Synthesis of ZSM-5 zeolite from diatomite for fluid catalytic cracking (FCC) application

Yang Li,Hongman Sun,Youhe Wang,Zhongdong Zhang,Rui Feng,Zifeng Yan,Zhaoyong Liu,Fazle Subhan

doi:10.1007/s13203-015-0113-2

Abstract

In this study, ZSM-5 zeolite was successfully synthesized hydrothermally from cheap and easily accessible natural mineral diatomite in the presence of tetrapropyl ammonium bromide. The pore structure, acidic sites and surface features of as-synthesized ZSM-5 zeolite were well characterized by X-ray diffraction, scanning electron microscopy, pyridine-adsorbed Fourier transform infrared spectroscopy, and N2 adsorption. The analysis results revealed that the as-synthesized ZSM-5 zeolite exhibited excellent hydrothermal stability, high specific surface area (223 m2 g−1) and more acidic cites than diatomite. After mixing ZSM-5 zeolite with a FCC base catalyst, the catalytic performance was evaluated in a micro-fixed bed reactor using vacuum gas oil (VGO) as feedstock. The high surface area and more acidic sites of as-synthesized ZSM-5 zeolite played an important role in the production of light olefins (propylene and butylene) during catalytic cracking of VGO.

Highlights

Zeolites have received much attention for chemical industry and academia owing to their high thermal stability, shape selectivity and high catalytic activity
The analysis results revealed that the as-synthesized ZSM-5 zeolite exhibited excellent hydrothermal stability, high specific surface area (223 m2 g-1) and more acidic cites than diatomite
After mixing ZSM-5 zeolite with a FCC base catalyst, the catalytic performance was evaluated in a micro-fixed bed reactor using vacuum gas oil (VGO) as feedstock

Summary

Introduction

Zeolites have received much attention for chemical industry and academia owing to their high thermal stability, shape selectivity and high catalytic activity. The pore structure, acidic sites and surface features of as-synthesized ZSM-5 zeolite were well characterized by X-ray diffraction, scanning electron microscopy, pyridine-adsorbed Fourier transform infrared spectroscopy, and N2 adsorption. The analysis results revealed that the as-synthesized ZSM-5 zeolite exhibited excellent hydrothermal stability, high specific surface area (223 m2 g-1) and more acidic cites than diatomite.

Results

Conclusion