scholarly journals Deep Oxidation of Fluorinated Hydrocarbons in Molten Catalysts

2016 ◽  
Vol 5 (2) ◽  
pp. 137 ◽  
Author(s):  
Yu.S. Chekryshkin ◽  
T.A. Rozdyalovskaya ◽  
Z.R. Ismagilov ◽  
M.A. Kerzhentsev ◽  
O.A. Tetenova ◽  
...  
Keyword(s):  
Partial Pressure ◽  
Alkali Metals ◽  
Eutectic Mixture ◽  
Equilibrium Mixture ◽  
Deep Oxidation ◽  
Organic Substances ◽  
Alkali Metal Chloride ◽  
Gaseous Products ◽  
Fluorinated Alcohol ◽  
Fluorinated Hydrocarbons

<p>The oxidation of fluorine-containing organic substances: fluorocarbon liquid M-1, fluorinated alcohol H(CF<sub>2</sub>)<sub>8</sub>CH<sub>2</sub>OH, and powder polytetrafluoroethylene with air has been studied in melts: NaOH; 43 mol.% LiCl  - 33 mol.% NaCl - 24 mol.% KCl (eutectic mixture); (LiCl-NaCl-KCl)eutec. + 10 mass.% V<sub>2</sub>O<sub>5</sub>; (LiCl-NaCl-KCl) eutec. + 15 mass.% V<sub>2</sub>O<sub>5</sub>; 56 mol.% Na<sub>2</sub>CO<sub>3</sub> - 44 mol.% K<sub>2</sub>CO<sub>3</sub> (eutectic), (Na<sub>2</sub>CO<sub>3 </sub>K<sub>2</sub>CO<sub>3</sub>)eutect. + 15 mass.% V<sub>2</sub>O<sub>5</sub>, and K<sub>3</sub>V<sub>5</sub>O<sub>14</sub>. The compositions of the melts have been examined by GC, DTA, chemical analysis and XRD, and they have been shown to change during the reaction, depending on the composition and partial pressure of the gaseous products over the melt surface. The alkali metal chloride melt containing 15 mass.% V<sub>2</sub>O<sub>5</sub> has been found to be most stable to the action of fluorine compounds. Possibility of deep oxidation of fluorine-containing organic substances in melts based on hydroxides, carbonates and chlorides of alkali metals doped with oxides of vanadium has been proved. The process of deep oxidation of fluorinated hydrocarbons is accompanied by formation of an equilibrium mixture containing hydroxides, carbonates, chlorides and fluorides of alkali metals, as well as their vanadates, if V<sub>2</sub>O<sub>5</sub> additive is used. The relative amounts of these substances in molten systems are determined by the partial pressure of oxygen, CO<sub>2 </sub>and water vapor.</p>

scholarly journals Mass spectrometric production of heterogeneous metal clusters using Knudsen cell

2016 ◽  
Vol 70 (6) ◽  
pp. 629-637
Author(s):  
Filip Veljkovic ◽  
Aleksandra Peric-Grujic ◽  
Suzana Velickovic
Keyword(s):  
Mass Spectrometry ◽  
Partial Pressure ◽  
Thermodynamic Parameters ◽  
Alkali Metals ◽  
Saturated Vapor ◽  
Cell Mass ◽  
Chemical Species ◽  
Knudsen Cell ◽  
Knudsen Effusion Mass Spectrometry

Knudsen effusion mass spectrometry or high-temperature method of mass spectrometry for decades gives new information about saturated vapor of hardly volatile compounds and it is an important method in the discovery of many new molecules, radicals, ions and clusters present in the gas phase. Since pioneering works until now, this method has been successfully applied to a large number of systems (ores, oxides, ceramics, glass materials, borides, carbides, sulfides, nitrates, metals, fullerenes, etc) which led to the establishment of various research branches such as chemistry of clusters. This paper describes the basic principles of Knudsen cell use for both identification of chemical species created in the process of evaporation and determination of their ionization energies. Depending on detected ions intensities and the partial pressure of each gaseous component, as well as on changes in partial pressure with temperature, Knudsen cell mass spectrometry enables the determination of thermodynamic parameters of the tested system. A special attention is paid to its application in the field of small heterogeneous and homogeneous clusters of alkali metals. Furthermore, experimental results for thermodynamic parameters of some clusters, as well as capabilities of non-standard ways of using Knudsen cells in the process of synthesis of new clusters are presented herein.

