Effect of synthesis time on physical properties and catalytic activities of synthesized HZSM-5 on the fast pyrolysis of Jatropha waste

The catalytic fast pyrolysis of Jatropha waste using synthesized HZSM-5 zeolites was investigated using an analytical pyrolysis-GC/MS (Py-GC/MS) technique. HZSM-5 zeolite was successfully synthesized by hydrothermal method at 160 °C with various synthesis times of 0, 24, and 72 h. From the XRD results, the as-synthesized powder before crystallization (HZSM5-0 h) showed the amorphous phase, while samples with synthesis times of 24 and 72 h (HZSM5-24 h and HZSM5-72 h) showed the high crystalline phase of HZSM-5 with the main peaks at the 2θ of 7.9°, 8.8°, 23.1°, 23.7°, and 23.9°. The particle of HZSM5-72 h appeared in cubic-shaped crystal compared to the HZSM5-24 h. HZSM5-72 h had a higher surface area of 625 m²/g with an average larger pore diameter of 27.97 Å and pore volume of 0.28 cm³/g. The effect of biomass to catalyst ratios of 1:1, 1:5, and 1:10 was investigated at 500 °C. It was found that the aromatic and aliphatic selectivity depended on the synthesis time of HZSM-5 reflected in their surface areas, pore sizes, and catalyst content. The highest aromatic and aliphatic hydrocarbon of almost 95 % was obtained when a large amount of HZSM-5 (synthesized for 72 h) was used which could lead to the high heating values of bio-oils. The HZSM5-72 h also contributed to eliminate the undesirable oxygenated compounds such as acids, aldehydes, and ketones. Nevertheless, there are still a few percentages of N-containing components that may require further denitrogenation prior to utilization of the obtained liquid fuel.