Kinetics of vanillin oxidation

• Type: Article in International Scientific Journal
• Date: 1996

Authors

Fargues, C (Author) Other; Mathias, A (Author) Other; Silva, J (Author) Other; Alírio Rodrigues (Author) FEUP

Journal

Title: Chemical Engineering and Technology

Vol. 19

Pages: 127-136

ISSN: 0930-7516

Publisher: Wiley-Blackwell

Indexing

ISI Web of Knowledge - 16 Citations

Scopus - 16 Citations

Other information

Authenticus ID: P-001-EFT

DOI: 10.1002/ceat.270190206

Abstract (EN): Vanillin can be produced by oxidation of kraft lignin, with air, in alkaline medium. The optimal conditions for vanillin production strongly depend on pH and temperature. This paper addresses the effect of temperature and pH on vanillin degradation by oxidation. Experiments were carried out in a wide range of vanillin concentration, oxygen partial pressure, temperature and pH. Simple models are proposed to explain the observed rate of vanillin consumption under conditions of high alkalinity (pH > 12) and lower alkalinity (pH < 12). At pH > 12, the reaction rate of vanillin oxidation is first order in dissolved oxygen concentration [O-2] and in vanillin concentration [C], i.e., (-r(C))proportional to[O-2][C]; at pH < 12, the rate is zero order in oxygen concentration and second order in vanillin concentration, i.e., (-r(C)>proportional to f(pH)[C](2).

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10