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9 pages, 8032 KiB

Open AccessFeature PaperArticle

Cyclic Stability of a Bifunctional Catalyst in the Sorption-Enhanced Reverse Water–Gas Shift Reaction

by Johannis A. Z. Pieterse, Saskia Booneveld, Gerard D. Elzinga, Vladimir Dikic, Galina Skorikova, Jurriaan Boon and Andreas Geisbauer

Catalysts 2025, 15(5), 480; https://doi.org/10.3390/catal15050480 - 13 May 2025

Viewed by 616

Abstract

Sorption-enhanced reverse water–gas shift (SE-RWGS), designated as COMAX, was studied using a Pt4A bifunctional catalyst (reactive adsorbent). The bifunctional Pt4A catalyst integrates CO₂ activation and reaction with water adsorption functionality, where the active phase is loaded onto a carrier that provides a [...] Read more.

Sorption-enhanced reverse water–gas shift (SE-RWGS), designated as COMAX, was studied using a Pt4A bifunctional catalyst (reactive adsorbent). The bifunctional Pt4A catalyst integrates CO₂ activation and reaction with water adsorption functionality, where the active phase is loaded onto a carrier that provides a surface area for Pt dispersion as well as H₂O adsorption capacity. The 0.3 wt% Pt-4A molecular sieve reactive sorbent was tested at a kg scale in a pressure swing (reactive) adsorption–regeneration process. More than 400 cycles over 50 days of operation were successfully demonstrated without significant decay. Cyclic stability was achieved, provided that the regeneration temperature was sufficiently high to ensure near-complete dehydration. The single-bead structure withstood the pressure swing operation effectively, with only a maximum of 2% of the total recovered reactive sorbent turning to fines (<500 μm). The successful integration of catalytic activity and water adsorption capacity into a single particle presents opportunities for the further intensification of sorption-enhanced reactions for CO₂ conversion. Full article

(This article belongs to the Special Issue Catalytic Activity on Thermochemical and Non-Thermal Plasma Conversion/Utilization of Methane and Carbon Dioxide)

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19 pages, 1740 KiB

Open AccessEditor’s ChoiceArticle

Numerical Simulation Approach for a Dynamically Operated Sorption-Enhanced Water-Gas Shift Reactor

by Tabea J. Stadler, Jan-Hendrik Knoop, Simon Decker and Peter Pfeifer

Processes 2022, 10(6), 1160; https://doi.org/10.3390/pr10061160 - 9 Jun 2022

Cited by 4 | Viewed by 3355

Abstract

A dynamically operated sorption-enhanced water–gas shift reactor is modelled to leverage its performance by means of model-based process design. This reactor shall provide CO₂-free synthesis gas for e-fuel production from pure CO. The nonlinear model equations describing simultaneous adsorption and reaction [...] Read more.

A dynamically operated sorption-enhanced water–gas shift reactor is modelled to leverage its performance by means of model-based process design. This reactor shall provide CO₂-free synthesis gas for e-fuel production from pure CO. The nonlinear model equations describing simultaneous adsorption and reaction are solved with three numerical approaches in MATLAB: a built-in solver for partial differential equations, a semi-discretization method in combination with an ordinary differential equation solver, and an advanced graphic implementation of the latter method in Simulink. The novel implementation in Simulink offers various advantages for dynamic simulations and is expanded to a process model with six reaction chambers. The continuous conditions in the reaction chambers and the discrete states of the valves, which enable switching between reactive adsorption and regeneration, lead to a hybrid system. Controlling the discrete states in a finite-state machine in Stateflow enables automated switching between reactive adsorption and regeneration depending on predefined conditions, such as a time span or a concentration threshold in the product gas. The established chemical reactor simulation approach features unique possibilities in terms of simulation-driven development of operating procedures for intensified reactor operation. In a base case simulation, the sorbent usage for serial operation with adjusted switching times is increased by almost 15%. Full article

(This article belongs to the Special Issue Numerical Simulation of Nonlinear Dynamical Systems)

