Showing papers in "Preprints-American Chemical Society Division of Petroleum Chemistry in 1994"
Journal Article•
TL;DR: In this article, surface deposition from hydrocarbons when heated to temperatures where pyrolysis (thermal cracking) begins with the formation of light gases (C 1 -C 4 ).
Abstract: This paper focuses on surface deposition from hydrocarbons when heated to temperatures where pyrolysis (thermal cracking) begins with the formation of light gases (C 1 -C 4 ).
10 citations
Journal Article•
TL;DR: The method described in this paper is different from previously published procedures in that, although conducted by GC methods, no separation of fuel and dissolved gases occurs in the chromatographic column but rather only in the injector.
Abstract: There are a variety of measurement techniques for determining the solubility of dissolved oxygen (or nitrogen) in liquid hydrocarbons. The method described in this paper is different from previously published procedures in that, although conducted by GC methods, no separation of fuel and dissolved gases occurs in the chromatographic column but rather only in the injector. The mass spectrometer is the major disengagement device (separation by masses) and not the chromatographic column
7 citations
Journal Article•
TL;DR: In this article, the second in a series evaluating the high temperature behavior of hydrocarbon fuels, a fuel thermally stable to 480°C (900°F) was designed as JP-900.
Abstract: This paper is the second in a series evaluating the high temperature behavior of hydrocarbon fuels. The goal of this work is a fuel thermally stable to 480°C (900°F), designed as JP-900. This paper expands the fuels tested to include other advanced (high temperature) fuels, such as decalin, JP-10, JPTS and MCH. Several other Jat A fuels are used as the baseline for tests involving varying pressures, flow rates, and other parameters.
6 citations
Journal Article•
TL;DR: In this article, it was shown that even under strongly oxidizing reaction conditions, a significant fraction of the copper remains as cuprous ion in a reaction mixture containing an olefinic compound, propene.
Abstract: In this paper, we will show that even under strongly oxidizing reaction conditions, a significant fraction of the copper remains as cuprous ion in a reaction mixture containing an olefinic compound, propene. By further analyzing the temperature dependance and energy shift of the electronic transition associated with the cuprous species, we hope to shed light on th reaction mechanism of this interesting catalytic system.
6 citations
Journal Article•
TL;DR: In this paper, the catalytic behavior of a series of transition metal carbides and nitrides for hydroprocessing in a three-phase trickle-bed reactor at 3.1 MPa and 643 °K was investigated.
Abstract: This paper deals with a study of the catalytic behavior of a series of transition metal carbides (Mo 2 C,VC,WC and NbC) and nitrides (Mo 2 N,VN and TiN) for hydroprocessing in a three-phase trickle-bed reactor at 3.1 MPa and 643 °K. The hydrodenitrogenation activity of the carbides and nitrides was compared to that of a commercial sulfided Ni-Mo/Al 2 O 3 (Shell 324) catalyst studied at the same conditions.
6 citations
Journal Article•
TL;DR: In this article, the authors determined systematic temperature trends in surface and bulk fuel fouling within the autoxidation-chemistry regime, and provided a quantitative baseline for a representative Jet-A fuel with which to evaluate the effectiveness of additives.
Abstract: The goal of this study was twofold : 1) to determine systematic temperature trends in surface and bulk fuel fouling within the autoxidation-chemistry regime, and 2) to provide a quantitative baseline for a representative Jet-A fuel with which to evaluate the effectiveness of additives.
6 citations
Journal Article•
TL;DR: In this article, the authors used TG/MS to determine the adsorptive capacity of commercially available activated carbons produced from coal, coconut and petroleum pitch, and explored the relation-ship between their chemical and physical characteristics relative to NO x adorptive capacities.
Abstract: This work use TG/MS to determine adsorptive capacity of commercially available activated carbons produced from coal, coconut and petroleum pitch. The relation-ship between their chemical and physical characteristics relative to NO x adsorptive capacities was explored
6 citations
Journal Article•
TL;DR: In this article, the adsorbed species formed from NO-C 3 H 6 -O 2 and their dynamic behavior on Ce-ZSM-5 catalyst were investigated by means of infrared spectroscopy and the quantitative analysis of gas phase.
