TY - GEN A1 - González-Castaño, Miriam A1 - Navarro de Miguel, Juan Carlos A1 - Sinha, F. A1 - Ghomsi Wabo, Samuel A1 - Klepel, Olaf A1 - Arellano-Garcia, Harvey T1 - Cu supported Fe-SiO2 nanocomposites for reverse water gas shift reaction T2 - Journal of CO2 Utilization N2 - This work analyses the catalytic activity displayed by Cu/SiO2, Cu-Fe/SiO2 and Cu/FSN (Fe-SiO2 nanocomposite) catalysts for the Reverse Water Gas Shift reaction. Compared to Cu/SiO2 catalyst, the presence of Fe resulted on higher CO’s selectivity and boosted resistances against the constitution of the deactivation carbonaceous species. Regarding the catalytic performance however, the extent of improvement attained through incorporation Fe species strongly relied on the catalysts’ configuration. At 30 L/gh and H2:CO2 ratios = 3, the performance of the catalysts’ series increased according to the sequence: Cu/SiO2 < Cu-Fe/SiO2 << Cu/FSN. The remarkable catalytic enhancements provided by Fe-SiO2 nanocomposites under different RWGS reaction atmospheres were associated to enhanced catalyst surface basicity’s and stronger Cu-support interactions. The catalytic promotion achieved by Fe-SiO2 nanocomposites argue an optimistic prospective for nanocomposite catalysts within future CO2-valorising technologies. KW - Cu catalysts KW - Fe-doped silica KW - Nanocomposites KW - Reverse water gas shift reaction Y1 - 2021 U6 - https://doi.org/10.1016/j.jcou.2021.101493 SN - 2212-9820 VL - 46 ER - TY - GEN A1 - González-Castaño, Miriam A1 - Ivanova, Svetlana A1 - Ioanides, Theophiles A1 - Centeno, Miguel Angel A1 - Arellano-Garcia, Harvey A1 - Odriozola, José Antonio T1 - Zr and Fe on Pt/CeO2-MOx/Al2O3 catalysts for WGS reaction T2 - International Journal of Energy Research N2 - By evaluating the functional modifications induced by Zr and Fe as dopants in Pt/CeO2‐MOx/Al2O3 catalysts (M = Fe and Zr), the key features for improving water gas shift (WGS) performance for these systems have been addressed. Pt/ceria intrinsic WGS activity is often related to improved H2 surface dynamics, H2O absorption, retentions and dissociation capacities which are influenced greatly by the support nature. Two metals, iron and zirconia, were chosen as ceria dopants in this work, either in separate manner or combined. Iron incorporation resulted in CO‐redox properties and oxygen storage capacities (OSC) improvement but the formation of Ce‐Fe solid solutions did not offer any catalytic benefit, while the Zr incorporation influenced in a great manner surface electron densities and shows higher catalytic activity. When combined both metals showed an important synergy evidenced by 30% higher CO conversions and attributed to greater surface electron densities population and therefore absorption and activity. This work demonstrates that for Pt/ceria catalysts OSC enhancement does not necessarily imply a catalytic promotion. KW - doped ceria KW - FE KW - H2-TPD KW - Pt/ceria catalysts KW - WGS reaction KW - WGS-TPSR KW - Zr Y1 - 2021 U6 - https://doi.org/10.1002/er.6646 SN - 1099-114X ER - TY - GEN A1 - González-Arias, Judith A1 - González-Castaño, Miriam A1 - Arellano-García, Harvey A1 - Lichtfouse, Eric A1 - Zhang, Zhien T1 - Unprofitability of small biogas plants without subsidies in the Brandenburg region T2 - Environmental Chemistry Letters N2 - The circular economy is calling for the rapid use of already-developed renewable energies. However, the successful implementation of those new fuels is limited by economic and political issues. For instance, in the Brandenburg region, Germany, biogas production from anaerobic digestion of biomass and wastes is a current alternative. However, the upgrading biogas to biomethane is still challenging and the economic viability is unknown. Therefore, we performed an economic analysis for biogas upgrading to biomethane in the Brandenburg region. Five biogas plant sizes were analyzed by the method of discounted cash flow. This method yields the net present value of the projects, thus revealing the profitability or non-profitability of the plants. Results indicate profitable outputs for medium and large plants, with net present values between 415 and 7009 k€. However, the smallest plants have net present values from -4250 to -3389 k€, thus needing further economic efforts or subsidies to reach profitability. Indeed, biomethane prices should range between 52.1 and 95.6 €/MWh to make these projects profitable. Combinations of 50% of investment subsidized and 11.5 €/MWh feed-in tariffs subsidies could make the projects reach profitability. These findings reveal that political actions such as green policies and subsidies are needed to implement green energy. This case study should serve as a potential tool for policy-makers toward a sustainable bioeconomy. KW - Biomethane production KW - Biogas upgrading KW - Green energy KW - Brandenburg development KW - Waste valorization KW - Energy independence Y1 - 2021 U6 - https://doi.org/10.1007/s10311-020-01175-7 SN - 1610-3661 ER - TY - GEN A1 - Baena-Moreno, Francisco Manuel A1 - González-Castaño, Miriam A1 - Arellano-Garcia, Harvey A1 - Ramirez Reina, Tomas T1 - Exploring profitability of bioeconomy paths: Dimethyl ether from biogas as case study T2 - Energy N2 - Herein a novel path is analysed for its economic viability to synergize the production of biomethane and dimethyl ether from biogas. We conduct a profitability analysis based on the discounted cash flow method. The results revealed an unprofitable process with high cost/revenues ratios. Profitable scenarios would be reached by setting prohibitive DME prices (1983–5566 €/t) or very high feed-in tariffs subsidies (95.22 €/MWh in the best case scenario). From the cost reduction side, the analysis revealed the need of reducing investment costs. For