scholarly journals Permeation of a Range of Species through Polymer Layers under Varying Conditions of Temperature and Pressure: In Situ Measurement Methods

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1056 ◽  
Author(s):  
Bernadette Craster ◽  
Timothy Jones
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Elevated Temperatures ◽  
Chloride Ions ◽  
Polyphenylene Sulfide ◽  
Polymer Layers ◽  
Barrier Layers ◽  
Major Interest ◽  
Temperature And Pressure

Minimising the transport of corrosive reactants such as carbon dioxide, hydrogen sulfide and chloride ions to the surfaces of carbon steel pipes by the use of polymer barrier layers is of major interest in the oil and gas sector. In these applications, there is a requirement to assess the performance of these barrier layers although it is difficult to perform long-term predictions of barrier properties from the results of short-term measurements. New methodologies have been successfully developed to study the permeability of carbon dioxide (CO2) and hydrogen sulfide (H2S) through polymer layers under variable conditions of elevated temperatures of 100 °C and pressures of the order of 400 barg. In situ variation of the temperature and the inlet pressure of the gas (or gas mixture) allowed the activation energy and pressure dependence of the permeability to be determined without outgassing of the specimen. These methodologies have been applied to the measurement of the permeability of moulded polyphenylene sulfide (PPS) to supercritical CO2 in the presence of H2S. The diffusion coefficients of sodium chloride and potassium chloride through both PPS and polyether ether ketone (PEEK) at ambient temperature and pressure have also been measured.

Metal-Support Interactions and C1 Chemistry: Transforming Pt-CeO2 into a Highly Active and Stable Catalyst for the Conversion of Carbon Dioxide and Methane

2020 ◽  
Author(s):  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pablo Lustemberg ◽  
Zongyuan Liu ◽  
Ning Rui ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Metal Oxide ◽  
Elevated Temperatures ◽  
Chemical Properties ◽  
Oxide Interface ◽  
Highly Active ◽  
Metal Support ◽  
Metal Support Interactions ◽  
Methane Dissociation

There is an ongoing search for materials which can accomplish the activation of two dangerous greenhouse gases like carbon dioxide and methane. In the area of C1 chemistry, the reaction between CO2 and CH4 to produce syngas, known as methane dry reforming (MDR), is attracting a lot of interest due to its green nature. On Pt(111), elevated temperatures are necessary to activate the reactants and massive deposition of carbon makes this metal surface ineffective for the MDR process. In this study, we show that strong metal-support interactions present in Pt/CeO2(111) and Pt/CeO2 powders lead to systems which can bind well CO2 and CH4 at room temperature and are excellent and stable catalysts for the MDR process at moderate temperature (500 ºC). The behaviour of these systems was studied using a combination of in-situ/operando methods which pointed to an active Pt-CeO2-x interface. In this interface, the oxide is far from being a passive spectator. It modifies the chemical properties of Pt, facilitating improved methane dissociation, and is directly involved in the adsorption and dissociation of CO2 making the MDR catalytic cycle possible. A comparison of the benefits gained by the use of an effective metal-oxide interface and those obtained by plain bimetallic bonding indicates that the former is much more important when optimizing the C1 chemistry associated with CO2 and CH4 conversion. The presence of elements with a different chemical nature at the metal-oxide interface opens the possibility for truly cooperative interactions in the activation of C-O and C-H bonds.

scholarly journals Metal-Support Interactions and C1 Chemistry: Transforming Pt-CeO2 into a Highly Active and Stable Catalyst for the Conversion of Carbon Dioxide and Methane

2020 ◽  
Author(s):  
Feng Zhang ◽  
Ramón A. Gutiérrez ◽  
Pablo Lustemberg ◽  
Zongyuan Liu ◽  
Ning Rui ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Metal Oxide ◽  
Elevated Temperatures ◽  
Chemical Properties ◽  
Oxide Interface ◽  
Highly Active ◽  
Metal Support ◽  
Metal Support Interactions ◽  
Methane Dissociation