Abstract: In this paper, the authors investigated the adsorbed species formed from NO-C 3 H 6 -O 2 and their dynamic behavior on Ce-ZSM-5 catalyst by means of infrared spectroscopy and the quantitative analysis of gas phase.
6 citations
TL;DR: In this paper, the effects of metal leaching on catalyst characteristics are reported and discussed and samples of spent catalyst and chemically treated catalysts were characterized for surface area, porosity and chemical composition.
Abstract: The effects of metal leaching on catalyst characteristics are reported and discussed. Samples of spent catalyst and chemically treated catalysts were characterized for surface area, porosity and chemical composition. The influence of chemical treatment on the distributuion of foulant metals (V and Ni) and the active metals (Co and Mo) within the catalyst pellet was examined by electron microphobe analysis.The samples were also tested for HDS activity recovery as a result of the rejuvenation process.
6 citations
Journal Article•
TL;DR: In this paper, a comparison is made between the catalytic activities of CoMo and NiMo for hydrodesulfurization (HDS) of gas oil fractions containing different sulfur species.
Abstract: Deep desulfurization of petroleum products is strongly desired with minimum severity to protect the environment. In this paper, a comparison is made between the catalytic activities of CoMo and NiMo for hydrodesulfurization (HDS) of gas oil fractions containing different sulfur species. The HDS mechanisms of refractory sulfur compounds are discussed, which is favorable to the catalyst design for the deep HDS.
6 citations
Journal Article•
TL;DR: In this article, a mechanistic study of supported platinum catalysts on γ-alumina for the selective reduction of NO in the presence of excess oxygen using both microreactor and temporal analysis of products (TAP) techniques is presented.
Abstract: For automotive uses, alternative catalyst systems must be developed. In this paper we present a mechanistic study of supported platinum catalysts on γ-alumina for the selective reduction of NO in the presence of excess oxygen using both microreactor and temporal analysis of products (TAP) techniques.
Journal Article•
TL;DR: In this paper, the polar constituents of crude oils were identified as the major precursors to sludge and other sediments, although other constituents also played a role in their development.
Abstract: The stability of fuels has been well researched over the past decades and there have been inroads into the chemistry of fuel stability or incompatibility. A key to decreasing incompatibility during refinery operations is to develop an understanding of the principal precursors to sludge and other sediments. Such precursor are the polar constituents of crude oils that are, for the most part, the asphaltenes and the resins. And for convenience here, reference is made to the asphaltene as the major precursors to sludge and to sediments although it must be recognized that other constituents also play a role
Journal Article•
TL;DR: In this article, the effects of loading and the zeolite type on the reaction of NO + C 3 H 6 + O 2 are revealed by the change in the activity profiles over a wide range of temperatures.
Abstract: In this paper, the effects of Cu-loading and the zeolite-type on the reaction of NO + C 3 H 6 + O 2 are revealed by the change in the activity profiles over a wide range of temperatures. The Cu-zeolite catalysts used in this study were all characterized. The results of this study indicate distinct differences between the activity profiles of two types of Cu.
Journal Article•
TL;DR: In this article, the autoxidation process of jet fuel in flowing systems is simulated numerically usin the CFDC code of Katta et al. The role of fluid dynamics in the autooxidation of fuel in fluid flow systems is also examined.
Abstract: As the operating temperature in aircraft fuel systems is increased, the thermal stability of the jet fuel must be improved to minimize the fouling problem in fuel components. In this paper, the autoxidation process of jet fuel in flowing systems is simulated numerically usin the CFDC code of Katta et al. The role of fluid dynamics in the autoxidation of fuel in flowing systems is also examined
Journal Article•
TL;DR: In this article, the acid catalyzed isomerization of anthracene under FCC conditions was investigated and it was found that this reaction occurs through a partially hydrogenated Anthracene intermediate formed via hydrogen transfer.
Abstract: This paper reports an experimental study on the acid catalyzed isomerization of anthracene under FCC conditions. It was found that this isomerization reaction occurs through a partially hydrogenated anthracene intermediate formed via hydrogen transfer.
Journal Article•
TL;DR: In this paper, the authors describe hydrogen transfer processes in pure hydrocarbon cracking on acid catalysts and show how hydrogen transfer participates in the overall reaction, including the formation of aromatics and coke.
