Kinetics and Thermodynamics Studies of Biodiesel Synthesis From Castor Oil Using Calcium Oxide Doped Titanium (IV) Oxide Nanocatalyst

This study examines the thermodynamic and kinetic factors that are involved in the integration of renewable diesel from castor oil. The production of renewable diesel was achieved by transesterifying castor oil with methanol using calcium oxide supported on titanium oxide nanocatalysts. To enhance the transesterification process, the following parameters were implemented: MTOR (10:1), CW (1.1 wt.%), RT (60 OC), Rtime (60 minutes), AS (300 rpm) with maximum biodiesel product of 96.28%. During the transesterification process, reaction rate constants of 0.0402 min-1, 0.0447 min-1, and 0.0459 min-1 were obtained at 323, 328, and 333 K, respectively, as observed by the differential method as a function of time and percent oil yield. The activation energy, Ea, was ascertained to be 46.19 kJ.mol-1, and the frequency factor, A, was 5.56×10-4 min-1. The following thermodynamic parameters were determined: entropy (∆S) of -0.129 kJ•mol⁻¹ and enthalpy (∆H) of 43.78 kJ•mol⁻¹. At temperatures of 323 K, 328 K, and 333 K, the Gibbs free energy ∆G was found to be 85.50 kJ.mol-1, 86.14 kJ/mol-1, and 86.79 kJ/mol-1, respectively. The rate constants for the reactions increased in direct proportion to the increase in reaction temperature, as indicated by the kinetic analysis. The positive values of ∆H, ∆S, and ∆G represent the reaction's endothermic and non-spontaneous nature. Furthermore, the fact that ∆S is negative implies that the transesterification process is disorder-free. A high biodiesel conversion rate demonstrates the catalyst's effective properties