Greenhouse Gases: Science and Technology最新文献

The transportation of CO₂ from the capture site to the storage location is a crucial phase in carbon capture, utilisation and storage (CCUS) process. For offshore operations, ship transportation is considered a viable alternative, and this would entail operations at low temperatures (down to 223.15 K). A review of the literature revealed that there is limited experimental data on CO₂-rich systems at low temperatures, thus, the need to investigate the phase behaviour of CO₂-rich systems at these conditions. This study validated and compared the accuracies of Peng–Robinson (PR) equation of state (EoS) with three different mixing rules (the classical with original and adjusted binary interaction parameters, the Wong–Sandler, and the Orbey–Wong–Sandler mixing rules) against the multi-fluid helmholtz energy approximation (MFHEA - with original and adjusted binary-specific reducing parameters) EoS in the prediction of bubble points of CO₂-rich binary systems (CO₂-CH₄, CO₂–O₂, CO₂–Ar, and CO₂–N₂) for CCUS applications. The experimental studies used for the validation of the models were conducted at low temperatures (228.15–273.15 K with overall uncertainties of 0.14 K) and for five different CO₂ mole ratios (99.5, 99, 98.5, 98 and 95% with overall uncertainties of 0.032%) using the constant composition expansion method. The overall uncertainty of the pressure measurements was 0.03 MPa. From the study, it was observed that there was a significant effect of binary interaction parameters (BIP) adjustment on the performance of PR-EoS with classical mixing rule, especially for the CO₂–N₂ system. For all the systems, the predictions of PR-EoS with the classical mixing rules and the adjusted BIPs were the most accurate in terms of the average absolute deviations from the experimental data. The model also predicted the literature data well in comparison with the other models (with less than 5% deviations for all the data points). Further analysis also proved that the model dew point predictions were in reasonable agreement with the available literature data at the considered conditions. As a result, the model could be adopted to fill the existing knowledge gaps of the studied systems at conditions (143.15–223.15 K) where experimental studies were not feasible. © 2024 The Author(s). Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd.

The persistent increase in atmospheric carbon dioxide (CO₂) concentration poses a significant contemporary challenge. Contemporary chemistry is heavily focused on sustainable solutions, particularly the photo-/electrocatalytic reduction of CO₂ and its utilization for energy storage. Despite promising prospects, efficient chemical CO₂ conversion faces obstacles such as ineffective CO₂ uptake/activation and catalyst mass transport. Covalent organic frameworks (COFs) have emerged as potential catalysts due to their precise structural design, functionalizable chemical environments, and robust architectures. COF-based materials, especially those incorporating diverse active sites like single metal sites, metal nanoparticles, and metal oxides, hold promise for CO₂ conversion and energy storage. This review sheds light on CO₂ photoreduction/electroreduction and storage in Li-CO₂ batteries catalyzed by COF-based composites, focusing on recent advancements in integrating COFs with nanoparticles for CO₂ reduction. It discusses design principles, synthesis methods, and catalytic mechanisms driving the enhanced performance of COF-based nanocomposites across various applications, including electrochemical reduction, photocatalysis, and lithium CO₂ batteries. The review also addresses challenges and prospects of COF-based catalysts for efficient CO₂ utilization, aiming to steer the development of innovative COF-based nanocomposites, thus advancing sustainable energy technologies and environmental stewardship. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

