Photocatalytic Oxidation of Glycerol over ZnO: Systematic Evaluation of Reaction Parameters

2015 ◽  
Vol 18 (2) ◽  
Author(s):  
Natanael A. Hermes ◽  
André R. Corsetti ◽  
Amise S. Pacheco ◽  
Marla A. Lansarin
Keyword(s):  
Photocatalytic Oxidation ◽  
Batch Reactor ◽  
Oxidation Products ◽  
Biodiesel Production ◽  
Systematic Evaluation ◽  
Main Reaction ◽  
Significant Variable ◽  
Reaction Parameters ◽  
Glycerol Conversion ◽  
Optimum Result

AbstractPhotocatalytic oxidation of glycerol emerges as a potential alternative to contribute to the utilization of surplus glycerol from biodiesel production. In this work, we studied the main reaction parameters for ZnO, i.e. catalyst concentration (Ccat), initial pH and temperature (T), evaluating their influence on the conversion, selectivity and yield of the main C3 products (glyceraldehyde - GAD and dihydroxyacetone - DHA). The tests were carried out in a batch reactor (slurry) under UV radiation. The oxidation products were analysed by HPLC. When the parameters were varied individually, glycerol conversion and C3 yield increased with the increase in Ccat, pH and T, but C3 selectivity remained practically unchanged. When the parameters were varied simultaneously in a design of experiments, again the conversion increased as the parameters increased, whereby pH was the most significant variable for conversion and T for the selectivity of both GAD and DHA. The optimum result for conversion after 1h was 65%, achieved at Ccat = 4 g L

Ozonation and reductive deiodination of iopromide to reduce the environmental burden of iodinated X-ray contrast media

2007 ◽  
Vol 56 (11) ◽  
pp. 159-165 ◽  
Author(s):  
A. Putschew ◽  
U. Miehe ◽  
A.S. Tellez ◽  
M. Jekel
Keyword(s):  
Contrast Media ◽  
Tap Water ◽  
Batch Reactor ◽  
Pure Water ◽  
Transformation Products ◽  
Zero Valent Iron ◽  
Oxidation Products ◽  
Reductive Dehalogenation ◽  
Main Reaction ◽  
X Ray

The potential of ozonation for the removal of iodinated X-ray contrast media (ICM) with focus on the oxidation products was examined. Iopromide used as model compound was dissolved in tap water, respectively in the effluent of a membrane bioreactor and was ozonated. Ozone (10 mg/L) was continuously introduced into a semi-batch reactor (35 L/h). After 30 minutes the ozone concentration was increased to 30 mg/L. In all experiments the iopromide concentration decreased very fast, whereas the decrease of the amount of organic bound iodine (AOI) was much lower. The concentration of iodate, the inorganic oxidation product increases with time, depending on the AOI decrease. The data clearly show that the ozonation of iopromide using a common applied ozone dosage leads to the formation of numerous iodinated transformation products, which are detectable by LC-ESI-MS. As an alternative treatment, especially for the treatment of urine or hospital waste water, the source for the contamination, it was tested if iopromide can be deiodinated by zero-valent iron. First experiments done in stirred batch reactors using iopromide dissolved in ultra pure water and urine with an initial pH of 2 showed that iopromide can be deiodinated completely by zero-valent iron. Even in contaminated urine collected in a hospital a deiodination of ICM was possible. Kinetic studies at constant pH showed that the deiodination can be described by pseudo-first order for equal iopromide and iron concentrations. The observed rate constant kobs increased with decreasing pH with a maximum at pH 3 with 4.76 × 10−4 s−1. The concentration of iopromide can be decreased by ozonation and by the reductive dehalogenation. In case of ozonation iodinated organic compounds are the main reaction products, whereas the reductive dehalogenation leads to transformation products which are not iodinated and are thus most probable biodegradable.

