Greenhouse Gases: Science and Technology最新文献

This research applied a concurrent activation and surface modification (CAM) process to synthesize palm kernel shell-derived activated carbon (PKSdAC) to obtain CO₂ affinity surface functionalization. The CAM process is a simplified activated carbon activation process that is cost-effective. The CAM process used in this study integrates sulphuric acid activation and barium chloride functionalization. The formation of barium sulphate is targeted to incorporate barium through a reduction process with carbon-containing material at elevated temperatures into PKSdAC to obtain basic metal surfaces functional group for chemical adsorption. The optimal temperature for CAM-PKSdAC CO₂ adsorption performance was at 40–60 °C, established through temperature-programmed desorption of CO₂ (TPD-CO₂) analysis. The CAM-PKSdAC adsorption performance was tested using a lab-scale adsorption system. The bed CO₂ content was determined using gas chromatography coupled with a thermal conductivity detector (GC-TCD) by manual syringe injection. CAM-PKSdAC exhibited a high CO₂ adsorption capacity of 0.89 mmol g⁻¹ from TPD-CO₂, and 1.91 mmol g⁻¹ from GC-TCD at 40 °C and 1 bar. It showed comparable CO₂ adsorption capacity to conventional surface modified-activated PKSdAC (1.96 mmol g⁻¹) while higher than commercial and modified ACs (1.14–1.60 mmol g⁻¹), but lower than potassium hydroxide modified ACs (1.81–2.10 mmol g⁻¹) at 40 °C and 1 bar. Barium promoted chemisorption of CO₂ as supplementary reaction, which increases adsorption capacity. The non-linear Dubinin Radushkevich model strongly correlates with the experimental adsorption data for CAM-PKSdAC adsorption, indicating the physisorption process via micropore filling on CAM-PKSdAC. CAM-PKSdAC showed moderate reusability with negligible variation in adsorption capacity after 10 adsorption–desorption cycles. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

CO₂ huff and puff is a widely used enhanced oil recovery method in many oil fields, but its implementations in shale fields is scarce. This paper reports trials of CO₂ huff and puff in a shale field in China. Laboratory studies revealed that CO₂ effectively reduced oil viscosity, increased oil volume, and improved oil recovery under miscible conditions. For the three wells that received CO₂ huff and puff treatments, one well showed satisfactory results, while the other two wells demonstrated poor economics. Discussions and recommendations are made based on field experiences. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Urban environments play a significant role in global carbon emissions and sequestration, necessitating a comprehensive understanding of their spatial distribution. This study presents a micro-scale spatial modeling framework to elucidate the complex interplay between CO₂ sources and sinks within urban settings. Utilizing advanced geospatial analysis, remote sensing data, and geographically weighted regression (GWR) modeling techniques, we provide a detailed characterization of emission patterns and identify the spatial distribution of carbon dioxide sequestration. Employing the bottom-up method and geographic information system techniques, we quantified carbon dioxide emissions in Isfahan City, Iran, attributing 81.68% to stationary combustion sources (residential, commercial, industrial, and power plant sectors) and 18.32% to mobile combustion sources (road-rail transportation, and non-road transportation [agricultural machinery]). To model carbon sequestration, we calculated tree biomass using allometric equations and estimated carbon sequestration per tree unit. Subsequently, we employed GWR to map the spatial distribution of carbon deposition across the city. The results revealed an annual carbon sequestration capacity of 7,704 tons, equivalent to storing 28,275 tons of CO₂. Our findings highlight the substantial contribution of urban areas to greenhouse gas emissions and the potential of urban green spaces to mitigate these emissions. The spatial modeling framework developed in this study provides a valuable tool for urban planners to optimize carbon management strategies and promote sustainable urban development. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

For shallow buried mines, the cracks generated due to the mining activities will connect the surface ground and the working face through the gob, which may result in the gas exchange between the surface and underground. In this study, we proposed the gob gas flow model and verified its applicability based on the measured data on site in our previous research and discussed the effect of delay time of pressure variation between working face and surface ground on the airflow direction according to the simulation. The results suggest that the delay time of pressure variation is the main factor affecting the pressure difference between surface and working face and airflow direction. Due to the characteristics of the surface pressure changes, the effect of delay time on airflow in gob is small in a short time, but this effect gradually increases with time. According to the airflow law in a cycle of pressure variation, the airflow direction in the gob is predictable when the delay time reaches a certain value, which can be interpreted clearly on the surface pressure variation diagram. This research may provide references for the measures taken against mine disasters caused by different airflow directions. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

CO₂ capture by absorption and stripping with aqueous amine is a well-understood and widely used technology. However, drawbacks still exist in the practical applications, such as high energy consumption and easy degradation of the absorbents during the desorption process. In this paper, a novel NE-1 absorbent was developed, and its suitable operating conditions were determined: concentration (45 wt.%), absorption temperature (40 °C), and desorption temperature (100 °C). The NE-1 absorbent exhibits a high CO₂ absorption capacity of 3.73 mol/kg, 1.33 times that of 30% monoethanolamine (MEA). After optimizing with carbamide as a corrosion inhibitor, 45% NE-1a1 may attain an effective CO₂ capacity of 2.5 mol/kg and over 70% desorption rate in five cycles, demonstrating excellent cycling stability performance. The research results have significant implications for developing an efficient and stable commercial carbon capture solvent and promoting the development of carbon reduction technologies. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

