Oxidation and mineralisation of substituted phenols by Fenton's reagent and catalytic wet oxidation

2007 ◽  
Vol 55 (12) ◽  
pp. 37-45
Author(s):  
A. Santos ◽  
S. Rodriguez ◽  
F. Garcia-Ochoa ◽  
P. Yustos
Keyword(s):  
Activated Carbon ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Wet Oxidation ◽  
Fenton’S Reagent ◽  
Catalytic Wet Oxidation ◽  
Fenton Reagent ◽  
Substituted Phenols ◽  
Fenton's Reagent ◽  
Catalytic Systems

Catalytic abatement of solutions of 1,000 mg/L in phenol, ortho and para nitrophenol and ortho and para cresols was acomplished by using two catalytic systems. Fenton's reagent was used at 50 °C by adding 10 mg/L of ferrous cation and different dosages of H2O2. The mixture was reacting isothermically in a batch way during 3 hours. Catalytic wet oxidation (CWO) was carried out by using a commercial Activated Carbon, Industrial React FE01606A, CWO runs were carried out in a fixed bed reactor (FBR) with concurrent upflow. Temperature and oxygen pressure of the reactor were set to 160 °C and 16 bar, respectively. While phenols are quicky oxidised by the Fenton reagent higher mineralisation was obtained in the CWO process.

Kinetics and mechanism of oxidative decomposition of Congo red by Fenton’s reagent and its synergic effects on exposure to UV radiation

2021 ◽  
Vol 25 (7) ◽  
pp. 8-12
Author(s):  
P. Rajendran ◽  
K. Geethu ◽  
P. Bashpa ◽  
K. Bijudas
Keyword(s):  
Congo Red ◽  
Homogeneous Medium ◽  
Ultra Violet ◽  
Kinetics And Mechanism ◽  
Fenton’S Reagent ◽  
Fenton Reagent ◽  
Fenton's Reagent ◽  
Oxidative Decomposition ◽  
Ultra Violet Radiation ◽  
Thermodynamic Variables

Congo red is a toxic azo dye which is used extensively in industries like textile, paper, pulp and paper. Very high amount of Congo red from these industrial sources is discharged into natural water bodies resulting environmental pollution. The present work reports the kinetics and mechanism of oxidative decomposition of Congo red by Fenton’s reagent in homogeneous medium and also under ultra violet light irradiation. Kinetic parameters like effect of [Fe2+], [H2O2], [Congo red] and temperature on the decomposition of Congo red were studied. The reaction is found to be fractional order with [Fe2+] and first order with [H2O2] and [Congo red]. The rate of oxidative decomposition of Congo red by Fenton’ reagent showed a rapid increase of three times when irradiated with ultra violet radiation and completion of reaction occurred within 5-6 minute. Various thermodynamic variables were determined and the presence of isosbestic points on sequential scanning of oxidation kinetics proves that the reaction is very smooth, spontaneous and endothermic. A suitable mechanism is suggested based on the experimental results obtained.

Preparation of activated carbon from Canadian coals using a fixed-bed reactor and a spouted bed-kiln system

Fuel ◽  
1996 ◽  
Vol 75 (2) ◽  
pp. 227-237 ◽  
Author(s):  
Ajay K. Dalai ◽  
Jasimuz Zaman ◽  
E.Stanley Hall ◽  
Eric L. Tollefson
Keyword(s):  
Activated Carbon ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Spouted Bed

scholarly journals Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC)

2012 ◽  
Vol 1 (3) ◽  
pp. 81 ◽  
Author(s):  
A Buasri ◽  
B Ksapabutr ◽  
M Panapoy ◽  
N Chaiyut
Keyword(s):  
Activated Carbon ◽  
Ethyl Ester ◽  
Calcium Oxide ◽  
Residence Time ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Palm Shell ◽  
Bed Height

: The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR). Transesterification of palm stearin (PS) and waste cooking palm oil (WCPO) with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC) solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE) with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG). The fuel properties of biodiesel were determined. Keywords: biodiesel, calcium oxide, ethyl ester, fixed bed reactor, palm shell activated carbon

scholarly journals Biogas production in the methane fermentation of excess sludge oxidized with Fenton’s reagent

2019 ◽  
Vol 116 ◽  
pp. 00104
Author(s):  
Iwona Zawieja ◽  
Kinga Brzeska
Keyword(s):  
Fermentation Process ◽  
Biogas Production ◽  
Process Conditions ◽  
Oh Radicals ◽  
Fenton’S Reagent ◽  
Iron Ions ◽  
Fenton Reagent ◽  
Excess Sludge ◽  
Methane Fermentation ◽  
Fenton's Reagent

The advanced oxidation processes (AOPs) play an important role in the degradation of hardly decomposable organic pollutants. AOPs methods rely on the production of highly reactive hydroxyl OH• radicals. The aim of the conducted research was to intensify biogas production in the methane fermentation process of excess sludge subjected to the process of deep oxidation with Fenton's reagent. In the process of oxidation of sewage sludge with the Fenton reagent, doses of iron ions in the range 0.02–0.14 g Fe2+/g TS (total solids) were used Hydrogen peroxide was measured in the proportions 1: 1–1:10 in relation to the mass of iron ions. The basic substrate of the study was excess sludge. In the case of excess sludge oxidation with the use of Fenton's reagent, the most favorable process conditions were considered to be the dose of iron ions 0.08 g Fe2+/g d.m. and a Fe2+: H2O2 ratio of 1:5. As a result of subjecting the excess sludge to disintegration with the Fenton reagent in the above-mentioned dose, with respect to the fermentation process of unprocessed sludge, about two-fold increase in the digestion degree of excess sludge and about 35% increase of the biogas yield was obtained.