GLYCEROL AS ADDITIVE FOR FUELS – A REVIEW

2014 ◽  
Vol 44 (1) ◽  
pp. 47-56
Author(s):  
M. O. FERREIRA ◽  
L. CARDOZO-FILHO ◽  
C. SILVA ◽  
E.M. B.D. SOUSA
Keyword(s):  
Process Optimization ◽  
Vegetable Oils ◽  
Transesterification Reaction ◽  
Biodiesel Production ◽  
Main Reaction ◽  
Environmental Concerns ◽  
Glycerol Production ◽  
Reaction Parameters ◽  
Production Processes ◽  
New Applications

Growing environmental concerns, along with the search for renewable energies that emit less CO2, put biodiesel in a favorable position. Biodiesel is commonly produced by the transesterification reaction between vegetable oils and methanol or ethanol, in the presence of a catalyst. With government incentives for biodiesel production in Brazil, there was an exaggerated increase in their production and hence the concern about the disposal of surplus glycerol. Therefore research is being developed with respect to the use of the surplus of glycerol. In this context, emerged as the alternative use of fuel additives, from glycerin to contribute to the development of new applications for innovative and environmentally-friendly processes. The bibliographic review presented here starts with describing the different glycerol production processes, characterization and analysis methods. Next, Glycerol-based processing methods are described, evaluating the main reaction parameters that interfere in process optimization.

scholarly journals THE SYNTHESIS OF GLYCEROL CARBONATE FROM BIODIESEL BYPRODUCT GLYCEROL AND UREA OVER AMBERLYST 36

2017 ◽  
Vol 6 (1) ◽  
pp. 1-5
Author(s):  
Astri Senania ◽  
Hary Sulistyo ◽  
Agus Prasetya
Keyword(s):  
Reaction Temperature ◽  
Catalyst Concentration ◽  
Batch Reactor ◽  
Raw Material ◽  
Biodiesel Production ◽  
Glycerol Carbonate ◽  
Glycerol Conversion ◽  
Pharmaceutical Industries ◽  
Derivative Products ◽  
Glycerol Derivative

The increasing use of biodiesel as renewable fuels leads to the increasing of glycerol amount as a byproduct of biodiesel production. One of the glycerol derivative products that is environmentally friendly and renewable is glycerol carbonate. Glycerol carbonate is commonly used as a raw material for polymers, surfactants, emulsifiers, lubricants, paints, also used in the cosmetics and pharmaceutical industries. In this study, the research was carried out by using a batch reactor with a three-neck flask equipped with reverse cooling, thermometers, mercury stirrer, and heating mantle with the conditions of the reaction temperature around 373 413 K, mole ratio of reactants of urea: glycerol were 1:0,5, 1:1, 1:1,5, 1:2 and 1:4 and the concentration of catalyst were 1%, 2%, 3%, 4% and 5% respectively. Reaction was done for four hours. The results showed that the formation of glycerol carbonate from glycerol and urea using a catalyst Amberlyst 36 is affected by the catalyst concentration, reaction temperature and the ratio of reactants used. The highest glycerol conversion was obtained at 55.07% at a temperature of 393 K with mole ratio of urea and glycerol 1:0,5 and the percentage of catalyst 3% of the amount of glycerol.

Photocatalytic oxidation and subsequent adsorption characteristics of humic acids

1996 ◽  
Vol 34 (9) ◽  
pp. 65-72 ◽  
Author(s):  
Miray Bekbölet ◽  
Ferhan Çeçen ◽  
Gülhan Özkösemen
Keyword(s):  
Activated Carbon ◽  
Humic Acid ◽  
Humic Acids ◽  
Photocatalytic Oxidation ◽  
Irradiation Time ◽  
Batch Reactor ◽  
Freundlich Isotherm ◽  
Oxidation Products ◽  
Adsorption Characteristics ◽  
Significant Change

Effect of TiO2 photocatalyzed oxidation on the degradation and decolorization of humic acids was studied. The photocatalytic oxidation products were further investigated in terms of adsorptivity on activated carbon. With photocatalytic oxidation in a lab-scale batch reactor significant decolorization and a decrease in UV280 and UV254 took place. Simultaneously there was a decrease in TOC and COD. Parallel to this an evolution of BOD5 was observed. Thus the BOD5/COD ratio increased with irradiation time and more biodegradable substances have been formed. A significant change in the structure of compounds in humic acid took place only after 3-4 hours of irradiation as determined by the decrease in COD/TOC ratio. Generally there was a slight decrease of adsorptivity after irradiation as concluded from the comparison of Freundlich isotherm constants for raw and irradiated humic acid. This decrease increased as the irradiation time increased. But for irradiation times to be used in practice in photocatalytic oxidation no significant change in adsorption is expected.

