relative humidity is ranged from 0 to 90\% and two air temperatures (20 degrees C and 40 degrees C) are used. Experimental data of EMCs obtained from adsorption and desorption for the mentioned woods were compared with the predicted results using Nelson\&$\#$39;s sorption model by the application of the same operating conditions (i.e. temperatures and relative humidity conditions). The results showed that the predicted ones were in good agreement with the experimental data, when the relative humidity varied from 1.2 to 90\%. Both adsorption and desorption phase presented a mean relative errors value inferior to 6.3\%. The parameters that define the sorption isotherm varied with the wood type and the sorption mode. Thus, Nelson\&$\#$39;s sorption isotherm model is a useful tool that can be used for prediction of the moisture change in wood under different environmental conditions and for predicting indirectly the thermodynamic parameters such as NIHS, NES and SFEG. In adsorption and desorption mode, the NIHS are estimated using Clausius-Clapeyron\&$\#$39;s equation. The desorption values were higher than the adsorption ones. NIHS versus EMC varied exponentially and the parameters of the function were presented variable with the sorption mode and the wood type. The total energy that we needed to extract and evaporate all bounded water is 12,398.6 J/mol for obeche and 11,627.7J/mol for lotofa. The total energy that we needed to condense and fix all bounded water taken from the state vapour is 11,829.34 J/mol for obeche and 11,379.39 J/mol for lotofa. Water molecules are more mobile during desorption than adsorption in the case of obeche. In the case of lotofa, these molecules are more mobile during adsorption. SFEG is higher in desorption than adsorption and it is influenced by species and less by the temperature. When the temperature increased, the SFEG increased as well. At low values of EMC, NIHS and SFEG are higher and decreased with the increase of EMC until reaching the fibre saturation point.</p>},
	url = {https://hal.archives-ouvertes.fr/hal-02521244/},
	author = {M. SIMO-TAGNE and L. BENNAMOUN and A. LEONARD and Y. ROGAUME}
}
@article {1788,
	title = { Modeling of coupled heat and mass transfer during drying of ebony wood using indirect natural convection solar dryer },
	journal = { DRYING TECHNOLOGY },
	volume = {37},
	year = {2019},
	pages = {1863-1878},
	abstract = {<p>This study presented the behavior of a laboratory scale solar dryer, which was designed with the objective of meeting the needs of low income carpenters of the tropical region of Africa. The following materials were used to build the solar dryer: aluminum sheets painted in black, a wooden support, and a plastic polyethylene used as a cover. Drying was carried out in the city of Yaounde in Cameroon, and the tested boards were ebony (Diospyros crassiflora). Drying must be performed with the following conditions: slow process at a low temperature in order to maintain the proper air relative humidity. Since, no apparatus was used to force the circulation of the air, natural convection was the mode used by the dryer. The solar dryer was mathematically modeled by applying heat and mass transfer balance to the different components of the solar dryer. It is important to mention that the used heat and mass coefficients were proposed as variable with the operating conditions. The mathematical model was a reasonable description of the physical phenomena taking place in the dryer. The results show that the average relative error between numerical and experimental moisture contents was equal to 2.102\%. Heat transfer convective coefficients and global mass transfer coefficients varied with drying time from 0.25 to 5.5 W/(m(2)K) and from 1 x 10(-8) to 5.5 x 10(-8) m/s, respectively. The proposed model allowed designing and dimensioning the solar dryer, to the industrial scale. It allowed following the evolution of the different temperatures and moisture content of the tested material and then optimizing the design of the dryer and the drying process conditions. Based on the model, proposing the opening of the drying chamber during the night time and the use of substances capable of retaining heat in the chamber were some proposed solutions in order to have more efficient drying process. The modeling results showed also that an improvement can be obtained at the addition of a solar collector.</p>},
	url = {https://hal.archives-ouvertes.fr/hal-02521718/},
	author = {M. SIMO-TAGNE and B. BONOMA and L. BENNAMOUN and L. MONKAM and A. LEONARD and A. ZOULALIAN and Y. ROGAUME}
}
