Catalytic Performance of Nanosized Pt–Au Alloy Catalyst in Oxidation of Methanol and Toluene

2007 ◽  
Vol 7 (11) ◽  
pp. 3795-3799
Author(s):  
Ki-Joong Kim ◽  
Yong-Hwa Kim ◽  
Ho-Geun Ahn
Keyword(s):  
Flow Rate ◽  
Catalytic Performance ◽  
Exhaust Gas ◽  
Complete Oxidation ◽  
Feed Flow Rate ◽  
Group Viii ◽  
Alumina Support ◽  
Oxidation Activity ◽  
Oxidation Of Methanol ◽  
Monolith Catalyst

The alloy formed between a group-VIII metal such as platinum and a group-IB metal such as gold changes the catalytic behavior compared to the monometallic phase, increasing the selectivity toward certain products and also decreasing the deactivation rate. Pt–Au alloy nanoparticles coated on alumina support were found to be catalytically very active for complete oxidation of methanol and toluene. Furthermore, the nanosized Pt–Au particles were added to ZnO/Al2O3 on monolith catalyst. Also, effect of various parameters such as concentration of methanol and toluene and feed flow rate was investigated. Au particles were sized in 20∼30 nm and Pt particles were well dispersed. In case of alumina supported powder catalyst, complete oxidation of methanol occurred at a temperature lower than that of toluene. From oxidation activity of monolithic honeycomb with Pt and Au particles, the conversion of methanol was increased with increasing the concentration of methanol, but conversion of toluene showed a decreasing tendency as the concentration of toluene increased. Also, conversion of methanol over honeycomb catalyst was not largely affected by feed flow rate, while conversion in toluene oxidation was decreased rapidly as feed flow rate was increased. As a result, the Pt-Au/ZnO/Al2O3/M catalyst used is likely to efficiently treat a large volume of exhaust gas containing VOCs.

Catalytic Performance of Nanosized Pt–Au Alloy Catalyst in Oxidation of Methanol and Toluene

2007 ◽  
Vol 7 (11) ◽  
pp. 3795-3799
Author(s):  
Ki-Joong Kim ◽  
Yong-Hwa Kim ◽  
Ho-Geun Ahn
Keyword(s):  
Flow Rate ◽  
Catalytic Performance ◽  
Exhaust Gas ◽  
Complete Oxidation ◽  
Feed Flow Rate ◽  
Group Viii ◽  
Alumina Support ◽  
Oxidation Activity ◽  
Oxidation Of Methanol ◽  
Monolith Catalyst

The alloy formed between a group-VIII metal such as platinum and a group-IB metal such as gold changes the catalytic behavior compared to the monometallic phase, increasing the selectivity toward certain products and also decreasing the deactivation rate. Pt–Au alloy nanoparticles coated on alumina support were found to be catalytically very active for complete oxidation of methanol and toluene. Furthermore, the nanosized Pt–Au particles were added to ZnO/Al2O3 on monolith catalyst. Also, effect of various parameters such as concentration of methanol and toluene and feed flow rate was investigated. Au particles were sized in 20∼30 nm and Pt particles were well dispersed. In case of alumina supported powder catalyst, complete oxidation of methanol occurred at a temperature lower than that of toluene. From oxidation activity of monolithic honeycomb with Pt and Au particles, the conversion of methanol was increased with increasing the concentration of methanol, but conversion of toluene showed a decreasing tendency as the concentration of toluene increased. Also, conversion of methanol over honeycomb catalyst was not largely affected by feed flow rate, while conversion in toluene oxidation was decreased rapidly as feed flow rate was increased. As a result, the Pt-Au/ZnO/Al2O3/M catalyst used is likely to efficiently treat a large volume of exhaust gas containing VOCs.

Experimental and Modelling of Aqueous Radioactive Waste Treatment by Ultrafiltration

2018 ◽  
Vol 69 (5) ◽  
pp. 1149-1151
Author(s):  
Laura Ruxandra Zicman ◽  
Elena Neacsu ◽  
Felicia Nicoleta Dragolici ◽  
Catalin Ciobanu ◽  
Gheorghe Dogaru ◽  
...  
Keyword(s):  
Flow Rate ◽  
Suspended Solids ◽  
Waste Treatment ◽  
Operating Pressure ◽  
Feed Flow Rate ◽  
Permeate Flux ◽  
Independent Variables ◽  
Opposite Trend ◽  
Process Factors ◽  
Volumetric Flux

