Evaluation of the Physical-Chemical Properties in Petroleum Coke

In this paper, commercial petroleum cokes were analyzed, before and after heat treatment in order to evaluate the physical-chemical properties. The content of moisture, volatile matter, sulphur, ash and metals (Fe Ni, Cr) was determined. The results showed that temperature increasing led to the removal of volatile matter and sulphur content; higher separation of sulphur was observed for coke obtained from atmospheric residue and from decanted oil. The ash content indicates the presence of inorganic admixtures in coke. Metal concentrations increased through calcining, due to the weight loss from removal of the volatile matter; the coke samples revealed the higher content of nickel (151 to 279 ppm) which is the most represented metal component in the coking feedstock. Physical-chemical parameters indicate that the analyzed cokes can be used in anode –grade production.Key words: Anode materials; Petroleum coke; Moisture; Sulphur; Volatile matter; Metal

New Approaches for Pb(II) Removal from Aqueous Media Using Nanopowder Sodium Titanosilicate: Kinetics Study and Thermodynamic Behavior

Microporous sodium titanosilicate, Na2TiSiO5, has been successfully prepared using the sol–gel method. The structural and morphological characterization of synthesized product has been made via thermal analyses (TG-DTG), X-ray diffraction (XRD), and electron microscopy (SEM and TEM). Adsorption properties of the synthesized Na2TiSiO5 nanopowder for Pb(II) removal of aqueous media was investigated in different experimental conditions such as the contact time, the initial metal concentration, the pH, and the temperature. The Pb(II) adsorption on Na2TiSiO5 was discussed according to the kinetics and thermodynamics models. The adsorption kinetics of Pb(II) have been better described by the PS-order kinetic model which has the highest fitting correlation coefficients (R2: 0.996–0.999) out of all the other models. The adsorption results have been successfully fitted with the Langmuir and Redlich–Paterson models (R2: 0.9936–0.9996). The calculated thermodynamic parameters indicate that the Pb(II) adsorption is an endothermic process, with increased entropy, having a spontaneous reaction. The results have revealed a maximum adsorption capacity of 155.71 mg/g at 298 K and a very high adsorption rate at the beginning, more than 85% of the total amount of Pb(II) being removed within the first 120 min, depending on the initial concentration