The geological storage of carbon dioxide (CO₂) represents a promising strategy for mitigating climate change by securely sequestering CO₂ emissions. This review article aims to provide a comprehensive overview of the current state of research and development in the field of geological carbon dioxide (CO₂) sequestration. We systematically examined a wide range of recent literature, focusing on advancements in numerical simulations, experimental studies, risk assessments, and monitoring techniques related to CO₂ sequestration. Literature was selected based on relevance, recency, and contribution to the understanding of key challenges and solutions in CO₂ storage, with sources spanning peer-reviewed journals, conference proceedings, and significant technical reports. Our review highlights several key themes: the integration of machine learning and advanced numerical models in predicting CO₂ behavior in subsurface formations; innovative experimental approaches to understanding the physicochemical interactions between CO₂, brine, and geological substrates; and the development of robust risk assessment frameworks to address potential leakage and induced seismicity. We also explore recent advancements in monitoring technologies, emphasizing their critical role in ensuring the long-term integrity and effectiveness of CO₂ storage sites. Overall, this review synthesizes the latest findings and identifies gaps in current knowledge, providing a roadmap for future research directions. Our aim is to enhance the understanding of CO₂ sequestration processes, support the development of safer and more efficient storage methods, and contribute to the global effort in mitigating climate change through effective carbon management strategies. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Geological sequestration of carbon dioxide (CO₂) is an effective method to reduce greenhouse gases and an important technology for carbon neutralization. Among all geological sequestration sites, coal reservoirs are potentially effective and practicable. The Xiangzhong Depression of Hunan Province of China is selected as the research area, and the coal seam of Longtan Formation is the target reservoir in this paper. CO₂-enhanced coalbed methane (CO₂-ECBM) and CO₂ sequestration capacity are both simulated according to the laboratory experiments on reservoir parameters. During simulation, four production wells and one injection well were designed, and the simulation process can be divided into two stages: CO₂-ECBM and CO₂ geological storage. The CO₂-ECBM stage refers to CO₂ injection for increasing methane production, and the CO₂ geological storage stage aims to predict the CO₂ sequestration capacity. After that, sensitivity analyses of sequestration effect are carried out. During the simulation, when maintaining a constant pressure injection of CO₂ under the original conditions of 0.01 mD permeability, 9% porosity, and 1.47 MPa reservoir methane pressure, the total storage amount is only 0.14 × 10⁶ m³. However, the storage amount increases significantly to 6.62 × 10⁶ m³ if the permeability increases to 1.5 mD. Orthogonal simulation indicates that permeability has the greatest impact on CO₂ sequestration. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Carbon capture and storage technologies play crucial roles in mitigating atmospheric greenhouse gases (GHGs). Pipeline transportation is the primary method of CO₂ transportation, making pipeline safety a priority. In this study, Fluent software was used to create a model for annular edge leakage flanges, which significantly differs from the traditional pinhole leakage model. This study aims to examine the impact of CO₂ pipeline flow and pressure on the diffusion of gas leaking from the flange and to develop a precise correlation between the diffusion distance and substance concentration. The results indicate that an increase in flow and pressure intensifies the diffusion of the flange leakage. Specifically, for a leakage lasting 96 s at flow rates of 0.7 and 10 m³/h, the diffusion ranges for the 5% concentration alarm threshold are 0.47 and 2.86 m, respectively. Furthermore, at a speed of 10 m/s and a pressure of 0.4 MPa, the diffusion ranges for 5 and 2% alarms are similar, spanning from 0.33 to 0.35 m. This study provides theoretical support and technical improvements to ensure the safe operation of pipelines. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

There are many economic obstacles and complex engineering problems associated with CO₂ capture and storage in saline aquifers that need to be addressed. Overcoming such challenges requires precise knowledge on the fluid phase equilibria of CO_2-brine systems. Having accurate CO₂ solubility data over a wide range of temperature and pressure can greatly assist in resolving these obstacles by improving the performance and accuracy of the thermodynamic modeling and subsequent CCS engineering success.

CO₂ solubility in pure water and NaCl solutions has been widely studied in the literature, however, there is a lack of data on CO₂ solubility at lower temperatures (below 298 K). Furthermore, limited phase equilibria data are available for CO₂ solubility in CaCl₂, MgCl₂, and KCl solutions at elevated temperatures (i.e., T > 323.15 K).

In this work, the phase equilibria of CO₂ and brine systems are investigated experimentally and theoretically. In this study, solubilities of CO₂ in pure water and various concentrations of NaCl (10, 15, 20, and 22 wt%), KCl (10, 15, and 22 wt%), CaCl₂ (7.5, 10, 15.7, and 23.4 wt%), and MgCl₂ (6.7, 11, 18, and 29 wt%) aqueous solutions are reported. All CO₂ solubilities were measures at 323.15, 373.15, and 423.15 K and over various pressure ranges, while solubilities in 10 and 20 wt% NaCl aqueous solutions were also measured over the temperature range of 263 to 298 K and pressures up to the hydrate dissociation pressure of each system. Equation of state modelling using the PC-SAFT and the Cubic Plus Association equations of state, is performed in the theoretical part of the study to validate the measured solubility data. © 2024 The Author(s). Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd.

