Pyrolysis of hydrocarbons in the presence of elemental sulfur

The effect of elemental sulfur on the kinetics and selectivity of conversion of heptane was studied with regard to the inhibition of the coke formation during pyrolysis of raffinates from naphtha reforming. The experiments were conducted in stainless steel tubular through-flow reactors at atmospheric pressure. The heptane decomposition rate in the absence of sulfur was compared with that in the presence of 0.01, 0.02, and 0.1 wt.% sulfur at 700°C and with the steam-to-feed ratio 3:1. The influence of the inner surface of the reactor was investigated by using reactors with different equivalent volumes. The effect of sulfur on the coke formation during the pyrolysis of the reformer raffinate was examined at 820°C without any inert diluent.

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Elemental Distribution in Pt-Re:Al2O3 Naphtha Reforming Catalysts

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600000866 ◽

1980 ◽

Vol 38 ◽

pp. 200-201

Author(s):

R. L. Freed ◽

M. J. Kelley

Keyword(s):

Bimetallic Catalyst ◽

Supported Catalysts ◽

Coke Formation ◽

Materials Characterization ◽

Metal Catalyst ◽

Elemental Distribution ◽

Exact Nature ◽

Naphtha Reforming ◽

Reforming Catalysts ◽

Commercial Introduction

The commercial introduction of Pt-Re supported catalysts to replace Pt alone on Al2O3 has brought improvements to naphtha reforming. The bimetallic catalyst can be operated continuously under conditions which lead to deactivation of the single metal catalyst by coke formation. Much disagreement still exists as to the exact nature of the bimetallic catalyst at a microscopic level and how it functions in the process so successfully. The overall purpose of this study was to develop the materials characterization tools necessary to study supported catalysts. Specifically with the Pt-Re:Al2O3 catalyst, we sought to elucidate the elemental distribution on the catalyst.

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Probabilistic evaluation of detection capability of eddy current testing to inspect pitting on a stainless steel clad using multiple signal features

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209306 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 47-55

Author(s):

Takuma Tomizawa ◽

Haicheng Song ◽

Noritaka Yusa

Keyword(s):

Stainless Steel ◽

Eddy Current ◽

Pressure Vessels ◽

Eddy Current Testing ◽

Probability Of Detection ◽

Current Testing ◽

Multiple Signal ◽

Signal Features ◽

Inner Surface ◽

Drill Holes

This study proposes a probability of detection (POD) model to quantitatively evaluate the capability of eddy current testing to detect flaws on the inner surface of pressure vessels cladded by stainless steel and in the presence of high noise level. Welded plate samples with drill holes were prepared to simulate corrosion that typically appears on the inner surface of large-scale pressure vessels. The signals generated by the drill holes and the noise caused by the weld were examined using eddy current testing. A hit/miss-based POD model with multiple flaw parameters and multiple signal features was proposed to analyze the measured signals. It is shown that the proposed model is able to more reasonably characterize the detectability of eddy current signals compared to conventional models that consider a single signal feature.

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Inner surface biofilm inactivation by atmospheric pressure helium porous plasma jet

Plasma Processes and Polymers ◽

10.1002/ppap.201800055 ◽

2018 ◽

Vol 15 (12) ◽

pp. 1800055 ◽

Cited By ~ 3

Author(s):

Peng Lu ◽

Dana Ziuzina ◽

Patrick J. Cullen ◽

Paula Bourke

Keyword(s):

Atmospheric Pressure ◽

Plasma Jet ◽

Inner Surface

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An Experimental and Numerical Methodology to Investigate Crack Growth in a 304L Austenitic Stainless Steel Pipe Under Thermal Fatigue

ASME 2010 Pressure Vessels and Piping Conference: Volume 3 ◽

10.1115/pvp2010-25386 ◽

2010 ◽

Cited By ~ 1

Author(s):

Pauline Bouin ◽

Antoine Fissolo ◽

Ce´dric Gourdin

Keyword(s):

Finite Element ◽

Stainless Steel ◽

Austenitic Stainless Steel ◽

Crack Growth ◽

Thermal Fatigue ◽

Thermal Loading ◽

Steel Pipe ◽

Design Stage ◽

Inner Surface ◽

Stainless Steel Pipe

This paper covers work carried out by the French Atomic Energy Commission (CEA) to investigate on mechanisms leading to cracking of piping as a result of thermal loading existing in flow mixing zones. The main purpose of this work is to analyse, with a new experiment and its numerical interpretation, and to understand the mechanism of propagation of cracks in such components. To address this issue, a new specimen has been developed on the basis of the Fat3D experiment. This thermal fatigue test consists in heating a 304L steel pre-cracked tube while cyclically injecting ambient water onto its inner surface. The tube is regularly removed from the furnace for a crack characterisation. Finally, the crack growth is evaluated from the crack length differences between two stops. In parallel, a finite element analysis is developed using the finite element Cast3M code. A pipe with a semi-elliptical crack on its inner surface is modelled. A cyclic thermal loading is imposed on the tube. This loading is in agreement with experimental data. The crack propagates through the thickness. A prediction of the velocity of the crack is finally assessed using a Paris’ law type criteria. Finally, this combined experimental and numerical work on 304L austenitic stainless steel pipes will enable to improve existing methods to accurately predict the crack growth under cyclic thermal loadings in austenitic stainless steel pipe at the design stage.

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