ISSN 1925-542X [Print] ISSN 1925-5438 [Online] www.cscanada.net www.cscanada.org Advances in Petroleum Exploration and Development Vol. 6, No. 2, 2013, pp. 28-31 DOI:10.3968/j.aped.1925543820130602.1758 28 Copyright © Canadian Research & Development Center of Sciences and Cultures Evaluation of the Physical-Chemical Properties in Petroleum Coke Semaghiul Birghila [a],* ; Ionela Carazeanu Popovici [a] [a] Ovidius University of Constanta, Chemistry and Chemical Engineering Department, 124 Mamaia, Constanta, Romania. * Corresponding auhtor. Received 26 October 2013; accepted 6 December 2013 Abstract 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; Metals Birghila , S., & Carazeanu Popovici, I. (2013). Evaluation of the Physical-Chemical Properties in Petroleum Coke. Advances in Petroleum Exploration and Development , 6 (2), 28-31. Available from: http://www.cscanada.net/index. php/aped/article/view/j.aped.1925543820130602.1758 DOI: http://dx.doi.org/10.3968/j.aped.1925543820130602.1758 INTRODUCTION Coke is a gray to black solid carbonaceous residue (90- 95% carbon) which is produced from petroleum during thermal processing. The two most important categories are green coke and calcinated coke; green petroleum coke are mostly used as utility fuels and as feedstocks for further upgrading caltinations. The calcinated petroleum coke are used in production of aluminium, anode-grade, graphite electrodes, needle-grade, TiO 2 pigments [1] . A number of factors determine the quality of petroleum coke, such as: density, metal and sulphur content, electrical resistivity. Knowledge of structure parameters also contributes to the characterization and utilization of petroleum coke [2] . The chemical composition of petroleum coke is determined by the composition of the feedstocks used in the coking process, which to their turn depend on the composition of the crude oil and refinery processing from which the feedstock is derived. Cokes produced from feedstocks high in asphaltenes will contain higher concentrations of sulphur and metals than cokes produced from high aromatic feedstocks, because the asphaltenes contain a disproportionate fraction of those heteroatoms [3] . The sulphur content of petroleum coke varies from 0.5% to 10%, depending on its content in oil (cokinf feedstock) and on the coking process variable. Organic sulphur may exist in the coke in many forms: as thiophenes attached to the aromatic carbon skeleton; as attached to side chains of aromatic or naphthenic molecules; between the aromatic sheets or on the surface of clustered molecules. Inorganic sulphur compounds are mostly found on the coke surface or in coke pores bound by capillary condensation, adsorption or chemisorption. Separation of sulphur can be achieved in several ways: through calcination at higher temperature, hydrodesuphurization and chemical treatment with different agents [4-6] . Metals, mainly vanadium and nickel, occur as metal chelates or porphyrins in the asphaltene fraction. Some metals are intercalated in the coke structure and are not chemically bonded, so they become part of the ash and particulates.