this purpose, we propose a percentage of investment as incentive scheme. Although the size increase benefits cost/revenues ratio, only the 1000 m3/h biogas plant size will reach profitability if 90% of the investment is subsidized. A sensitivity analysis to check the influence of some important economical parameters is also included. Overall this study evidences the big challenge that our society faces in the way towards a circular economy. KW - Biomethane production KW - Biogas upgrading KW - CO2 utilization KW - Green energy production KW - Waste valorization KW - Dimethyl ether Y1 - 2021 U6 - https://doi.org/10.1016/j.energy.2021.120230 SN - 0360-5442 VL - 225 ER - TY - GEN A1 - González-Castaño, Miriam A1 - Saché, Estelle le A1 - Berry, Cameron A1 - Pastor-Pérez, Laura A1 - Arellano-Garcia, Harvey A1 - Wang, Qiang A1 - Ramirez Reina, Tomas T1 - Nickel Phosphide Catalysts as Efficient Systems for CO2 Upgrading via Dry Reforming of Methane T2 - Catalysts N2 - This work establishes the primordial role played by the support’s nature when aimed at the constitution of Ni2P active phases for supported catalysts. Thus, carbon dioxide reforming of methane was studied over three novel Ni2P catalysts supported on Al2O3, CeO2 and SiO2-Al2O3 oxides. The catalytic performance, shown by the catalysts’ series, decreased according to the sequence: Ni2P/Al2O3 > Ni2P/CeO2 > Ni2P/SiO2-Al2O3. The depleted CO2 conversion rates discerned for the Ni2P/SiO2-Al2O3 sample were associated to the high sintering rates, large amounts of coke deposits and lower fractions of Ni2P constituted in the catalyst surface. The strong deactivation issues found for the Ni2P/CeO2 catalyst, which also exhibited small amounts of Ni2P species, were majorly associated to Ni oxidation issues. Along with lower surface areas, oxidation reactions might also affect the catalytic behaviour exhibited by the Ni2P/CeO2 sample. With the highest conversion rate and optimal stabilities, the excellent performance depicted by the Ni2P/Al2O3 catalyst was mostly related to the noticeable larger fractions of Ni2P species established KW - Ni2P KW - supported catalysts KW - dry reforming of methane KW - Al2O3 KW - CeO2 KW - SiO2-Al2O3 Y1 - 2021 U6 - https://doi.org/10.3390/catal11040446 SN - 2073-4344 VL - 11 IS - 4 ER - TY - GEN A1 - González-Arias, Judith A1 - Gomez, X. A1 - Gonzalez-Castano, Miriam A1 - Sanchez, Marta Elena A1 - Rosas, J. G. A1 - Cara-Jiménez, Jorge T1 - Insights into the product quality and energy requirements for solid biofuel production: A comparison of hydrothermal carbonization, pyrolysis and torrefaction of olive tree pruning T2 - Energy N2 - For a bio-economy establishment, understanding the energy consumption needs to produce solid biofuels is a key point. Herein, olive tree pruning was treated by both dry (pyrolysis and torrefaction) and wet (hydrothermal carbonization) thermal treatments. Product yield, solid quality and energy consumption were assessed. The solids were characterized by means of chemical and thermogravimetric analysis. For all treatments, coal-like solid products were obtained, with higher heating values (HHV) of almost 30 MJ kg−1 in most of the conditions evaluated. Chars from pyrolysis presented the greater carbon content (between 76 and 85 wt%) but also the higher ash content (ranging from 6 to 9 wt%). From an energy consumption perspective, torrefaction registered the lowest energy consumption (between 5.85 and 20.76 MJ kg−1 char). The highest energy contents per kilogram of char produced were also reflected in torrefaction samples, with values around 11 MJ kg−1 char. Although the obtained HHVs were greater for pyrolysis chars the higher mass yields obtained in torrefaction makes it more profitable. The least severe conditions allowed to obtain a positive energy balance only with the solid phase considered. Nonetheless, further room for improvement is possible since the gas and liquid phases may also be valorised. KW - Hydrothermal carbonization KW - Slow pyrolysis KW - Torrefaction KW - Olive tree pruning KW - Biofuel Y1 - 2021 U6 - https://doi.org/10.1016/j.energy.2021.122022 SN - 0360-5442 VL - Vol. 238, part C (2022) ER - TY - GEN A1 - González-Castaño, Miriam A1 - Hani Kour, M. A1 - González-Arias, Judith A1 - Baena-Moreno, Francisco Manuel A1 - Arellano-Garcia, Harvey T1 - Promoting bioeconomy routes: From food waste to green biomethane. A profitability analysis based on a real case study in eastern Germany T2 - Journal of Environmental Management N2 - Profitability studies are needed to establish the potential pathways required for viable biomethane production in the Brandenburg region of Germany. This work study the profitability of a potential biomethane production plant in the eastern German region of Brandenburg, through a specific practical scenario with data collected from a regional biogas plant located in Alteno (Schradenbiogas GmbH & Co. KG). Several parameters with potential economic influence such as distance of the production point to the grid, waste utilization percentage, and investment, were analyzed. The results illustrate a negative overall net present value with the scenario of no governmental investment, even when considering trading the CO2 obtained throughout the process. Subsidies needed to reach profitability varied with distance from 13.5 €/MWh to 19.3 €/MWh. For a fixed distance of 15 kms, the importance of percentage of waste utilization was examined. Only 100% of waste utilization and 75% of waste utilization would reach profitability under a reasonable subsidies scheme (16.3 and 18.8 €/MWh respectively). Concerning the importance of investment, a subsidized investment of at least 70% is demanded for positive net present values. Besides, the sensitivity analysis remarks the energy