Bangka Kaolin and Bayat Zeolite-based ZSM-5 zeolite as heterogeneous catalyst for hexadecane cracking reaction

Abstract

Microporous ZSM-5 material was synthesized using natural aluminosilicate minerals, i.e. Bayat zeolite and Bangka kaolin as silica and alumina sources. Prior to use, Bayat zeolite was treated with several treatments, i.e. purification, fragmentation and dealumination. While Bangka Kaolin was used as the source of additional silica, in which the silica was extracted using aqua regia. After that, ZSM-5 zeolite was synthesized using tetrapropylammonium hydroxide (TPAOH) as template. Then, it was characterized using Fourier Transform Infrared (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM-EDX). Based on XRD pattern, mordenite inverted framework (MFI) structure was obtained. SEM-EDX images showed that the natural aluminosilicate-based ZSM-5, so called ZSM-5 MA, has a coffin-like shape with average crystal size and Si/Al ratio are 1.6 μm and 14.26, respectively. As reference, another as-synthesized ZSM-5 was prepared from pro-analysis reagents, and labelled as ZSM-5MS. It also has mordenite inverted framework (MFI) structure, Si/Al ratio of 21.45 and average crystal size of 0.8 μm. ZSM-5 was tested with micro activity test (MAT) method for hexadecane cracking reaction at 500 °C. Prior to be used, the ZSM-5 was subjected to NH4− exchanged followed by calcination at 550 °C to obtain H/ZSM-5. The products that obtained from hexadecane cracking reaction are gas (H2, C1–C4) and gasoline (C5–C12) fractions. The catalytic test shows that both H/ZSM-5MA and H/ZSM-5MS gave similar results, despite their differences in Si/Al ratio and particle sizes. Therefore, zeolite synthesis using natural minerals as Si and Al sources is promising to be explored further.