Search Results (673)

Dry reforming of methane (DRM) enables the simultaneous conversion of CH₄ and CO₂, yet rapid coking severely restricts the stability of Ni-based catalysts. In this study, Co was incorporated into Ce-, La-, and Zr-promoted Ni catalysts to construct Ni-Co alloy active sites, and their catalytic behavior was systematically evaluated. While single-promoter modification partially suppressed coke deposition at the expense of activity, Ni-Co alloy formation maintained high reforming performance and significantly enhanced stable catalytic performance within the 20 h evaluation period, with the Ce-promoted Ni-Co catalyst exhibiting the most durable anti-coking performance. CO₂-TPD and coke characterization results indicate that promoter species enhance medium-strength basicity and oxygen mobility, thereby facilitating CO₂ adsorption and accelerating the oxidation of surface coke intermediates; in particular, Ce supplies mobile active oxygen species through its oxygen storage-release capacity. DFT calculations further reveal that Co incorporation modulates the electronic structure of Ni sites, optimizing the balance between CH₄ dissociation and CO₂ activation and thus suppressing excessive methane cracking. These findings elucidate the synergistic effect of Ni-Co alloying and promoter modification in DRM and provide mechanistic insight for the rational design of coke-resistant Ni-based catalysts. Full article

Waste management is a vital component of modern economies, requiring not only technological solutions, but also economic and social approaches that reflect human needs while minimizing environmental harm. Within the European Union, sustainable development remains a central objective, promoting strategies in which waste is not merely disposed of, but is also recovered and reused whenever feasible. Landfill gas, primarily composed of methane, can be captured and managed in a controlled way. If left unregulated, methane emissions present serious risks to human health and contribute significantly to environmental degradation. At the same time, methane represents a valuable yet underutilized renewable energy source. In Poland, emission monitoring is conducted through the National Pollutant Release and Transfer Register, which operates as part of a broader European system. Landfill operators must report methane emissions and pay associated environmental fees. This study aimed to estimate methane emissions across Polish voivodeships from 2019 to 2023, considering both economic and social dimensions of sustainability. The analysis relied on official register data and landfill documentation, enabling evaluation of reporting accuracy and regulatory effectiveness. The findings indicate that current policies insufficiently encourage emission reductions, highlighting the need for systemic reforms, improved transparency, and clearer regulatory thresholds to drive meaningful environmental progress. Full article

Amid growing pressure to reduce carbon emissions, carbon capture, utilization, and storage (CCUS) has become an important pathway toward deep decarbonization. However, the conventional separated “capture–release–conversion” process suffers from high energy consumption and system complexity, which severely limits its large-scale application. Integrated CO₂ Capture and Utilization (ICCU), which enables the capture, activation, and conversion of CO₂ within a single system, has attracted widespread attention because it can effectively reduce intermediate energy-intensive steps and improve carbon utilization efficiency. This review systematically summarizes recent progress in ICCU technology, with particular emphasis on reaction mechanisms and interfacial coupling characteristics. The performance features of solvent-based chemical absorption and solid-sorbent adsorption, two widely studied capture routes, are summarized, and typical integrated conversion pathways, including reverse water–gas shift, methanation, and dry reforming of methane, are discussed. On this basis, the roles of non-conventional energy-assisted strategies, such as photocatalysis, electrocatalysis, non-thermal plasma, and microwave irradiation, in expanding ICCU systems are further examined, together with their system-level coupling potential in carbon-intensive industries such as steel, cement, and power generation. Finally, the key scientific issues and engineering challenges currently facing ICCU are analyzed from the perspectives of fundamental mechanisms, material design, and system engineering, and future development directions are proposed. This review highlights that elucidating multiscale synergistic mechanisms, developing high-performance dual-function materials, and optimizing system integration are crucial to promoting the industrial application of ICCU technology. Full article

Dry reforming of methane (DRM) is an attractive route for H₂ production and simultaneous CO₂ utilization, but its practical implementation is limited by catalyst deactivation. This study experimentally investigates the catalytic performance of Ni/Al₂O₃ and Gd-doped ceria-promoted Ni/GDC–Al₂O₃ catalysts for DRM in a fixed-bed quartz reactor over 400–800 °C at gas residence times of 0.1 s and 0.4 s. Increasing temperature and residence time enhanced CH₄ and CO₂ conversion as well as H₂ and CO yields for both catalysts. The GDC-promoted catalyst exhibited markedly improved activity, achieving conversions and product yields at 0.1 s comparable to those of Ni/Al₂O₃ at 0.4 s and reaching complete CH₄ conversion at about 650 °C, approximately 100 °C lower than the Ni/Al₂O₃ catalyst. Long-term testing at 650 °C showed stable catalytic behavior of the Ni/GDC–Al₂O₃ catalyst, while operational observations qualitatively suggested the absence of significant carbon deposition, consistent with equilibrium calculations. Full article