consumption of the biogas upgrading stage, the electricity price, and the energy consumption of biogas production as major parameters to be tackled for the successful implementation of biogas upgrading plants. The results here obtained invite to ponder about potential strategies to further improve the economic viability of this kind of renewable projects. In this line, using the CO2 separated to produce added-value chemicals can be an interesting alternative. KW - Biomethane production KW - Biogas upgrading KW - Green energy KW - Governmental incentives KW - Waste valorization Y1 - 2021 U6 - https://doi.org/10.1016/j.jenvman.2021.113788 SN - 0301-4797 VL - 300 ER - TY - GEN A1 - González-Arias, Judith A1 - González-Castaño, Miriam A1 - Sánchez, Marta Elena A1 - Cara-Jiménez, Jorge A1 - Arellano-Garcia, Harvey T1 - Valorization of biomass-derived CO2 residues with Cu-MnOx catalysts for RWGS reaction T2 - Renewable Energy N2 - This study delivers useful understanding towards the design of effective catalytic systems for upgrading real CO2erich residual streams derived from biomass valorization. Within this perspective, a catalysts' series based on (5 wt%) Cu - (X wt%) Mn/Al2O3with X¼0, 3, 8, and 10 is employed. The improved catalyst performance achieved through Mn incorporation is ascribed to enhanced Cu dispersions and promoted surface basic concentrations. Under standard RWGS conditions, the highest reaction rates achieved by(5 wt%) Cu - (8 wt%) Mn/Al2O3catalyst were associated to improved Cu dispersions along with the constitution of highly active Cu-MnOxdomains. Remarkably, variations on the optimal Cu to Mn ratios were detected as a function of the RWGS reaction conditions. Thus, under simulated CO2-rich residual feedstock's, i.e., in presence of CO and CH4, the further promotion on the Cu dispersion attained by the larger amounts of MnOxrendered the (5 wt%) Cu - (10 wt%) Mn/Al2O3catalyst as the best performing sample. Overall, the presented outcomes underline operative strategies for developing catalytic systems with advanced implementation potentialities. KW - CO2 waste valorization KW - CO2-Rich residues KW - Reverse water gas shift KW - CO2 reduction KW - Cu-catalysts KW - Manganese oxide Y1 - 2022 U6 - https://doi.org/10.1016/j.renene.2021.10.029 SN - 1879-0682 IS - 182 SP - 443 EP - 451 ER - TY - GEN A1 - González-Arias, Judith A1 - Baena-Moreno, Francisco Manuel A1 - González-Castaño, Miriam A1 - Arellano-Garcia, Harvey T1 - Economic approach for CO2 valorization from hydrothermal carbonization gaseous streams via reverse water-gas shift reaction T2 - Fuel N2 - In this work the economic performance of valorizing the gaseous stream coming from hydrothermal carbonization (HTC) of olive tree pruning is presented as a novel strategy to improve the competitiveness of HTC. The valorization of the commonly disregarded gaseous stream produced in this thermochemical treatment was proposed via the Reverse Water–Gas Shift reaction. This allows to obtain syngas for selling and therefore improving the overall economic performance of the process. To this end, three plant sizes were selected (312.5, 625 and 1250 kg/h of biomass processing). The parameters with a higher share in the total cost distribution along with the revenues from the hydrochar and the syngas selling were further evaluated. The results evidenced that with the assumptions taken, the overall process is still not profitable. To reach profitability, syngas selling prices between 2.2 and 3.4 €/m3 are needed, revealing that this proposal is not economically attractive. Alternatively, a lack of competitiveness in the current market is revealed with hydrochar selling prices between 0.41 and 0.64 €/kg to make the project profitable. The catalyst cost, sharing approximately 20% of the total cost, is the parameter with the highest impact in the total economics of the process. The second one is the hydrogen price production, representing almost 16% of the total. Investment subsidies are also examined as a potential tool to cover part of the initial investment. These results evidenced that further efforts and measures are needed to push forward in the path towards circular economy societies. KW - Hydrothermal carbonization KW - CO2 waste valorization KW - Reverse water gas shift KW - Profitability analysis Y1 - 2022 U6 - https://doi.org/10.1016/j.fuel.2021.123055 SN - 0016-2361 VL - 313 SP - 1 EP - 7 ER - TY - GEN A1 - Mahmood, Safdar A1 - González-Castaño, Miriam A1 - Penkova, Anna A1 - Centeno, Miguel Angel A1 - Odriozola, José Antonio A1 - Arellano-Garcia, Harvey T1 - CO2 methanation on Ni/YMn1-xAlxO3 perovskite catalysts T2 - Applied Materials Today N2 - Seeking for advanced catalytic systems for the CO2 methanation reaction, the use of Ni supported catalysts over redox materials is often proposed. Profiting the superior redox properties described for layered perovskite systems, this work has investigated a series Ni supported YMn1-xAlxO3 (x = 0, 0.2, 0.5, 0.8, 1) perovskite catalysts. The obtained results evidenced the impact of the support nature on the systems redox properties and Ni-support interactions. Within the catalysts series, the greater methanation rates displayed by Ni/YMn0.5Al0.5O3 catalyst (0.748 mmolCO2,conv.s–1 gNi –1 at 400 ◦C and 60 L/gh) were associated to the interplay between the support redox properties and superior Ni dispersion. The improved redox behavior attained through the Al-incorporation (up to x = 0.5) was associated to the layered perovskite structures which, being distorted and constituted by smaller crystal sizes, facilitated the behavior of Mn redox couples as surface species readily interconverted. Exhibiting catalytic performances comparable to precious metals based catalysts, this work proposes the Ni/YMn0.5Al0.5O3 