Catalytic wet-air oxidation of lignin in a three-phase reactor with aromatic aldehyde production
Open Access
- 1 June 2004
- journal article
- Published by FapUNIFESP (SciELO) in Brazilian Journal of Chemical Engineering
- Vol. 21 (2) , 211-218
Abstract
In the present work a process of catalytic wet air oxidation of lignin obtained from sugar-cane bagasse is developed with the objective of producing vanillin, syringaldehyde and p-hydroxybenzaldehyde in a continuous regime. Palladium supported on g-alumina was used as the catalyst. The reactions in the lignin degradation and aldehyde production were described by a kinetic model as a system of complex parallel and series reactions, in which pseudo-first-order steps are found. For the purpose of producing aromatic aldehydes in continuous regime, a three-phase fluidized reactor was built, and it was operated using atmospheric air as the oxidizer. The best yield in aromatic aldehydes was of 12%. The experimental results were compatible with those values obtained by the pseudo-heterogeneous axial dispersion model (PHADM) applied to the liquid phase.Keywords
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