Zirconia catalysed acetic acid ketonisation for pre-treatment of biomass fast pyrolysis vapours.

Abstract

Crude pyrolysis bio-oil contains significant quantities of carboxylic acids which limit its utility as a biofuel. Vapour phase ketonisation of organic acids contained within biomass fast-pyrolysis vapours offers a potential pre-treatment to improve the stability and energy content of resulting bio-oils formed upon condensation. Zirconia is a promising catalyst for such reactions, however little is known regarding the impact of thermal processing on the physicochemical properties of zirconia in the context of their corresponding reactivity for the vapour phase ketonisation of acetic acid. Here we show that calcination progressively transforms amorphous Zr(OH)4 into small tetragonal ZrO2 crystallites at 400 °C, and subsequently larger monoclinic crystallites >600 °C. These phase transitions are accompanied by an increase in the density of Lewis acid sites, and concomitant decrease in their acid strength, attributed to surface dehydroxylation and anion vacancy formation. Weak Lewis acid sites (and/or resulting acid-base pairs) are identified as the active species responsible for acetic acid ketonisation to acetone at 350 °C and 400 °C, with stronger Lewis acid sites favouring competing unselective reactions and carbon laydown. Acetone selectivity is independent of acid strength.

Publication DOI: https://doi.org/10.1039/C7CY02541F
Dataset DOI: https://doi.org/10.17036/researchdata.aston.ac.uk.00000323
Divisions: College of Engineering & Physical Sciences
Additional Information: © Royal Society of Chemistry, 2018. Funding: EPSRC (EP/K036548/2, EP/K014676/1, EP/N009924/1) and FP7-funded CAScade deoxygenation process using tailored nanoCATalysts for the production of BiofuELs from lignocellulosic biomass (CASCATBEL) project (Grant Agreement No. 604307).
Publication ISSN: 2044-4761
Last Modified: 08 Mar 2024 08:13
Date Deposited: 19 Jan 2018 12:15
Full Text Link:
Related URLs: http://pubs.rsc ... 8/CY/C7CY02541F (Publisher URL)
PURE Output Type: Article
Published Date: 2018-01-18
Published Online Date: 2018-01-18
Accepted Date: 2018-01-17
Authors: Jahangiri, Hessam
Osatiashtiani, Amin (ORCID Profile 0000-0003-1334-127X)
Bennett, James
Isaacs, Mark
Gu, Sai
Lee, Adam
Wilson, Karen

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