There is an ongoing search for materials which can accomplish the activation of two dangerous greenhouse gases like carbon dioxide and methane. In the area of C1 chemistry, the reaction between CO2 and CH4 to produce syngas, known as methane dry reforming (MDR), is attracting a lot of interest due to its green nature. On Pt(111), elevated temperatures are necessary to activate the reactants and massive deposition of carbon makes this metal surface ineffective for the MDR process. In this study, we show that strong metal-support interactions present in Pt/CeO2(111) and Pt/CeO2 powders lead to systems which can bind well CO2 and CH4 at room temperature and are excellent and stable catalysts for the MDR process at moderate temperature (500 ºC). The behaviour of these systems was studied using a combination of in-situ/operando methods which pointed to an active Pt-CeO2-x interface. In this interface, the oxide is far from being a passive spectator. It modifies the chemical properties of Pt, facilitating improved methane dissociation, and is directly involved in the adsorption and dissociation of CO2 making the MDR catalytic cycle possible. A comparison of the benefits gained by the use of an effective metal-oxide interface and those obtained by plain bimetallic bonding indicates that the former is much more important when optimizing the C1 chemistry associated with CO2 and CH4 conversion. The presence of elements with a different chemical nature at the metal-oxide interface opens the possibility for truly cooperative interactions in the activation of C-O and C-H bonds.

scholarly journals RESEARCH OF DYNAMICS OF HYDROGEN SULPHIC CORROSION OF METAL OF CASING UNDER THE LAYER OF MODIFIED CONCRETE

2020 ◽  
Vol 3 (156) ◽  
pp. 49-55
Author(s):  
A. Nemah ◽  
S. Nesterenko ◽  
D. Donskyi ◽  
Yu. Skrypiy
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Gas Permeability ◽  
Chloride Ions ◽  
Cement Stone ◽  
Oil Well ◽  
Protective Properties ◽  
Geological Conditions ◽  
Grouting Materials ◽  
Anticorrosion Properties

The issue of protection of problem areas of oil well casings, which are operated in aggressive environments of formation fluids of Iraq, containing hydrogen sulfide, carbon dioxide and chlorides, is considered. It is pro-posed to reduce the influence of aggressive factors by using modified cement compositions. The chemical composi-tion of Portland cements and modified compositions based on them was studied, experimental samples of cement stone were obtained and tested in a simulated aggressive environment (80% CO2 and 20% H2S) at a temperature of 105˚ C for 1200 hours. The dynamics of corrosion development in steel 45 under the cement layer is analyzed. It is shown that the rate of crevice corrosion of casing metal (steel 45), protected by modified concrete, obtained on the basis of Port-land cement grade G is much lower (5-6 times) relative to protection by unmodified concrete, and the protective effect of modified cement stone increases over time. It is concluded that the modification has a positive effect on the protective properties of cement stone. In the process of researching new grouting materials having improved anticorrosion properties, optimal for-mulations of the developed compositions were selected, the dependence of the strength characteristics, adhesion and gas permeability of the stone, as well as its anticorrosion properties on the ratio of components in grouting mixtures were studied. The use of new grouting materials with improved inhibitory properties will help to reduce the risks of prema-ture deformation of the deep sections of the casing string as a result of the corrosion destruction of its external surface, as well as improve the quality of formation demarcation in oil and gas wells with aggressive fluids con-taining hydrogen sulfide, carbon dioxide and a significant amount of dissolved in formation water of chloride ions, has practical value. The results of the work have the prospect of practical application for fastening deep wells, including direc-tional ones, in difficult mining and geological conditions on exploration areas and industrial oil fields of Iraq. Keywords: casing string, formation fluids, hydrogen sulfide, carbon dioxide, chlorides, corrosion, Portland cement, grouting materials, protective properties

Activation of (salen)CoI complex by phosphorane for carbon dioxide transformation at ambient temperature and pressure