scholarly journals Photocatalytic Pretreatment of Commercial Lignin Using TiO2-ZnO Nanocomposite-Derived Advanced Oxidation Processes for Methane Production Synergy in Lab Scale Continuous Reactors

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 54
Author(s):  
Yu-Ming Chu ◽  
Hafiz Muhammad Asif Javed ◽  
Muhammad Awais ◽  
Muhammad Ijaz Khan ◽  
Sana Shafqat ◽  
...  
Keyword(s):  
Photocatalytic Oxidation ◽  
Advanced Oxidation Processes ◽  
Synergistic Effects ◽  
Oxidation Products ◽  
Methane Yield ◽  
Zno Nanoparticle ◽  
Coumaric Acid ◽  
Stirred Tank Reactors ◽  
Lignin Oxidation ◽  
Constant Operation

The photocatalytic pretreatment of lignocellulosic biomass to oxidize lignin and increase biomass stability has gained attention during the last few years. Conventional pretreatment methods are limited by the fact that they are expensive, non-renewable and contaminate the anaerobic digestate later on. The present study was focused to develop a metal-derived photocatalyst that can work with visible electromagnetic spectra light and oxidize commercial lignin liquor. During this project the advanced photocatalytic oxidation of lignin was achieved by using a quartz cube tungsten T3 Halogen 100 W lamp with a laboratory manufactured TiO2-ZnO nanoparticle (nanocomposite) in a self-designed apparatus. The products of lignin oxidation were confirmed to be vanillic acid (9.71 ± 0.23 mg/L), ferrulic acid (7.34 ± 0.16 mg/L), benzoic acid (6.12 ± 0.17 mg/L) and p-coumaric acid (3.80 ± 0.13 mg/L). These all products corresponded to 85% of the lignin oxidation products that were detectable, which is significantly more than any previously reported lignin pretreatment with even more intensity. Furthermore, all the pretreatment samples were supplemented in the form of feedstock diluent in uniformly operating continuously stirred tank reactors (CSTRs). The results of pretreatment revealed 85% lignin oxidation and later on these products did not hinder the CSTR performance at any stage. Moreover, the synergistic effects of pretreated lignin diluent were seen that resulted in 39% significant increase in the methane yield of the CSTR with constant operation. Finally, the visible light and nanoparticles alone could not pretreat lignin and when used as diluent, halted and reduced the methane yield by 37% during 4th HRT.

scholarly journals Solvent-Free Benzylation of Glycerol by Benzyl Alcohol Using Heteropoly Acid Impregnated on K-10 Clay as Catalyst

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Devendra P. Tekale ◽  
Ganapati D. Yadav ◽  
Ajay K. Dalai
Keyword(s):  
Heterogeneous Catalysis ◽  
Benzyl Alcohol ◽  
Batch Reactor ◽  
Value Added ◽  
Solvent Free ◽  
Biodiesel Production ◽  
Area Measurement ◽  
Solid Catalyst ◽  
Glycerol Ether ◽  
Insight Into

Value addition to glycerol, the sole co-product in biodiesel production, will lead to reform of the overall biodiesel economy. Different valuable chemicals can be produced from glycerol using heterogeneous catalysis and these valuable chemicals are useful in industries such as cosmetics, pharmaceuticals, fuels, soap, paints, and fine chemicals. Therefore, the conversion of glycerol to valuable chemicals using heterogeneous catalysis is a noteworthy area of research. Etherification of glycerol with alkenes or alcohols is an important reaction in converting glycerol to various value-added chemicals. This article describes reaction of glycerol with benzyl alcohol in solvent-free medium by using a clay supported modified heteropolyacid (HPA), Cs2.5H0.5PW12O40/K-10 (Cs-DTP/K-10) as solid catalyst and its comparison with other catalysts in a batch reactor. Mono-Benzyl glycerol ether (MBGE) was the major product formed in the reaction along with formation of di-benzyl glycerol ether (DBGE). The effects of different parameters were studied to optimize the reaction parameters. This work provides an insight into characterization of Cs2.5H0.5PW12O40/K-10 catalyst by advanced techniques such as surface area measurement, X-ray analysis, ICP-MS, FT-IR, and SEM. Reaction products were characterized and confirmed by using the GCMS method. The kinetic model was developed from an insight into the reaction mechanism. The apparent energy of activation was found to be 18.84 kcal/mol.