The efficient conversion of methane into hydrogen-rich syngas is essential for sustainable energy; however, integrating methane partial oxidation (POM) with the water–gas shift (WGS) reaction remains a significant challenge due to thermal and kinetic mismatches. This research presents a spatially decoupled dual-bed reactor configuration, utilizing Ni/GDC and Cu/GDC catalysts, to achieve synergistic hydrogen production. Unlike conventional physically mixed systems, which suffer from thermal hotspots and the unintended promotion of the endothermic Reverse Water–Gas Shift (RWGS) reaction, the dual-bed architecture effectively segregates the reaction zones. Advanced characterization, including O₂-TPO and Raman spectroscopy, reveals that the GDC support acts as a critical oxygen buffer via the Mars-van Krevelen mechanism, modulating the dynamic redox state of the active metal sites to prevent deep oxidation and carbonaceous deactivation. Furthermore, macroscopic performance and carbon–oxygen mass balance analyses confirm that this rational architectural design facilitates a seamless integration of POM and WGS pathways, resulting in significantly maximized H₂ yield. From a broader engineering perspective, this dual-bed strategy offers a practical, low-complexity alternative to intensive integrated technologies such as sorption-enhanced reforming (SER) or chemical looping, providing a robust and scalable framework for durable, high-efficiency hydrogen production. Full article

Tri-reforming of methane (TRM) has emerged as a promising pathway for low-carbon syngas production by integrating steam reforming, dry reforming, and partial oxidation within a single process. This coupling enables simultaneous CH₄ utilization and CO₂ valorization while enabling internal heat generation and flexible adjustment of the H₂/CO ratio for downstream synthesis. However, TRM performance cannot be adequately evaluated using conversion or energy efficiency alone, because the process involves complex interactions among competing reaction pathways, transport phenomena, catalyst stability, and thermodynamic irreversibility. This review provides a multiscale critical assessment of TRM from both first-law energy and second-law exergy perspectives, linking reaction-network fundamentals to reactor-level behavior and system-level performance. The literature evidence shows that although high temperatures and near-autothermal operation can enhance CH₄ conversion and reduce external heat demand, these conditions may simultaneously intensify deep oxidation, hotspot formation, carbon-forming tendencies, and exergy destruction. While equilibrium analyses help define feasible operating windows, they are insufficient without kinetic modeling and reactor-scale studies that capture spatial non-uniformities and pathway competition. Across reported TRM systems, exergy destruction is consistently concentrated within the reformer, identifying the reacting core as the dominant thermodynamic bottleneck. Accordingly, the key challenge in TRM is not simply to maximize conversion but to preserve chemical work potential while maintaining syngas quality and operational stability. Viewed from this perspective, TRM is better understood as an irreversibility-aware multiscale design problem in which optimal performance depends on the integrated optimization of catalyst functionality, reactor architecture, heat management, and system-level operation. Full article

The reaction scheme of the partial oxidation of methane is still currently undetermined for many catalysts due to a lack of accurate experimental data to develop kinetic studies. In this work, a kinetic modeling study of partial oxidation of methane was performed using experimental data from the literature. A kinetic model is proposed, and a new set of kinetic parameters was obtained in view of the failed reproduction of a model from the literature. The kinetic parameters of the proposed model were calculated and determined by using an optimization approach based on non-lineal parameter estimation, proper selection of initial values of parameters, and sensitivity and statistical analyses. Experimental data from the literature obtained in a packed-bed reactor with a Pt/Al₂O₃ catalyst at reaction temperatures of 465–574 °C were used to develop the kinetic model. Experimental data were accurately predicted by the proposed model with determination coefficient of 0.988. Full article

The integration of artificial intelligence (AI), machine learning (ML), and computational modeling with experimental catalysis is reshaping materials design and chemical process development. Tailored heterogeneous catalysts including supported metals, zeolites, defect-engineered materials, and multi-element systems exhibit enhanced activity, selectivity, and stability through engineered active sites and porosity. AI and ML approaches enable predictive modeling, high-throughput screening, mechanistic insight, and rational catalyst design by linking synthesis conditions, structural features, and performance metrics across scales. Applications span CO₂ conversion, methane reforming, hydrogen production, polymer recycling, and photocatalysis, with platforms such as PHOTOREAC, QMOF, and PhotoCatDB facilitating the translation from laboratory experiments to reactor-scale processes. Hybrid strategies that combine mechanistic understanding with data-driven models improve interpretability, predictive accuracy, and process optimization. These advances underscore a paradigm shift toward data-driven catalysis, accelerating discovery, supporting sustainable chemical technologies, and emphasizing the role of human expertise in guiding responsible AI deployment. Full article