Ultrafiltration of untreated and pretreated aqueous radioactive wastes was conducted using a spiral-wound polysulphonamide membrane. The influence of process factors on its performances was experimental studied and predicted. Permeate volumetric flux and permeate total suspended solids (TSS) were measured at different values of feed flow rate (7 and 10 m3/h), operating pressure (0.1-0.4 MPa), and feed TSS (15 and 60 mg/L). Permeate flux (42-200 L/(m2�h)) increased with feed flow rate and operating pressure as well as it decreased with an increase in feed TSS, whereas permeate TSS (0.1-33.2 mg/L) exhibited an opposite trend. A 23 factorial plan was used to establish correlations between dependent and independent variables of ultrafiltration process.

scholarly journals Influence of Alumina Precursor Properties on Cu-Fe Alumina Supported Catalysts for Total Toluene Oxidation as a Model Volatile Organic Air Pollutant

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 252
Author(s):  
Tadej Žumbar ◽  
Alenka Ristić ◽  
Goran Dražić ◽  
Hristina Lazarova ◽  
Janez Volavšek ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Iron Concentration ◽  
Catalytic Performance ◽  
Air Pollutant ◽  
Molar Ratio ◽  
Homogeneous Distribution ◽  
Total Oxidation ◽  
Alumina Support ◽  
Determining Factors ◽  
Volatile Organic

The structure–property relationship of catalytic supports for the deposition of redox-active transition metals is of great importance for improving the catalytic efficiency and reusability of the catalysts. In this work, the role of alumina support precursors of Cu-Fe/Al2O3 catalysts used for the total oxidation of toluene as a model volatile organic air pollutant is elucidated. Surface characterization of the catalysts revealed that the surface area, pore volume and acid site concentration of the alumina supports are important but not the determining factors for the catalytic activity of the studied catalysts for this type of reaction. The determining factors are the structural order of the support precursor, the homogeneous distribution of the catalytic sites and reducibility, which were elucidated by XRD, NMR, TEM and temperature programed reduction (TPR). Cu–Fe/Al2O3 prepared from bayerite and pseudoboehmite as highly ordered precursors showed better catalytic performance compared to Cu-Fe/Al2O3 derived from the amorphous alumina precursor and dawsonite. Homogeneous distribution of FexOy and CuOx with defined Cu/Fe molar ratio on the Al2O3 support is required for the efficient catalytic performance of the material. The study showed a beneficial effect of low iron concentration introduced into the alumina precursor during the alumina support synthesis procedure, which resulted in a homogeneous metal oxide distribution on the support.

scholarly journals Effects of Fe-Doped Electrolyte and Feed Flow Rate Evaluation in Home Made Solid Oxide Fuel Cell

2021 ◽  
Vol 1143 (1) ◽  
pp. 012007
Author(s):  
Hary Devianto ◽  
Isdiriyani Nurdin ◽  
Pramujo Widiatmoko ◽  
Kafi Adi Prasetya ◽  
Basil Pradipta
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Flow Rate ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Feed Flow Rate ◽  
Rate Evaluation

Column Study for Adsorption of Methylene Blue Dye using Azadirachta indica Adsorbent

2020 ◽  
Vol 17 (4) ◽  
pp. 47-52
Author(s):  
Vibha Goswami ◽  
Renu Upadhyaya ◽  
Sumanta Kumar Meher
Keyword(s):  
Methylene Blue ◽  
Flow Rate ◽  
Azadirachta Indica ◽  
Packed Bed ◽  
Blue Dye ◽  
Feed Flow Rate ◽  
Methylene Blue Dye ◽  
Packed Bed Column ◽  
Bed Height ◽  
Percentage Removal

In this study, synthesised Azadirachta indica adsorbent was used for the removal of methylene blue dye using a packed bed column. The effect of feed flow rate, feed methylene blue dye concentration, and bed height of column on percentage removal of dye was studied. It was observed that the column bed exhausted rapidly at a higher flow rate and therefore, a breakthrough occurred faster. However, it was observed that bed exhaustion time increases on increasing the bed height from 2 to 10 inch at 10 mg/L feed dye concentration and feed flow rate of 40 ml/min. It was also found that the breakthrough curve is more dispersed and the percentage removal of dye increases on decreasing the feed methylene dye concentration from 150 to 10 mg/L. The percentage removal was found to be 96.89% at 20 ml/min of feed flow rate under 10 inch of bed height and 10 mg/L of feed dye concentration. The atomic absorption spectrophotometer and scanning electron microscope were used for estimating the effluent dye concentration from the column and morphological study, respectively.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

Dynamic Simulation of a HRSG System for a Given Start-Up/Shut Down Curve

2011 ◽  
Author(s):  
Hun Cha ◽  
Yoo Seok Song ◽  
Kyu Jong Kim ◽  
Jung Rae Kim ◽  
Sung Min KIM
Keyword(s):  
Dynamic Analysis ◽  
Gas Turbine ◽  
Flow Rate ◽  
Exhaust Gas ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Start Up ◽  
Gas Turbine Exhaust ◽  
Main Steam ◽  
Duct Burner

