scholarly journals Synthesis of Ti Powder from the Reduction of TiCl4 with Metal Hydrides in the H2 Atmosphere: Thermodynamic and Techno-Economic Analyses

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1567
Author(s):  
Mohammad Rezaei Ardani ◽  
Sheikh Abdul Rezan Sheikh Abdul Hamid ◽  
Dominic C. Y. Foo ◽  
Abdul Rahman Mohamed
Keyword(s):  
Critical Role ◽  
Metal Hydrides ◽  
Equilibrium Composition ◽  
Molar Ratio ◽  
Production Scale ◽  
Technoeconomic Analysis ◽  
Powder Production ◽  
Energy Saving Process ◽  
Economic Analyses ◽  
Ti Powder

Titanium hydride (TiH2) is one of the basic materials for titanium (Ti) powder metallurgy. A novel method was proposed to produce TiH2 from the reduction of titanium tetrachloride (TiCl4) with magnesium hydride (MgH2) in the hydrogen (H2) atmosphere. The primary approach of this process is to produce TiH2 at a low-temperature range through an efficient and energy-saving process for further titanium powder production. In this study, the thermodynamic assessment and technoeconomic analysis of the process were investigated. The results show that the formation of TiH2 is feasible at low temperatures, and the molar ratio between TiCl4 and metal hydride as a reductant material has a critical role in its formation. Moreover, it was found that the yield of TiH2 is slightly higher when CaH2 is used as a reductant agent. The calculated equilibrium composition diagrams show that when the molar ratio between TiCl4 and metal hydrides is greater than the stoichiometric amount, the TiCl3 phase also forms. With a further increase in this ratio to greater than 4, no TiH2 was formed, and TiCl3 was the dominant product. Furthermore, the technoeconomic study revealed that the highest return on investment was achieved for the production scale of 5 t/batch of Ti powder production, with a payback time of 2.54 years. The analysis shows that the application of metal hydrides for TiH2 production from TiCl4 is technically feasible and economically viable.

Influence of Mo Content of Fe/Mo/Al2O3 on Flame Synthesis of Carbon Nanotubes

2012 ◽  
Vol 486 ◽  
pp. 8-11
Author(s):  
Yuan Yuan ◽  
Bao Min Sun ◽  
Xiao Tian Wang ◽  
Yang Wang ◽  
Yong Hong Guo
Keyword(s):  
Carbon Nanotubes ◽  
Critical Role ◽  
Molar Ratio ◽  
Flame Synthesis ◽  
Products Analysis ◽  
Series Of Experiments ◽  
Mo Content ◽  
Synthesis Of Carbon Nanotubes ◽  
The Impact

Catalysts play a critical role in the synthesis of carbon nanotubes. In this paper, we design a series of experiments to explore the impact of contents of Mo on the products. Analysis show, when the molar ratio of Fe: Mo: Al is 1: 0.2: 16, the carbon nanotubes show the best yields and quality.

scholarly journals Thermodynamic and experimental simulation of interactions in the Ta-ZnS system

2020 ◽  
Vol 63 (9) ◽  
pp. 94-98
Author(s):  
Lyudmila Yu. Udoeva ◽  
◽  
Sergey N. Agafonov ◽  
Sofia A. Petrova ◽  
◽  
...  
Keyword(s):  
Profile Analysis ◽  
Rietveld Method ◽  
Experimental Studies ◽  
Equilibrium Composition ◽  
Basic Structure ◽  
Inert Atmosphere ◽  
Experimental Simulation ◽  
Molar Ratio ◽  
Optimum Operating ◽  
Experimental Conditions

