Performance of Trickle Bed Reactor and Active Carbon in the Liquid Phase Oxidation of Phenol

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Nigus Gabbiye ◽  
Josep Font ◽  
Agusti Fortuny ◽  
Christophe Bengoa ◽  
Azael Fabregat ◽  
...  
Keyword(s):  
Liquid Flow ◽  
Active Carbon ◽  
Operating Conditions ◽  
Catalyst Stability ◽  
Wastewater Remediation ◽  
Air Oxidation ◽  
Trickle Bed Reactor ◽  
Phenolic Pollutants ◽  
Wide Range ◽  
Trickle Bed

Application of trickle-bed reactor and active carbon catalyst to catalytic wet air oxidation of phenolic pollutants is explored over a wide range of operating conditions. The study focuses on the assessment of key engineering aspects such as reactor start-up, gas-liquid flow directions and effects of temperature, pressure, phenol feed concentration and liquid flow rate on activity and stability performance of unsupported active carbon. Moreover, for analyzing the potential integration of CWAO as a pre-treatment in biological wastewater remediation, intermediate distribution and biodegradability enhancement of treated effluents are obtained from HPLC analysis and respirometry assays, respectively. Finally, since slow carbon burn-off is occurring at CWAO conditions, some promising options for improvement of catalyst stability are pointed out on both molecular (iron coating of active carbon) and reactor (periodic reactor operation) scale.

Modelling wet-air oxidation of phenol in a trickle-bed reactor using active carbon as a catalyst

2014 ◽  
Vol 91 (3) ◽  
pp. 596-607 ◽  
Author(s):  
Daniel Janecki ◽  
Anna Szczotka ◽  
Andrzej Burghardt ◽  
Grażyna Bartelmus
Keyword(s):  
Active Carbon ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Trickle Bed Reactor ◽  
Oxidation Of Phenol ◽  
Trickle Bed

scholarly journals Applications of Biocatalysts for Sustainable Oxidation of Phenolic Pollutants: A Review

2021 ◽  
Vol 13 (15) ◽  
pp. 8620
Author(s):  
Sanaz Salehi ◽  
Kourosh Abdollahi ◽  
Reza Panahi ◽  
Nejat Rahmanian ◽  
Mozaffar Shakeri ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Operating Conditions ◽  
Phenolic Pollutants ◽  
Petroleum Refinery Wastewater ◽  
Start Up ◽  
Low Concentrations ◽  
Effective Removal ◽  
Wide Range ◽  
Loading Effects ◽  
Spent Caustic

Phenol and its derivatives are hazardous, teratogenic and mutagenic, and have gained significant attention in recent years due to their high toxicity even at low concentrations. Phenolic compounds appear in petroleum refinery wastewater from several sources, such as the neutralized spent caustic waste streams, the tank water drain, the desalter effluent and the production unit. Therefore, effective treatments of such wastewaters are crucial. Conventional techniques used to treat these wastewaters pose several drawbacks, such as incomplete or low efficient removal of phenols. Recently, biocatalysts have attracted much attention for the sustainable and effective removal of toxic chemicals like phenols from wastewaters. The advantages of biocatalytic processes over the conventional treatment methods are their ability to operate over a wide range of operating conditions, low consumption of oxidants, simpler process control, and no delays or shock loading effects associated with the start-up/shutdown of the plant. Among different biocatalysts, oxidoreductases (i.e., tyrosinase, laccase and horseradish peroxidase) are known as green catalysts with massive potentialities to sustainably tackle phenolic contaminants of high concerns. Such enzymes mainly catalyze the o-hydroxylation of a broad spectrum of environmentally related contaminants into their corresponding o-diphenols. This review covers the latest advancement regarding the exploitation of these enzymes for sustainable oxidation of phenolic compounds in wastewater, and suggests a way forward.

