Call:
Email: juanmcd@unizar.es
Address: Office 41.020. C/Mariano Esquillor s/n, Edificio I+D+i, I3A, Zaragoza, España
ABOUT ME
Research Interests
Chemical processes, combustion, kinetic modeling, sulfur chemistry, biomass, pellets, PAH. My latest work is related to experimental and kinetic modeling of gas-phase chemistry. I am familiar with laboratory reactors (atmospheric and high pressure), some experience with catalysts gained through my Erasmus in Denmark doing the Master Thesis, some knowledge about PAH formation from biomass in a stay in Lisbon at IST and several hours modeling with Chemkin-PRO.
PUBLICATIONS
2021
Colom-Díaz, Juan Manuel; Millera, Ángela; Bilbao, Rafael; Alzueta, María U
Conversion of H2S/O2/NO mixtures at different pressures. Experiments and kinetic modeling Journal Article
In: Fuel, vol. 290, pp. 120060, 2021, ISSN: 00162361.
@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}
}
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).
Colom-Díaz, Juan Manuel; Millera, Ángela; Bilbao, Rafael; Alzueta, María U
New results of H2S oxidation at high pressures. Experiments and kinetic modeling Journal Article
In: Fuel, vol. 285, pp. 119261, 2021, ISSN: 00162361.
@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}
}
Colom-Díaz, Juan Manuel; Alzueta, María U; Zeng, Z; Altarawneh, M; Dlugogorski, B Z
Oxidation of H2S and CH3SH in a jet-stirred reactor: Experiments and kinetic modeling Journal Article
In: Fuel, vol. 283, 2021, ISSN: 00162361.
@article{Colom-Diaz2021bb,
title = {Oxidation of H2S and CH3SH in a jet-stirred reactor: Experiments and kinetic modeling},
author = {Juan Manuel Colom-Díaz and María U Alzueta and Z Zeng and M Altarawneh and B Z Dlugogorski},
doi = {10.1016/j.fuel.2020.119258},
issn = {00162361},
year = {2021},
date = {2021-01-01},
journal = {Fuel},
volume = {283},
publisher = {Elsevier Ltd},
abstract = {This contribution reports experimental measurements of the oxidation of H2S and CH3SH, under atmospheric pressure in a jet-stirred reactor (JSR), in the temperature range of 600–1100 K and for stoichiometric and oxidizing conditions. We update a recent kinetic model, originally developed based on the measurements of oxidation of H2S and CH3SH in a tubular flow-reactor and apply it to simulate the experimental data. The CH3SH subset of the kinetic model features new reactions based on a recent theoretical work and the rate parameters proposed in the present investigation. The oxidation of CH3SH proceeds mainly through an intersystem crossing process that leads to the formation of sulfine (CH2SO). The unimolecular decomposition of CH2SO in two competing reactions produces CO + H2S and COS + H2. The results from the model concur well with the experimental measurements, both from the present work and from the literature. We demonstrate that, both H2S and CH3S exhibit a similar ignition temperature, due to the initiation step that involves the abstraction of H initially bonded to sulfur. It is expected that, the results from the present investigation find application in processing of sour gas, including shale gas, especially in the direct combustion of the gas (i.e., without purification) for energy production.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This contribution reports experimental measurements of the oxidation of H2S and CH3SH, under atmospheric pressure in a jet-stirred reactor (JSR), in the temperature range of 600–1100 K and for stoichiometric and oxidizing conditions. We update a recent kinetic model, originally developed based on the measurements of oxidation of H2S and CH3SH in a tubular flow-reactor and apply it to simulate the experimental data. The CH3SH subset of the kinetic model features new reactions based on a recent theoretical work and the rate parameters proposed in the present investigation. The oxidation of CH3SH proceeds mainly through an intersystem crossing process that leads to the formation of sulfine (CH2SO). The unimolecular decomposition of CH2SO in two competing reactions produces CO + H2S and COS + H2. The results from the model concur well with the experimental measurements, both from the present work and from the literature. We demonstrate that, both H2S and CH3S exhibit a similar ignition temperature, due to the initiation step that involves the abstraction of H initially bonded to sulfur. It is expected that, the results from the present investigation find application in processing of sour gas, including shale gas, especially in the direct combustion of the gas (i.e., without purification) for energy production.
Colom-Díaz, Juan Manuel; Alzueta, María U; Zeng, Z; Altarawneh, M; Dlugogorski, B Z
Oxidation of H2S and CH3SH in a jet-stirred reactor: Experiments and kinetic modeling Journal Article
In: Fuel, vol. 283, pp. 119258, 2021, ISSN: 0016-2361.
