Optimizing an electrochemical deposition process by use of design of computer experiments

International audienceA response surface methodology only based in this case on computer experiments was used in conjunction with the desirability concept to optimize a priori an electrodeposition process designed for production of gold-tin alloy bumps on a 4 inches wafer. The efficiency of the method was used to achieve at a cheap cost with a small number of computer experiments the technical specifications required in term of metal deposit thickness uniformity

kinetic study of the support acidity effects of nimo sulfide catalysts on quinoline hydrodenitrogenation

SSCI-VIDE+ECI2D+MNG:MTF:CGEInternational audienceThe improvement of hydrodenitrogenation (HDN) catalytic activity is important due to poisoning effects of nitrogen compounds on acidic catalysts and their inhibiting effects on hydrotreating reactions [1,2]. HDN reaction networks usually comprise a complex set of hydrogenation, ring opening and C-N bond breaking reactions. In order to understand how modifications of HDN catalysts act on this complex reaction network, a detailed kinetic analysis is necessary. In this work we present a very detailed kinetic study of the HDN of quinoline in a batch reactor. The Langmuir-Hinshelwood model includes liquid-vapor mass transfer, which is essential for obtaining reliable kinetic parameters. Each catalyst is tested at different concentrations of quinoline and different temperatures. Thus, 981 experimental points are obtained, which allow the simultaneous estimation of 39 parameters, i.e. activation energies and heat of adsorption. The catalytic tests were carried out over NiMo(P) sulfide catalysts supported on γ-Al2O3 and SiO2-Al2O3. Table 1 summarizes the characteristics and catalytic properties of the two catalysts.Table 1 â Characteristics and catalytic properties of the NiMo catalysts NiMo(P)/Al2O3NiMo(P)/SiO2-Al2O3Weight content of MoO3 / NiO, wt %18.6 / 3.8414 / 2.97Cyclohexane isomerization conversion, %2288NiMoS promoted phase content (mmol/g catal.)0.3260.205Position of NiMoS band in IR Spectroscopy of adsorbed CO (cm-1)21292134Effective rate constant of 14THQ â DHQ step (s-1)0.070.12Effective rate constant of OPA â PB step (s-1)0.0460.173Our kinetic modeling shows that the hydrogenation of 1,2,3,4-tetrahydroquinoline (14THQ) into decahydroquinoline (DHQ) is the determining rate step of the main reaction pathway for both catalysts. The NiMo(P)/SiO2-Al2O3 exhibits a higher rate constant in the hydrogenation of 14THQ and Csp2-N bond cleavage of o-propylaniline (OPA) into propylbenzene (PB). This is attributed to the modification of the electronic properties of promoted phase due to the higher acidity of NiMo(P)/SiO2-Al2O3, as confirmed by Infrared Spectroscopy of CO. The adsorption constants of nitrogen compounds are higher on NiMoP/SiO2-Al2O3 than on NiMoP/γ-Al2O3, which results in higher self-inhibition effects of quinoline and N compounds over NiMoP/SiO2-Al2O3. As a consequence of this higher self-inhibition, the overall activity of the silica-alumina supported catalyst becomes lower than for the alumina-supported catalyst

Development of heart-cutting multidimensional gas chromatography coupled to time of flight mass spectrometry for silicon speciation at trace levels in gasoline samples

cited By 8International audienceTo improve the understanding of hydrotreatment (HDT) catalyst poisoning by silicon species, these molecules must be characterized in petroleum products using powerful analytical systems. Heart-cutting gas chromatography coupled to time of flight mass spectrometry (GC-GC/TOFMS) method equipped with a Deans switch (DS) system was developed for the direct characterization of target silicon compounds at trace level (μgkg-1) in gasoline samples. This method was performed to identify silicon compounds never characterized before. After the selection of the second dimension column using GC-GC-FID, GC-GC/TOFMS was performed. The calibration curves obtained by the GC-GC/TOFMS method were linear up to 1000μgkg-1. Limits of detection (LOD) were ranging from 5 to 33μgkg-1 in spiked gasoline. The method provided sufficient selectivity and sensitivity to characterize known silicon compounds thanks to their specific ions and their retention times. The analysis of a naphtha sample by GC-GC/TOFMS has shown the presence of cyclic siloxanes (Dn) as major compounds of PDMS thermal degradation with the occurrence of linear siloxanes, especially hexamethyldisiloxane (L2), which was never characterized in petroleum products but already known as severe poison for catalyst. © 2012 Elsevier B.V