Abstract: This paper describes hydrogen transfer processes in pure hydrocarbon cracking on acid catalysts and shows how hydrogen transfer participates in the overall reaction. Some details of the hydrogen transfer processes responsible for the formation of aromatics and coke, and hence for catalyst decay, are also sketched out.
Journal Article•
TL;DR: In this paper, the effects of cocations on the catalytic activity of Cu/ZSM-5 and metal modified ZSM-6 catalysts in both O 2 -free and O 2-containing gases were investigated.
Abstract: The removal of nitric oxide from exhaust gas streams in power plants, industrial boilers and engine systems continues to be a challenge in view of now more stringent regulations. A particularly high-priority need is the efficient control of NO x in lean-burn exhausts. In this paper, we are adressing questions concerning effects of cocations on the catalytic activity of Cu/ZSM-5 and metal modified Cu/ZSM-5 catalysts in both O 2 -free and O 2 -containing gases, as well as water vapor effects on both Cu/ZSM-5 and Mg/Cu-ZSM-5 catalysts.
Journal Article•
TL;DR: In this article, a portable method suitable for use in remote areas as well as laboratories was developed to determine the hydroperoxide contents of transported and stored fuels, which eliminates the nitrogen purge and chlorinated solvent requirements of the ASTM method.
Abstract: A rapid, portable method suitable for use in remote areas as well as laboratories was developed to determine the hydroperoxide contents of transported and stored fuels. The new method eliminates the nitrogen purge and chlorinated solvent requirements of the ASTM method. The new method also reduces the reaction solution quantities from 147 to 5 milliliters
Journal Article•
TL;DR: In this article, the authors investigated the hydrogen transfer activity of ZSM-5 zeolites, with a particular focus on the effects of silica to alumina ratio, reaction temperature, and space velocity on hydrogen transfer over zeolite catalysts.
Abstract: Among the complex network of reactions involved in FCC, hydrogen transfer is presented as being critical to the distribution of paraffinic and olefinic products during fluid catalytic cracking. In this study, the hydrogen transfer activity of ZSM-5 zeolites is investigated, with a particular focus on the effects of silica to alumina ratio, reaction temperature, and space velocity on hydrogen transfer over zeolite catalysts.
Journal Article•
TL;DR: In this paper, an experimental study about cracking of FC and coker naphtas by ZSM-5 catalyst and FC catalyst is presented. And the influence of the catalyst nature on the properties of the cracked products is discussed.
Abstract: This paper describes an experimental study about cracking of FC and coker naphtas by ZSM-5 catalyst and FC catalyst. Experimental conditions and results are presented and hydrogen transfer effects is studied. The influence of the catalyst nature (ZSM-5 or FC catalyst) on the properties of the cracked products is discussed.
Journal Article•
TL;DR: In this paper, in depth poisoning mechanisms acting on the molybdenum component in catalysts were initiated. Special attention was given to a TiO 2 -Mo-V oxide catalyst which shows clear differences in its catalytic deactivation behavior and other characteristics compared with catalysts obtained by formation of a monolayer dispersion of V 2 O 5 and MoO 3 on TiO2.
Abstract: Investigations of in depth poisoning mechanisms acting on the molybdenum component in catalysts were initiated. Special attention was given to a TiO 2 -Mo-V oxide catalyst which shows clear differences in its catalytic deactivation behavior and other characteristics compared with catalysts obtained by formation of a monolayer dispersion of V 2 O 5 and MoO 3 on TiO 2 .
Journal Article•
TL;DR: In this article, the performance of 5 w% Pt/CoO x /SiO 2 catalysts with different cobalt oxide loadings was compared with 3 w% Co 3 O 4.
Abstract: The reduction of NO x is one of the most important issues in automotive pollution control. In this paper we describe the performance of Pt/CoO x /SiO 2 catalysts. We have made a series of 5 w% Pt/CoO x /SiO 2 catalysts, with different cobalt oxide loadings. It was found that adding 3 w% Co 3 O 4 resulted in a catalyst that oxidizes CO already at room temperature. In the present paper we report results of comparative studies of the CO/NO and NO/H 2 reactions over Pt/CoO x /SiO 2 , Pt/SiO 2 and CoO x /SiO 2 catalysts.
Journal Article•
TL;DR: In this paper, the authors used a QCM device in a static type test, but they limit the oxygen availability to that present in the air satured fuel and the small air headspace.
