International Journal of Petroleum and Gas Engineering ISSN 5675-0715 Vol. 3 (9), pp. 001-010, September, 2016. © International Scholars Journals
Full Length Research Paper
Pyrolysis behaviour and kinetics of Moroccan oil shale with polystyrene
A. Aboulkas1,2*, K. El harfi1,2, M. Nadifiyine1 and M. Benchanaa1
1Laboratoire de Recherche sur la Réactivité des Matériaux et l’Optimisation des Procédés «REMATOP», Département de chimie, Faculté des Sciences Semlalia, Université Cadi Ayyad, BP 2390, 40001 Marrakech, Maroc, Morroco.
2Laboratoire Interdisciplinaire de Recherche en Sciences et Techniques, Faculté polydisciplinaire de Béni-Mellal, Université Sultan Moulay Slimane, BP 592, 23000 Béni-Mellal, Maroc, Morroco.
Accepted 15 June, 2016
Abstract
Pyrolysis of oil shale/polystyrene mixture was performed in a thermogravimetric analyzer (TGA) from room temperature of 1273K, at heating rates of 2, 10, 20, 50 and 100 K/min. The global mass loss during oil shale/polystyrene pyrolysis was modelled by a combination of mass-loss events for oil shale and polystyrene volatiles. TGA results indicate that mixture pyrolysis can be identified in three phases. The first is attributed to the drying of absorbed water; the second was dominated by the overlapping of organic matter and plastic pyrolysis, while the third was linked to the mineral matter pyrolysis, which occurred at much higher temperatures. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis (10% of the difference between experimental and calculated curves in the temperature range 600 to 900K). The maximum degradation temperature of each component in the mixture was higher than those of the individual components. The calculated residue was found to be higher than experimental. These experimental results indicate a significant synergistic effect during pyrolysis of mixture of oil shale and polystyrene. The kinetic studies were performed using Flynn-Wall-Ozawa (FWO) method. The overall activation energies were 87 kJ/mol for organic matter of oil shale, 169 kJ/mol for polystyrene, and 161 kJ/mol for the mixture. Thus, it has been found that there exists an overall synergy, when two materials were pyrolysed together.
Key words: Thermogravimetric, pyrolysis, kinetics, oil shale, polystyrene.