2017 ◽  
Vol 19 (16) ◽  
pp. 3908-3915 ◽  
Author(s):  
Feng Zhou ◽  
Shi-Liang Xie ◽  
Xiao-Tong Gao ◽  
Rong Zhang ◽  
Cui-Hong Wang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ambient Temperature ◽  
Bifunctional Catalyst ◽  
Carbon Dioxide Pressure ◽  
Temperature And Pressure

The activation of a (salen)CoI complex by phosphorane in situ formed a bifunctional catalyst for the reaction of carbon dioxide with terminal epoxides or aziridines at ambient temperature and 1 bar carbon dioxide pressure.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

The threshold energy for atom displacement in fcc metals

1990 ◽  
Vol 48 (4) ◽  
pp. 530-531
Author(s):  
Wilfried Sigle ◽  
Matthias Hohenstein ◽  
Alfred Seeger
Keyword(s):  
Growth Rate ◽  
Elevated Temperatures ◽  
Threshold Energy ◽  
Dislocation Loops ◽  
Absolute Minimum ◽  
Voltage Electron ◽  
Atom Displacement ◽  
Electron Microscopes ◽  
Fcc Metal

Prolonged electron irradiation of metals at elevated temperatures usually leads to the formation of large interstitial-type dislocation loops. The growth rate of the loops is proportional to the total cross-section for atom displacement,which is implicitly connected with the threshold energy for atom displacement, Ed . Thus, by measuring the growth rate as a function of the electron energy and the orientation of the specimen with respect to the electron beam, the anisotropy of Ed can be determined rather precisely. We have performed such experiments in situ in high-voltage electron microscopes on Ag and Au at 473K as a function of the orientation and on Au as a function of temperature at several fixed orientations.Whereas in Ag minima of Ed are found close to <100>,<110>, and <210> (13-18eV), (Fig.1) atom displacement in Au requires least energy along <100>(15-19eV) (Fig.2). Au is thus the first fcc metal in which the absolute minimum of the threshold energy has been established not to lie in or close to the <110> direction.

In Situ Polymerized Protic Ionogels for Fuel Cells at Elevated Temperatures

2021 ◽  
Author(s):  
Mengdou Zou ◽  
Jie Luo ◽  
Xurui Wang ◽  
Shuai Tan ◽  
Caihong Wang ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Elevated Temperatures

scholarly journals Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

2021 ◽  
pp. 000370282199044
Author(s):  
Wubin Weng ◽  
Shen Li ◽  
Marcus Aldén ◽  
Zhongshan Li
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Elevated Temperatures ◽  
Uv Absorption ◽  
Energy Utilization ◽  
Quantitative Detection ◽  
Absorption Cross ◽  
Hot Gas

Ammonia (NH3) is regarded as an important nitrogen oxides (NOx) precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of NH3, accurate in situ detection of NH3 in high temperature environments is desirable. Ultraviolet (UV) absorption spectroscopy is a feasible technique. To achieve quantitative measurements, spectrally resolved UV absorption cross-sections of NH3 in hot gas environments at different temperatures from 295 K to 590 K were experimentally measured for the first time. Based on the experimental results, vibrational constants of NH3 were determined and used for the calculation of the absorption cross-section of NH3 at high temperatures above 590 K using the PGOPHER software. The investigated UV spectra covered the range of wavelengths from 190 nm to 230 nm, where spectral structures of the [Formula: see text] transition of NH3 in the umbrella bending mode, v2, were recognized. The absorption cross-section was found to decrease at higher temperatures. For example, the absorption cross-section peak of the (6, 0) vibrational band of NH3 decreases from ∼2 × 10−17 to ∼0.5 × 10−17 cm2/molecule with the increase of temperature from 295 K to 1570 K. Using the obtained absorption cross-section, in situ nonintrusive quantification of NH3 in different hot gas environments was achieved with a detection limit varying from below 10 parts per million (ppm) to around 200 ppm as temperature increased from 295 K to 1570 K. The quantitative measurement was applied to an experimental investigation of NH3 combustion process. The concentrations of NH3 and nitric oxide (NO) in the post flame zone of NH3–methane (CH4)–air premixed flames at different equivalence ratios were measured.

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