scholarly journals Alumina-based Coating for Coke Reduction in Steam Crackers

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2025
Author(s):  
Stamatis A. Sarris ◽  
Steffen H. Symoens ◽  
Natalia Olahova ◽  
Marie-Françoise Reyniers ◽  
Guy B. Marin ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Base Alloy ◽  
Product Distribution ◽  
X Ray ◽  
Barrier Coating ◽  
Sulfur Addition ◽  
Steam Cracking ◽  
On Line ◽  
Set Up ◽  
Section Analysis

Alumina-based coatings have been claimed as being an advantageous modification in industrial ethylene furnaces. In this work, on-line experimentally measured coking rates of a commercial coating (CoatAlloy™) have pointed out its superiority compared to an uncoated reference material in an electrobalance set-up. Additionally, the effects of presulfiding with 500 ppmw DMDS per H2O, continuous addition of 41 ppmw S per HC of DMDS, and a combination thereof were evaluated during ethane steam cracking under industrially relevant conditions (Tgasphase = 1173 K, Ptot = 0.1 MPa, XC2H6 = 70%, dilution δ = 0.33 kgH2O/kgHC). The examined samples were further evaluated using online thermogravimetry, scanning electron microscopy and energy diffractive X-ray for surface and cross-section analysis together with X-ray photoelectron spectroscopy and wavelength-dispersive X-ray spectroscopy for surface analysis. The passivating coating illustrated a better performance than the reference Ni-Cr Fe-base alloy after application of an improved pretreatment, followed by piddling changes on the product distribution. Presulfiding of the coating affected negatively the observed coking rates in comparison with the reference alloy, so alternative presulfiding and sulfur addition strategies are recommended when using this barrier coating.

scholarly journals Yttrium Doped TiO2 Thin Film for Gas Sensing Application Prepared by Spin Coating Method

2020 ◽  
Author(s):  
M Abdul Kaiyum ◽  
Naim Ahmed ◽  
Arif Alam ◽  
M Shamimur Rahman
Keyword(s):  
Thin Film ◽  
Photoelectron Spectroscopy ◽  
Gas Sensing ◽  
Low Cost ◽  
Pure Titanium ◽  
X Ray ◽  
Sensing Applications ◽  
Coating Method ◽  
Set Up ◽  
Spin Coater

Abstract Yttrium (Y) doped and pure Titanium Di-oxide (TiO2) thin films were prepared by using spin coater. The coater was set up in laboratory with low cost investment. The films were calcined at 450 °C for 1 hour. For characterization, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Atomic Force Microscopy (AFM) were carried out. LCR Bridge - GW Instek LCR-821 was used for gas sensing applications. XPS showed that the change of electronic structure due to Y doping. SEM and AFM analysis were carried out to determine the surface morphology of the films. Yttrium (Y) decreased the crystallite size of the films and increased the surface roughness and porosity value, which was very good for many sensing applications. Gas sensing property of the deposited films were improved by the incorporation of yttrium impurities and the sensing property improved almost two times than pure TiO2 thin film. Different researches have been done their research related to this topic but no one researchers provide a precise explanation of their results, authors of this research have tried to do that. Moreover the films were prepared by a simple spin coater to reduce the production cost also.

Rapid Photon-Excited Energy-Dispersive X-Ray Fluorescence Analysis for Solid and Liquid Mineralogical Samples

1975 ◽  
Vol 19 ◽  
pp. 267-272 ◽  
Author(s):  
W. Ratyński ◽  
J. Parus ◽  
J. Tys ◽  
A. Ciszek
Keyword(s):  
Fluorescence Analysis ◽  
Semiconductor Detectors ◽  
X Rays ◽  
Copper Ore ◽  
X Ray ◽  
Large Numbers ◽  
Important Benefit ◽  
Versatile Tool ◽  
On Line ◽  
Set Up

X-ray fluorescence spectroscopy is new becoming a tool in research and. industry. Semiconductor detectors are proving valuable in measuring fluorescent X rays, and so are providing a versatile tool for rapid multielement analysis of many types of samples. This paper will mainly be concerned with, different types of copper ore. An experimental setup has been designed to determine Cu, Fe and Pb of concentration ranging from 0.1 to 20, to 5, and to 4 percent, respectively, with analytical precision of 20% relative at 0.1% Cu, and 3% relative at 20% Cu. For excitation a 100 mCi Pu-238 source and/or a low power air-cooled X-ray tube were used. Data acquisition and “on-line” evaluation for each sample takes about 100 seconds. Electronics blocks and sub-systems used In the set-up are available commercially. The most important benefit to be obtained from the setup is the ability to provide precise, reproducible determinations of large numbers of samples day after day.