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44 pages, 6387 KiB

Open AccessReview

Hydrogen Production with In Situ CO₂ Capture at High and Medium Temperatures Using Solid Sorbents

by Paula Teixeira, Carmen Bacariza, Patrícia Correia, Carla I. C. Pinheiro and Isabel Cabrita

Energies 2022, 15(11), 4039; https://doi.org/10.3390/en15114039 - 31 May 2022

Cited by 29 | Viewed by 5550

Abstract

Hydrogen is a versatile vector for heat and power, mobility, and stationary applications. Steam methane reforming and coal gasification have been, until now, the main technologies for H₂ production, and in the shorter term may remain due to the current costs of [...] Read more.

Hydrogen is a versatile vector for heat and power, mobility, and stationary applications. Steam methane reforming and coal gasification have been, until now, the main technologies for H₂ production, and in the shorter term may remain due to the current costs of green H₂. To minimize the carbon footprint of these technologies, the capture of CO₂ emitted is a priority. The in situ capture of CO₂ during the reforming and gasification processes, or even during the syngas upgrade by water–gas shift (WGS) reaction, is especially profitable since it contributes to an additional production of H₂. This includes biomass gasification processes, where CO₂ capture can also contribute to negative emissions. In the sorption-enhanced processes, the WGS reaction and the CO₂ capture occur simultaneously, the selection of suitable CO₂ sorbents, i.e., with high activity and stability, being a crucial aspect for their success. This review identifies and describes the solid sorbents with more potential for in situ CO₂ capture at high and medium temperatures, i.e., Ca- or alkali-based sorbents, and Mg-based sorbents, respectively. The effects of temperature, steam and pressure on sorbents’ performance and H₂ production during the sorption-enhanced processes are discussed, as well as the influence of catalyst–sorbent arrangement, i.e., hybrid/mixed or sequential configuration. Full article

(This article belongs to the Special Issue Advances in Hydrogen Energy Production and Storage)

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17 pages, 3321 KiB

Open AccessArticle

Parametric Study on the Adjustability of the Syngas Composition by Sorption-Enhanced Gasification in a Dual-Fluidized Bed Pilot Plant

by Selina Hafner, Max Schmid and Günter Scheffknecht

Energies 2021, 14(2), 399; https://doi.org/10.3390/en14020399 - 12 Jan 2021

Cited by 17 | Viewed by 3654

Abstract

Finding a way for mitigating climate change is one of the main challenges of our generation. Sorption-enhanced gasification (SEG) is a process by which syngas as an important intermediate for the synthesis of e.g., dimethyl ether (DME), bio-synthetic natural gas (SNG) and Fischer–Tropsch [...] Read more.

Finding a way for mitigating climate change is one of the main challenges of our generation. Sorption-enhanced gasification (SEG) is a process by which syngas as an important intermediate for the synthesis of e.g., dimethyl ether (DME), bio-synthetic natural gas (SNG) and Fischer–Tropsch (FT) products or hydrogen can be produced by using biomass as feedstock. It can, therefore, contribute to a replacement for fossil fuels to reduce greenhouse gas (GHG) emissions. SEG is an indirect gasification process that is operated in a dual-fluidized bed (DFB) reactor. By the use of a CO₂-active sorbent as bed material, CO₂ that is produced during gasification is directly captured. The resulting enhancement of the water–gas shift reaction enables the production of a syngas with high hydrogen content and adjustable H₂/CO/CO₂-ratio. Tests were conducted in a 200 kW DFB pilot-scale facility under industrially relevant conditions to analyze the influence of gasification temperature, steam to carbon (S/C) ratio and weight hourly space velocity (WHSV) on the syngas production, using wood pellets as feedstock and limestone as bed material. Results revealed a strong dependency of the syngas composition on the gasification temperature in terms of permanent gases, light hydrocarbons and tars. Also, S/C ratio and WHSV are parameters that can contribute to adjusting the syngas properties in such a way that it is optimized for a specific downstream synthesis process. Full article

(This article belongs to the Special Issue Progress and Novel Applications of Fluidized Bed Technology)

