Green Synthesis and Application of ZSM-5 Zeolite

Ou Chen,Si Cheng Liu,Pei Qing Zhang,Shu Qin Zheng

doi:10.15255/kui.2020.041

Ou Chen, Si Cheng Liu + Show 2 more

Open Access

https://doi.org/10.15255/kui.2020.041

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Abstract

A ZSM-5 molecular sieve composite with a wide pore prepared by the solid phase in-situ synthesis method and fluid catalytic cracking, and an FCC catalyst additive prepared by the same ZSM-5 molecular sieve for increasing the amount of light olefin yield were investigated. The samples were characterized by XRD, N2 adsorption/desorption, SEM, and NH3-TPD, respectively. The results showed that the structure of the ZSM-5 molecular sieve composite prepared by solid phase in-situ synthesis method was pure MFI-type zeolite material. The crystallinity of ZSM-5 molecular sieve was 59.8 wt%. The synthesized ZSM-5 molecular sieve had more acid content and a wide-pore structure. The average pore size was 5.9 nm, and BET specific surface area and micropore specific surface area of sample were 213 m2 g–1 and 124 m2 g–1, respectively. The evaluated results indicated that the FCC catalyst additive had good selectivity for LPG, propylene, and butene, increasing propylene and butene yields by 2.28 wt% and 2.15 wt%, respectively, as well as had better heavy oil cracking capability and coke selectivity.

Highlights

As the simplest olefin compounds, ethylene and propylene are important crude oil cracking products in industry
A ZSM-5 molecular sieve composite with a wide pore prepared by the solid phase in-situ synthesis method and fluid catalytic cracking, and an FCC catalyst additive prepared by the same ZSM-5 molecular sieve for increasing the amount of light olefin yield were investigated
The research found that the residual active silicon and active aluminum in the mother liquor after in-situ hydrothermal synthesis, proved that the components of the reaction system were excessive, which might lead to the waste of resources

Summary

Introduction

As the simplest olefin compounds, ethylene and propylene are important crude oil cracking products in industry. ZSM-5 molecular sieve was synthesized by the green method of solid phase in-situ synthesis, and FCC catalyst additive of increasing amount of light olefin was prepared from this synthesized ZSM-5 molecular sieve. The physicochemical properties and catalytic performance of samples were tested, and the differences in catalytic performance of FCC catalyst additive prepared by the green method of solid phase in-situ synthesis and traditional in-situ hydrothermal method were investigated, respectively. The above materials were ground for 20 min, and transferred to the reactor, where they were crystallized at a constant temperature of 150 °C for 80 h After the reaction, it was washed with pure water, and dried.

Materials The following materials were used in this study

Traditional in-situ hydrothermal synthesis of ZSM-5 molecular sieve

Results and discussion

Conclusion