The use of waste eggshell as a support material for nickel catalysts in the dry reforming of methane (DRM) aims to enhance hydrogen production while controlling catalyst deactivation caused by carbon deposition. Catalyst samples were prepared by wet impregnation and characterized by N₂ adsorption–desorption measurements, X-ray diffractometry (XRD), thermogravimetric analysis (TGA), temperature-programmed reduction, desorption of CO₂ and oxidation (H₂-TPR, CO₂-TPD and TPO), and scanning electron microscopy (SEM). Catalyst activity experiments were conducted at temperatures ranging from 500 to 750 °C, with both reduced and unreduced samples, utilizing a 1.5:1 mixture of CH₄ and CO₂ in a fixed-bed reactor, accompanied by online gas chromatography for analysis. By employing a low calcination temperature (500 °C), the integrity of the eggshell support was maintained. The Ni20 catalyst, with an intermediate nickel loading, exhibited the highest CH₄ (24.5%) and CO₂ (60.5%) conversion and showed minimal carbon formation. Notably, the basicity of the eggshell support contributed to the suppression of carbon deposition, as evidenced by the TPO and SEM analyses. The results suggest that the inherent basicity of the eggshell enhances catalyst resistance to coking while also contributing to the mitigation of eggshell waste. Full article

This study investigates the influence of isomorphous substitution of Aluminum by V, Zr, La, and Ni in Beta zeolite frameworks used as supports for Ni-based dry reforming of methane catalysts. The research focuses on how the nature of the incorporated metal affects catalytic activity and long-term stability. Catalysts were synthesized using both co-impregnation and sequential impregnation strategies. Physicochemical characterization—including gas adsorption, X-ray diffraction, transmission electron microscopy, and H₂ temperature-programmed reduction—revealed distinct structural roles for each metal. Results indicate that V primarily occupies T-vacancy sites within the dealuminated Beta framework, whereas Ni resides as charge-compensating extra-framework species or highly dispersed NiO clusters. Zr and La tend to form highly dispersed oxide species or occupy enlarged silanol nests. Notably, the addition of La₂O₃ was found to significantly enhance the long-term stability of the catalysts during the dry reforming of methane process. V-modified catalysts exhibited the highest activity but suffered from low stability; conversely, Zr incorporation offered the best overall performance, balancing high activity with enhanced stability, achieving 85% CO₂ and 75% CH₄ conversion, with no detectable carbon deposition after 98 h on stream. Full article

Steam methane reforming (SMR) powered by induction heating offers a promising route for low CO₂-emission hydrogen production, but predictive modelling remains challenging because the available experimental data are limited and heterogeneous. This study proposes a hybrid Bayesian neural network (H-BNN) to predict the mass of hydrogen (MoH) from literature-derived SMR data using operating variables including temperature, flow rate, power input, time-on-stream, and interval duration. Feedforward neural network (FNN) and classical Bayesian neural network (BNN) models were also developed as benchmarks, and all three architectures were evaluated with ReLU, Tanh, and GELU activation functions. To address data scarcity, only the training split was augmented at scales of $k=2$, 5, and 10, while the validation and test sets were kept unchanged. The H-BNN combines deterministic feature extraction with Bayesian uncertainty-aware prediction, enabling a balance between accuracy and uncertainty representation. Across the validation-selected models, test performance reached R² ∼ 0.9894 to 0.9969, with mean absolute errors of 0.0126 g to 0.0217 g. The strongest advantage appeared at k = 2, where the H-BNN outperformed the benchmark models. Overall, the proposed H-BNN is a promising framework for hydrogen prediction under data-scarce conditions, although its predictive intervals remain informative rather than fully calibrated. Full article

Dry reforming of methane (DRM) is a key reaction for syngas production and greenhouse gas utilisation, involving multiple interacting operating variables. In this work, an interpretable machine learning approach based on CatBoost regression coupled with SHapley Additive exPlanations (SHAP) is applied to a previously published DRM dataset to analyse the influence of reaction temperature, CH₄/CO₂ feed ratio, and Ni loading on CH₄ and CO₂ conversions and H₂ and CO yields. The objective of this study is methodological rather than experimental, focusing on the use of interpretable machine learning to extract variable importance hierarchies and conditional interaction effects from data-limited DRM studies. The analysis confirms that reaction temperature is the dominant controlling parameter, while feed ratio and Ni loading exhibit secondary, regime-dependent influences. No new catalytic mechanisms or experimental findings are proposed. The results illustrate how CatBoost–SHAP analysis can complement experimental DRM research by providing transparent, quantitative interpretation of published datasets under realistic data constraints. These findings are consistent with established DRM thermodynamic and kinetic behaviour, where temperature governs endothermic reforming reactions, while feed composition and metal loading influence carbon formation pathways and catalytic activity. Full article

