Heterogeneous Photocatalysis Applied to Indoor Building Material: Towards an Improved Indoor Air Quality

In the present article, kinetics of the photocatalytic oxidation (PCO) of nitric oxide (NO, as a typical air pollutant) is addressed. An extended Langmuir-Hinshelwood reaction rate model is proposed to describe the PCO of NO under indoor air conditions. The derived model incorporates the influence of the indoor air conditions in the process of the PCO. The good agreement between the predictions from the model and experimental results indicates the validity of the proposed model.

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Synergistic Effect of Nanophotocatalysis and Nonthermal Plasma on the Removal of Indoor HCHO

International Journal of Photoenergy ◽

10.1155/2012/354032 ◽

2012 ◽

Vol 2012 ◽

pp. 1-8 ◽

Cited By ~ 15

Author(s):

Yuanwei Lu ◽

Dinghui Wang ◽

Yuting Wu ◽

Chongfang Ma ◽

Xingjuan Zhang ◽

...

Keyword(s):

Synergistic Effect ◽

Indoor Air ◽

Photocatalytic Oxidation ◽

Reaction Rate ◽

Nonthermal Plasma ◽

Pollutant Removal ◽

Pollutant Concentration ◽

Air Purification ◽

Plate Electrode ◽

Air Treatment

Photocatalysis is an effective method of air purification at the condition of a higher pollutant concentration. However, its wide application in indoor air cleaning is limited due to the low level of indoor air contaminants. Immobilizing the nanosized TiO2particles on the surface of activated carbon filter (TiO2/AC film) could increase the photocatalytic reaction rate as a local high pollutant concentration can be formed on the surface of TiO2by the adsorption of AC. However, the pollutant removal still decreased quickly with the increase in flow velocity, which results in a decrease in air treatment capacity. In order to improve the air treatment capacity by the photocatalytic oxidation (PCO) method, this paper used formaldehyde (HCHO) as a contaminant to study the effect of combination of PCO with nonthermal plasma technology (NTP) on the removal of HCHO. The experimental results show that HCHO removal is more effective with line-to-plate electrode discharge reactor; the HCHO removal and the reaction rate can be enhanced and the amount of air that needs to be cleaned can be improved. Meanwhile, the results show that there is the synergistic effect on the indoor air purification by the combination of PCO with NTP.

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Modelling and Simulation of the Radiant Field in an Annular Heterogeneous Photoreactor Using a Four-Flux Model

International Journal of Photoenergy ◽

10.1155/2018/1678385 ◽

2018 ◽

Vol 2018 ◽

pp. 1-16 ◽

Cited By ~ 3

Author(s):

O. Alvarado-Rolon ◽

R. Natividad ◽

R. Romero ◽

L. Hurtado ◽

A. Ramírez-Serrano

Keyword(s):

Photocatalytic Oxidation ◽

Reaction Rate ◽

Comsol Multiphysics ◽

Discrete Ordinate Method ◽

Discrete Ordinate ◽

Cylindrical Coordinates ◽

Volumetric Rate ◽

Flux Model ◽

Reaction Rate Equation ◽

Good Agreement

This work focuses on modeling and simulating the absorption and scattering of radiation in a photocatalytic annular reactor. To achieve so, a model based on four fluxes (FFM) of radiation in cylindrical coordinates to describe the radiant field is assessed. This model allows calculating the local volumetric rate energy absorption (LVREA) profiles when the reaction space of the reactors is not a thin film. The obtained results were compared to radiation experimental data from other authors and with the results obtained by discrete ordinate method (DOM) carried out with the Heat Transfer Module of Comsol Multiphysics® 4.4. The FFM showed a good agreement with the results of Monte Carlo method (MC) and the six-flux model (SFM). Through this model, the LVREA is obtained, which is an important parameter to establish the reaction rate equation. In this study, the photocatalytic oxidation of benzyl alcohol to benzaldehyde was carried out, and the kinetic equation for this process was obtained. To perform the simulation, the commercial software COMSOL Multiphysics v. 4.4 was employed.

