scholarly journals Synthesis and Characterization of Nanosize Catalyst for the RWGS Process and Performance Examination using a Pilot-Scale High-Pressure Reactor

2019 ◽  
Vol 9 (1) ◽  
pp. 5215-5220
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
High Pressure ◽  
Raw Materials ◽  
Chemical Characterization ◽  
Calorific Value ◽  
Pilot Scale ◽  
Ammonium Molybdate ◽  
X Ray

Catalyst reduces the activation energy of molecules and is generally composed of an active part distributed on a large surfaced stable support or ligand. Since the catalytic reactions occur at the surface of the catalyst, this necessitates the method of catalysts preparation after suitable pretreatment to have an active, moderately high and accessible surface area. Also, the pretreated catalysts should have sufficient mechanical strength and stability so that the particles will remain relatively unchanged during their use as catalysts. Nanosize metal oxide catalysts deposited on alpha-alumina are prepared using combustion synthesis in the present work. Alumina acts as support, a promoter as well as a catalyst in this process. Aluminum nitrate, cobaltous chloride, nickel chloride, ammonium molybdate, and urea are used as raw materials to synthesize cobalt-nickel-molybdenum on alumina by combustion method. The solution at 500oC in a muffle furnace produced voluminous solid within 5 minutes. Particle size, morphology, chemical characterization of the sample were analyzed by scanning electron microscopy (500 nm), X-ray diffraction, and energy disperses X-ray analysis techniques. The results showed that the concentration of nickel among all three promoters was the least. Increasing levels of carbon dioxide in the atmosphere have detrimental effects such as an increase in temperatures, melting of glaciers, the rise in the levels of seas and oceans, submergence of low-lying land areas and disruptions in the ecological cycles. In order to combat this, the present work was extended to convert carbon dioxide to carbon monoxide by reverse water gas shift reaction. Carbon monoxide can be later used to produce methanol and dimethyl ether which has a higher calorific value. Present process was carried out in a pilot-scale high-pressure reactor at 400 ℃ and 7 bar using nanoparticles of nickel-cobalt-molybdenum on alumina. Product stream was analyzed by gas chromatography with a thermal conductivity detector.

Chemical Characterization of Sardine Meat Powder Produced by Dehydration with High Osmotic Pressure Resin and Defatting with High Pressure Carbon Dioxide

1989 ◽  
Vol 54 (2) ◽  
pp. 265-268 ◽  
Author(s):  
KENSHIRO FUJIMOTO ◽  
YASUSHI ENDO ◽  
SOON-YEONG CHO ◽  
RITSUKO WATABE ◽  
YASUO SUZUKI ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
High Pressure ◽  
Osmotic Pressure ◽  
Chemical Characterization

Synthesis and Chemical Characterization of New Derivative Complexes from UO22+and Th4+ Ions with the (iso)polioxomolybdate and (iso)polioxotungstate Clusters

2008 ◽  
Vol 59 (9) ◽  
Author(s):  
Romeo-Iulian Olariu ◽  
Doina Humelnicu ◽  
Cecilia Arsene ◽  
Ion Sandu ◽  
Gabriela Carja
Keyword(s):  
Self Assembly ◽  
Raw Materials ◽  
Chemical Characterization ◽  
Uranyl Acetate ◽  
Thorium Nitrate ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Fourier Transformed Infrared Spectroscopy ◽  
The Mean

New isopolyoxomolybdates and isopolyoxotungstates with both UO22+ and Th4+ ions have been synthesized by self-assembly from raw materials as Na2MoO4�2H2O, Na2WO4�2H2O, uranyl acetate and thorium nitrate in acidic media under controlled conditions of temperature and pH. Accomplishments for the chemical characterization of the newly synthesized units is foreseen through the data obtained by the mean of state of art technique as Fourier Transformed Infrared Spectroscopy (FTIR), UV-vis spectrophotometry, scanning electronic microscopy (SEM) with electron diffraction X-ray (EDX) detection, and thermogravimetric analysis.

scholarly journals New Insights into the Crystal Chemistry of Elpidite, Na2Zr[Si6O15]·3H2O and (Na1+YCax□1−X−Y)Σ=2Zr[Si6O15]·(3−X)H2O, and Ab Initio Modeling of IR Spectra