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22 pages, 3512 KiB

Open AccessArticle

Sorption-Enhanced Water-Gas Shift Reaction for Synthesis Gas Production from Pure CO: Investigation of Sorption Parameters and Reactor Configurations

by Tabea J. Stadler, Philipp Barbig, Julian Kiehl, Rafael Schulz, Thomas Klövekorn and Peter Pfeifer

Energies 2021, 14(2), 355; https://doi.org/10.3390/en14020355 - 11 Jan 2021

Cited by 14 | Viewed by 4421

Abstract

A sorption-enhanced water-gas shift (SEWGS) system providing CO₂-free synthesis gas (CO + H₂) for jet fuel production from pure CO was studied. The water-gas shift (WGS) reaction was catalyzed by a commercial Cu/ZnO/Al₂O₃ catalyst and carried [...] Read more.

A sorption-enhanced water-gas shift (SEWGS) system providing CO₂-free synthesis gas (CO + H₂) for jet fuel production from pure CO was studied. The water-gas shift (WGS) reaction was catalyzed by a commercial Cu/ZnO/Al₂O₃ catalyst and carried out with in-situ CO₂ removal on a 20 wt% potassium-promoted hydrotalcite-derived sorbent. Catalyst activity was investigated in a fixed bed tubular reactor. Different sorbent materials and treatments were characterized by CO₂ chemisorption among other analysis methods to choose a suitable sorbent. Cyclic breakthrough tests in an isothermal packed bed microchannel reactor (PBMR) were performed at significantly lower modified residence times than those reported in literature. A parameter study gave an insight into the effect of pressure, adsorption feed composition, desorption conditions, as well as reactor configuration on breakthrough delay and adsorbed amount of CO₂. Special attention was paid to the steam content. The significance of water during adsorption as well as desorption confirmed the existence of different adsorption sites. Various reactor packing concepts showed that the interaction of relatively fast reaction and relatively slow adsorption kinetics plays a key role in the SEWGS process design at low residence time conditions. Full article

(This article belongs to the Special Issue Hydrogen and Syngas Generation)

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15 pages, 5957 KiB

Open AccessFeature PaperArticle

Syngas Production from Combined Steam Gasification of Biochar and a Sorption-Enhanced Water–Gas Shift Reaction with the Utilization of CO₂

by Supanida Chimpae, Suwimol Wongsakulphasatch, Supawat Vivanpatarakij, Thongchai Glinrun, Fasai Wiwatwongwana, Weerakanya Maneeprakorn and Suttichai Assabumrungrat

Processes 2019, 7(6), 349; https://doi.org/10.3390/pr7060349 - 7 Jun 2019

Cited by 15 | Viewed by 5466

Abstract

This research aims at evaluating the performance of a combined system of biochar gasification and a sorption-enhanced water–gas shift reaction (SEWGS) for synthesis gas production. The effects of mangrove-derived biochar gasification temperature, pattern of combined gasification and SEWGS, amount of steam and CO [...] Read more.

This research aims at evaluating the performance of a combined system of biochar gasification and a sorption-enhanced water–gas shift reaction (SEWGS) for synthesis gas production. The effects of mangrove-derived biochar gasification temperature, pattern of combined gasification and SEWGS, amount of steam and CO₂ added as gasifying agent, and SEWGS temperature were studied in this work. The performances of the combined process were examined in terms of biochar conversion, gaseous product composition, and CO₂ emission. The results revealed that the hybrid SEWGS using one-body multi-functional material offered a greater amount of H₂ with a similar amount of CO₂ emissions when compared with separated sorbent/catalyst material. The gasification temperature of 900 °C provided the highest biochar conversion of ca. 98.7%. Synthesis gas production was found to depend upon the amount of water and CO₂ added and SEWGS temperature. Higher amounts of H₂ were observed when increasing the amount of water and the temperature of the SEWGS system. Full article

(This article belongs to the Special Issue Hydrogen Production Technologies)