The article presents the results of studies to estimation the possibility of sulfiding of metallic tantalum by zinc sulfide in an inert atmosphere. To theoretically substantiate the possibility of the process, the HSC 6.12 Chemistry software package (Outotec) was used, which allows predicting the equilibrium composition of the interaction products. The Gibbs energies of possible reactions in the ZnS-Ta system are calculated, the optimum operating parameters of the process of complete transformation of metallic tantalum into TaS2 are determined. Experimental studies were carried out in a tubular furnace in a flow of an inert gas (helium) supplied through a closed loop of an alundum reactor. Components with different molar ratios compressed into tablets were kept at the temperature 1300 ° C for 90 minutes. It has been found tantalum disulfide of two modifications (hexagonal and trigonal systems) and Ta5S8 (14.1%) are formed at a stoichiometric ZnS / Ta molar ratio of 2.0. Its subsulfides (Ta1.23S2, Ta3.1S6, TaS (y)), which are intermediate phases in the transformation of tantalum-to-TaS2, are formed if a sulfidizer is deficient. The identification of the phases and the estimation of their proportion in the sulfiding product were made by the full-profile analysis by Rietveld method. The experimental conditions did not reveal the formation of complex sulfides like the ZnxTaS2, the formation of which is possible because of zinc intercalation between the layers of the tantalum disulfide basic structure of the crystal lattice.

scholarly journals Critical Role of Virion-Associated Cholesterol and Sphingolipid in Hepatitis C Virus Infection

2008 ◽  
Vol 82 (12) ◽  
pp. 5715-5724 ◽  
Author(s):  
Hideki Aizaki ◽  
Kenichi Morikawa ◽  
Masayoshi Fukasawa ◽  
Hiromichi Hara ◽  
Yasushi Inoue ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Cell Attachment ◽  
Critical Role ◽  
Molar Ratio ◽  
Complete Life Cycle ◽  
Rna Accumulation ◽  
Hydrolysis Of ◽  
Hcv Structural Proteins

ABSTRACT In this study, we establish that cholesterol and sphingolipid associated with hepatitis C virus (HCV) particles are important for virion maturation and infectivity. In a recently developed culture system enabling study of the complete life cycle of HCV, mature virions were enriched with cholesterol as assessed by the molar ratio of cholesterol to phospholipid in virion and cell membranes. Depletion of cholesterol from the virus or hydrolysis of virion-associated sphingomyelin almost completely abolished HCV infectivity. Supplementation of cholesterol-depleted virus with exogenous cholesterol enhanced infectivity to a level equivalent to that of the untreated control. Cholesterol-depleted or sphingomyelin-hydrolyzed virus had markedly defective internalization, but no influence on cell attachment was observed. Significant portions of HCV structural proteins partitioned into cellular detergent-resistant, lipid-raft-like membranes. Combined with the observation that inhibitors of the sphingolipid biosynthetic pathway block virion production, but not RNA accumulation, in a JFH-1 isolate, our findings suggest that alteration of the lipid composition of HCV particles might be a useful approach in the design of anti-HCV therapy.

Thermodynamic Analysis of Hydrogen Production from Ethanol in Supercritical Water Oxidation

2011 ◽  
Vol 110-116 ◽  
pp. 77-82
Author(s):  
Nawadee Srisiriwat
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Production ◽  
Thermodynamic Analysis ◽  
Supercritical Water ◽  
Water Oxidation ◽  
Equilibrium Composition ◽  
Operating Conditions ◽  
Molar Ratio ◽  
Hydrogen Yield

A thermodynamic analysis was performed for hydrogen production from ethanol reforming and oxidation in supercritical water (SCW) conditions. The minimization of Gibbs free energy was used to calculate the equilibrium composition to investigate the effect of operating conditions, pressure, temperature, H2O2:EtOH molar ratio and H2O:EtOH molar ratio, on product yields. The theoretical results indicated that the yields of hydrogen and carbon monoxide decreased as the pressure increased but a H2/CO ratio at atmospheric pressure was lower than that at SCW conditions. High temperatures increased the efficiency of hydrogen production although the amount of carbon monoxide also increased. The presence of oxygen led to great decreases in methane oxidized to carbon dioxide and water. The spending of some hydrogen oxidized to water resulting in a lower hydrogen yield. High H2O:EtOH ratios increased the yields of hydrogen and carbon dioxide but decreased the methane and carbon monoxide production. It is possible to conclude that high temperature, high H2O:EtOH ratio and low addition of oxygen should lead to best results in the SCWO of ethanol.

