Thermogravimetric–mass spectrometric study on the evolution of nitrogen compounds during coal devolatilisation

Arenillas, A.; Rubiera, F.; Pevida, C.; Pís, J.J.

doi:10.1016/s0165-2370(01)00180-2

Cited by 15 publications

(6 citation statements)

References 37 publications

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“…This would explain the signal observed at 46 m / z for temperatures above 500 °C in air and nitrogen when the carbon decomposes. The species giving rise to the signal could be C 2 H 5 OH + or in a small proportion isotopes of the CO 2 + ion. , On the other hand, heating the nitrophenyl modified carbon in nitrogen leads to the onset for the production of NO at about 100 °C that is followed by the simultaneous liberation of NO and NO 2 between 350 and 600 °C. The liberation of CO 2 seems to occur within the same temperature range of NO although there is some difference in the shape of the TGA-MS profiles.…”

Section: Resultsmentioning

confidence: 99%

Thermal Stability Study of Aryl Modified Carbon Black by in Situ Generated Diazonium Salt

2007

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The thermal stability of functionalized Vulcan XC72R powders and the chemical species liberated upon their heat treatment in air and nitrogen were investigated by a series of physicochemical techniques. First, Vulcan was modified by a "one pot" synthesis with 4-nitrophenyl, p-azobenzene, and benzene groups by spontaneous reaction with in situ generated aryl diazonium cations, from the corresponding amine, in aqueous solution. The presence of organic moieties at the carbon surface was demonstrated by elemental analysis and X-ray photoelectron spectroscopy (XPS) which yielded a nitrogen content of 1.5 atom % and 3.0 atom %, respectively. The covalent bonding of the organic groups was indirectly evidenced by thermogravimetric analysis (TGA), which revealed that a high temperature (e.g., above 200 °C) is needed to lose a significant weight of grafted groups. Thermogravimetric analysis-mass spectrometry (TGA-MS) and XPS data suggest that the 4-nitrophenyl grafted groups undergo the cleavage of the N-O bond of the nitro group that is followed by the liberation of NO. The liberated NO then reacted with the carbon support to generate pyrrolic and pyridinic type species, as identified by XPS from the lower binding energy components on the N 1s core level spectra.

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Section: Resultsmentioning

confidence: 99%

Thermal Stability Study of Aryl Modified Carbon Black by in Situ Generated Diazonium Salt

2007

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“…The interferences of other fragments in m/z signals 27 and 30 have been taken into account and subtracted [18]. The formation of NO in a reducing environment can be justified by the presence of oxygen in the PVP composition, as in coals, where NO has also been detected [18][19][20][21][22]. The fact that the detection of HCN and NO by FTIR is negligible, is surely due to the lower sensitivity of the equipment compared to the MS.…”

Section: Characterisation Of the Individual Model Compoundsmentioning

confidence: 99%

Characterisation of model compounds and a synthetic coal by TG/MS/FTIR to represent the pyrolysis behaviour of coal

Arenillas

Pevida

Rubiera

et al. 2004

Journal of Analytical and Applied Pyrolysis

112

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Coal pyrolysis is the initial, accompanying reaction of a number of coal conversion processes such as hydrogenation, combustion and gasification. However, because of the inherent complexity of coal composition, it is difficult to describe coal pyrolysis clearly. Single model compounds have been used before in order to provide additional insight into the complex processes that occur in the pyrolysis of coal. Yet the picture obtained is a simplified one and certain important aspects such as coal structure, interactions between different surface groups and cross-links are omitted. The approach used in this work involves the preparation of a synthetic coal, SC, with a known structure by curing a mixture of single, well-defined model compounds. By means of chemical characterisation, the SC was shown to contain the macroscopic features of a high volatile coal (proximate and ultimate analyses). FTIR characterisation revealed the presence of functional groups similar to those of coal in the structure of the SC. Temperature-programmed pyrolysis tests were performed in a thermobalance linked to a mass spectrometer and a Fourier transform infrared analyser (TG/MS/FTIR). The thermal behaviour of the synthetic coal (i.e., rate of mass loss and the evolution profiles of gaseous compounds during pyrolysis tests) is very similar to that of the high volatile bituminous coal which was used as a reference material. The great advantage of using SC lies in the fact that its composition and structure can be accurately determined and employed in subsequent applications in basic and mechanistic studies.

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“…A single peak between 350 and 500 ºC was also observed in the DTG profile of PVP into account and subtracted [18]. The formation of NO in a reducing environment can be justified by the presence of oxygen in the PVP composition, as in coals, where NO has also been detected [18][19][20][21][22].…”

Section: Characterisation Of the Individual Model Compoundsmentioning

confidence: 99%

“…The formation of NO in a reducing environment can be justified by the presence of oxygen in the PVP composition, as in coals, where NO has also been detected [18][19][20][21][22]. The fact that the detection of HCN and NO by FTIR is negligible, is surely due to the lower sensitivity of the equipment compared to the MS.…”

Section: Characterisation Of the Individual Model Compoundsmentioning

confidence: 99%

04/02222 Characterisation of model compounds and a synthetic coal by TG/MS/FTIR to represent the pyrolysis behaviour of coal

2004

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Thermogravimetric–mass spectrometric study on the evolution of nitrogen compounds during coal devolatilisation

Cited by 15 publications

References 37 publications

Thermal Stability Study of Aryl Modified Carbon Black by in Situ Generated Diazonium Salt

Thermal Stability Study of Aryl Modified Carbon Black by in Situ Generated Diazonium Salt

Characterisation of model compounds and a synthetic coal by TG/MS/FTIR to represent the pyrolysis behaviour of coal

04/02222 Characterisation of model compounds and a synthetic coal by TG/MS/FTIR to represent the pyrolysis behaviour of coal

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