Pyrolysis of Colombian spent coffee grounds (SCGs), characterization of bio-oil, and study of its antioxidant properties

Coffee is the second most consumed beverage in the world. Spent coffee grounds (SCGs) are promising raw material for pyrolysis. The Kissinger-Akahira-Sunose model (KAS) and Ozawa-Flynn Wall (OFW), determined the pyrolysis activation energy to be 142.40 and 66.08 kJ/mol, respectively. The pyrolysis products were bio-oil with a 22.5% yield and a calorific power of 28.91 MJ/kg. The bio-oil composition was 50.86% fatty acids, 31.65% linear hydrocarbons, and 11.31% aromatics, as determined by GC-MS. The total phenolic content (TPC) was 362 & PLUSMN; 44 mg GA g(-1), with DPPH activity of 24.8 & PLUSMN; 2% inhibition and antioxidant activity of 108.5 & PLUSMN; 13.6 mg L-1 of Trolox equivalents. The results showed that bio-oil could be used as a biofuel and a source of chemical compounds.

Keywords

Pyrolysis, SCGs, Coffee, Biofuels, Antioxidant activity

Citation

International Journal of Sustainable Energy. 2023, vol. 42, issue 1, p. 811-829.
https://www.tandfonline.com/doi/full/10.1080/14786451.2023.2235025

Document type

Peer-reviewed

Document version

Published version

Language of document

en

Document licence

Creative Commons Attribution 4.0 International
http://creativecommons.org/licenses/by/4.0/