Catalysis and Reaction Engineering Commons^™

Band Gap Narrowing Of Titanium Dioxide (Tio2) Nanocrystals By Electrochemically Active Biofilm And Their Visible Light Activity, S. Kalathil, Mohammad Mansoob Khan Dr, Sajid A. Ansari, M. H. Cho, J. Lee

Dr. Mohammad Mansoob Khan

We report a simple biogenic-route to narrow the band gap of TiO2 nanocrystals for visible light application by offering a greener method. When an electrochemically active biofilm (EAB) was challenged with a solution of Degussa-TiO2 using sodium acetate as electron donor, greyish blue-colored TiO2 nanocrystals were obtained. Band gap study showed that band gap of the modified TiO2 nanocrystals was significantly reduced (Eg = 2.85 eV) compared to the unmodified white Degussa TiO2 (Eg = 3.10 eV).

Solar And Visible Light Driven Photocatalysis For Sacrificial Hydrogen Generation And Water Detoxification With Chemically Modified Ti02, Pankaj Chowdhury

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Photocatalysis is a recognized approach where light energy is employed to excite the semiconductor material producing electron/hole pair which eventually involves in the detoxification of pollutants and/or water splitting producing hydrogen. Existing photocatalysts suffer from poor activity or no activity in visible light irradiation which restricts them from solar light utilization. This work is focused on two key applications of photocatalysis (i) sacrificial hydrogen generation, and (ii) phenol degradation in visible and/or solar light. Platinum was loaded on TiO2 photocatalyst by solar photo-deposition method. Eosin Y dye was used as a sensitizer for sensitization of platinum loaded TiO2 photocatalyst. The …

Optimization And Statistical Modeling Of Catalytic Oxidation Of 2-Propanol Over Cumn_Mco_(2-M)O4 Nano Spinels By Unreplicated Split Design Methodology, Seyed Ali Hosseini, Aligholi Niaei, Dariush Salari, Raimundo K. Vieira, Shamil Sadigov, Reza Nabavi

Seyed Reza nabavi

Optimization of 2-propanol oxidation over CuMn_mCo_(2-m)O4 nanospinels was carried out by a split design method. 15-term model was proposed to fit the experimental data. The model revealed that both whole plot and subplot variables have significant effects on conversion of 2-propanol. The model predicted the interaction of subplot and whole plot variables as well as their importance. The maximum conversion of 2-propanol was observed over CuMn2O4 (x1 = 0.33, x2 = 0, x3 = 0.67) at calcination and reaction temperatures of 800 8C (z1 = 1) and 300 8C (z2 = 1), respectively. The predicted response and the response obtained …

Effect Of The Oil Acidity On The Methanolysis Performances Of Lime Catalyst Biodiesel From Waste Frying Oils (Wfo), João F. Gomes

João F Gomes

No abstract provided.

Gomes, J.F.P., Bordado, J., Tomás, R., P-Xylene Oxidation To Terephthalic Acid. A Literature Review Oriented Toward Process Optimization And Development”, Chemical Reviews (2013), João F. Gomes

João F Gomes

No abstract provided.

Biodiesel Production From Waste Trying Oils Over Lime Catalysts, João F. Gomes

João F Gomes

No abstract provided.

Fast Catalytic Oxidation Of Phenol Over Modified Zeolite L Nanocrystals, Eng-Poh Ng Dr.

Eng-Poh Ng

Iron modified zeolite L nanocrystals (Fe/KL) were synthesized hydrothermally by the incorporation of Fe3+ in zeolite L lattice. XRD results showed an increase in the inter-planar spacing and lattice parameters. Transition characteristic of the tetrahedral Fe3+ species were observed in the UV–Vis spectrum. The oxidation of phenol in the presence of acetic acid over Fe/KL gave 93.40% conversion in 30 min with selective formation of 77.47% catechol and 22.53% hydroquinone. The catalytic activity was significantly enhanced by the addition of acetic acid. It was found that the acetic acid was oxidized by hydrogen peroxide to form peracetic acid, which served …

Chapter 5 Adsorption, Eng-Poh Ng Dr.

Eng-Poh Ng

No abstract provided.