Effect of Hydrogen Partial Pressure on Hydrocarbon Production from Deoxygenation of Stearic Acid

2013 ◽  
Vol 779-780 ◽  
pp. 165-169 ◽  
Author(s):  
Cheng Zhang ◽  
Pei Pei Sun ◽  
Wu Di Zhang ◽  
Yu Bao Chen ◽  
Fang Yin ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Stearic Acid ◽  
Partial Pressure ◽  
Rotational Speed ◽  
Conversion Rate ◽  
Mesoporous Carbon ◽  
Acid Value ◽  
Hydrogen Partial Pressure ◽  
Hydrocarbon Production ◽  
Gaseous Products

The catalytic deoxygenation experiments of stearic acid and hydrogen were performed for 6 hours in the presence of a solvent, dodecane, in a temperature range of 295-305°C and the rotational speed of 100rpm, under a certain hydrogen partial pressure (in argon), using palladium supported on active and mesoporous carbon as a catalyst. The results showed, the main liquid-phase product was n-heptadecane, while the main gaseous products were CO2and CO. When the partial pressure of hydrogen is 3.0MPa, the acid value of primary product is the lowest and the reaction tends to be gentle, conversion rate of stearic acid and selectivity to n-heptadecane is the highest.

Partial Pressure Contributions to the Equation of State of Alkali Metals

1980 ◽  
Vol 100 (2) ◽  
pp. 701-704 ◽  
Author(s):  
J. M. López ◽  
M. P. I??guez ◽  
J. A. Alonso
Keyword(s):  
Equation Of State ◽  
Partial Pressure ◽  
Alkali Metals

Branched Pentablock Poly(L-lactide-co-∊-caprolactone) Synthesis in scCO2

2007 ◽  
Vol 19 (5-6) ◽  
pp. 649-664 ◽  
Author(s):  
B. Saner ◽  
Y. Z. Menceloglu ◽  
N. Bilgin Oncu
Keyword(s):  
Gel Permeation Chromatography ◽  
Environmentally Benign ◽  
Side Chains ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Temperature And Pressure ◽  
Fluorinated Alcohol ◽  
Pentablock Copolymer ◽  
Fluorinated Hydrocarbons

Pentablock poly(L-lactide-co-∊-caprolactone) (PLLA/PCL), with a central fluorinated segment and four PLLA/PCL side chains was synthesized by sequential ring-opening polymerization (ROP) with stannous octoate catalyst in an environmentally benign and clean medium, scCO2. Copolymers of PLLA and PCL are extensively researched for biomedical applications. Fluorinated hydrocarbons are similarly promising for biomedicine, and especially for oxygen-carrying substitute applications. Initially, a fluorinated reactive triblock stabilizer (prepolymer, PCL-FLKT-PCL) with inner fluorinated segment and PCL side chains was synthesized in bulk from a tetraol fluorinated alcohol (FLKT) with a 99% conversion. The prepolymer was then utilized for the synthesis of copolymers in scCO2, where PLLA segments were successively incorporated to the ends of the prepolymer, forming a pentablock structure with four polyester side chains. Reactions were carried out at 75°C and 4000-4500 psi. Solubility studies of the prepolymer and the pentablock copolymer in scCO2 showed effective solubilization at the reaction temperature and pressure. The molecular weights of the products were measured with the aid of gel permeation chromatography; the prepolymer and the copolymer possessed average number molecular weights (Mn) in the range of 13 000 and 24 000 (for 96% conversion of LLA), respectively. Low poly-dispersity indexes were obtained: 1.34 for the prepolymer and 1.08-1.34 for the pentablock copolymer. Material characterization was carried out by 1H NMR, 13C NMR, 19F NMR, differential scanning calorimetry (DSC), gel permeation chromatography (GPC) and scanning electron microscopy (SEM).

scholarly journals Hydrogenolysis of lignin in ZnCl2 and KCl as an inorganic molten salt medium

