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Thermal properties of Jatropha curcas L. kernels
Author(s)
Posom, Jetsada
Date Issued
December 1, 2012
Type
Article
Abstract
The thermal properties of Jatropha curcas L. kernels, including thermal diffusivity and conductivity were studied where kernels in 3 different forms were investigated, i.e. whole kernels, 1/4 kernels and kernel powder. The specific heat of kernels in 2 different forms was also assessed (i.e. small piece of kernel and powdered kernel). The experiments were undertaken using kernels obtained at 2 different harvesting periods, a mature, ripe stage (yellow fruit) and a fully ripe stage (black fruit). The thermal diffusivity of whole kernels, 1/4 kernels and kernel powder obtained from yellow fruit were 9.303 × 10-6, 8.370 × 10-6 and 7.456 × 10-6 m2 s-1, respectively, while those obtained from black fruit were 8.792 × 10-6, 7.723 × 10-6 and 6.652 × 10-6 m2 s-1, respectively. The thermal conductivity of whole kernels, 1/4 kernels and powdered kernels increased with increasing temperature from 25 to 100 °C, ranged from 0.0663 to 0.1181, 0.0593 to 0.1087 and from 0.0536 to 0.1015 W m-1 °C-1 for the 3 kernel forms derived from yellow fruit, respectively. For the different kernel forms obtained from the black fruit the corresponding values were 0.0608-0.0977, 0.0527-0.0841 and 0.0452-0.0740 W m-1 °C-1, respectively. The specific heat of the small piece kernel and powder obtained from yellow fruit, ranged from 0.7852 to 1.3929 and from 1.3823 to 2.4510 kJ kg-1 °C-1, respectively. For black fruit, the values ranged from 0.6258 to 0.9933 and from 0.8930 to 1.7810 kJ kg-1 °C-1, respectively. Linear relationships between thermal conductivity and specific heat with temperature are reported. © 2012 IAgrE.
Citation
Biosystems Engineering, 113(4), 402-409, 2012