scholarly journals MgO Dispersed on Activated Carbon as Water Tolerant Catalyst for the Conversion of Ethanol into Butanol

2019 ◽  
Vol 9 (7) ◽  
pp. 1371 ◽  
Author(s):  
Stefano Cimino ◽  
Jessica Apuzzo ◽  
Luciana Lisi
Keyword(s):  
Activated Carbon ◽  
Surface Area ◽  
Fixed Bed ◽  
High Water ◽  
Fixed Bed Reactor ◽  
High Dispersion ◽  
Water Tolerance ◽  
Butanol Yield

MgO supported on activated carbon (AC) with a load ranging from 10% to 30% has been investigated as catalyst for the conversion of ethanol into butanol at 400 °C in a fixed bed reactor at different GHSV. Catalysts have been characterized by XRD, SEM/EDX, and N2 physisorption at 77 K. The high dispersion of MgO into the pores of the support provides strongly enhanced performance with respect to bulk MgO. MgO/AC catalysts have been also tested under wet feed conditions showing high water tolerance and significantly larger butanol yield with respect to an alumina supported Ru/MgO catalyst. After wet operation, the increased surface area of the catalyst leads to better performance once dry feed conditions are restored.

Advances in fixed-bed reactor modeling using particle-resolved computational fluid dynamics (CFD)

2019 ◽  
Vol 35 (2) ◽  
pp. 139-190 ◽  
Author(s):  
Nico Jurtz ◽  
Matthias Kraume ◽  
Gregor D. Wehinger
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fixed Bed ◽  
Review Article ◽  
Catalyst Design ◽  
Fixed Bed Reactor ◽  
Reactor Modeling ◽  
Catalytic Systems ◽  
Heterogeneous Catalytic ◽  
Computational Fluid Dynamics Cfd

Abstract In 2006, Dixon et al. published the comprehensive review article entitled “Packed tubular reactor modeling and catalyst design using computational fluid dynamics.” More than one decade later, many researchers have contributed to novel insights, as well as a deeper understanding of the topic. Likewise, complexity has grown and new issues have arisen, for example, by coupling microkinetics with computational fluid dynamics (CFD). In this review article, the latest advances are summarized in the field of modeling fixed-bed reactors with particle-resolved CFD, i.e. a geometric resolution of every pellet in the bed. The current challenges of the detailed modeling are described, i.e. packing generation, meshing, and solving with an emphasis on coupling microkinetics with CFD. Applications of this detailed approach are discussed, i.e. fluid dynamics and pressure drop, dispersion, heat and mass transfer, as well as heterogeneous catalytic systems. Finally, conclusions and future prospects are presented.

Adsorption Kinetics of Oxytetracycline onto Activated Carbon in a Closed-Loop Fixed Bed Reactor

2013 ◽  
Vol 11 (1) ◽  
pp. 569-576 ◽  
Author(s):  
Djamila Djedouani ◽  
Malika Chabani ◽  
Abdeltif Amrane ◽  
Aicha Bensmaili
Keyword(s):  
Mass Transfer ◽  
Activated Carbon ◽  
Closed Loop ◽  
Solid Phase ◽  
Positive Impact ◽  
Fixed Bed ◽  
Sorption Process ◽  
Fixed Bed Reactor ◽  
Dynamic Interactions ◽  
Initial Concentration

Abstract Batch experiments were carried out for the adsorption of oxytetracycline (OTC) onto powdered activated carbon (PAC). The operating variables examined were the initial concentration (20–150 mg L−1) and the adsorbent concentration (0.75–1.75 g L−1). As observed increasing the initial concentration, while decreasing the adsorbent dosage, had a positive impact on the amount of OTC uptake (mg g−1). The kinetics was examined in a closed-loop fixed bed adsorber to propose an adsorption mechanism, to understand the dynamic interactions of OTC with ECA08 activated carbon and to predict its fate with time. The sorption results were analyzed using chemical and physical kinetics models. For concentrations lower than 70 mg L−1, the sorption process was found to be controlled by both surface reactions and mass transfer. The average external mass transfer coefficient and intraparticle diffusion coefficient were found to be 0.0051 min−1 and 1.97 mg g−1 min−0.5, respectively. For concentrations higher than 70 mg L−1, mass transfer became rapid and the chemical reaction at the surface of the solid phase was the rate-limiting step. The results showed that the adsorption reaction was accurately described by the pseudo-second-order model.

Effect of Fractal Dimension of Powder Activated Carbon on SO2 Adsorption

2014 ◽  
Vol 955-959 ◽  
pp. 2169-2172 ◽  
Author(s):  
Bing Li ◽  
Jian Ming Xue ◽  
Yue Yang Xu ◽  
Hong Liang Wang ◽  
Chun Yuan Ma ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Activated Carbon ◽  
Adsorption Capacity ◽  
Activated Carbons ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Removal Capacity ◽  
Powder Activated Carbon

Five kinds of powder activatedcarbons were studied to investigate the removal of SO2 from flue gasin a fixed bed reactor. The fractal dimension of activated carbon was determined by N2 adsorption isothermat 77Kand SO2 adsorptioncapacity was correlated with thefractal dimension. The results show thatthe activated carbons prepared from different precursors by differentactivation methods have different fractal dimension. Big differences in SO2 adsorption capacity are found between fivekinds of activated carbons. SO2 adsorption capacity increases with the fractaldimension increasing. The results indicate that the fractal dimension could be used as a indicator of SO2removal capacity on powder activated carbon.

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