Biomolecule Assisted Hydrothermal Synthesis of Chainlike Network of Silver Sulfide Nanostructures

2008 ◽  
Vol 8 (2) ◽  
pp. 986-992
Author(s):  
Subhajit Biswas ◽  
Subhadra Chaudhuri
Keyword(s):  
Critical Role ◽  
Silver Sulfide ◽  
Synthesis Temperature ◽  
Molar Ratio ◽  
Complexing Agent ◽  
Sulfur Source ◽  
X Ray Diffraction ◽  
Tree Model ◽  
Hydrothermal Route ◽  
Experimental Parameters

A L-cysteine assisted hydrothermal route has been utilized for the growth of Ag2S nanostructures with chainlike network. It was observed that the experimental parameters such as the synthesis temperature and variation in the molar ratio of the anionic and cationic precursors play critical role in determining the morphology and crystal structure of the products. X-ray diffraction study revealed the formation of monoclinic acanthite Ag2S. L-cysteine was acting as complexing agent as well as sulfur source. The branching fractal morphology was explained through Cayley tree model and structure of L-cysteine.

scholarly journals Synthesis of MIL-101(Cr) Metal Organic Framework by Green Synthesis for CO2 Gas Adsorption

2021 ◽  
Vol 945 (1) ◽  
pp. 012074
Author(s):  
Pui San Ho ◽  
Kok Chung Chong ◽  
Soon Onn Lai ◽  
Shee Keat Mah ◽  
Sze Shin Lee ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Gas Adsorption ◽  
Metal Organic Framework ◽  
Critical Role ◽  
Operating Cost ◽  
Solvent Free ◽  
Molar Ratio ◽  
Promising Alternative ◽  
Metal Organic ◽  
Organic Framework

Abstract Global warming issue due to the excessive carbon dioxide gas emission have raised strong interest in capturing or reducing the CO2 from flue gas or atmosphere. Physisorption-based CO2 capture applying the metal organic framework (MOF) provides a promising alternative for capturing CO2 due to the simplicity, low operating cost, and low energy requirement of the adsorption approach combined with the high CO2 adsorption capacity MOF material. In this study, a series of Chromium based MIL MOF with a variety molar ratio of chromium metal to 1,4-Benzene Dicarboxylate (BDC) organic linker were prepared via the solvent-free method (mechanochemical) to develop a clean and efficient way of synthesising MOF samples as promising CO2 adsorbents. The XRD results and FTIR spectra have confirmed the successful fabrication of MIL-101(Cr) MOF using the solvent-free method. The SEM images illustrated fine growth of irregular shaped coarse particles for Cr MOF with equal mole ratio of Cr to BDC. The MIL-101(Cr) samples were also tested on their CO2 adsorption capacity to understand the influence of molar ratio of the starting materials on the CO2 adsorption capacity. It was found that the MIL-101(Cr)1 led to the formation of a product with the highest CO2 uptake capacity of 18.78 mmol/g. In contrast, the EDS analysis result revealed that all the samples synthesised in this work were well incorporated with the Chromium element. It is therefore suggested that the molar ratio of Cr to BDC plays a critical role in determining the CO2 gas adsorption capacity.

Theoretical and experimental study of chemical equilibrium in the systems Si-Cl and Si-Cl-H. Calculation of chemical equilibrium in the systems Si-Cl and Si-Cl-H

1989 ◽  
Vol 54 (11) ◽  
pp. 2896-2909 ◽  
Author(s):  
Jindřich Leitner ◽  
Čestmír Černý ◽  
Petr Voňka ◽  
Jan Mikulec
Keyword(s):  
Gas Phase ◽  
Chemical Equilibrium ◽  
Atmospheric Pressure ◽  
Total Pressure ◽  
Equilibrium Composition ◽  
Molar Ratio ◽  
Initial Composition ◽  
Chemical Equilibria ◽  
First Time ◽  
Equilibrium Calculations

