Pablo Aragüés Aldea

@article{ARAGUESALDEA2027141925,

title = {Distributed feeding for improved CH4 selectivity in Ni-Fe catalyzed CO2/biogas methanation},

author = {P. Aragüés-Aldea and C. Gimeno-Izquierdo and P. Durán and S. Renda and V. D. Mercader and E. Francés and J. A. Peña and J. Herguido},

url = {https://www.sciencedirect.com/science/article/pii/S001623612603680X},

doi = {https://doi.org/10.1016/j.fuel.2026.141925},

issn = {0016-2361},

year  = {2027},

date = {2027-01-01},

journal = {Fuel},

volume = {431},

pages = {141925},

abstract = {Carbon dioxide methanation is a promising route for renewable natural gas production, although its performance is often limited by kinetic constraints under severe operating conditions. In this work, distributed reactant feeding in a four-inlet polytropic fixed-bed reactor was investigated as a process intensification strategy for CO2 methanation and biogas upgrading over a conventional methanation catalyst (Ni-Fe). The effects of feeding configuration, GHSV, temperature and feed composition on CO2 conversion and CO selectivity were systematically assessed and compared with conventional co-feeding operation. Distributed CO2 feeding consistently outperformed both conventional and hydrogen-distributed configurations, providing higher CO2 conversions and lower CO selectivities. The beneficial effect was particularly evident at high space velocities and low conversions, where kinetic limitations and selectivity to the unwanted CO are more pronounced, reaching reduction of 50 % in this parameter in the more kinetically-hindered conditions. The same qualitative behaviour was observed when upgrading a synthetic sweetened biogas (70 vol% CH4 and 30 vol% CO2), demonstrating the applicability of the proposed strategy under feed compositions relevant in practice. The improved performance is attributed to the establishment of locally H2-rich environments along the catalytic bed, which promote methane formation and mitigate CO accumulation without modifying the global operating conditions. These results highlight the potential of distributed reactant feeding as an effective reactor engineering approach for enhancing methanation performance and intensifying renewable natural gas production processes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{MERCADER2026136698,

title = {Intensifying synthetic natural gas production by functionalization of a NiFe/γ-Al2O3 catalyst with alkaline and alkaline-earth materials},

author = {V. D. Mercader and P. Sanz-Monreal and P. Durán and P. Aragüés-Aldea and E. Francés and J. Herguido and J. A. Peña},

url = {https://www.sciencedirect.com/science/article/pii/S0016236125024238},

doi = {https://doi.org/10.1016/j.fuel.2025.136698},

issn = {0016-2361},

year  = {2026},

date = {2026-01-01},

journal = {Fuel},

volume = {406},

pages = {136698},

abstract = {This study demonstrates the influence of the functionalization method (Mechanical Mixture -MM- and Dual Function Materials -DFM-) of two CO2 adsorbent species (Na and Ca) in a catalytic fixed-bed reactor for CO2 methanation. The experiments consisted of cycles beginning with a CO2 adsorption stage followed by a methanation stage (with H2), interspersed with or without inert purge periods. The greatest enhancement in methane generation was observed in experiments with a mechanical mixture (MM) of NiFe/γ-Al2O3 catalyst and Na2O/γ-Al2O3. The methane production capacity was tested over a temperature range comprised between 200 and 400 °C, with values over 380 μmol/g obtained under moderate conditions (350 °C and pCO2 = 0.12 bar) and selectivity to methane close to 100 %. Since the ultimate goal is the methanation of the CO2 present in a biogas (without removing CH4), the potential effect of the presence of methane during the CO2 adsorption stages was also investigated. To achieve this task, a feed stream representative of a sweetened biogas coming from the anaerobic decomposition of municipal solid waste (MSW) (70 %v CH4 and 30 %v CO2) was used. The results showed no adverse effects along the successive cycles, paving the way to the use of these solids for biogas upgrading. On the other hand, the catalyst did not show a significant loss of activity after several hours of repetitive adsorption-methanation cycles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ARAGUESALDEA2026115899,

title = {Packed-bed membrane reactors as a strategy for selective CO2 methanation},

author = {P. Aragüés-Aldea and P. Durán and V. D. Mercader and S. Renda and E. Francés and J. A. Peña and J. Herguido},

url = {https://www.sciencedirect.com/science/article/pii/S0920586126002233},

doi = {https://doi.org/10.1016/j.cattod.2026.115899},

issn = {0920-5861},

year  = {2026},

date = {2026-01-01},

journal = {Catalysis Today},

volume = {476},

pages = {115899},

abstract = {CO2 methanation represents a key route within Power-to-X strategies for converting captured carbon into synthetic natural gas. However, its efficiency is limited by thermodynamic constraints, heat management issues, and undesired CO formation due to the reverse water–gas shift reaction. In this work, a novel packed-bed membrane reactor (PBMR), conceived as an evolution of the polytropic packed-bed reactor (PPBR), is proposed and experimentally validated for selective CO2 methanation. The reactor enables distributed reactant feeding through a porous membrane wall, allowing enhanced control over local reaction environments along the catalytic bed. A Ni–Fe/Al2O3 catalyst was employed and tested under various operating conditions, including different weight hourly space velocities (WHSV) and feeding configurations (conventional, co-current, and counter-current). The influence of distributing either H2 or CO2 was systematically investigated in terms of CO2 conversion, temperature profiles, and CO selectivity. While distributed configurations did not improve overall CO2 conversion compared to conventional operation, they significantly affected selectivity. In particular, CO2-distributed feeding consistently reduced CO selectivity under iso-conversion conditions, achieving up to a 40% decrease in the most favorable case. This significant reduction highlights the effectiveness of spatial reactant management in driving the reaction pathway toward methane. Overall, these results underline the critical role of reactor design in overcoming selectivity limitations and demonstrate the potential of membrane-assisted distributed feeding as a process intensification strategy for CO2 methanation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}