catalyst as an effective system for the CO2 methanation reaction. KW - CO2 methanation KW - Perovskites KW - Ni catalyst KW - Manganese KW - Aluminium Y1 - 2022 U6 - https://doi.org/10.1016/j.apmt.2022.101577 SN - 2352-9407 VL - 29 SP - 1 EP - 11 ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - González-Castaño, Miriam A1 - Baena-Moreno, Francisco Manuel A1 - Arellano-Garcia, Harvey ED - Kmiotek, M. ED - Kordos, A. T1 - CO2 methanation: on the modeling of reacting laminar flows in structured Ni/MgAl2O4 catalysts T2 - XXV Fluid Mechanics Conference, Rzeszów, Poland, 7-9 September 2022, Book of Abstracts Y1 - 2022 SN - 978-83-7934-590-8 SP - 98 EP - 100 PB - Publishing House of Rzeszów University of Technology CY - Rzeszów, Poland ER - TY - GEN A1 - Medina Méndez, Juan Ali A1 - González-Castaño, Miriam A1 - Baena-Moreno, Francisco Manuel A1 - Arellano-Garcia, Harvey T1 - CO2 methanation: on the modeling of reacting laminar flows in structured Ni/MgAl2O4 catalysts T2 - Journal of Physics: Conference Series Y1 - 2022 UR - https://iopscience.iop.org/article/10.1088/1742-6596/2367/1/012015 U6 - https://doi.org/10.1088/1742-6596/2367/1/012015 IS - 2367 PB - IOP Publishing ER - TY - GEN A1 - Gonzalez-Castaño, Miriam A1 - Gonzalez-Arias, Judith A1 - Bobadilla, Luis F. A1 - Ruiz-Lopez, E. A1 - Odriozola, Jose Antonio A1 - Arellano-Garcia, Harvey T1 - In-Situ Drifts Steady-State Study of Co2 and Co Methanation Over Ni-Promoted Catalysts T2 - Fuel N2 - Promoting the performance of catalytic systems by incorporating small amount of alkali has been proved effective for several reactions whilst controversial outcomes are reported for the synthetic natural gas production. This work studies a series of Ni catalysts for CO2 and CO methanation reactions. In-situ DRIFTS spectroscopy evidenced similar reaction intermediates for all evaluated systems and it is proposed a reaction mechanism based on: i) formate decomposition and ii) hydrogenation of lineal carbonyl species to methane. Compared to bare Ni, the enhanced CO2 methanation rates attained by NiFe/Al and NiFeK/Al systems are associated to promoted formates decomposition into lineal carbonyl species. Also for CO methanation, the differences in the catalysts’ performances were associated to the relative concentration of lineal carbonyl species. Under CO methanation conditions and opposing the CO2 methanation results where the incorporation of K delivered promoted catalytic behaviours, worsened CO methanation rates were discerned for the NiFeK/Al system. Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S0016236122040650?via%3Dihub U6 - https://doi.org/10.1016/j.fuel.2022.127241 SN - 1873-7153 VL - 338 ER - TY - GEN A1 - Bobadilla, Luis F. A1 - Azancot, Lola A1 - Luque-Alvarez, Ligia A. A1 - Torres-Sempere, Guillermo A1 - Gonzalez-Castano, Miriam A1 - Pastor-Perez, Laura A1 - Yu, Jie A1 - Ramirez Reina, Tomas A1 - Ivanova, Svetlana A1 - Centeno, Miguel Angel A1 - Odriozola, José Antonio T1 - Development of Power-to-X Catalytic Processes for CO2 Valorisation: From the Molecular Level to the Reactor Architecture T2 - Chemistry N2 - Nowadays, global climate change is likely the most compelling problem mankind is facing. In this scenario, decarbonisation of the chemical industry is one of the global challenges that the scientific community needs to address in the immediate future. Catalysis and catalytic processes are called to play a decisive role in the transition to a more sustainable and low-carbon future. This critical review analyses the unique advantages of structured reactors (isothermicity, a wide range of residence times availability, complex geometries) with the multifunctional design of efficient catalysts to synthesise chemicals using CO2 and renewable H2 in a Power-to-X (PTX) strategy. Fine-chemistry synthetic methods and advanced in situ/operando techniques are essential to elucidate the changes of the catalysts during the studied reaction, thus gathering fundamental information about the active species and reaction mechanisms. Such information becomes crucial to refine the catalyst’s formulation and boost the reaction’s performance. On the other hand, reactors architecture allows flow pattern and temperature control, the management of strong thermal effects and the incorporation of specifically designed materials as catalytically active phases are expected to significantly contribute to the advance in the valorisation of CO2 in the form of high added-value products. From a general perspective, this paper aims to update the state of the art in Carbon Capture and Utilisation (CCU) and PTX concepts with emphasis on processes involving the transformation of CO2 into targeted fuels and platform chemicals, combining innovation from the point of view of both structured reactor design and multifunctional catalysts development. Y1 - 2022 UR - https://www.mdpi.com/2624-8549/4/4/83 U6 - https://doi.org/10.3390/chemistry4040083 SN - 2624-8549 VL - 4 IS - 4 SP - 1250 EP - 1280 ER - TY - GEN A1 - Gonzalez-Arias, Judith A1 - Gonzalez-Castano, Miriam A1 - Arellano-Garcia, Harvey T1 - Utilization of CO2-Rich Residues for Syngas Production: Strategies for Catalyst Design T2 - AIChE Annual Meeting, November 15, 2021 N2 - Compared to a Reverse Water Gas Shift (RWGS) process carried out under ideal conditions, the valorization of CO2-rich residues involve additional challenges. Indeed, for an ideal RWGS reaction unit, the CO2 methanation reaction and the constitution of carbon deposits via Boudouard reaction are the main side reactions to take into consideration. For CO2-rich residues derived from biomass treatment and heavy metal industries, the presence of CH4 and CO species (among others) constitute an, although often disregarded, much complex panorama where side reactions like