Sulfonic Acid Functionalized Mcm-41 As Solid Acid Catalyst For Tert-Butylation Of Hydroquinone Enhanced By Microwave Heating, Eng-Poh Ng

Eng-Poh Ng

Covalently linked sulfonic acid (-SO3H) modified MCM-41 mesoporous catalysts was prepared, characterized and its catalytic activity under microwave irradiation was evaluated. The NH2-MCM-41 was first prepared by anchoring (3-aminopropyl)triethoxysilane (APTES) on Si-MCM-41 and further reacted with 1,4-butane-sultone to yield the desired acid catalyst. The mesophase and porosity of samples were determined by XRD, TEM and N2 sorption isotherm analyses. The presence of sulfonic acid moiety was confirmed by FT-IR, TG/DTA, sulfur elemental analysis and in situ IR study of pyridine and ammonia adsorptions. The catalyst showed high catalytic activity and high selectivity in tert-butylation of hydroquinone under microwave irradiation. No …

Mechaniczny Rozdział Faz Proj., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Challenges And Prospects Of Processes Utilising Carbonic Anhydrase For Co2 Separation, Patrycja Szeligiewicz, Wojciech M. Budzianowski

Wojciech Budzianowski

This article provides an analysis of processes for separation CO2 by using carbonic anhydrase enzyme with particular emphasis on reactive-membrane solutions. Three available processes are characterised. Main challenges and prospects are given. It is found that in view of numerous challenges practical applications of these processes will be difficult in near future. Further research is therefore needed for improving existing processes through finding methods for eliminating their main drawbacks such as short lifetime of carbonic anhydrase or low resistance of reactive membrane systems to impurities contained in flue gases from power plants.

Sacrificial Hydrogen Generation From Formaldehyde With Pt/Tio2 Photocatalyst In Solar Radiation, Pankaj Chowdhury, Ghodsieh Malekshoar, Madhumita Ray, Jesse Zhu, Ajay Ray

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In this work, solar TiO2 photocatalysis was used for sacrificial hydrogen generation from formaldehyde. Platinum was loaded onto a TiO2 photocatalyst by a solar photodeposition method to suppress the electron/hole recombination process. The photocatalyst inside the reactor was irradiated from the top with a solar simulator. Photocatalytic hydrogen generation from formaldehyde was influenced by the solution pH, platinum loading (wt %) on TiO2, catalyst concentration, light intensity, and initial formaldehyde concentration. A Langmuir-type model fitted well with the experimental data, and the values of surface reaction rate constant, k, and the adsorption equilibrium constant, K, are 2.3598 × 10–6 mol …

Biodiesel Production Over Lithium Modified Lime Catalysts: Activity And Deactivation, João F. Gomes

João F Gomes

No abstract provided.

Determination Of Kinetic Parameters From The Thermogravimetric Data Set Of Biomass Samples, Karol Postawa, Wojciech M. Budzianowski

Wojciech Budzianowski

This article describes methods of the determination of kinetic parameters from the thermogravimetric data set of biomass samples. It presents the methodology of the research, description of the needed equipment, and the method of analysis of thermogravimetric data. It describes both methodology of obtaining quantitative data such as kinetic parameters as well as of obtaining qualitative data like the composition of biomass. The study is focused mainly on plant biomass because it is easy in harvesting and preparation. Methodology is shown on the sample containing corn stover which is subsequently pyrolysed. The investigated sample show the kinetic of first order …

Determination Of The Kinetic Parameter In The Photodegradation Of Phenol By A Unified Kinetic Model By Using Least Square Curve Fitting And The Genetic Algorithm., Jesus Moreira Del Rio, Benito Serrano, Hugo De Lasa

Jesus Moreira del Rio

No abstract provided.

A Unified Kinetic Model For Phenol Photocatalytic Degradation Over Tio2 Photocatalysts, Jesus Moreira Del Rio, Benito Serrano, Aaron Ortiz, Hugo De Lasa

Jesus Moreira del Rio

This study reports the kinetics of the photocatalytic degradation of phenol using four different TiO2 catalysts. It is shown that phenol yields hydroquinone, catechol, benzoquinone and acetic and formic acids as main intermediate species. A phenomenological unified kinetic model (UKM) based in a “series-parallel” reaction network is proposed. The UKM follows a Langmuir-Hinshelwood kinetics with this being applicable to the various TiO2 photocatalysts studied. The UKM requires a number of significant assumptions in order to be used effectively avoiding overparametization. This approach also requires that the adsorption constants be obtained independently. As a result, the UKM is adapted for each …

Experimental And Modeling Study Of Continuous Catalytic Transesterification To Biodiesel In A Bench-Scale Fixed-Bed Reactor, Yang Xiao, Guomin Xiao