scholarly journals Combining X-ray scattering and spectroscopy as structure resolving tool

2014 ◽  
Vol 70 (a1) ◽  
pp. C1074-C1074
Author(s):  
Sylvio Haas ◽  
Thomás Plivelic ◽  
Cedric Dicko
Keyword(s):  
Molecular Mechanisms ◽  
Basic Research ◽  
Sample Volume ◽  
Complex Behaviour ◽  
X Ray ◽  
Complex Interactions ◽  
X Ray Scattering ◽  
On Line ◽  
Set Up ◽  
Ray Scattering

Modern applications and basic research in medicine, biotechnology and materials are often concerned with hybrid (organic-inorganic) and synergetic systems. In other words, systems that brings enhanced properties and performances. The challenge is now in the understanding of the complex interactions leading to their assembly and operation. Due to their inherent chemical and structural complexities a combination of several techniques is necessary to determine unambiguously the molecular mechanisms of assembly and operation. [1, 2] To address this need, we have implemented a simultaneous measurement platform called SURF [3] that consists of SAXS, UV-Vis, Raman and fluorescence techniques. The SURF platform provides simultaneous measurements on the same sample volume and a multivariate framework to associate the spectroscopic and X-ray scattering information. Convex constraint analysis (CCA) and two dimensional correlation analyses (2DCOS and 2DHCOS) had been introduced to enhance the interpretation and integration of the data from the different techniques producing self-consistent models and resolving complex behaviour details (structure and chemistry). Additional benefits of the SURF are sample quality control and "on line" diagnostics. In this contribution, we illustrate the benefits of the SURF approach on selected examples. Acknowledgements: The SURF set-up has been mainly financial supported by MAX IV laboratory. S. Haas has a postdoctoral grant of MAX IV lab. S Canton and Q. Zhu are acknowledged for fruitful discussions.

On line shape analysis in X-ray photoelectron spectroscopy

2001 ◽  
Vol 470 (3) ◽  
pp. 325-336 ◽  
Author(s):  
Wolfgang S.M. Werner ◽  
Thomas Cabela ◽  
Josef Zemek ◽  
Petr Jiricek
Keyword(s):  
Shape Analysis ◽  
Photoelectron Spectroscopy ◽  
Line Shape ◽  
X Ray ◽  
Line Shape Analysis ◽  
On Line

scholarly journals Effect of Long-Term High Temperature Oxidation on the Coking Behavior of Ni-Cr Superalloys

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1899 ◽  
Author(s):  
Stamatis Sarris ◽  
Manjunath Patil ◽  
Kim Verbeken ◽  
Marie-Françoise Reyniers ◽  
Kevin Van Geem
Keyword(s):  
Cross Section ◽  
Temperature Oxidation ◽  
X Ray ◽  
Microstructure Stability ◽  
Ni Content ◽  
Steam Cracking ◽  
Improved Stability ◽  
Section Analysis

The service time of an industrial cracker is strongly dependent on the long-term coking behavior and microstructure stability of the reactor coil alloy. Super alloys are known to withstand temperatures up to even 1400 K. In this work, several commercially available alloys have been first exposed to a long term oxidation at 1423 K for 500 h, so-called metallurgic aging. Subsequently, their coking behavior was evaluated in situ in a thermogravimetric setup under ethane steam cracking conditions (Tgasphase = 1173 K, Ptot = 0.1 MPa, XC2H6 = 70%, continuous addition of 41 ppmw S/HC of DMDS, dilution δ = 0.33 kgH2O/kgHC) and compared with their unaged coking behavior. The tested samples were also examined using scanning electron microscopy and energy diffractive X-ray for surface and cross-section analysis. The alloys characterized by increased Cr-Ni content or the addition of Al showed improved stability against bulk oxidation and anti-coking behavior after application of metallurgic aging due to the formation of more stable oxides on the top surface.