The vision for global net-zero carbon emissions by 2050 has intensified the demand for sustainable and low-carbon energy resources. Within this context, recent discoveries of substantial methane (CH₄) reserves, coupled with the rapidly growing interest in hydrogen (H₂) as a clean energy carrier, have underscored the strategic importance of developing efficient and economically viable technologies for methane conversion. This current review investigates hydrogen production specifically from coalbed methane (CBM), a methane-rich unconventional gas resource embedded in coal seams. Both catalytic and non-catalytic pathways for hydrogen generation are reviewed, including steam methane reforming (SMR), partial oxidation (POX), autothermal reforming (ATR), direct methane decomposition (DMD), and plasma-assisted pyrolysis. Catalytic processes such as SMR remain the most mature and cost-effective, though they emit significant CO₂ unless integrated with carbon capture and storage (CCS) technologies. Non-catalytic routes, including thermal and plasma-based decomposition, offer CO₂-free hydrogen generation while producing solid carbon byproducts with potential commercial value. Hybrid coal–CBM systems are also discussed as integrated approaches for improving energy efficiency and resource utilization. The techno-economic assessment compares hydrogen yield, production cost, and environmental impact across methods, emphasizing the advantages of CBM as a high-purity methane source. Case studies, particularly from China, highlight the practical potential of CBM in supporting hydrogen infrastructure. The paper concludes that catalytic routes such as SMR are the most commercially mature and cost-effective but remain CO₂-intensive unless coupled with carbon capture and storage. Non-catalytic approaches, including direct methane decomposition and plasma pyrolysis, enable CO₂-free hydrogen generation while yielding solid carbon byproducts of potential commercial value, though they are less developed. Hybrid coal–CBM systems offer a balanced pathway to improve efficiency, resource utilization, and sustainability in future hydrogen production strategies. Full article

Ni coarsening is a primary degradation mechanism in Ni-based anodes, significantly contributing to performance decline and diminished lifespan of methane steam reforming solid oxide fuel cells (SOFCs) during long-term operation. In this study, a novel algorithm is introduced to reconstruct two-dimensional Ni-YSZ anode microstructures, complemented by the development of a multi-physics model that integrates phase-field modeling (PFM) with the Lattice Boltzmann Method (LBM). This coupled PFM-LBM framework is employed to investigate the effects of Ni agglomeration on microstructural evolution and methane-steam mass transport under diverse conditions. The results demonstrate that the initial Ni particle diameter exerts a significant influence on Ni agglomeration dynamics. Furthermore, the mass transport analysis reveals that the necking structures formed during Ni coarsening pose a substantial impediment to mass transfer efficiency. Finally, optimized structural parameters for Ni-YSZ are proposed to enhance anode performance in Ni-based electrodes. Full article

Given the large natural gas (NG) reserves of the Intermountain West (I-WEST) region in the USA, it can emerge as a leader in hydrogen (H₂) production. Currently, H₂ production via steam methane reforming (SMR) of NG releases carbon dioxide (CO₂) and the natural gas infrastructure has fugitive NG and H₂ losses during production, conversion and transportation. Integrated carbon capture and sequestration (CCS) is a promising approach for producing hydrogen and CO₂ from the SMR process for industrial uses including power, chemicals and fuels. However, the NG losses and regional water availability can be limiting factors for H₂ production. H₂ production assessments are often made at the global scale and neglect regional factors such as abundant gas and limited water in the I-WEST. We demonstrate that a regional SMR process unit sitting near NG wells offers opportunities to significantly reduce fugitive NG losses. We show that regional H₂ production by SMR has a lower emissions profile than widespread natural gas combustion in the I-WEST and reduces the H₂ production cost as well. Replacing the I-WEST transportation sector with H₂ fuel cell vehicles and using 100% H₂-powered electricity can provide substantial reductions in water consumption and fuel costs. This is better than blending H₂ with NG which is more expensive. The captured CO₂ can be effectively used for enhanced oil recovery in I-WEST. Finally, the potential of utilizing produced, brackish and treated impaired water sources is assessed to meet the water needs for H₂ production in the I-WEST. Full article