The estimation of primary aromatic amines and other basic nitrogen compounds in some coal liquefaction products

Burchill, Paul; Herod, Alan A.; Mitchell, Catherine

doi:10.1007/bf02311678

Cited by 14 publications

(4 citation statements)

References 32 publications

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“…(2) Derivatization has been used to distinguish primary amines produced by hydrogenation in coal liquefaction and to indicate pyridinic aromatic species …”

Section: Mass Spectrometry Of the Lower-mass-range Components (Up To ...mentioning

confidence: 99%

“…(2) Derivatization has been used to distinguish primary amines produced by hydrogenation in coal liquefaction 79 and to indicate pyridinic aromatic species. 80 (3) Fractionation on silica and organometallic coordination chromatography [80][81][82] have been used to remove aromatics from the basic nitrogen components of coal tar aza compounds.…”

Section: Mass Spectrometry Of the Lower-mass-rangementioning

confidence: 99%

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Characterization of Heavy Hydrocarbons by Chromatographic and Mass Spectrometric Methods: An Overview

2007

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This paper reviews analytical methods that have been developed for characterizing complex liquid mixtures derived from fossil fuels. The analysis of fractions with masses up to ∼400−450 u normally involves gas and liquid chromatography, coupled with mass spectrometry (GC−MS and LC−MS, respectively). However, these techniques cannot readily be adapted to examine samples that contain higher-molecular-mass materials. Chromatographic and mass spectrometric methods are often limited by the volatility of the samples, while liquid chromatographic methods may be limited by solubility in the solvents used. Materials of higher mass are characterized using methods that have been developed to overcome the limitations imposed by volatility and solubility in common solvents. As outlined in the text, they have been the subject of some debate. Much of the work that indicates upper mass limits of ∼1000−1500 u for coal tars, pitches, and petroleum asphaltenes can be explained in terms of limitations of the particular analytical techniques. The new emphasis on characterizing increasingly heavier materials grows out of a need in oil refineries and elsewhere, for fresh ideas about processing higher-mass feedstocks. Currently, above the ∼450−500 u range, no single method is unambiguously capable of indicating molecular mass distributions or chemical structural features in complex fuel-derived mixtures. Advances in this field require a comparison of evidence from several independent analytical methods. This review is mainly focused on the results from size exclusion chromatography (SEC), laser-desorption mass spectroscopy (LD−MS) and matrix-assisted laser desorption/ionization mass spectroscopy (MALDI−MS). SEC, using 1-methyl-2-pyrrolidinone (NMP) as an eluent, has shown agreement with LD-MS and MALDI-MS up to ∼3000 u and to within a factor of 2−2.5 at up to 15 000 u. Suggestions that the samples formed aggregates have been investigated. There is no confirmable experimental evidence, either from our work or in the literature, showing that aggregation occurs under the dilute conditions prevailing during SEC, using NMP as an eluent.

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“…(2) Derivatization has been used to distinguish primary amines produced by hydrogenation in coal liquefaction and to indicate pyridinic aromatic species …”

Section: Mass Spectrometry Of the Lower-mass-range Components (Up To ...mentioning

confidence: 99%

Section: Mass Spectrometry Of the Lower-mass-rangementioning

confidence: 99%

Characterization of Heavy Hydrocarbons by Chromatographic and Mass Spectrometric Methods: An Overview

2007

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“…Coal and crude oil contain significant amounts of fuel‐bound nitrogen , which, unless entirely removed prior to combustion, leads to NO x formation (predominantly NO and NO 2 ) that are subject to stringent environmental regulations due to their contribution to smog and acid rain. Denitrogenation units in crude oil refinery streams are also essential since nitrogen in heterocyclic compounds poisons many catalysts, especially those used in desulfurization units .…”

Section: Introductionmentioning

confidence: 99%

Automated Reaction Mechanism Generation Including Nitrogen as a Heteroatom

Dana

Buesser

Merchant

et al. 2018

Int J of Chemical Kinetics

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The open source rate‐based Reaction Mechanism Generator (RMG) software and its thermochemical and kinetics databases were extended to include nitrogen as a heteroatom. Specific changes to RMG and the mining of thermochemistry and reaction kinetics data are discussed. This new version of RMG has been tested by generating a detailed pyrolysis and oxidation model for ethylamine (EA, CH3CH2NH2) at ∼1400 K and ∼2 bar, and comparing it to recent shock tube studies. Validation of the reaction network with recent experimental data showed that the generated model successfully reproduced the observed species as well as ignition delay measurements. During pyrolysis, EA initially decomposes via a CC bond scission, and the CH2NH2 product subsequently produces the first H radicals in this system via β‐scission. As the concentration of H increases, the major EA consuming reaction becomes H abstraction at the α‐site by H radicals, leading to a chain reaction since its product generates more H radicals. During oxidation, the dominant N2‐producing route is mediated by NO and N2O. The observables were found to be relatively sensitive to the CC and CN EA bond scission reactions as well as to the thermodynamic values of EA; thermodynamic data for EA were computed at the CBS‐QB3 level and reported herein. This work demonstrates the ability of RMG to construct adequate kinetic models for nitrogenous species and discusses the pyrolysis and oxidation mechanisms of EA.

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“…Derivatization produced more distinct MS fragmentation patterns, and eliminated peak tailing problems prevalent in separations of basic compounds with GC columns available at that time. Since then, several researchers have reported using acetylation and trifluoroacetylation to help distinguish between primary and tertiary aromatic amines in gasoline (16), creosote oil (17) and coal liquids (18)(19)(20)(21)…”

Section: Introductionmentioning

confidence: 99%