Use of kinetic modeling for investigating support acidity effects of NiMo sulfide catalysts on quinoline hydrodenitrogenation

SSCI-VIDE+ECI2D+MNG:MTF:CGEInternational audienceA detailed kinetic study of the hydrodenitrogenation (HDN) network of quinoline was carried out over Ni-promoted MoS2 catalysts supported either on gamma-Al2O3 or on amorphous silica alumina (ASA), the objective is to identify the role of the support acidity in HDN reactions. The kinetic data obtained from catalytic tests in a batch reactor were analyzed by a model including the liquid-vapor mass transfer. The adsorption constants of all intermediates and the kinetic constants of all elementary steps were estimated. We found that the NiMo(P)/ASA exhibited a higher rate constant in the hydrogenation of tetrahydroquinoline, which was the rate determining step of the main reaction pathway, and in exocyclic carbon-nitrogen bond cleavage reactions, than the NiMo(P)/Al2O3. Characterization data by Infra-Red spectroscopy of CO suggested that this result might be related to the modification of the electronic properties of promoted NiMoS phase due to higher acidity of ASA. However, the stronger self-inhibiting effect due to stronger adsorption of nitrogen compounds over NiMo(P)/ASA and its lower content of NiMoS phase decreased its global catalytic activity. (C) 2016 Elsevier B.V. All rights reserved

the effects of support acidity on quinoline and indole hydrodenitrogenation - a detailed kinetic study

SSCI-VIDE+ECI2D+MNG:CGEInternational audienceA detailed kinetic modeling including the liquid-vapor mass transfer was proposed to estimate kinetic and adsorption constants in complex reaction scheme and discriminate the support acidity effects on quinoline and indole HDN. The catalytic tests were carried out in a batch reactor, over two sulfide catalysts: NiMo(P)/γ-Al2O3 and NiMo(P)/SiO2-Al2O3 (ASA). Over both catalysts, the hydrogenation of aromatic ring of nitrogen compounds is the rate determining step of the main reaction pathway. The NiMo(P)/ASA exhibited higher rate constants for this step and denitrogenation steps (without ring opening). The adsorption constants of all nitrogen compounds were compared. As expected, nitrogen compounds adsorbed more strongly on NiMo(P)/ASA than Al2O3 counterpart. Quinoline showed a strong inhibiting effect on indole HDN whereas the inhibiting effect of indole on quinoline HDN was negligible over NiMo(P)/Al2O3 and slightly more important over NiMo(P)/ASA

How Does an Acidic Support Affect the Hydrotreatment of a Gas Oil with High Nitrogen Content?

SSCI-VIDE+ECI2D+CGEInternational audience--

Electrodeposition and characterization of manganese–bismuth system from chloride based acidic bath

International audienceIn this work, Mn–Bi system has been successfully electrodeposited on Cu/Si substrates from aqueous ammonium chloride containing electrolyte. A thermodynamic study of the electrolysis bath highlights the possible formation of manganese complexes (MnCl+, MnCl2, MnCl-) and bismuth complexes (BiCl 2+, BiCl2 +, BiCl3, BiCl4 -, BiCl5 2-, BiCl6 3-) The mechanism process involving Mn and Bi electrodeposition is investigated by cyclic voltammetry. Mn–Bi films can be grown under potentiostatic control. The physico-chemical, morphological and structural characterizations of the deposits were carried out by scanning electron microscopy (SEM) and X-rays analysis (XRD). The results reveal a granular surface quality and a heterogeneous chemical composition of the films. The energy dispersive spectroscopy (EDS) analysis reveals the presence of manganese and bismuth peaks whose relative intensities vary according to the imposed potential and the position on the sample. The X-rays diffraction analysis showed three different crystalline phases: α-manganese (body centred cubic system), γ-manganese (body centred tetragonal system) and bismuth (rhombohedral system)