CO methanation, dry reforming of methane, the forward Water Gas Shift reaction and the decomposition of CO and CH4 resulting in carbon deposits, are occurring to some extent within the catalytic reactor. This work aimed at designing advanced catalytic systems capable of converting the CO2/CO/CH4 feedstocks into syngas mixtures. Thus, with the RWGS reaction considered as the major process, this work focusses on the side reactions involving CO/CH4 species. In this context, a series Cu-MnOx/Al2O3 spinel derived catalysts were optimized for syngas production in presence of CO and CH4 fractions. Once the optimal active phase was determined, the optimal Cu contents and the impact of the support nature (Al2O3, SiO2-Al2O3 and CeO2-Al2O3) was evaluated for the valorization of realistic CO2-rich feedstocks. Remarkably, the obtained outcomes underline operative strategies for developing catalytic systems with advanced implementation potential. For that aim, the catalyst design should present, along with an active and selective phase for RWGS reaction, superior cooking resistances, activities towards methane reforming and low tendencies towards the forward WGS reaction. Further developments should tackle difficult tasks like improving the RWGS reaction rate while inhibiting the forwards WGS reaction as well as improving the CH4 conversion to CO without affecting the process selectivity. Strategies towards advancing catalytic systems capable of operating under variable conditions also arise as appealing routes. Y1 - 2021 UR - https://www.aiche.org/academy/conferences/aiche-annual-meeting/2021/proceeding/paper/661v-utilization-co2-rich-residues-syngas-production-strategies-catalyst-design UR - https://plan.core-apps.com/aiche2021/event/30d89249d0653ff1de80a79e11b79a16 SN - 978-0-8169-1116-5 ER - TY - GEN A1 - Tarifa, Pilar A1 - Gonzalez-Castano, Miriam A1 - Cazana, Fernando A1 - Monzon, Antonio A1 - Arellano-Garcia, Harvey T1 - Hydrophobic RWGS catalysts: valorization of CO2-rich streams in presence of CO/H2O T2 - Catalysis Today N2 - Nowadays, the majority of the Reverse Water Gas Shift (RWGS) studies assume somehow model feedstock (diluted CO2/H2) for syngas production. Nonetheless, biogas streams contain certain amounts of CO/H2O which will decrease the obtained CO2 conversion values by promoting the forward WGS reaction. Since the rate limiting step for the WGS reaction concerns the water splitting, this work proposes the use of hydrophobic RWGS catalysts as an effective strategy for the valorization of CO2-rich feedstock in presence of H2O and CO. Over Fe-Mg catalysts, the different hydrophilicities attained over pristine, N- and B-doped carbonaceous supports accounted for the impact on the activity of the catalyst in presence of CO/H2O. Overall, the higher CO productivity (4.12 μmol/(min·m2)) attained by Fe-Mg/CDC in presence of 20% of H2O relates to hindered water adsorption and unveil the use of hydrophobic surfaces as a suitable approach for avoiding costly pre-conditioning units for the valorization of CO2-rich streams based on RWGS processes in presence of CO/H2O. Y1 - 2023 U6 - https://doi.org/10.1016/j.cattod.2023.114276 SN - 1873-4308 VL - Vol. 423 ER - TY - GEN A1 - Jafari, Mitra A1 - Safdar, Muddasar A1 - Dorneanu, Bogdan A1 - Gonzalez-Castaño, Miriam A1 - Arellano-Garcia, Harvey T1 - Green and sustainable fuel from syngas via the Fischer-Tropsch synthesis process: Bifunctional cobalt-based catalysts T2 - 14th European Congress of Chemical Engineering and 7th European Congress of Applied Biotechnology N2 - This paper reviews and compares state-of-the-art cobalt-based catalysts and catalytic systems used to produce green and sustainable fuels using FTS. Being focused on comparing the effect of the catalyst formulation and synthesis method, the reactor type and operating parameters, as well as the quality of the obtained fuels, the aim is to identify the research gaps between these relevant research areas concerning production of green and sustainable fuels. Y1 - 2023 UR - https://dechema.converia.de/frontend/index.php?page_id=15565&additions_conferenceschedule_action=detail&additions_conferenceschedule_controller=paperList&pid=44228&hash=be231d3139d7d89da32b1610b7a0d1af3770c06640f246348e3ca8cfa7dd324a ER - TY - GEN A1 - Miah, Kamal Uddin Mohammad A1 - Kloshek, Alexander A1 - González-Castaño, Miriam A1 - Kehm, Christian A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Herstellen hocheffektiver Mikroreaktoren durch selektives Laserstrahlschmelzen T2 - DVS Congress 2022, Große Schweißtechnische Tagung, DVS Campus ; Kurzfassungen der Vorträge der Veranstaltung in Koblenz vom 19. bis 21. September 2022 ; (Langfassungen der Beiträge auf USB-Karte) N2 - Das pulverbasierte 3D-Metalldrucken ermöglicht die Fertigung von hochkomplexen Integralbauteilen, die als Trägerstruktur für Mikroreaktoren benutzt werden. Nach einer Beschichtung der Struktur mit einem Katalysatormaterial, können diese Mikroreaktoren höchst effizient für die CO2-Methanisierung eingesetzt werden. Durch die additive Fertigung mit dem selektiven Laserstrahlschmelzen (SLM) wurden adaptierte dreidimensionale periodische Gitterstrukturen mit sehr geringen Wandstärken hergestellt. Diese weisen ein sehr günstiges Verhältnis von Oberfläche zu Volumen (TPMS - Triply periodic minimal surface) auf. Des Weiteren zeigen die TPMS-Strukturen vorteilhafte Strömungseigenschaften, die sowohl für die Beschichtung mit dem Katalysator-Material als auch die Durchströmung mit den Reaktionsmedien im Betrieb essentiell sind. So ist es beispielsweise möglich, durch die Variation der Dimension einer TPMS-Struktur die Oberfläche pro Volumeneinheit, den hydraulischen Durchmesser des Reaktors und somit auch den Transportprozess des Fluids deutlich zu verbessern. Diese