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2160
Author(s):  
Alexander Bogdanov ◽  
Ekaterina Kaneva ◽  
Roman Shendrik
Keyword(s):  
Ir Spectra ◽  
Structural Models ◽  
Chemical Characterization ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Special Group ◽  
X Ray ◽  
Influence Of Water ◽  
Radioactive Species

Elpidite belongs to a special group of microporous zirconosilicates, which are of great interest due to their capability to uptake various molecules and ions, e.g., some radioactive species, in their structural voids. The results of a combined electron probe microanalysis and single-crystal X-ray diffraction study of the crystals of elpidite from Burpala (Russia) and Khan-Bogdo (Mongolia) deposits are reported. Some differences in the chemical compositions are observed and substitution at several structural positions within the structure of the compounds are noted. Based on the obtained results, a detailed crystal–chemical characterization of the elpidites under study was carried out. Three different structure models of elpidite were simulated: Na2ZrSi6O15·3H2O (related to the structure of Russian elpidite), partly Ca-replaced Na1.5Ca0.25ZrSi6O15·2.75H2O (close to elpidite from Mongolia), and a hypothetical CaZrSi6O15·2H2O. The vibration spectra of the models were obtained and compared with the experimental one, taken from the literature. The strong influence of water molecule vibrations on the shape of IR spectra of studied structural models of elpidite is discussed in the paper.

scholarly journals High-pressure synthesis and characterization of the non-centrosymmetric scandium borate ScB6O9(OH)3

2020 ◽  
Vol 75 (6-7) ◽  
pp. 597-603
Author(s):  
Birgit Fuchs ◽  
Hubert Huppertz
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Pressure High Temperature ◽  
Structure Solution ◽  
Temperature Experiment ◽  
Pressure Synthesis

AbstractThe non-centrosymmetric scandium borate ScB6O9(OH)3 was obtained through a high-pressure/high-temperature experiment at 6 GPa and 1473 K. Single-crystal X-ray diffraction revealed that the structure is isotypic to InB6O9(OH)3 containing borate triple layers separated by scandium layers. The compound crystallizes in the space group Fdd2 with the lattice parameters a = 38.935(4), b = 4.4136(4), and c = 7.6342(6) Å. Powder X-ray diffraction and vibrational spectroscopy were used to further characterize the compound and verify the proposed structure solution.

scholarly journals Nanotechnology in Roman Opaque Red Glass from the 2nd Century AD. Archaeometric Investigation in Red Sectilia from the Decoration of the Lucius Verus Villa in Rome

Heritage ◽  
2019 ◽  
Vol 2 (3) ◽  
pp. 2597-2611 ◽  
Author(s):  
Mario Bandiera ◽  
Patrice Lehuédé ◽  
Marco Verità ◽  
Luis Alves ◽  
Isabelle Biron ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Chemical Characterization ◽  
Second Step ◽  
Colorimetric Analysis ◽  
Historical Sources ◽  
Pixe Analysis ◽  
X Ray ◽  
Colorimetric Measurements ◽  
Shed Light

This work aims to characterise the chemical composition of Roman opaque red glass sectilia dated to the 2nd century A.D and to shed light on Roman glassmaking production of different shades of red, from red to reddish-brown. Due to the lack of technical historical sources for this period many questions about technological aspects still remain. In this project a multi-disciplinary approach is in progress to investigate the red glass sectilia with several red hues from the Imperial Villa of Lucius Verus (161–169 A.D.) in Rome. First, colorimetric measurements were taken to identify the various red hues. The second step was chemical characterization of the samples and the identification of crystalline colouring phases. Particle Induced X-Ray Emission (PIXE) analysis was used to investigate the chemical composition of these glass samples, while the crystalline phases were identified by Raman Spectroscopy and Scanning Electrons Microscope with Energy Dispersive X-ray Spectrometry (SEM-EDS). Using SEM-EDS nanoparticles were detected as a colouring agent, the chemical composition and the morphology of which has been studied in depth. This information has been compared with the colorimetric analysis to establish any correlation with the different colour hues.

