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Istituto di ricerche sulla combustione
Soppresso il 01/10/2020

Torna all'elenco Contributi in rivista anno 2020

Contributo in rivista

Tipo: Articolo in rivista

Titolo: Oxidation and pyrolysis of ammonia mixtures in model reactors

Anno di pubblicazione: 2020

Formato: Elettronico Cartaceo

Autori: Maria Virginia Manna, Pino Sabia, Raffaele Ragucci, Mara de Joannon

Affiliazioni autori: Istituto di Ricerche sulla Combustione-CNR, P.le Tecchio 80, 80125 Naples, Italy

Autori CNR:

  • MARIAROSARIA DE JOANNON
  • MARIA VIRGINIA MANNA
  • RAFFAELE RAGUCCI
  • PINO SABIA

Lingua: inglese

Abstract: The present work was devoted to an experimental characterization of NH3 oxidation and pyrolysis processes in model reactors. The oxidation tests were performed in a Jet Stirred Flow Reactor (JSFR) for stoichiometric ammonia/oxygen/argon and ammonia/oxygen/argon/water mixtures, as a function of mixture inlet tempera- ture (Tin), at fixed pressure and residence time. Following, the behavior of ammonia/oxygen/argon mixture was analyzed in two tubular laminar flow reactors (LFRs) made of different materials (quartz and alumina), to evaluate potential surface heterogeneous effects. Pyrolysis tests were performed in both the reference model reactors, by substituting oxygen with argon. Experimental results realized in the JSFR allowed to identify three different kinetics regimes in ammonia oxidation: low (Tin < 1130 K), intermediate (1130 < Tin < 1250 K) and high temperatures (Tin > 1250 K). Surface heterogeneous reactions seemed to be negligible on ammonia reactivity and hydrogen profiles, but some effect could be observed on NOx concentration in the low-intermediate temperature range. Experiments realized in presence of water suggested that such species may passivate the surface, minimizing heterogeneous effects. Experimental tests realized in the LFRs confirmed these results, as hydrogen and oxygen profiles were in- dependent of the reactor material, while NOx concentrations exhibited significant changes. Experimental results suggested that heterogeneous reactions were more relevant under pyrolytic conditions. Numerical simulations were performed with different kinetic mechanisms available in literature to value their capability to describe ammonia chemistry. None of them could accurately reproduce the experimental data for ammonia oxidation process, while they completely failed to predict ammonia pyrolysis features.

Lingua abstract: inglese

Rivista:

Fuel Butterworth Scientific,
Paese di pubblicazione: Regno Unito
Lingua: inglese
ISSN: 0016-2361

Numero volume: 264

DOI: 10.1016/j.fuel.2019.116768

Referee: Sė: Internazionale

Stato della pubblicazione: Published version

Parole chiave:

  • Ammonia oxidation
  • Ammonia pyrolysis
  • Heterogeneous effects
  • Combustion

URL: https://doi.org/10.1016/j.fuel.2019.116768

Strutture CNR:

 
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