Silicon speciation by gas chromatography coupled to mass spectrometry in gasolines

cited By 14International audienceA method for the speciation of silicon compounds in petroleum products was developed using gas chromatography coupled to mass spectrometry (GC-MS). Prior to analysis, several precautions about storage and conservation were applied for all samples. In spiked gasoline samples, limits of detection between 24 and 69μgkg -1 for cyclic siloxanes (D 4-D 6) and between 1 and 7μgkg -1 for other species were obtained. In this study, cyclic siloxanes (D n) and one ethoxysilane were quantified for the first time in petroleum products by a specific method based on response factor calculation to an internal standard. This method was applied to four samples of naphthas and gasolines obtained from a steam cracking process. Cyclic siloxanes were predominant in four investigated samples with concentrations ranging between 101 and 2204μgkg -1. Cyclic siloxane content decreased with an increase in their degree of polymerization. During a steam cracking process, silicon concentrations determined by GC-MS SIM (single ion monitoring) significantly increase. This trend was confirmed by ICP-OES (inductively coupled plasma optical emission spectroscopy) measurements but a difference on the total silicon content was observed, certainly highlighting the presence of unknown silicon species. GC-MS SIM method gives access to the chemical nature of the silicon species, which is crucial for the understanding of hydrotreatment catalyst poisoning in the oil and gas industry. © 2011 Elsevier B.V

Combining fourier transform-ion cyclotron resonance/mass spectrometry analysis and kendrick plots for silicon speciation and molecular characterization in petroleum products at trace levels

cited By 13International audienceA new method combining FT-ICR/MS analysis and Kendrick plots for the characterization of silicon species at trace levels in light petroleum products is presented. The method provides efficient instrumental detection limits ranging from 80 ng/kg to 5 μg/kg and reliable mass accuracy lower than 0.50 ppm for model silicon molecules in spiked gasoline. More than 3000 peaks could be detected in the m/z 50-500 range depending on the nature of the gasoline sample analyzed. An in-house software program was used to calculate Kendrick plots. Then, an algorithm searched, selected, and represented silicon species classes (O 2Si, O 3Si, and O 4Si classes) in Kendrick plots by incorporating model molecules' information (i.e., exact mass and intensity). This procedure allowed the complete characterization of more than 50 new silicon species with different degrees of unsaturation in petroleum products. © 2012 American Chemical Society

kinetic study of the support acidity effects of nimo sulfide catalysts on quinoline hydrodenitrogenation

SSCI-VIDE+ECI2D+MNG:MTF:CGEInternational audienceThe improvement of hydrodenitrogenation (HDN) catalytic activity is important due to poisoning effects of nitrogen compounds on acidic catalysts and their inhibiting effects on hydrotreating reactions [1,2]. HDN reaction networks usually comprise a complex set of hydrogenation, ring opening and C-N bond breaking reactions. In order to understand how modifications of HDN catalysts act on this complex reaction network, a detailed kinetic analysis is necessary. In this work we present a very detailed kinetic study of the HDN of quinoline in a batch reactor. The Langmuir-Hinshelwood model includes liquid-vapor mass transfer, which is essential for obtaining reliable kinetic parameters. Each catalyst is tested at different concentrations of quinoline and different temperatures. Thus, 981 experimental points are obtained, which allow the simultaneous estimation of 39 parameters, i.e. activation energies and heat of adsorption. The catalytic tests were carried out over NiMo(P) sulfide catalysts supported on γ-Al2O3 and SiO2-Al2O3. Table 1 summarizes the characteristics and catalytic properties of the two catalysts.Table 1 â Characteristics and catalytic properties of the NiMo catalysts NiMo(P)/Al2O3NiMo(P)/SiO2-Al2O3Weight content of MoO3 / NiO, wt %18.6 / 3.8414 / 2.97Cyclohexane isomerization conversion, %2288NiMoS promoted phase content (mmol/g catal.)0.3260.205Position of NiMoS band in IR Spectroscopy of adsorbed CO (cm-1)21292134Effective rate constant of 14THQ â DHQ step (s-1)0.070.12Effective rate constant of OPA â PB step (s-1)0.0460.173Our kinetic modeling shows that the hydrogenation of 1,2,3,4-tetrahydroquinoline (14THQ) into decahydroquinoline (DHQ) is the determining rate step of the main reaction pathway for both catalysts. The NiMo(P)/SiO2-Al2O3 exhibits a higher rate constant in the hydrogenation of 14THQ and Csp2-N bond cleavage of o-propylaniline (OPA) into propylbenzene (PB). This is attributed to the modification of the electronic properties of promoted phase due to the higher acidity of NiMo(P)/SiO2-Al2O3, as confirmed by Infrared Spectroscopy of CO. The adsorption constants of nitrogen compounds are higher on NiMoP/SiO2-Al2O3 than on NiMoP/γ-Al2O3, which results in higher self-inhibition effects of quinoline and N compounds over NiMoP/SiO2-Al2O3. As a consequence of this higher self-inhibition, the overall activity of the silica-alumina supported catalyst becomes lower than for the alumina-supported catalyst