@article{Colom-Diaz2021bc,
title = {Oxidation of H2S and CH3SH in a jet-stirred reactor: Experiments and kinetic modeling},
author = {Juan Manuel Colom-Díaz and María U Alzueta and Z Zeng and M Altarawneh and B Z Dlugogorski},
doi = {10.1016/J.FUEL.2020.119258},
issn = {0016-2361},
year = {2021},
date = {2021-01-01},
journal = {Fuel},
volume = {283},
pages = {119258},
publisher = {Elsevier},
abstract = {This contribution reports experimental measurements of the oxidation of H2S and CH3SH, under atmospheric pressure in a jet-stirred reactor (JSR), in the temperature range of 600–1100 K and for stoichiometric and oxidizing conditions. We update a recent kinetic model, originally developed based on the measurements of oxidation of H2S and CH3SH in a tubular flow-reactor and apply it to simulate the experimental data. The CH3SH subset of the kinetic model features new reactions based on a recent theoretical work and the rate parameters proposed in the present investigation. The oxidation of CH3SH proceeds mainly through an intersystem crossing process that leads to the formation of sulfine (CH2SO). The unimolecular decomposition of CH2SO in two competing reactions produces CO + H2S and COS + H2. The results from the model concur well with the experimental measurements, both from the present work and from the literature. We demonstrate that, both H2S and CH3S exhibit a similar ignition temperature, due to the initiation step that involves the abstraction of H initially bonded to sulfur. It is expected that, the results from the present investigation find application in processing of sour gas, including shale gas, especially in the direct combustion of the gas (i.e., without purification) for energy production.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This contribution reports experimental measurements of the oxidation of H2S and CH3SH, under atmospheric pressure in a jet-stirred reactor (JSR), in the temperature range of 600–1100 K and for stoichiometric and oxidizing conditions. We update a recent kinetic model, originally developed based on the measurements of oxidation of H2S and CH3SH in a tubular flow-reactor and apply it to simulate the experimental data. The CH3SH subset of the kinetic model features new reactions based on a recent theoretical work and the rate parameters proposed in the present investigation. The oxidation of CH3SH proceeds mainly through an intersystem crossing process that leads to the formation of sulfine (CH2SO). The unimolecular decomposition of CH2SO in two competing reactions produces CO + H2S and COS + H2. The results from the model concur well with the experimental measurements, both from the present work and from the literature. We demonstrate that, both H2S and CH3S exhibit a similar ignition temperature, due to the initiation step that involves the abstraction of H initially bonded to sulfur. It is expected that, the results from the present investigation find application in processing of sour gas, including shale gas, especially in the direct combustion of the gas (i.e., without purification) for energy production.
2020
Colom-Díaz, Juan Manuel; Leciñena, M; Peláez, A; Abián, María; Millera, Ángela; Bilbao, Rafael; Alzueta, María U
Study of the conversion of CH4/H2S mixtures at different pressures Journal Article
In: Fuel, vol. 262, pp. 116484, 2020, ISSN: 00162361.
@article{Colom-Diaz2020,
title = {Study of the conversion of CH4/H2S mixtures at different pressures},
author = {Juan Manuel Colom-Díaz and M Leciñena and A Peláez and María Abián and Ángela Millera and Rafael Bilbao and María U Alzueta},
doi = {10.1016/j.fuel.2019.116484},
issn = {00162361},
year = {2020},
date = {2020-02-01},
journal = {Fuel},
volume = {262},
pages = {116484},
publisher = {Elsevier Ltd},
abstract = {Due to the different scenarios where sour gas is present, its composition can be different and, therefore, it can be exploited through different processes, being combustion one of them. In this context, this work deals with the oxidation of CH4 and H2S at different pressures and under a wide variety of conditions. The oxidation has been evaluated experimentally in two different flow reactor set-ups, one working at atmospheric pressure and another one operating from atmospheric to high pressures (40 bar). Different CH4/H2S mixtures have been tested, together with different oxygen concentrations and in the temperature range of 500–1400 K. The experimental results obtained show that the oxidation of the CH4/H2S mixtures is shifted to lower temperatures as pressure increases, obtaining the same trends at atmospheric pressure in both experimental set-ups. H2S oxidation occurs prior to CH4 oxidation at all conditions, providing radicals to the system that promote CH4 oxidation to lower temperatures (compared to neat CH4 oxidation). This effect is more relevant as pressure increases. H2S oxidation is inhibited by CH4 at atmospheric pressure, being more noticeable when the CH4/H2S ratio is higher. At higher pressures, the H2S conversion occurs similarly in the absence or presence of CH4. The experimental results have been modeled with an updated kinetic model from previous works from the literature, which, in general, matches well the experimental trends, while some discrepancies between experimental and modeling results at atmospheric pressure and 40 bar are found in the conversion of H2S and CH4.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Due to the different scenarios where sour gas is present, its composition can be different and, therefore, it can be exploited through different processes, being combustion one of them. In this context, this work deals with the oxidation of CH4 and H2S at different pressures and under a wide variety of conditions. The oxidation has been evaluated experimentally in two different flow reactor set-ups, one working at atmospheric pressure and another one operating from atmospheric to high pressures (40 bar). Different CH4/H2S mixtures have been tested, together with different oxygen concentrations and in the temperature range of 500–1400 K. The experimental results obtained show that the oxidation of the CH4/H2S mixtures is shifted to lower temperatures as pressure increases, obtaining the same trends at atmospheric pressure in both experimental set-ups. H2S oxidation occurs prior to CH4 oxidation at all conditions, providing radicals to the system that promote CH4 oxidation to lower temperatures (compared to neat CH4 oxidation). This effect is more relevant as pressure increases. H2S oxidation is inhibited by CH4 at atmospheric pressure, being more noticeable when the CH4/H2S ratio is higher. At higher pressures, the H2S conversion occurs similarly in the absence or presence of CH4. The experimental results have been modeled with an updated kinetic model from previous works from the literature, which, in general, matches well the experimental trends, while some discrepancies between experimental and modeling results at atmospheric pressure and 40 bar are found in the conversion of H2S and CH4.