Faktoren ermöglichen eine effektivere Gas-Katalysator-Reaktion. Im Vergleich zu Mikroreaktorstrukturen aus den traditionellen Herstellungsverfahren liefern die additiv gefertigten Strukturen sowohl eine höhere CO2-Umwandlungsrate als auch eine CH4-Selektivität innerhalb des diffusionskontrollierten Bereichs. Y1 - 2022 SN - 978-3-96144-189-1 SP - 708 EP - 713 PB - DVS Media GmbH CY - Düsseldorf ER - TY - GEN A1 - Baena-Moreno, Francisco Manuel A1 - González-Castaño, Miriam A1 - Navarro de Miguel, Juan Carlos A1 - Miah, Kamal Uddin Mohammad A1 - Ossenbrink, Ralf A1 - Odriozola, José Antonio A1 - Arellano-Garcia, Harvey T1 - Stepping toward Efficient Microreactors for CO2 Methanation: 3D Printed Gyroid Geometry T2 - ACS Sustainable Chemistry & Engineering N2 - This work presents a comparative study towards the development of efficient micro-reactors based on 3D-printed structures. Thus, the study evaluates the influence of the metal substrate geometry on the performance of structured catalysts for the CO2 methanation reaction. For this purpose, 0.5%Ru–15%Ni/MgAl2O4 catalyst is wash coated over two different micro-monolithic metal substrates: a conventional parallel channel honeycomb structure and a novel 3D-printed structure with a complex gyroid geometry. The effect of the metal substrate geometry is analyzed for several CO2 sources including ideal flue gas atmospheres, the presence of residual CH4 and CO in the flue gas, as well as simulated biogas sources. The advantages of the gyroid-3D complex geometries over the honeycomb structures are shown for all evaluated conditions, providing at the best-case scenario a 14% improvement of CO2 conversion. Moreover, this contribution shows that systematically tailoring geometrical features of structured catalysts becomes an effective strategy to achieve improved catalysts performances independent of the flue gas composition. By enhancing the transport processes and the gas-catalyst interactions, the employed gyroid 3D metal substrates enable boosted CO2 conversions and greater CH4 selectivity within diffusional controlled regimes. KW - CO2 methanation KW - gyroid geometry KW - CH4 selectivity KW - gyroid-3D complex Y1 - 2021 U6 - https://doi.org/10.1021/acssuschemeng.1c01980 SN - 2168-0485 VL - 9 IS - 24 SP - 8198 EP - 8206 ER - TY - GEN A1 - Gonzalez-Castano, Miriam A1 - Navarro de Miguel, Juan Carlos A1 - Boelte, Jens-H. A1 - Centeno, Miguel Angel A1 - Klepel, Olaf A1 - Arellano-Garcia, Harvey T1 - Assessing the impact of textural properties in Ni–Fe catalysts for CO2 methanation performance T2 - Microporous and Mesoporous Materials N2 - In heterogeneous catalysis, the benefits of employing adequate textural properties on the catalytic performances are usually stated. Nevertheless, the quantification of the extent of improvement is not an easy task since variations on the catalysts’ specific areas and pore structures might involve modifications on a number of other surface catalytic features. This study establishes the impact of the catalyst textural properties on the CO2 methanation performance by investigating bimetallic Ni–Fe catalysts supported over carbon supports with different textural properties regarding surface area and pore structure. The comparable metal loading and dispersions attained for all systems enabled establishing forthright relationships between the catalyst textural properties and CO2 methanation rate. Once the influence of the external mass diffusions on the catalysts’ performance was experimentally discarded, the estimated Thiele modulus and internal effectiveness (φ and ηEff) values showed that the catalyst performance was majorly governed by the surface reaction rate whilst the pore size affected in no significant manner within the examined range (Dpore = 10.2 to 5.8 nm). Therefore, the rapport between the catalyst performance and surface area was quantified for the CO2 methanation reaction over Ni–Fe catalysts: increasing the surface area from 572 to 802 m2/g permit obtaining ca. 10% higher CO2 conversions. KW - Ni-Fe catalysts KW - CO2 methanation KW - Surface area KW - Pore size KW - Thiele modulus Y1 - 2021 U6 - https://doi.org/10.1016/j.micromeso.2021.111405 SN - 1387-1811 VL - 327 ER - TY - GEN A1 - González-Castaño, Miriam A1 - González-Arias, Judith A1 - Sánchez, Marta Elena A1 - Cara-Jiménez, Jorge A1 - Arellano-García, Harvey T1 - Syngas production using CO2-rich residues: From ideal to real operating conditions T2 - Journal of CO2 utilization KW - RWGS KW - Cu-Mn catalyst KW - CO2-rich residual gas KW - alumina KW - SiO2 KW - CeO2 Y1 - 2021 U6 - https://doi.org/10.1016/j.jcou.2021.101661 SN - 2212-9839 VL - 52 ER - TY - GEN A1 - González-Castaño, Miriam A1 - Dorneanu, Bogdan A1 - Arellano-Garcia, Harvey T1 - The Reverse Water Gas Shift Reaction: A Process Systems Engineering Perspective T2 - Reaction Chemistry & Engineering N2 - The catalytic reduction of CO2 into value-added products has been considered a compelling solution for alleviating global warming and energy crises. The reverse water gas shift (RWGS) reaction plays a pivotal role among the various CO2 utilization approaches, due to the fact that it produces syngas, the building block of numerous conversion processes. Although a lot of work has been carried out towards the development of a RWGS process, ranging from efficient catalytic systems to reactor units, and even pilot scale processes, there is still a lack of understanding of the fundamental phenomena that take place at the various levels and scales of the process. This contribution presents the main solutions and remaining challenges for a structured, trans- and multidisciplinary framework in which catalysis engineering and process systems engineering can work together to incorporate understanding and methods from