Ga/HZSM-5 Catalysed Acetic Acid Ketonisation for Upgrading of Biomass Pyrolysis Vapours

Abstract

Pyrolysis bio-oils contain significant amounts of carboxylic acids which limit their utility as biofuels. Ketonisation of carboxylic acids within biomass pyrolysis vapours is a potential route to upgrade the energy content and stability of the resulting bio-oil condensate, but requires active, selective and coke-resistant solid acid catalysts. Here we explore the vapour phase ketonisation of acetic acid over Ga-doped HZSM-5. Weak Lewis acid sites were identified as the active species responsible for acetic acid ketonisation to acetone at 350 ◦C and 400 ◦C. Turnover frequencies were proportional to Ga loading, reaching ~6 min −1 at 400 ◦C for 10Ga/HZSM-5. Selectivity to the desired acetone product correlated with the weak:strong acid site ratio, being favoured over weak Lewis acid sites and reaching 30% for 10Ga/HZSM-5. Strong Brønsted acidity promoted competing unselective reactions and carbon laydown. 10Ga/HZSM-5 exhibited good stability for over 5 h on-stream acetic acid ketonisation.

Publication DOI: https://doi.org/10.3390/catal9100841
Divisions: Engineering & Applied Sciences > European Bioenergy Research Institute (EBRI)
Engineering & Applied Sciences
Additional Information: © 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). Funding: EPSRC (EP/K036548/2, EP/K014676/1, EP/N009924/1), the Royal Society Industry Fellowship.
Uncontrolled Keywords: Bio-oil,Ketonisation,Pyrolysis,Turnover frequencies (TOFs),Catalysis,Physical and Theoretical Chemistry
Full Text Link:
Related URLs: https://www.mdp ... 3-4344/9/10/841 (Publisher URL)
http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2019-10-11
Accepted Date: 2019-10-05
Authors: Jahangiri, Hessam
Osatiashtiani, Amin ( 0000-0003-1334-127X)
Ouadi, Miloud
Hornung, Andreas
Lee, Adam
Wilson, Karen

Download

[img]

Version: Published Version

License: Creative Commons Attribution

| Preview

Export / Share Citation


Statistics

Additional statistics for this record