Surface activity of Rh/KL catalyst in waste tire pyrolysis

Abstract

This research work elucidated the surface activity of KL and Rh/KL through the changes of hydrocarbon compounds in tire-derived oil (TDO). Maltenes, TDOs after separation of asphaltene, were analyzed by using a comprehensive 2D gas chromatography with time-of-flight mass spectrometry (GC × GC- TOF/MS). The hydrocarbon compounds in TDOs were categorized into seven groups; that are, saturated hydrocarbons (SATs), olefins (OLEs), terpenes (TERs), mono-aromatics (MAHs), di-aromatics (DAHs), poly-aromatics (PAHs), and polar-aromatics (PPAHs). Moreover, mono-aromatics were classified into those with saturated and unsaturated substituents. The changes in molecular structures of hydrocarbon compounds with the uses of catalysts were confirmed by using two-dimension Heteronuclear Single-Quantum Correlation-Nuclear Magnetic Resonance (2D- HSQC-NMR). As a result, the KL catalyst can provide hydrogenation of C11 - and C12-alkylbenzenes; moreover, the KL can enhance the cracking of Cl3- and Cl4- indenes, whereas the Rh/KL catalyst can provide dehydrogenation of Cl2- teralins (mostly, 2-ethyltetralin) to C12-DAHs (mostly, 2-ethlynaphthalene), and C11-alkylbenzenes (mostly, cyclopentylbenzene) to Cl1-alkenylbenzenes (mostly, cyclopentenylbenzene). Furthermore, the Rh/KL can crack C12-alkylbenzenes via multiplet mechanism.