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15 pages, 8654 KiB

Open AccessArticle

Hydrothermal Fabrication of High Specific Surface Area Mesoporous MgO with Excellent CO₂ Adsorption Potential at Intermediate Temperatures

by Wanlin Gao, Tuantuan Zhou, Benoit Louis and Qiang Wang

Catalysts 2017, 7(4), 116; https://doi.org/10.3390/catal7040116 - 15 Apr 2017

Cited by 50 | Viewed by 8729

Abstract

In this work, we report on a novel sodium dodecyl sulfate (SDS)-assisted magnesium oxide (MgO)-based porous adsorbent synthesized by hydrothermal method for intermediate CO₂ capture. For industrial MgO, its CO₂ adsorption capacity is normally less than 0.06 mmol g⁻¹, [...] Read more.

In this work, we report on a novel sodium dodecyl sulfate (SDS)-assisted magnesium oxide (MgO)-based porous adsorbent synthesized by hydrothermal method for intermediate CO₂ capture. For industrial MgO, its CO₂ adsorption capacity is normally less than 0.06 mmol g⁻¹, with a specific surface area as low as 25.1 m² g⁻¹. Herein, leaf-like MgO nanosheets which exhibited a disordered layer structure were fabricated by the introduction of SDS surfactants and the control of other synthesis parameters. This leaf-like MgO adsorbent showed an excellent CO₂ capacity of 0.96 mmol g⁻¹ at moderate temperatures (~300 °C), which is more than ten times higher than that of the commercial light MgO. This novel mesoporous MgO adsorbent also exhibited high stability during multiple CO₂ adsorption/desorption cycles. The excellent CO₂ capturing performance was believed to be related to its high specific surface area of 321.3 m² g⁻¹ and abundant surface active adsorption sites. This work suggested a new synthesis scheme for MgO based CO₂ adsorbents at intermediate temperatures, providing a competitive candidate for capturing CO₂ from certain sorption enhanced hydrogen production processes. Full article

(This article belongs to the Special Issue C1 Chemistry—C1-Platform Chemicals as Cornerstone for a Sustainable Energy)

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15 pages, 371 KiB

Open AccessArticle

Hydrogen-Rich Gas Production by Sorption Enhanced Steam Reforming of Woodgas Containing TAR over a Commercial Ni Catalyst and Calcined Dolomite as CO₂ Sorbent

by Mario Sisinni, Andrea Di Carlo, Enrico Bocci, Andrea Micangeli and Vincenzo Naso

Energies 2013, 6(7), 3167-3181; https://doi.org/10.3390/en6073167 - 1 Jul 2013

Cited by 43 | Viewed by 9661

Abstract

The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR) and CH₄ and to produce pure H₂ by means of a CO₂ [...] Read more.

The aim of this work was the evaluation of the catalytic steam reforming of a gaseous fuel obtained by steam biomass gasification to convert topping atmosphere residue (TAR) and CH₄ and to produce pure H₂ by means of a CO₂ sorbent. This experimental work deals with the demonstration of the practical feasibility of such concepts, using a real woodgas obtained from fluidized bed steam gasification of hazelnut shells. This study evaluates the use of a commercial Ni catalyst and calcined dolomite (CaO/MgO). The bed material simultaneously acts as reforming catalyst and CO₂ sorbent. The experimental investigations have been carried out in a fixed bed micro-reactor rig using a slipstream from the gasifier to evaluate gas cleaning and upgrading options. The reforming/sorption tests were carried out at 650 °C while regeneration of the sorbent was carried out at 850 °C in a nitrogen environment. Both combinations of catalyst and sorbent are very effective in TAR and CH₄ removal, with conversions near 100%, while the simultaneous CO₂ sorption effectively enhances the water gas shift reaction producing a gas with a hydrogen volume fraction of over 90%. Multicycle tests of reforming/CO₂capture and regeneration were performed to verify the stability of the catalysts and sorbents to remove TAR and capture CO₂ during the duty cycle. Full article

(This article belongs to the Special Issue Biomass and Biofuels 2013)

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