Kinetics of phenol oxidation in a trickle bed reactor over active carbon catalyst

2005 ◽  
Vol 80 (6) ◽  
pp. 677-687 ◽  
Author(s):  
Athanasios Eftaxias ◽  
Josep Font ◽  
Agusti Fortuny ◽  
Azael Fabregat ◽  
Frank Stüber
Keyword(s):  
Active Carbon ◽  
Phenol Oxidation ◽  
Carbon Catalyst ◽  
Trickle Bed Reactor ◽  
Trickle Bed ◽  
Kinetics Of

Axial and Radial Investigation of Hydrodynamics in a Bubble Column; Influence of Fluids Flow Rates and Sparger Type

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Hélène Chaumat ◽  
Anne-Marie Billet ◽  
Henri Delmas
Keyword(s):  
Liquid Flow ◽  
Gas Flow ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Pressure Sensors ◽  
Operating Conditions ◽  
Batch Mode ◽  
Flow Rates ◽  
Wide Range ◽  
Injection Zone

A detailed investigation of local hydrodynamics in a pilot plant bubble column has been performed using various techniques, exploring both axial and radial variations of the gas hold-up, bubble average diameter and frequency, surface area. A wide range of operating conditions has been explored up to large gas and liquid flow rates, with two sparger types. Two main complementary techniques were used: a quasi local measurement of gas hold-up via series of differential pressure sensors to get the axial variation and a double optic probe giving radial variations of gad hold-up, bubble average size and frequency and surface area.According to axial evolutions, three zones, where radial evolutions have been detailed, have been separated: at the bottom the gas injection zone, the large central region or column bulk and the disengagement zone at the column top. It was found that significant axial and radial variations of the two phase flow characteristics do exist even in the so called homogeneous regime. The normalized profiles of bubble frequency appear sparger and gas velocity independent contrary to bubble diameter, gas hold-up and interfacial area normalized profiles. In any case bubbles are larger in the sparger zone than elsewhere.The main result of this work is the very strong effect of liquid flow on bubble column hydrodynamics at low gas flow rate. First the flow regime map observed in batch mode is dramatically modified with a drastic reduction of the homogeneous regime region, up to a complete heterogeneous regime in the working conditions (uG> 0.02 m/s). On the contrary, liquid flow has limited effects at very high gas flow rates.A large data bank is provided to be used for example in detailed comparison with CFD calculations.

Catalytic Oxidation of Substituted Phenols in a Trickle Bed Reactor

1997 ◽  
Vol 62 (6) ◽  
pp. 866-874 ◽  
Author(s):  
Vratislav Tukač ◽  
Jiří Hanika
Keyword(s):  
Active Carbon ◽  
Space Velocity ◽  
Hydrodynamic Effect ◽  
Catalytic Wet Oxidation ◽  
Trickle Bed Reactor ◽  
Three Phase ◽  
Comparable Activity ◽  
Trickle Bed ◽  
The Stability ◽  
Active Carbon Black

The catalytic wet oxidation was studied of phenol, 2-aminophenol, salicylic acid and 5-sulfosalicylic acid performed in a laboratory trickle bed reactor. A three-phase high-pressure catalytic reactor with an inside diameter of 18 mm and length of catalytic bed of 200 mm was operated at temperatures 90-180 °C, pressures 2-7 MPa and liquid space velocity 1-10 h-1. Simultaneously, the catalytic activity and the stability of extruded active carbon black Chezacarb and active carbon Chemviron were tested. At a comparable activity, the active carbon Chemviron exhibited a greater mechanical strength and stability. The influence of phenol substituents on the oxidation conversion corresponded to their inductive effect: The electropositive amino group supported the oxidation, on the contrary, the presence of carboxy and sulfo groups on aromatic ring led to only low conversion. The complications on evaluating the experimental data are caused by the non-isothermal temperature profile along the catalyst bed, the non-ideal oxygen dissolution in aqueous solutions and especially the hydrodynamic effect of flow rate on the degree of catalyst wetting and thus on the entire effectiveness of the oxidation process.

The effect of liquid flow distribution on the behaviour of a trickle bed reactor

1981 ◽  
Vol 36 (6) ◽  
pp. 1045-1067 ◽  
Author(s):  
V. Staněk ◽  
J. Hanika ◽  
V. Hlaváček ◽  
O. Trnka
Keyword(s):  
Liquid Flow ◽  
Flow Distribution ◽  
Trickle Bed Reactor ◽  
Trickle Bed
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