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THE KINETICS OF THE DECOMPOSITION REACTIONS OF THE LOWER PARAFFINS: I. n-BUTANE

Canadian Journal of Research ◽

10.1139/cjr38b-025 ◽

1938 ◽

Vol 16b (5) ◽

pp. 176-193 ◽

Cited By ~ 8

Author(s):

E. W. R. Steacie ◽

I. E. Puddington

Keyword(s):

Reaction Rate ◽

High Pressures ◽

The Other ◽

First Order ◽

Decomposition Reactions ◽

Temperature And Pressure ◽

Products Of Reaction ◽

Kinetics Of ◽

Good Agreement ◽

Mechanism Of The Reaction

The kinetics of the thermal decomposition of n-butane has been investigated at pressures from 5 to 60 cm. and temperatures from 513 to 572 °C. The initial first order rate constants at high pressures are given by[Formula: see text]The results are in good agreement with the work of Frey and Hepp, but differ greatly from that of Paul and Marek. The reaction rate falls off strongly with diminishing pressure; this is rather surprising for a molecule as complex as butane. The first order constants in a given run fall rapidly as the reaction progresses. The last two facts suggest that chain processes may be involved.A large number of analyses of the products of reaction have been made at various pressures, temperatures, and stages of the reaction, the method being that of low-temperature fractional distillation. The products are virtually independent of temperature and pressure over the range investigated. The initial products, obtained by extrapolation to zero decomposition, are:—H2, 2.9; CH4, 33.9; C3H6, 33.9; C2H4, 15.2; C2H6, 14.1%. The mechanism of the reaction is discussed, and the results are compared with those of the other paraffin decompositions.

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THE KINETICS OF THE THERMAL DECOMPOSITIONS OF THE LOWER PARAFFINS: V. THE NITRIC OXIDE INHIBITED DECOMPOSITION OF n-BUTANE

Canadian Journal of Research ◽

10.1139/cjr40b-001 ◽

1940 ◽

Vol 18b (1) ◽

pp. 1-11 ◽

Cited By ~ 3

Author(s):

E. W. R. Steacie ◽

H. O. Folkins

Keyword(s):

Nitric Oxide ◽

Thermal Decomposition ◽

Free Radical ◽

High Pressures ◽

Free Radical Processes ◽

Temperature Range ◽

Radical Recombination ◽

Radical Processes ◽

Kinetics Of ◽

Good Agreement

A detailed investigation of the inhibition by nitric oxide of the thermal decomposition of n-butane has been carried out over the temperature range 500° to 550 °C.In all cases it was found that inhibition decreased with increasing butane concentration. This suggests that radical recombination occurs in the normal decomposition by ternary collisions with butane molecules acting as third bodies.The activation energies of the normal and inhibited reactions have been determined. For high pressures the two values are in good agreement, viz., 58,200 and 57,200 cal. per mole respectively. The products of the inhibited reaction were also found to be the same as those of the normal reaction.It is concluded that free radical processes predominate, involving comparatively short chains.

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Photocatalytic oxidation of methyl ethyl ketone over sol-gel and commercial TiO2 for the improvement of indoor air

Water Science & Technology ◽

10.2166/wst.2006.343 ◽

2006 ◽

Vol 53 (11) ◽

pp. 107-115 ◽

Cited By ~ 18

Author(s):

C. Raillard ◽

V. Héquet ◽

P. Le Cloirec ◽

J. Legrand

Keyword(s):

Methyl Ethyl Ketone ◽

Indoor Air ◽

Photocatalytic Oxidation ◽

Degradation Kinetics ◽

Sol Gel ◽

Degradation Pathway ◽

Air Pollutant ◽

Methyl Ethyl ◽

Fixed Temperature ◽

Glass Plates

This work focuses on the photocatalytic oxidation of gaseous methyl ethyl ketone chosen as a typical indoor air pollutant. Two types of TiO2 coatings were prepared and deposited on glass plates: one using the commercial Degussa P25 TiO2 and the other one by sol-gel method. The first objective of this study was to compare different ways of preparing thin films of sol-gel TiO2 coated on glass plates, taking into account their general aspect and their photocatalytic efficiency. Several parameters were tested, such as the stabilising agent, the glass type of the support, the number of coatings and the calcination temperature. One of the synthesised materials was then kept to carry out the following study. The study aimed to assess the influence of TiO2 coating types on the effect of water vapour. This was achieved by performing MEK photocatalytic degradation kinetics under two levels of humidity at a fixed temperature. Experimental results were then modelled by the Langmuir-Hinshelwood equation. The obtained parameters gave specific trends in function of the considered catalyst. The second part of this work was to identify MEK degradation byproducts during its photocatalytic oxidation. The main detected intermediate was acetaldehyde, followed by methyl formate. A MEK degradation pathway was then proposed.

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Effects of HMX Particle Size on the Shock Initiation of PBXC03 Explosive

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2011-0129 ◽

2012 ◽

Vol 13 (2) ◽

Cited By ~ 4

Author(s):

Li-Jing Wen ◽

Zhuo-Ping Duan ◽

Lian-Sheng Zhang ◽

Zhen-Yu Zhang ◽

Zhuo-Cheng Ou ◽

...

