Abstract

This study presents a way of using South African coal fly ash by extracting metals such as Al and Fe with concentrated sulphuric acid, and then using the solid residue as a feedstock for the synthesis of ZSM-5 zeolite. The percentage of aluminum and iron oxides decreased from 28.0 ± 0.2% and 5.0 ± 0.1% in coal fly ash to 24.6 ± 0.1% and 1.6 ± 0.01% in the acid treated coal fly ash respectively. The fly ash-based zeolite ZSM-5 sample synthesized from the solid residue after extraction of Al and Fe, contained 62% of ZSM-5 zeolite pure phase with a number of Brønsted acid site density of 0.61 mmol per gzeolite. By properly treating the as-prepared coal fly ash-based ZSM-5 zeolite, an active and selective methanol-to-olefins acid catalyst could be designed, leading to full methanol conversion during 15 h on stream. The optimized catalyst exhibited a cumulative methanol conversion capacity of 71 g(MeOHconverted)/g(catalyst) and a light olefin productivity of 21 g(C2=–C4=)/g(catalyst).

Department(s)

Mining Engineering

Keywords and Phrases

Acid leaching; Fly ash; Metal extraction; MTO catalyst; ZSM-5 zeolite

International Standard Serial Number (ISSN)

1631-0748

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 2024 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Jan 2017

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