An inappropriate design of HRSG (Heat Recovery Steam Generator) may lead to mechanical problems including the fatigue failure caused by rapid load change such as operating trip, start-up or shut down. The performance of HRSG with dynamic analysis should be investigated in case of start-up or shutdown. In this study, dynamic analysis for the HRSG system was carried out by commercial software. The HRSG system was modeled with HP, IP, LP evaporator, duct burner, superheater, reheater and economizer. The main variables for the analysis were the temperature and mass flow rate from gas turbine and fuel flow rate of duct burner for given start-up (cold/warm/hot) and shutdown curve. The results showed that the exhaust gas condition of gas turbine and fuel flow rate of duct burner were main factors controlling the performance of HRSG such as flow rate and temperature of main steam from final superheater and pressure of HP drum. The time delay at the change of steam temperature between gas turbine exhaust gas and HP steam was within 2 minutes at any analysis cases.

PHOTO-CATALYTIC ACTIVITY AND PHOTO-ABSORPTION OF PLASMA-SPRAYED NANO-STRUCTURED TiO2 COATINGS

2010 ◽  
Vol 24 (31) ◽  
pp. 6115-6127 ◽  
Author(s):  
MARYAMOSSADAT BOZORGTABAR ◽  
MEHDI SALEHI ◽  
MOHAMMADREZA RAHIMIPOUR ◽  
MOHAMMADREZA JAFARPOUR
Keyword(s):  
Catalytic Activity ◽  
Flow Rate ◽  
Test Chamber ◽  
Catalytic Efficiency ◽  
Surface Characteristics ◽  
Catalytic Performance ◽  
Atmospheric Plasma ◽  
Argon Flow Rate ◽  
Photo Catalytic Activity ◽  
Argon Flow

Titanium dioxide coatings were deposited by utilizing atmospheric plasma-spraying system. The agglomerated P25/20 nano-powder and different spraying parameters (e.g., Argon flow rate and spray distance) were used to determine their influences on the microstructure, crystalline structure, photo-absorption, and photo-catalytic performance of the coatings. The microstructure and phases of as-sprayed TiO 2 coatings were characterized by scanning electron microscope SEM and X-ray diffraction, respectively. Surface characteristics were investigated by Fourier Transform Infrared. Photo-catalytic efficiency of the elaborated samples was also determined in an environmental test chamber set-up and evaluated from the conversion rate of ethanol. The photo-absorption was determined by UV–Vis spectrophotometer. The as-sprayed TiO2 coating was photo-catalytically reactive for the degradation of ethanol. The photo-catalytic activity was influenced by spray conditions. It is found that the photo-catalytic activity is significantly influenced by anatase content, surface area, and surface state. The results showed that the argon flow rate has an influence on the microstructure, anatase content, and photo-catalytic activity of the TiO 2 coatings.

Optimization for Powder Yield of Spray-Dried Garlic Extract Powder Using Box-Behnken Experimental Design

2020 ◽  
Vol 859 ◽  
pp. 301-306
Author(s):  
Nattakanwadee Khumpirapang ◽  
Supreeya Srituptim ◽  
Worawut Kriangkrai
Keyword(s):  
Experimental Design ◽  
Spray Drying ◽  
Flow Rate ◽  
Interactive Effect ◽  
Garlic Extract ◽  
Process Conditions ◽  
Inlet Temperature ◽  
Feed Flow Rate ◽  
Air Inlet ◽  
Liquid Feed

Garlic exerts its pharmacological activities; antihyperglycemic, antihyperlipidemia, antihypercholesterolemic, and antihypertensive activity. Therefore, the aim of this study was to determine and optimize the influence of the individual and interactive effect of process conditions variables on the yield of garlic extract powders by three factors and three level-Box-Behnken design under response surface methodology. Spray drying processes the transformation of a garlic juice extract into a dried powder, where usually maltodextrin (MD) as a drying agent is used. According to experimental design, the mixing of garlic juice extract (85 – 95 %w/w) and MD (5 – 15 %w/w) were dried at an air inlet temperature 110°C - 150°C and liquid feed flow rate 5 – 35 rpm. The optimum spray-drying process conditions which maximized the yield of garlic extract powder (31%w/w) were found as follows: air inlet temperature of 150°C, the liquid feed flow rate of 16 rpm, and 5 %w/w MD. The experimental values slightly closed to the corresponding predicted values. Hence, the developed model was adequate and possible to use.

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