Radiological, structural and chemical characterization of raw materials and ceramic tiles in Serbia

2019 ◽  
Vol 323 (2) ◽  
pp. 861-874
Author(s):  
Predrag Kuzmanović ◽  
Nataša Todorović ◽  
Jovana Nikolov ◽  
Jovana Knežević ◽  
Bojan Miljević
Keyword(s):  
Raw Materials ◽  
Chemical Characterization ◽  
Ceramic Tiles

Influence of the Residue of Casting by Lost Wax in the Modulus of Elasticity and Porosity of Concretes

2014 ◽  
Vol 805 ◽  
pp. 343-349
Author(s):  
Carine F. Machado ◽  
Weber G. Moravia
Keyword(s):  
Construction Industry ◽  
Modulus Of Elasticity ◽  
Chemical Characterization ◽  
Microstructural Characterization ◽  
Cement Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardened State ◽  
Material Powder

This work evaluated the influence of additions of the ceramic shell residue (CSR), from the industries of Lost Wax Casting, in the modulus of elasticity and porosity of concrete. The CSR was ground and underwent a physical, chemical, and microstructural characterization. It was also analyzed, the environmental risk of the residue. In the physical characterization of the residue were analyzed, the surface area, and particle size distribution. In chemical characterization, the material powder was subjected to testing of X-ray fluorescence (XRF). Microstructural characterization was performed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The residue was utilized like addition by substitution of cement in concrete in the percentages of 10% and 15% by weight of Portland cement. It was evaluated properties of concrete in the fresh and hardened state, such as compressive strength, modulus of elasticity, absorption of water by total immersion and by capillarity. The results showed that the residue can be used in cement matrix and improve some properties of concrete. Thus, the CSR may contribute to improved sustainability and benefit the construction industry.

Physico-chemical Characterization of Forest and Agricultural Residues for Energy Conversion Processes

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Nguyen Hong Nam ◽  
Le Gia Thanh Truc ◽  
Khuong Duy Anh ◽  
Laurent Van De Steene
Keyword(s):  
Energy Conversion ◽  
Chemical Characterization ◽  
Calorific Value ◽  
Forest Residues ◽  
Physico Chemical ◽  
Wide Range ◽  
Biomass Resources ◽  
Thermochemical Processes ◽  
The Difference

Agricultural and forest residues are potential sources of renewable energy in various countries. However, the difference in characteristics of biomass resources presents challenges for energy conversion processes which often require feedstocks that are physically and chemically consistent. This study presented a complete and comprehensive database of characteristics of a wide range of agricultural and forest residues. Moisture, bulk density, calorific value, proximate and elemental compositions, as well as cellulose, hemicellulose, and lignin compositions of a wide range of biomass residues were analyzed. The major impacts of the variability in biomass compositions to biochemical and thermochemical processes were also discussed.

Deposition of gold nanoparticles on organo-kaolinite — Application in electrocatalysis for carbon monoxide oxidation

2011 ◽  
Vol 89 (7) ◽  
pp. 845-853 ◽  
Author(s):  
Sadok Letaief ◽  
Wendy Pell ◽  
Christian Detellier
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Fine Particles ◽  
Raw Materials ◽  
Carbon Monoxide Oxidation ◽  
Functional Materials ◽  
Metallic State ◽  
Oxidation Reactions ◽  
X Ray

The clay mineral kaolinite was used as support of gold nanoparticles for heterogeneous catalysis of oxidation reactions, particularly of carbon monoxide oxidation. The application of clay minerals in the preparation of new functional materials provides an alternative approach for the use of these abundant raw materials. To improve the physicochemical properties of kaolinite, as well as to ensure a strong immobilization of the adsorbed species, kaolinite was functionalized by grafting 2-amino-2-methyl-1,3-propanediol on the internal and external surfaces of the octahedral sheets by reaction with the aluminol groups. Gold nanoparticles were then deposited on the external surfaces of the fine particles of the functionalized kaolinite. The resulting gold kaolinite nanohybrid material was characterized by various physicochemical techniques. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and energy-dispersive X-ray spectrometry confirmed that gold was effectively reduced to the metallic state during adsorption onto the external surfaces of the modified kaolinite. The gold nanoparticles have a narrow size distribution: more than 88% are less than 4 nm in diameter. Gold nanoparticles deposited on kaolinite catalyze the electro-oxidation of carbon monoxide in alkaline solution at room temperature.

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