both sides, to accelerate the investigation, creation and operation of an efficient industrial CO2 conversion process based on the RWGS reaction. KW - Reverse water gas shift reaction KW - syngas production KW - catalysts KW - process engineering Y1 - 2021 U6 - https://doi.org/10.1039/D0RE00478B SN - 2058-9883 ER - TY - GEN A1 - González-Castaño, Miriam A1 - Navarro de Miguel, Juan Carlos A1 - Pernkova, A. A1 - Centeno, Miguel Angel A1 - Odriozola, José Antonio A1 - Arellano-Garcia, Harvey T1 - Ni/YMnO3 perovskite catalyst for CO2 methanation T2 - Applied Materials Today N2 - Ni/YMnO3 perovskite catalyst for CO2 methanation KW - Ni catalysts KW - CO2 methanation KW - YMnO3 perovskites KW - manganites Y1 - 2021 U6 - https://doi.org/10.1016/j.apmt.2021.101055 VL - 23 ER - TY - GEN A1 - González-Castaño, Miriam A1 - Baena-Moreno, Francisco Manuel A1 - Navarro de Miguel, Juan Carlos A1 - Miah, Kamal Uddin Mohammad A1 - Arroyo-Torralvo, Fátima A1 - Ossenbrink, Ralf A1 - Odriozola, José Antonio A1 - Benzinger, Walther A1 - Hensel, Andreas A1 - Wenka, Achim A1 - Arellano-García, Harvey T1 - 3D-printed structured catalysts for CO2 methanation reaction: Advancing of gyroid-based geometries T2 - Energy Conversion and Management N2 - This work investigates the CO2 methanation rate of structured catalysts by tuning the geometry of 3D-printed metal Fluid Guiding Elements (FGEs) structures based on periodically variable pseudo-gyroid geometries. The enhanced performance showed by the structured catalytic systems is mostly associated with the capability of the FGEs substrate geometries for efficient heat usages. Thus, variations on the channels diameter resulted in ca. 25% greater CO2 conversions values at intermediate temperature ranges. The highest void fraction evidenced in the best performing catalyst (3D-1) favored the radial heat transfer and resulted in significantly enhanced catalytic activity, achieving close to equilibrium (75%) conversions at 400 ◦C and 120 mL/min. For the 3D-1 catalyst, a mathematical model based on an experimental design was developed thus enabling the estimation of its behavior as a function of temperature, spatial velocity, hydrogen to carbon dioxide (H2/CO2) ratio, and inlet CO2 concentration. Its optimal operating conditions were established under 3 different scenarios: 1) no restrictions, 2) minimum H2:CO2 ratios, and 3) minimum temperatures and H2/CO2 ratio. For instance, for the lattest scenario, the best CO2 methanation conditions require operating at 431 ◦C, 200 mL/min, H2/CO2 = 3 M ratio, and inlet CO2 concentration = 10 %. KW - 3D-printing KW - Triply periodic minimal surfaces KW - Fluid guiding elements KW - CO2 methanation KW - Structured catalysts KW - Experiment design Y1 - 2022 U6 - https://doi.org/10.1016/j.enconman.2022.115464 SN - 2590-1745 VL - 258 ER - TY - GEN A1 - Tarifa, Pilar A1 - Ramirez Reina, Tomas A1 - González-Castaño, Miriam A1 - Arellano-Garcia, Harvey T1 - Catalytic Upgrading of Biomass-Gasification Mixtures Using Ni-Fe/MgAl₂O₄ as a Bifunctional Catalyst T2 - Energy and Fuels N2 - Biomass gasification streams typically contain a mixture of CO, H2, CH4, and CO2 as the majority components and frequently require conditioning for downstream processes. Herein, we investigate the catalytic upgrading of surrogate biomass gasifiers through the generation of syngas. Seeking a bifunctional system capable of converting CO2 and CH4 to CO, a reverse water gas shift (RWGS) catalyst based on Fe/MgAl2O4 was decorated with an increasing content of Ni metal and evaluated for producing syngas using different feedstock compositions. This approach proved efficient for gas upgrading, and the incorporation of adequate Ni content increased the CO content by promoting the RWGS and dry reforming of methane (DRM) reactions. The larger CO productivity attained at high temperatures was intimately associated with the generation of FeNi3 alloys. Among the catalysts' series, Ni-rich catalysts favored the CO productivity in the presence of CH4, but important carbon deposition processes were noticed. On the contrary, 2Ni-Fe/MgAl2O4 resulted in a competitive and cost-effective system delivering large amounts of CO with almost no coke deposits. Overall, the incorporation of a suitable realistic application for valorization of variable composition of biomass-gasification derived mixtures obtaining a syngas-rich stream thus opens new routes for biosyngas production and upgrading. Y1 - 2022 UR - https://pubs.acs.org/doi/10.1021/acs.energyfuels.2c01452 U6 - https://doi.org/10.1021/acs.energyfuels.2c01452 SN - 1520-5029 SN - 0887-0624 VL - 36 IS - 15 SP - 8267 EP - 8273 ER - TY - GEN A1 - Gonzalez-Arias, Judith A1 - Torres-Sempere, Guillermo A1 - Gonzalez-Castano, Miriam A1 - Baena-Moreno, Francisco Manuel A1 - Ramirez Reina, Tomas T1 - Hydrochar and synthetic natural gas co-production for a full circular economy implementation via hydrothermal carbonization and methanation: An economic approach T2 - Journal of Environmental Sciences N2 - Herein we study the economic performance of hydrochar and synthetic natural gas co-production from olive tree pruning. The process entails a combination of hydrothermal carbonization and methanation. In a previous work, we evidenced that standalone hydrochar production via HTC results unprofitable. Hence, we propose a step forward on the process design by implementing a methanation, adding value to the gas effluent in an attempt to boost the overall process techno-economic aspects. Three different plant capacities were analyzed (312.5, 625 and 1250 kg/hr). The baseline scenarios showed that, under the current circumstances, our circular economy strategy in unprofitable. An analysis of the revenues shows that hydrochar selling price have a high impact on NPV and subsidies