Rafael Bilbao

@article{Alzueta2022a,

title = {Conversion of NH3 and NH3-NO mixtures in a CO2 atmosphere. A parametric study},

author = {María U Alzueta and Jorge Giménez-López and Víctor D Mercader and Rafael Bilbao},

doi = {10.1016/j.fuel.2022.125133},

issn = {00162361},

year  = {2022},

date = {2022-01-01},

urldate = {2022-01-01},

journal = {Fuel},

volume = {327},

number = {April},

abstract = {The present work addresses the oxidation of ammonia and ammonia-nitric oxide mixtures in a CO2 atmosphere, characteristic of oxy-fuel processes and/or biogas combustion, from both experimental and kinetic modelling points of view. A parametric study of NH3 and NH3/NO mixtures oxidation is carried out, evaluating the influence of the temperature (700–1500 K), stoichiometry (from pyrolysis, $łambda$ = 0, to significantly oxidizing conditions, $łambda$ = 3.3), gas residence time (low values, 195/T(K) s and high values, 3100/T(K) s) and NH3/NO ratio (0.5–2.2), at atmospheric pressure under well-controlled laboratory conditions using two tubular flow reactor setups. Experimental results have been simulated with an updated literature reaction mechanism, which has been used to interpret the experimental observations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Alzueta2021,

title = {Interaction of NH3 and NO under combustion conditions. Experimental flow reactor study and kinetic modeling simulation},

author = {María U Alzueta and L Ara and Víctor D Mercader and M Delogu and Rafael Bilbao},

url = {https://linkinghub.elsevier.com/retrieve/pii/S001021802100434X},

doi = {10.1016/J.COMBUSTFLAME.2021.111691},

issn = {0010-2180},

year  = {2021},

date = {2021-08-01},

urldate = {2021-08-01},

journal = {Combustion and Flame},

pages = {111691},

publisher = {Elsevier},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Colom-Diaz2021b,

title = {Conversion of H2S/O2/NO mixtures at different pressures. Experiments and kinetic modeling},

author = {Juan Manuel Colom-Díaz and Ángela Millera and Rafael Bilbao and María U Alzueta},

doi = {10.1016/j.fuel.2020.120060},

issn = {00162361},

year  = {2021},

date = {2021-04-01},

journal = {Fuel},

volume = {290},

pages = {120060},

publisher = {Elsevier Ltd},

abstract = {The present study deals with the oxidation of H2S/NO mixtures, in the temperature range of 475–1400 K, at atmospheric pressure and 20 bar of manometric pressure. The experiments have been performed in two different set-ups, using tubular flow reactors, for different air excess ratios ($łambda$H2S = 0.3–6). A kinetic model has been updated with recent reactions from the literature. When NO is present, the oxidation of H2S at atmospheric pressure proceeds at slightly higher temperatures (25 K) with respect to neat H2S oxidation. At high pressure (20 bar), the experiments of the oxidation of H2S in the absence and presence of NO have been performed only at oxidizing conditions ($łambda$H2S = 2 and $łambda$H2S = 6), in order to avoid sulfur formation under reducing conditions. The outcomes of these experiments show that, in presence of NO, at the lowest temperature considered (475 K), at least 50% of H2S conversion for $łambda$H2S = 2 and 90% for $łambda$H2S = 6 is obtained. In order to further evaluate the influence of the presence of NO in H2S oxidation, additional experiments of neat NO oxidation have been performed. As NO2 formation is favored at high pressures and high O2 concentrations, the NO2-H2S interaction is thought to be responsible for the consumption of H2S, even at low temperatures (475 K). While the kinetic mechanism is able to reproduce the experimental results at atmospheric pressure, discrepancies are more relevant at high pressure (20 bar).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Colom-Diaz2021,

title = {New results of H2S oxidation at high pressures. Experiments and kinetic modeling},

author = {Juan Manuel Colom-Díaz and Ángela Millera and Rafael Bilbao and María U Alzueta},

url = {https://linkinghub.elsevier.com/retrieve/pii/S0016236120322572},

doi = {10.1016/j.fuel.2020.119261},

issn = {00162361},

year  = {2021},

date = {2021-02-01},

journal = {Fuel},

volume = {285},

pages = {119261},

publisher = {Elsevier},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Benes2021,

title = {Experimental Study of the Pyrolysis of NH3under Flow Reactor Conditions},

author = {Mario Benés and Guillermo Pozo and María Abián and Ángela Millera and Rafael Bilbao and María U Alzueta},

url = {https://dx.doi.org/10.1021/acs.energyfuels.0c03387},

doi = {10.1021/acs.energyfuels.0c03387},

issn = {15205029},

year  = {2021},

date = {2021-01-01},

journal = {Energy and Fuels},

publisher = {American Chemical Society},

abstract = {The possibility of using ammonia (NH3), as a fuel and as an energy carrier with low pollutant emissions, can contribute to the transition to a low-carbon economy. To use ammonia as fuel, knowledge about the NH3 conversion is desired. In particular, the conversion of ammonia under pyrolysis conditions could be determinant in the description of its combustion mechanism. In this work, pyrolysis experiments of ammonia have been performed in both a quartz tubular flow reactor (900-1500 K) and a non-porous alumina tubular flow reactor (900-1800 K) using Ar or N2 as bath gas. An experimental study of the influence of the reactor material (quartz or alumina), the bulk gas (N2 or Ar), the ammonia inlet concentration (1000 and 10a 000 ppm), and the gas residence time [2060/T (K)-8239/T (K) s] on the pyrolysis process has been performed. After the reaction, the resulting compounds (NH3, H2, and N2) are analyzed in a gas chromatograph/thermal conductivity detector chromatograph and an infrared continuous analyzer. Results show that H2 and N2 are the main products of the thermal decomposition of ammonia. Under the conditions of the present work, differences between working in a quartz or non-porous alumina reactor are not significant under pyrolysis conditions for temperatures lower than 1400 K. Neither the bath gas nor the ammonia inlet concentration influence the ammonia conversion values. For a given temperature and under all conditions studied, conversion of ammonia increases with an increasing gas residence time, which results into a narrower temperature window for NH3 conversion.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}