Fig. 17: FTIR spectrum of IGKO.
Conclusion
In this work, it has been established that process parameters (temperature, time and particles size), influenced the IGK oil yield. This is due to the fact that increases in temperature and time resulted in the increase in the IGK oil yield, while smaller particle size gave higher IGK oil yield. The highest oil yield of 68.80 % was obtained at 55 °C, 150 min., and 0.5 mm particle size. The physicochemical properties of the IGK oil indicated its potential for use as transformer fluid upon further treatment. Of the two kinetic models studied, pseudo second order gave better fitting to the experimental data than hyperbolic model. The activation energies determined using Arrhenius equation and modified form of Arrhenius equation for pseudo second order and hyperbolic models, respectively, were all positive, an indication that oil extraction from IGK is an endothermic process. The obtained results indicate that irrespective of the model used, the rate constant k and the constant related to maximum extraction yield C2, for pseudo second order and hyperbolic models, respectively were temperature dependent, as they increased with temperature increase. Also, the constants k and C2 for pseudo second order and hyperbolic models respectively were more temperature sensitive for larger particles size than for the smaller ones. This is manifested in the higher values of the activation energies obtained for larger average particles sizes. Kinetic models equations were successfully developed to describe the IGK oil extraction processes under the different process parameters (temperature, time and particle size) for both models. Finally, the ∆G, ∆S and ∆H values obtained at the different particles sizes during the extraction indicated that the process was spontaneous, irreversible and endothermic.