From the calculations of heterogenous chemical equilibria in the systems Si-Cl and Si-Cl-H the equilibrium composition of the gas phase and the amount of deposited or reacted solid silicon have been determined. For these calculations, the method based on the minimization of the Gibbs energy of the system and critically judged and selected values of input thermodynamic data have been used. The calculations have been performed for the temperature range 1 000-1 600 K, for the pressure 101.325 kPa and 10.133 kPa and for various input compositions of the gaseous phase. In the case of the system Si-Cl, the reaction of solid leading to the formation of silicon subchlorides takes place at all conditions investigated. At atmospheric pressure and at temperatures in the neighbourhood of 1 300 K, the dominant components of the gas phase are the following substances: SiCl4, SiCl3 and SiCl2. The dependence of the amount of deposited solid silicon on temperature and on the initial composition of the gas phase in the system Si-Cl-H shows–in the investigated range of variables – a maximum, the position of which depends on the total pressure of the system. At atmospheric pressure, at temperatures around 1 300 K and at the initial molar ratio Cl/H = 0.01, the dominant components of the gas phase are the following substances: SiCl4, SiCl3, SiCl2, SiHCl3, SiH2Cl2 and HCl. The substance SiHCl which has been included into the equilibrium calculations for the first time, is present in a significant amount at higher temperatures and especially at lower pressure.

Electrolytic Ti Powder Production from Ore Sources

2016 ◽  
pp. 57-63
Author(s):  
J.C. Withers ◽  
R.O. Loutfy ◽  
S.M. Pickard
Keyword(s):  
Powder Production ◽  
Ti Powder

scholarly journals The Critical Role of Aromatic-Aromatic Drug-Polymer Interactions to Provide Nanomedicines Containing Chloroquine: A Simple Proposal to Provide High Encapsulation, High Stability, and Prolonged Drug Release

2020 ◽  
Author(s):  
María Gabriela Villamizar-Sarmiento ◽  
Ignacio Moreno-Villoslada ◽  
Felipe Oyarzun-Ampuero
Keyword(s):  
Chronic Diseases ◽  
Drug Loading ◽  
Critical Role ◽  
Molar Ratio ◽  
High Yield ◽  
Prolonged Release ◽  
Aromatic Group ◽  
Aromatic Interactions ◽  
Very High

Abstract Background: Chloroquine (CQ) is a drug commonly used to treat malaria. CQ has also gained interest for the treatment of other chronic diseases such as arthritis, lupus, cancer, diabetes, atherosclerosis, and dermatomyositis, among others. Since CQ is hydrophilic and low molecular-weight, attractive interactions with polymers in aqueous medium are weaker than with water, so that low encapsulation together with uncontrolled and fast release is observed. Importantly, a long-term administration of CQ is suggested, thus the development of formulations with controlled and prolonged release is desirable. Results: Here we propose the use of aromatic interactions between the cationic CQ and the FDA approved polymer poly(sodium 4-styrenesulfonate) (PSS) for the formation and stabilization of nanoparticles (NPs). The strategy consists on the simple mixture of two aqueous solutions containing the oppositelly charged molecules. UV-vis and NMR spectroscopy evidence intimate aromatic-aromatic interactions between CQ and PSS. CQ/PSS molar ratios from 0.2 to 0.5 allow obtaining NPs with spherical shape, size in the range of 170-410 nm, zeta potential from -18 to -45 mV, and particles number in the range of 0.9 - 6.6 x 1010 NPs/mL. Selected NPs (CQ/PSS molar ratio 0.4) are stable to wide variations in ionic strength (0-200 mM), pH (2-10) and temperature (20-50 °C). In addition, CQ/polymer 0.4 was also tested but with the absence of the aromatic group in the polymer, and providing smaller (70 nm), lower-concentrated (6.1 x 109 NPs/mL), and unstable particles, confirming the key role of the aromatic group. Furthermore, CQ/PSS NPs are stable during months and can be converted to a reconstitutable powder. Importantly, the selected NPs (CQ/PSS 0.4) show full drug association efficiency (100 %), very high drug loading (49 %), very high yield (89 %), and evidencing a drug entrapment/release governed by kinetic associations (≈99 %). Finally, release studies evidence a controlled and prolonged delivery. Conclusions: Considering the potential uses of CQ for chronic diseases, and the simplicity and efficiency of our proposal, it could be considered as a valuable alternative to developed nanomedicines. In addition, this strategy could be used for other drugs and polymers showing similar characteristics to CQ and PSS.

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