Kinetics of wet oxidation of propionic and 3-hydroxypropionic acids

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie9900061· OSTI ID:680071

Shende, R V; Levec, J ^[1]

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1. National Inst. of Chemistry, Ljubljana (Slovenia). Lab. for Catalysis and Chemical Reaction Engineering

Oxidation of aqueous solutions of 3-hydroxypropionic (3-HPA) and propionic acids (PA) was studied in a titanium high-pressure reactor at 280--310 C using oxygen partial pressures between 10 and 45 bar. Oxidation of both acids was found to obey first-order kinetic with respect to their concentrations as well as to their lumped TOC concentrations. Oxidation rate revealed a half order dependence with respect to oxygen for oxidation of both acids. In the case of 3-HPA oxidation, the activation energy was found to be 135 kJ/mol, and it was 140 kJ/mol when lumped concentration TOC was used. The activation energy for PA oxidation is 150 kJ/mol, and it is slightly higher, 158 kJ/mol, for TOC reduction. Almost complete conversion of 3-HPA was achieved at 300 C after 1 h, whereas 95% conversion of PA acid was obtained at 310 C after 3 h. During oxidation of 3-HPA, 3-oxopropionic and acetic acids were identified as intermediate products. Oxidation of PA yielded acetic and formic acids as intermediates; at oxygen partial pressures above 25 bar and 310 C, the formation of acetic acid was appreciably reduced. In both cases, however, direct oxidation to carbon dioxide and water was found to be the main reaction route.

• OSTI ID: 680071
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 7 Vol. 38; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
54 ENVIRONMENTAL SCIENCES
ACTIVATION ENERGY
CHEMICAL REACTION KINETICS
LACTIC ACID
PROPIONIC ACID
REACTION INTERMEDIATES
WASTE WATER
WATER TREATMENT
WET OXIDATION PROCESSES