Holzforschung ◽  
2015 ◽  
Vol 69 (5) ◽  
pp. 523-529
Author(s):  
Jörn Appelt ◽  
Anne Gohrbandt ◽  
Jana Peters ◽  
Martina Bremer ◽  
Steffen Fischer
Keyword(s):  
Molten Salt ◽  
Residence Time ◽  
Reaction Temperature ◽  
Eutectic Mixture ◽  
Gas Chromatography Mass Spectrometry ◽  
Lignin Concentration ◽  
Gaseous Products ◽  
Organosolv Lignin ◽  
Liquid Products ◽  
Secondary Reactions

Abstract Lignin can be converted into monomeric products with the aid of molten salt media. Molten zinc chloride (ZnCl2)/potassium chloride (KCl) mixtures are suitable for this purpose. The application of an eutectic mixture with low melting points leads to similar main products as are obtained by pyrolysis. The hydrogenolysis of an organosolv lignin in molten salts of ZnCl2/KCl was investigated as a function of reaction temperature, residence time, and lignin concentration, and the composition of liquid products and monophenols was analyzed by gas chromatography-mass spectrometry (GC-MS). The yields can be optimized by the proper selection of the reaction temperature. A longer residence time and higher lignin concentrations lead to increased formation of solid residues and gaseous products. The liquid products mainly consist of substituted phenols derived from lignins. Polymeric products are the result of condensation reactions (i.e., the formation of new C-C linkages in the course of secondary reactions).

MODEL AND METHOD OF CONTROLLED PYROLYSIS OF ORGANIC SUBSTANCES OF VARIABLE COMPOSITION

2021 ◽  
Vol 1 ◽  
pp. 134
Author(s):  
Konstantin V. Beglov ◽  
◽  
Alexander I. Brunetkin ◽  
Maxim M. Maximov ◽  
Elena O. Ulitskaya ◽  
...  
Keyword(s):  
Water Vapor ◽  
Calorific Value ◽  
Variable Composition ◽  
Simultaneous Increase ◽  
Organic Substances ◽  
Reaction Products ◽  
Gaseous Reaction ◽  
Energy Value ◽  
Gaseous Products ◽  
Gasification Process

The issues of organization of the process of slow pyrolysis of organic substances, in the general case of unknown and variable composition, are considered. The relevance of the work is determined by considering the possibility of using various organic waste (domestic, agricultural, industrial) without their preliminary sorting and drying to obtain secondary energy resources of a known (controlled) composition. The novelty of the work is due to the development of a model for the method of controlled pyrolysis or gasification of organic substances with a minimum amount of solid residues at a maximum calorific value of the resulting mixture of combustible gases. A process based on filtration combustion in superadiabatic mode is considered. In existing devices, when this mode is implemented, a counter flow of the feedstock and reaction products is organized. As a result, a part of the water vapor generated at the drying stage is part of the mixture of reaction products and, accordingly, reduce their energy value. The scheme of the process proposed for consideration is based on the organization of the associated flow of feedstock and reaction products. As a result, the resulting carbon dioxide and water vapor are used as additional oxidizing agents. As a result, the carbonaceous residue decreases with a simultaneous increase in the composition of the mixture of gaseous products of carbon monoxide and hydrogen. A scheme for real-time monitoring of the composition of the feedstock during pyrolysis (gasification) is proposed. Knowledge of the composition makes it possible to control the process of its processing in order to: a) organize the optimal gasification process in terms of maximizing the amount and energy value of the mixture of gaseous reaction products; b) control the consumption of the processed feedstock in order to produce the required amount of product gas at any given time.

Catalysts Based on Nanopowders Supported on Foam Materials for Deep Oxidation of Organic Substances

2013 ◽  
Vol 872 ◽  
pp. 10-14
Author(s):  
Alexey Pestryakov ◽  
Vitalii Petranovskii
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Electronic State ◽  
High Surface ◽  
High Surface Area ◽  
Structural Type ◽  
Deep Oxidation ◽  
High Catalytic Activity ◽  
Organic Substances ◽  
Gas Dynamic

Foam catalysts have physicochemical, gas-dynamic and catalytic characteristics exceeding the indices of the traditional granular and honeycomb catalysts. Nanopowders have high catalytic activity due to high surface area and special electronic state. Catalysts of new structural type nanopowders supported on foam metals and foam ceramics - have been tested in the process of deep oxidation of organic substances.

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