Keyword(s):

Experimental Data ◽

Particle Size ◽

Reaction Rate ◽

Pressure Gauge ◽

Rate Model ◽

Shock Initiation ◽

Gauge Data ◽

Medium Formulation ◽

Good Agreement

AbstractA series of shock initiation experiments are performed on the PBXC03 explosives in different formulations to understand the influence of the explosive particle size on the shock initiation, and the in-situ pressure gauge data are obtained which show that shock sensitivity decreases with the explosive particle size under the test condition used in this paper. Moreover, a mesoscopic reaction rate model which is calibrated by the experimental data on a medium formulation PBXC03 explosive is adopted and then applied to predict numerically the shock initiation of other PBXC03 explosives in different formulations. The numerical results are in good agreement with the experimental data.

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Kinetic Model of Thermoelastic Martensite Transformation in Niti and NiMn Based Shape Memory Alloys

MRS Proceedings ◽

10.1557/proc-398-537 ◽

1995 ◽

Vol 398 ◽

Cited By ~ 3

Author(s):

K. H. Wu ◽

J.D. Shi ◽

F. Yang ◽

Z. J. Pu

Keyword(s):

Experimental Data ◽

Shape Memory Alloys ◽

Shape Memory ◽

Martensite Transformation ◽

Quantitative Model ◽

Proposed Model ◽

Series Of Experiments ◽

The Relationship ◽

Kinetics Of ◽

Good Agreement

ABSTRACTA new, quantitative model was developed to describe the martensite transformation kinetics of thermoelastic shape memory alloys (SMAs). In addition, a series of experiments were conducted to study the Kinetics of thermoelastic martensite transformation in four SMA systems: NiTi, NiTi-15at%Hf, NiTi-20at%Zr and NiMn-7.5at%Ti alloys. Comparisons between data of the kinetic of martensite transformation with the present theoretic models show that the proposed model is in good agreement and concurs with the experimental data. Also, a comparison of data from the proposed model with data from existing kinetic models, such as Liang's and Magee's [1,7], indicates that the proposed model can better describe the experimental data, including the relationship between dξ(T)/dT and ξ, and dξ(T)/dT and T.

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Photocatalytic Degradation of Bisphenol AF in TiO2 Suspension

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.2334 ◽

2014 ◽

Vol 955-959 ◽

pp. 2334-2339

Author(s):

Pin Wen Wang

Keyword(s):

Photocatalytic Degradation ◽

Reaction Rate ◽

Degradation Kinetics ◽

Fluoride Concentration ◽

Reaction Rate Constant ◽

Rate Model ◽

Initial Concentration ◽

Fluoride Pollution ◽

Kinetics Of ◽

Bisphenol Af

The photodegradation behavior of bisphenol AF (BPAF) in TiO2 suspension was investigated. The influence of dissolved oxygen, TiO2 dosage, fluoride, and initial BPAF concentration on the degradation of BPAF was studied and described in details. The main purposes were to clarify the degradation kinetics of BPAF and quantify the fluoride concentration during the degradation. At an initial concentration of 40 mol/L, more than 97% of TOC was removed efficiency was achieved within 540 min irradiation, and the concentration of fluoride was 0.98 mg/L. Degradation of BPAF followed the Langmuir–Hinshelwood kinetics rate model and the reaction rate constant kre was 1.21 μM/min. The results obtained indicated that TiO2 photocatalytic degradation is a highly effective way to remove BPAF without any generation of more toxic products or fluoride pollution.

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Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique

Ecological Chemistry and Engineering S ◽

10.2478/v10216-011-0006-y ◽

2012 ◽

Vol 19 (1) ◽

pp. 55-66 ◽

Cited By ~ 5

Author(s):

Marta Siemieniec ◽

Hanna Kierzkowska-Pawlak ◽

Andrzej Chacuk

Keyword(s):

Carbon Dioxide ◽

Reaction Kinetics ◽

Rate Constants ◽

Reaction Rate ◽

Reaction Rate Constant ◽

Stopped Flow ◽

First Order ◽

Pseudo First Order ◽

Kinetics Of ◽

Good Agreement

Reaction Kinetics of Carbon Dioxide in Aqueous Diethanolamine Solutions Using the Stopped-Flow Technique The pseudo-first-order rate constants (kOV) for the reactions between CO2 and diethanolamine have been studied using the stopped-flow technique in an aqueous solution at 293, 298, 303 and 313 K. The amine concentrations ranged from 167 to 500 mol·m-3. The overall reaction rate constant was found to increase with amine concentration and temperature. Both the zwitterion and termolecular mechanisms were applied to correlate the experimentally obtained rate constants. The values of SSE quality index showed a good agreement between the experimental data and the corresponding fit by the use of both mechanisms.

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