Catalytic liquid-phase oxidation of phenol aqueous solutions: A kinetic investigation

Journal Article · Thu Dec 01 00:00:00 EST 1994 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00036a023· OSTI ID:6593282

Pintar, A ^[1]; Levec, J ^[2]

---

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

Catalytic oxidation of aqueous phenol solutions was studied in a differential, liquid-full operated fixed-bed reactor. A proprietary catalyst comprised of supported copper, zinc, and cobalt oxides was found to be effective for converting phenol to benzenedioles and benzoquinones, the C-4 intermediates in total oxidation route, and carbon dioxide. The proposed intrinsic rate expression for the phenol disappearance is based on the Langmuir-Hinshelwood kinetic approach, considering both equilibrium phenol and dissociative oxygen adsorption processes on different types of active sites and assuming a bimolecular surface reaction between adsorbed reactant species to be the rate-controlling step. Apparent activation energies for catalytic phenol oxidation and heat of phenol adsorption, in the temperature range 150--180 C, were found to be 139 and [minus]62 kJ/mol, respectively. It is believed that the liquid-phase oxidation of an aqueous phenol solution undergoes a combined redox and heterogeneous free-radical mechanism. The involvement of a free-radical mechanism is indicated by the intermediates formed and by a pH as well as radical initiator effects on observed phenol disappearance rates.

• OSTI ID: 6593282
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Vol. 33:12; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COBALT OXIDES
CATALYTIC EFFECTS
COPPER OXIDES
PHENOL
OXIDATION
ZINC OXIDES
ACTIVATION ENERGY
ADSORPTION HEAT
CATALYSIS
INDUSTRIAL WASTES
KINETIC EQUATIONS
WASTE WATER
WATER TREATMENT
AROMATICS
CHALCOGENIDES
CHEMICAL REACTIONS
COBALT COMPOUNDS
COPPER COMPOUNDS
ENERGY
ENTHALPY
EQUATIONS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
LIQUID WASTES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHENOLS
PHYSICAL PROPERTIES
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
WASTES
WATER
ZINC COMPOUNDS
320305* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Industrial Waste Management