Catalytic upgradation of bio-oil over metal supported activated carbon catalysts in sub-supercritical ethanol. Issue 2 (April 2021)

• Record Type: Journal Article
• Authors: Baloch, Humair Ahmed; Nizamuddin, Sabzoi; Siddiqui, M.T.H.; Riaz, Sajid; Konstas, Kristina; Mubarak, N.M.; Srinivasan, M.P.; Griffin, G.J.
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 2(2021)
• Publication Date: 2021-04
• Subjects: Upgrading -- Catalysts -- Catalytic upgrading -- Sub-supercritical ethanol; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.105059
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The bio-oil was upgraded in sub-supercritical ethanol using metal supported platinum on activated carbon (Pt/AC) and palladium on activated carbon (Pd/AC) as catalysts. The supercritical upgrading process revealed more effective process compared to the subcritical conditions. Esterification during catalytic upgrading of bio-oil remained prominent which facilitates the conversion of acids present in bio-oil into esters in sub-supercritical ethanol. In addition, heavy compounds of crude bio-oil cracked into lighter compounds in the presence of catalysts. Furthermore, the changes in the upgraded bio-oil relative to crude bio-oil was extensively investigated through higher heating value (HHV), elemental analysis, solution pH, chemical composition (GC-MS), chemical functional groups (FTIR), and 13 C and 1 H nuclear magnetic resonance spectroscopy (NMR). The chemical composition analysis showed a significant decrease in acid fractions in sub-supercritical upgrading process, hence the solution pH varied from 2.5 in bio-oil to 5.3 after supercritical reaction. The HHV of bio-oil increased from 28.55 to 36.4 MJ/kg. This research has shown that crude bio-oil can be efficiently upgraded with carbon-supported metal catalysts in a sub-supercritical upgrading process. Graphical Abstract: ga1 Highlights: High Quality bio-oil obtained under supercritical conditions. HHV of bio-oil increased from 28.55 to 36.4 MJ/kg. Esterification and hydrogenation are the main reactions during bio-oil upgrading process. 1 H and 13 C NMR showed upgraded bio-oil contains aromatic and olefins.