for renewable coal production could help to boost the profitability of the process. On the contrary, the analysis for natural gas prices reveals that prices 8 times higher than the current ones in Spain must be achieved to reach profitability. This seems unlikely even under the presence of a strong subsidy scheme. The costs analysis suggests that a remarkable electricity cost reduction or electricity consumption of the HTC stage could be a potential strategy to reach profitability scenarios. Furthermore, significant reduction of green hydrogen production costs is deemed instrumental to improve the economic performance of the process. These results show the formidable techno-economic challenge that our society faces in the path towards circular economy societies. Y1 - 2023 UR - https://www.sciencedirect.com/science/article/pii/S1001074223001766 U6 - https://doi.org/10.1016/j.jes.2023.04.019 SN - 1878-7320 VL - Vol. 140(2024) SP - 69 EP - 78 ER - TY - CHAP A1 - González-Castaño, Miriam A1 - Tarifa, Pilar A1 - Monzon, Antonio A1 - Arellano-Garcia, Harvey T1 - Valorization of unconventional CO2-rich feedstock via Reverse Water Gas Shift reaction T2 - Circular Economy Processes for CO2 Capture and Utilization : Strategies and Case Studies N2 - The implementation of novel CO2 valorization technologies is one of the most promising approaches towards the achievement of sustainable energy models. This chapter highlights the importance of carbon capture and utilization technologies and proposes novel approaches for the valorization of CO2-rich feedstock derived from thermochemical biomass conversion through the production of syngas mixtures via the Reverse Water Gas Shift reaction. After, this classification of the different types of nonconventional gases and biomass-treatment processes, we have also revised the fundamentals of the Reverse Water Gas Shift reaction and the impact of species commonly present in CO2-rich streams on the performance of the catalytic systems are also reviewed. Finally, a catalytic bi-functionalization approach that ensures larger CO productivity from simulated biomass-derived CO2-rich feedstock is demonstrated. KW - Reverse Water Gas Shift KW - Valorization of CO2 KW - Syngas KW - Catalysts Y1 - 2024 SN - 9780323956697 U6 - https://doi.org/10.1016/B978-0-323-95668-0.00001-1 SP - 307 EP - 323 PB - Woodhead Publishing ER - TY - GEN A1 - Tarifa, Pilar A1 - González-Castaño, Miriam A1 - Cazaña, F. A1 - Monzón, Antonio A1 - Arellano-García, Harvey T1 - Development of one-pot Cu/cellulose derived carbon catalysts for RWGS reaction T2 - Fuel N2 - A series of Cu-based catalysts promoted with Fe, Ce and Al supported on cellulose derived carbon (CDC) was prepared by biomorphic mineralization technique for the RWGS reaction. The excellent Cu dispersions (7 nm at ca. 30 wt% Cu) along with the resilience toward metal sintering attained in the entire catalysts series highlight one-pot decomposition of cellulose under reducing atmosphere as an excellent synthesis method which enable obtaining well-dispersed Cu nanoparticles. The influence of incorporating a second metal oxide over biomorphic mineralized Cu systems was also investigated. With the Cu-Ce system exhibiting the best catalyst performance of the catalysts’ series, the enhanced catalyst performances were majorly ascribed to the catalysts redox properties. The lineal relationships stablished between oxygen exchange capacity and CO2 conversion rates remarks the employed sequential H2/CO2 cycles as an effective methodology for screening the catalytic performance of Cu catalysts for RWGS reaction. KW - RWGS KW - Cu catalysts KW - Oxygen exchange capacity KW - Cellulose derived carbon Y1 - 2022 U6 - https://doi.org/10.1016/j.fuel.2022.123707 SN - 0016-2361 VL - Vol. 319 ER - TY - GEN A1 - Gonzalez-Castãno, Miriam A1 - Morales, Carlos A1 - Navarro de Miguel, Juan Carlos A1 - Boelte, Jens H. A1 - Klepel, Olaf A1 - Flege, Jan Ingo A1 - Arellano-García, Harvey T1 - Are Ni/ and Ni5Fe1/biochar catalysts suitable for synthetic natural gas production? A comparison with γ-Al2O3 supported catalysts T2 - Green Energy & Environment N2 - Among challenges implicit in the transition to the post–fossil fuel energetic model, the finite amount of resources available for the technological implementation of CO2 revalorizing processes arises as a central issue. The development of fully renewable catalytic systems with easier metal recovery strategies would promote the viability and sustainability of synthetic natural gas production circular routes. Taking Ni and NiFe catalysts supported over γ-Al2O3 oxide as reference materials, this work evaluates the potentiality of Ni and NiFe supported biochar catalysts for CO2 methanation. The development of competitive biochar catalysts was found dependent on the creation of basic sites on the catalyst surface. Displaying lower Turn Over Frequencies than Ni/Al catalyst, the absence of basic sites achieved over Ni/C catalyst was related to the depleted catalyst performances. For NiFe catalysts, analogous Ni5Fe1 alloys were constituted over both alumina and biochar supports. The highest specific activity of the catalyst series, exhibited by the NiFe/C catalyst, was related to the development of surface basic sites along with weaker NiFe–C interactions, which resulted in increased Ni0:NiO surface populations under reaction conditions. In summary, the present work establishes biochar supports as a competitive material to consider within the future low-carbon energetic panorama. KW - Biochar catalysts KW - Carbon catalysts KW - Ni catalysts KW - NiFe alloy KW - Bimetallic catalysts KW - Synthetic natural gas KW - CO2 methanation Y1 - 2023 U6 - https://doi.org/10.1016/j.gee.2021.05.007 SN - 2468-0257 VL - 8 IS - 3 SP - 744 EP - 756 ER -