Kinetics of Pyrolysis of Date Kernels

Abstract

Abstract: The kinetics of pyrolysis of ground date kernels was investigated using thermogravimetric analysis in order to provide the necessary information for proper biochar formation and bioreactor design. Pyrolysis was carried out at heating rates of 5, 10, 15 and 20 o C.min -1 in a flow of nitrogen. One main DTG peak was obtained that corresponded to formation of bio-char. A second diffuse peak corresponds to constant rate cracking of the char formed and complete elimination of carbon leaving an ash residue. The composition of biochar was determined using EDX . Four different methods were used to follow up the kinetics of the three steps, namely, the Kissinger, the Flynn-Wall-Ozawa, the Coats-Redfern methods and multi-regression analysis. The activation energy of the main decomposition step was determined and the values obtained using different kinetic models compared. The decomposition step simply followed first order kinetics.

Modeling the kinetics of pyrolysis of date seeds using artificial neural networks

“…A comparison of the values of activation energy obtained at different conversion levels by the three methods is given in Table II. The values obtained for the activation energy using different non-model techniques are close to those obtained by Aly et al [40], on studying the kinetics of pyrolysis of date kernels, varying from 126.5 to 145 kJ.mol -1 , depending on the heating rate and method of calculation, although they did not specify the particle size used in their work. The results obtained by Rasa et al [41] (170 -190 kJ.mol -1 ) are less reliable, being obtained by the Coats -Redfern technique, which is unsuitable for use for complex reactions [23].…”

“…They used several model and non-model methods to evaluate the activation energy of degradation of lignocellulosic components and obtained values of activation energy ranging from 135 to 160 kJ.mol -1 depending on the technique used in calculations. On the other hand, Raza et al [41] used the Coats -Redfern technique to obtain a value of activation energy ranging from 170 to 190 kJ.mol -1 , depending on the heating rate used, a result close to that obtained by Aly et al [40].…”

“…In particular, the kinetics of pyrolysis of date seeds were investigated by Aly et al [40]. They used several model and non-model methods to evaluate the activation energy of degradation of lignocellulosic components and obtained values of activation energy ranging from 135 to 160 kJ.mol -1 depending on the technique used in calculations.…”