Yang Xiao

Visible-Solar-Light-Driven Photocatalytic Degradation Of Phenol With Dye-Sensitized Tio2: Parametric And Kinetic Study, Pankaj Chowdhury, Jesus Moreira Del Rio, Hassan Gomaa, Ajay K. Ray

Jesus Moreira del Rio

Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a …

Visible-Solar-Light-Driven Photocatalytic Degradation Of Phenol With Dye-Sensitized Tio2: Parametric And Kinetic Study, Pankaj Chowdhury, Jesus Moreira Del Rio, Hassan Gomaa, Ajay K. Ray

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Phenol degradation with TiO2 photocatalyst under UV light is known to be an effective method. Under solar radiation, however, this approach does not receive adequate photons for catalyst activation, as the solar spectrum comprises mostly visible light (46%). In this study, we applied the dye-sensitization technique to prepare visible-light-active catalyst and used it under visible solar light generated from a solar simulator with a UV cutoff filter (λ > 420 nm) for phenol degradation. Eosin Y dye was used as a sensitizer for the TiO2 catalyst with a very low level of platinum as a cocatalyst. Triethanolamine was used as a …

Photocatalytic Degradation Of Phenolic Compounds In Water: Irradiation And Kinetic Modeling, Jesus Moreira Del Rio

Jesus Moreira del Rio

Scaling up a photoreactor requires both knowledge of optical properties of the slurry medium and an established kinetic model. Measuring the scattering and absorption coefficients of particles suspended in water involves the use of specialized optical equipment, as well as the partial solution of the radiative transfer equation (RTE). In addition, modeling of the radiation field in photoreactors with complicated geometries offers special challenges. On the other hand, most of the kinetic models (KM) for phenol photodegradation reported in the literature were obtained for a single organic chemical species only. In fact, neglecting all the intermediate species generated during the …

Kinetic Analytical Method For Determination Of Uric Acid In Human Urine Using Analyte Pulse Perturbation Technique, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.

Monitoring Exposure To Airborne Ultrafine Particles In Lisbon, Portugal, João F. Gomes

João F Gomes

No abstract provided.

Comparison Of Deposited Surface Area Of Airborne Ultrafine Particles Generated From Two Welding Processes, João F. Gomes

João F Gomes

No abstract provided.

Capturing Ultrasmall Emt Zeolite From Template-Free Systems, Eng-Poh Ng Dr.

Eng-Poh Ng

No abstract provided.

Ogólnotechniczne Podstawy Biotechnologii Z Elementami Grafiki Inżynierskiej Ćw., Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Materiały Odstresowujące, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Oxidative Carbonylation Of 2-Propyn-1-Ol And 2-Methyl-3-Butyn-2-Ol In An Oscillatory Mode, Sergey N. Gorodsky

Sergey N. Gorodsky

No abstract provided.

Chemically Modified Multi-Walled Carbon Nanotubes (Mwcnts) With Anchored Acidic Groups, Nuruzatulifah Bt Asari Mansor, Jean-Philippe Tessonnier, Ali Rinaldi, Sylvia Reiche, M. G. Kutty

Jean-Philippe Tessonnier

Surface functionalization of multi-walled carbon nanotubes (MWCNTs) was carried out using a gas phase treatment in a Universal Temperature Program (UTP) reactor by flowing SO 3 gas onto the CNTs while being heated at different temperatures. The functionalized nanotubes were characterized using X-ray Fluorescence (XRF), Fourier Transform Infrared Spectroscopy (FT-IR) and Raman spectroscopy. The amount of oxyen and sulfur containing groups was determined by acid-base titration. The titration results were in good agreement with elemental analysis using X-ray fluorescence. FTIR analysis showed the presence of oxygen and sulfur containing groups, S=O, C-S, C=O and-COOH. Raman spectroscopy confirmed that oxygen and …

The Role Of The Phase Function In Monte Carlo Simulations For Modeling The Radiation Field In Photoreactors., Jesus Moreira Del Rio, Benito Serrano Rosales, Hugo De Lasa

Jesus Moreira del Rio

No abstract provided.

Determination Of Airborne Nanoparticles From Welding Operations, João F. Gomes

João F Gomes

The aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas (TIG), metal active gas (MAG) of carbon steel and friction stir welding (FSW) of aluminium) in terms of deposited area in pulmonary alveolar tract using a Nanoparticle Surface Area Monitor (NSAM) analyzer. The obtained results showed the dependence from process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and …