Carbon dioxide (CO₂) capture technologies are crucial for mitigating climate change, with post-combustion capture (PCC) using chemical absorption being a leading method. However, the energy-intensive solvent regeneration process presents a significant challenge, consuming up to 50% of the total energy in carbon sequestration. Despite extensive research on absorption, desorption studies remain limited. This study focuses on the desorption analysis through experimental runs in a pilot-scale tray column with varying flow rates, validating an Aspen Plus model. The research compares the impact of the number of stages, feed stage position, column pressure, and reflux ratio between equilibrium and rate-based models. The findings reveal enhanced desorption efficiency through optimized operational conditions, including reduced flow rates, additional equilibrium stages, feeding stage positioning closer to the condenser, elevated pressures, and lower reflux ratios. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

The extensive use of fossil energy leads to wanton emission of CO₂ and serious environmental problems. The exploration of high-performance catalysts plays a pivotal role in CO₂ resource utilization. In this paper, CuCe_yK catalysts are prepared by wet impregnation method using ordered mesoporous SiO₂ as support for the reverse water gas shift (RWGS) reaction. The physicochemical properties of the prepared catalysts are characterized by H₂-TPR, BET, XRD, Quasi in-situ XPS, H₂-TPD, and CO₂-TPD techniques. The results demonstrate thatthe Cu⁰ species can form synergistic effects with oxygen vacancies (O_v) to enhance the CuCe_yK catalytic performance. Additionally, the electronic effects between Ce and Cu not only enhances the adsorption and activation performances of the catalyst towards CO₂ and H₂ molecules, but also effectively suppresses the sintering of Cu⁰ species, thereby enhancing the stability of the corresponding catalyst. It is worth mentioning that the Ce content also directly affects the catalytic performances of the CuCe_yK catalyst. The CuCe₁₅K catalyst with a Ce content of 15% displays excellent CO₂ hydrogenation performances, and the CO₂ conversion and CO selectivity up to 41 % and 100 % at 420 °C, respectively. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

The CO₂-derived dimethyl carbonate (DMC) synthesis process becomes greatly attentive but suffers high energy consumption in DMC distillation process. In this work, the DMC-MeOH azeotropes separation process by pressure swing distillation and extractive distillation was compared, and key operating parameters, including the total number of trays and the feeding position of the mixture liquid, were optimized with the minimum total annual cost (TAC) as the objective function. On the basis of this optimization, economic evaluation of different distillation processes was conducted, and it was found that extractive distillation was more economical than pressure swing distillation. The application of the dividing-wall distillation process upgraded by extractive distillation can significantly reduce the minimum annual total cost by 37.4% and 10.7% compared to the original pressure swing distillation and extractive distillation process, respectively. The optimization of relevant heat exchange network based on pinch technology resulted in energy consumption reduction by 27.2% and 25.9% for its hot and cold utilities, respectively. Carbon life cycle assessment (LCA) on the DMC distillation process revealed over 50% of energy as well as carbon emissions from steam consumption, whose reduction can significantly minimize CO₂ emissions, energy consumption, and ultimate cost. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Natural gas hydrate (NGH), is a new green-sustainable energy source, and the process of recovering CH₄ from NGH by replacing CO₂ is regarded as an advantageous way to mine NGH. However, improving the replacement efficiency of CO₂-CH₄ hydrate is a critical problem in the CO₂ replacement mining process. The feasibility study of the replacement for CO₂-CH₄ hydrate, as well as the research status of the replacement characteristics for various situations, is examined in this review. Additionally, the microscopic mechanism of CO₂-CH₄ hydrate replacement in porous media is explored in detail. The basic molecular dynamic (MD) simulation method and primary influencing factors of CO₂-CH₄ hydrate replacement were summarized systematically. Finally, the shortcomings of MD simulation of CO₂-CH₄ hydrate replacement process in porous medium system and the future development direction are pointed out. The relevant results will offer helpful direction for future NGH exploitation. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.