Abstract
Waste tyre, a hydrocarbon-based material, exhibits potential to be used for a derivation of petrochemicals. Valuable chemicals such as benzene, toluene, and xylenes were observed in pyrolytic oils. Furthermore, sulphur compounds causing the low quality of oil products and environmental problem were also found. HBeta and HMOR acidic zeolites whose pore sizes are very close, which are 6.4x7.6 Å and 6.5x7.0 Å have different channel structures. The channel structure of HBETA is zigzag whereas that of HMOR is straight. Since the channel structure of zeolites may affect the residence time of molecules to stay in the pores; therefore, the objective of this work was to investigate the channel structure of zeolites that affect the structure and the size of pyrolysis products. The products were analyzed by using a SIMDIST-GC, GC and elemental analyser, whereas a GCxGC-TOF/MS was used to investigate species in oils. The catalysts were characterized by using XRD, TGA, and SAA. The results showed that the compositions of pyrolytic oils classified in terms of paraffins (P), olefins (O), naphthenes (N), and aromatics (A) were different with using different zeolites. Catalytic pyrolysis caused the decreases in olefins and naphthenes with the increases of aromatics. Furthermore, HBeta gave the higher amount of aromatics than HMOR, and gave the lower amounts of olefins and naphthenes than HMOR. It can be explained that the complex pore of HBeta converted more olefins and naphthenes to aromatics inside the pore than the straight pore of HMOR. In addition, HBeta gave a higher amount of light fractions in oils than HMOR that gave a higher amount of heavy fractions such as gas oil and long residue. However, these two zeolites can reduce sulphur in oils, and the species of sulphur were different. Moreover, both HBeta and HMOR catalysts caused the increment in the group of benzothiophenes and the reduction in the group of benzothiazoles.