Abstract: The Quartz Crystal Microbalance (QCM) has the ability to perform real time, in situ measurements of deposition at temperatures that closely approximate rreal fuel system conditions. In this paper, we use a QCM device in a static type test, but we limit the oxygen availability to that present in the air satured fuel and the small air headspace. We have also modified the QCM system for the present study by adding a pressure transducer. This allow us to follow the oxidation of the fuel in real-time bby measuring oxygen consumption.
Journal Article•
TL;DR: In this article, the relationship between surface hydrocarbonaceous intermediates identified with surface analytical techniques and gas phase products observed in the elevated pressure experiments is addressed, and the focus of the paper is on the relationship among surface hydrocarbons and their phase products.
Abstract: The focus of this work is to address the relationship between surface hydrocarbonaceous intermediates identified with surface analytical techniques and gas phase products observed in the elevated pressure experiments
Journal Article•
TL;DR: In this paper, the effects of quinoline and phenanthrene on the cracking and deactivation behavior of n-hexadecane have been assessed using a typical FCC catalyst.
Abstract: This study adresses the deactivation behavior of FCC catalysts. The effects of quinoline and phenanthrene on the cracking and deactivation behavior of n-hexadecane have been assessed using a typical FCC catalyst and an experimental rig for the standard MAT test. The resultant cokes have been characterized by mass spectrometry and the results have provided a comparison of the roles of quinoline and phenanthrene as poisons and coke inducers.
Journal Article•
TL;DR: In this article, the authors report a study of hydrodesulfurization of 4-methyl, 4,6-dimethyldibenzothiophene and dibenzethiophene over different molybdenum besed catalysts to compare their reaction mechanisms.
Abstract: Reduction of sulfur level in diesel fuel will soon be regulated in the advanced countries. This paper reports a study of hydrodesulfurization of 4-methyl-, 4,6-dimethyldibenzothiophene and dibenzothiophene over the different molybdenum besed catalysts to compare their reaction mechanisms. The influences of active composition of catalysts on the reaction route is discussed.
Journal Article•
TL;DR: In this article, the authors present gravimetric data for several representative jet fuels while examining the effects of temperature, metal surface basicity, an organic base additive, and oxygen availability on insoluble product distribution.
Abstract: This paper presents gravimetric data for several representative jet fuels while examining the effects of temperature, metal surface basicity, an organic base additive, and oxygen availability on insoluble product distribution. The implications for possible future additive development to improve thermal stability of jet fuels is discussed.
Journal Article•
TL;DR: In this paper, the authors briefly review the preparation of single layer MoS 2, then discuss some unique properties of this two dimensionnal system, and examples of new inclusion compounds are presnted.
Abstract: Molybdenum disulfide (MoS 2 ) in its various forms is of great interest in several catalytic reactions, such as hydrodesulfurization and hydrotreating. This paper briefly reviewes the preparation of single layer MoS 2 , then discusses some unique properties of this two dimensionnal system. Finally, examples of new inclusion compounds are presnted.
Journal Article•
TL;DR: In this paper, the authors investigated the dependence between structural parameters of asphaltenes and their kinetic behavior during pyrolysis, and deduced that molecular structure of a asphalte has a major influence on its thermal behavior.
Abstract: This paper reports the results concerning the pyrolysis of four asphaltenes with different analytical characteristics. The dependence between structural parameters of asphaltenes and their kinetic behavior during pyrolysis is investigated. It is deduced that molecular structure of asphaltenes have a major influence on their thermal behavior.
Journal Article•
TL;DR: In this paper, hydrogen transfer and bond formation during resid upgrading were reported, using field ionization mass spectrometry (FIMS) and GC-MS to identify some of the coke precursors generated during catalytic upgrading of coal-derived resids and the pyrolysis of long-chain alkylpyrenes.
Abstract: This paper reports about hydrogen transfer and bond formation during resid upgrading. Pyrolysis experiments were conducted, using field ionization mass spectrometry (FIMS) and GC-MS to identify some of the coke precursors generated during catalytic upgrading of coal-derived resids and the pyrolysis of long-chain alkylpyrenes. Conclusions concerning the cleavage of strong bonds by hydrodealkylation are given.