Adsorption thermodynamics and prediction of phase equilibria for activated carbon synthesized from waste grease

The research is conducted to evaluate the thermodynamic parameters of adsorption processes and to predict the phase equilibria for carbon produced from a mixture of waste grease and raw sulfur. Phenol and pnitrophenol were used for adsorption isotherm at different concentrations and temperatures. Thermodynamic functions such as Gibbs function (ΔG), enthalpy (ΔH) and entropy (ΔS) changes during adsorption were calculated. The melting point measurements of waste grease and raw sulfur mixtures were obtained for different ratios. The lever rule is used to represent a quantitative determination in the two-phase region of a phase diagram using a certain equation.The phenol adsorption was mostly an endothermic process while the p-nitrophenol adsorption was an endothermic process for all samples as indicated by positive values of the enthalpy. Generally the adsorption processes were spontaneous as pointed out by entropy and free energy values. Various phases and boundaries were occurred at three regions with 2-phase while 1 -phase is exist in the system especially at high temperatures. The ratio of lliquid/lsolid was increased with reducing temperature and the amounts of liquid were reduced.