Critical comparison of methods for surface coverage by extractives and lignin in pulps by X-ray photoelectron spectroscopy (XPS)

Holzforschung ◽  
2006 ◽  
Vol 60 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Pedro Fardim ◽  
Anette Heijnesson Hultén ◽  
Jean-Phillippe Boisvert ◽  
Leena-Sisko Johansson ◽  
Marie Ernstsson ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Surface Coverage ◽  
Component Analysis ◽  
X Ray ◽  
Chemical Pulp ◽  
Mercury Acetate ◽  
Set Up ◽  
Relative Comparisons ◽  
True Values ◽  
Selection Of

Abstract Different methods for estimation of the surface coverage by extractives and lignin were critically compared. For data collection, four state-of-the-art X-ray photoelectron spectroscopy (XPS) instruments located in four different laboratories were used. Hand sheets of one mechanical and two chemical pulp samples were prepared in one laboratory and distributed among the other participants. The XPS results based on O/C ratios and curve fitting of the C 1s peak had very good intra- and interlaboratory variation for extracted and non-extracted pulp samples. The estimations of surface coverage by extractives and lignin also had acceptable intra- and interlaboratory variation. However, significant differences were observed between the results for the various methods. Estimation of surface coverage by extractives based on O/C ratios was much higher than that based on the C1 component analysis in the case of mechanical and unbleached chemical pulp. The surface coverage by lignin of mechanical pulp was reproducibly detected based on O/C ratios, C1 component analysis and by labelling with mercury acetate. The same data were, however, rather scattered if they were collected with these three methods for bleached and unbleached chemical pulp. In spite of the differences, similar trends regarding the pulp type could be observed. We interpret the results as indicating that the surface coverage for both extractives and lignin should not be considered as absolute “true” values, but rather as relative values, which are reliable only for comparison of samples for the same instrument. Even for relative comparisons, we recommend the selection of a strict experimental set-up for spectral acquisition and data treatment when applying any of the instruments and calculation models currently available.

scholarly journals Evaluation of a Ti–Base Alloy as Steam Cracking Reactor Material

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2550 ◽  
Author(s):  
Stamatis A. Sarris ◽  
Kim Verbeken ◽  
Marie-Françoise Reyniers ◽  
Kevin M. Van Geem
Keyword(s):  
Base Alloy ◽  
Coke Formation ◽  
Surface Oxidation ◽  
Reactor Material ◽  
X Ray ◽  
Stirred Reactor ◽  
Initiation And Propagation ◽  
Steam Cracking ◽  
Temperature Pretreatment ◽  
Temperature Scanning

Low-coking reactor material technologies are key for improving the performance and sustainability of steam crackers. In an attempt to appraise the coking performance of an alternative Ti–base alloy during ethane steam cracking, an experimental study was performed in a jet stirred reactor under industrially relevant conditions using thermogravimetry (Tgasphase = 1173 K, Ptot = 0.1 MPa, XC2H6 = 70%, and dilution δ = 0.33 kgH2O/kgHC). Initially, a typical pretreatment used for Fe–Ni–Cr alloys was utilized and compared with a pretreatment at increased temperature, aiming at better surface oxidation and thus suppressing coke formation. The results revealed a decrease in coking rates upon high temperature pretreatment of the Ti–base alloy, however, its coking performance was significantly worse compared to the typically used Fe–Ni–Cr alloys, and carbon oxides formation increased by a factor of 30 or more. Moreover, the analyzed coupons showed crack propagation after coking/decoking and cooling down to ambient temperature. Scanning electron microscopy combined with energy-dispersive X-ray spectroscopy indicated that the prompt and unsystematic oxidation of the surface and bulk caused observable crack initiation and propagation due to alloy brittleness. Hence, the tested Ti–base alloy cannot be considered an industrially noteworthy steam cracking reactor alloy.

Research on Microstructure and Tribological Properties of the Cp/AlSn Coatings Deposited by Magnetron Sputtering

2013 ◽  
Vol 765 ◽  
pp. 703-707
Author(s):  
Qiao Qin Guo ◽  
Jian Ping Li ◽  
Yong Chun Guo
Keyword(s):  
Magnetron Sputtering ◽  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Composite Films ◽  
Closed Field ◽  
Carbon Target ◽  
X Ray ◽  
Pin On Disc ◽  
Set Up ◽  
Bearing Alloy

The influences of microstructure and tribological properties of Cp/AlSn (Cp: carbon particule) composite films were applied to AlZn4.5Mg bearing alloy substrates using the closed-field unbalanced magnetron sputtering ion plating technique. The microstructure, phases and bond states of the coatings were separately characterized by X-ray diffraction (XRD), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The friction coefficients were measured using a pin-on-disc set-up. Results showed that the grain size and roughness of the films both decreased with increasing of carbon target current (IC) from 0.2 A to 0.8 A. Phases in the films were Al, Sn and C, although the films transformed from a crystalline state to amorphous when the carbon target current was applied. Al and Sn existed as pure metals. Carbon, composed of sp2and sp3bonds, mainly as sp2bonds, provided transfer films to reduce the friction coefficient of the films from 0.35 to 0.15. The specific wear ratio was a minimum, when the carbon target current was 0.4 A.

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