Preparation of Ni Loaded on Zeolite and its Application for Conversion of Glycerol to Hydrogen

2013 ◽  
Vol 845 ◽  
pp. 457-461
Author(s):  
Ramli Mat ◽  
Junaidah Buhari ◽  
Mahadhir Mohamed ◽  
Anwar Johari ◽  
Tuan Amran Tuan Abdullah ◽  
...  
Keyword(s):  
Structural Characterization ◽  
Hydrogen Gas ◽  
Biodiesel Production ◽  
Esterification Reaction ◽  
Glycerol Conversion ◽  
Reactor Temperature

Glycerol is the main by-product of biodiesel production and during the trans-esterification reaction, about 10 wt % of glycerol is produced. In this study, different amount of Ni was loaded on HZSM-5 and tested for the conversion of glycerol to hydrogen. The studies were also conducted at different reactor temperature of 450, 500, 550, 600 and 650°C respectively. The structural characterization of the catalyst was carried out using the XRD. It was found that, the addition of 15 wt % of nickel loaded on HZSM-5 shows the highest glycerol conversion of 98.54%. In addition, it produces the highest yield of hydrogen gas operated at reactor temperature of 600°C.

THE KINETICS OF THE OXIDATION OF GASEOUS ACETALDEHYDE

1932 ◽  
Vol 7 (2) ◽  
pp. 149-161 ◽  
Author(s):  
W. H. Hatcher ◽  
E. W. R. Steacie ◽  
Frances Howland
Keyword(s):  
Carbon Dioxide ◽  
Formic Acid ◽  
Induction Period ◽  
Reaction Vessel ◽  
Oxidation Products ◽  
Main Reaction ◽  
Chain Mechanism ◽  
Subsequent Reaction ◽  
A Chain ◽  
Kinetics Of

The kinetics of the oxidation of gaseous acetaldehyde have been investigated from 60° to 120 °C. by observing the rate of pressure decrease in a system at constant volume. A considerable induction period exists, during which the main products of the reaction are carbon dioxide, water, and formic acid. The main reaction in the subsequent stages involves the formation of peroxides and their oxidation products. The heat of activation of the reaction is 8700 calories per gram molecule. The indications are that the reactions occurring during the induction period are heterogeneous. The subsequent reaction occurs by a chain mechanism. The chains are initiated at the walls of the reaction vessel, and are also largely broken at the walls.

scholarly journals PEMBUATAN BIOADITIF TRIACETIN DENGAN KATALIS PADAT SILICA ALUMINA

2017 ◽  
Vol 5 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Agus Aktawan ◽  
Zahrul Mufrodi
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Reaction Time ◽  
Biodiesel Production ◽  
Gas Chromatography Mass Spectrometry ◽  
Solid Catalyst ◽  
Heating Unit ◽  
Glycerol Conversion ◽  
Silica Alumina

Triasetin is a bioaditif to increase the octane number of the gasoline. Triasetin was generated from the reaction between giserol and acetic acid. Glycerol is a byproduct of biodiesel production. Triasetin production can reduce glycerol which is actually a waste by converting it into bioaditif having higher value. The reaction can be accelerated by addition of catalysts either solid or liquid catalyst. The reaction in this study used a solid catalyst types Silica Alumina. The reaction takes place in the three-neck flask reactor which is equipped with heating unit, mixers, and tools to take samples at regular intervals. Variables used in this research is the variety of reaction time and the reaction temperature (70, 80, 90, 100, and 1100C). The concentration of triasetin obtained will be known through the analysis of Gas Chromatography - Mass Spectrometry (GC-MS). The results of the analysis of GC or GC-MS treated or counted so getting glycerol conversion and selectivity of triasetin. The highest glycerol conversion 8,45% occurs at a temperature of 700C the reaction time of 90 minutes with triasetin selectivity 100%.

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