To effectively utilize ventilation air methane (VAM), it is proposed to pass it into the boiler of the coal-fired power plant for mixed combustion. However, the different types of thermal coal utilized present distinct characteristics when mixed with VAM. In this paper, lignite, bituminous coal, and anthracite are selected to study the CH₄ conversion rate, system ignition temperature, and NO emission characteristics of the VAM-pulverized coal coupled system on a fluidized bed experimental platform. The experimental results show that the ignition temperatures of VAM are 748, 736, and 732 °C when the CH₄ concentration is 0.25, 0.5, and 0.75%. After the addition of thermal coal, the ignition temperature decreased significantly. When the CH₄ concentration is 0.25%, the ignition temperature of the lignite-VAM system is the lowest, which is 450 °C. Anthracite has the strongest catalytic effect on CH₄ combustion. When the heating rate is 5 °C /min, the reaction rate of CH₄ is the fastest in the anthracite-VAM coupled system. Under laboratory conditions, the peak NO concentration in the coal-VAM coupled system was lignite > bituminous coal > anthracite at different CH₄ concentrations, and the CH₄ in VAM had a reducing action on the NO generated during mixed combustion, with a stronger reducing effect observed as the CH₄ concentration increased. The results of this study can lay the foundation for the industrial application of the mixed combustion of VAM and thermal coal, and be of great significance for solving the practical problems caused by the change of boiler coal types. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

When CO₂ saline aquifer storage is carried out, the heterogeneity of reservoir rock is an important factor affecting CO₂ transport, and the reservoir heterogeneity in numerical simulations is mainly manifested as the heterogeneity of the parameter field. Since the parameter distributions across the reservoir are not available with the existing probes, the stochastic finite element method is combined with a two-phase flow model to establish an unconditional random field of permeability, and computations are performed using the Monte Carlo method. The permeability, CO₂ maximum migration distance (M_d) and CO₂ sweep area (S_a) were analyzed for mutual correlation. The permeability correlation area affecting M_d and S_a was obtained, and the changes in the correlation area under the coefficient of variation (C_v) and correlation length (λ_x) of the permeability field in the different reservoirs were analyzed. The kriging superposition approach (KSA) was subsequently used to estimate both the M_d and S_a of the target reservoir by establishing conditional random fields based on the sampling parameters in regions with different correlations, resulting in errors of 0.66% for M_d and 0.96% for S_a in the high correlation region and 4.86% and 3.12% for M_d and S_a in the low correlation region, which suggested that the sampling results from the high correlation region were less biased in the estimation. Under limited sampling conditions, it is recommended that samples be collected in regions with high correlations to reduce the uncertainty of CO₂ transport analysis due to unknown heterogeneity. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

Calcium-looping dry reforming of methane (CaL-DRM) strategy mainly relies on novel Ni/CaO-based dual-functional materials, in which its microscopic mechanism remains to be further explored. In this work, molecular simulation of the adsorption and dissociation processes of CO₂ was performed on the surface of Ni/CaO dual-functional materials (DFMs) based on density functional theory (DFT). The analyses of electron density, partial density of states, and formation energy suggest that the Ni/CaO model has higher stability and activity than the CaO model. The analyses of the evolution of chemical bonds, adsorption energy, density of states, and charge population after the adsorption of CO₂ on the CaO surface and Ni/CaO shows that the modification with Ni made the adsorption of CO₂ on Ni/CaO more stable. The transient calculations indicate that the path with the lowest activation energy is the H-mediated dissociation path of chemisorption carboxyl COOH* as an intermediate, which is the possible dissociation path of CO₂ on the surface of Ni/CaO DFMs. The dissociation of COOH* into CO* and OH* is the rate-controlling step of the reaction. The DFT results demonstrate that the doping of Ni during the preparation of CaO materials can realize and enhance the CaL-DRM processes, which provide a theoretical basis for the optimum preparation of Ni/CaO-based DFMs. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

This study underscores the critical role of carbon capture and storage (CCS) in mitigating greenhouse gas emissions and addresses the potential for CCS projects in saline aquifers in Brazil, one of the world's largest carbon emitters. The country's ability to adopt CCS is significantly influenced by the availability of data related to regional CO₂ storage potential and identifying suitable geological framework for CO₂ injection. While oil and gas reservoirs have traditionally been prioritized, saline aquifers represent an underexplored and potentially higher capacity storage option. Despite Brazil's 31 sedimentary basins, the data quantity and availability for these contexts remain insufficient for advanced studies on the geological storage of CO₂ considering saline aquifers. An initial study was conducted indicating five potential targets in the Paraná and Potiguar Basins for geological storage in saline aquifers based on available public data, mainly drilling data. This review reveals substantial challenges related to the evaluation of Brazil's CO₂ storage capacity, such as the lack of modern seismic studies, the absence of a regulatory framework for CO₂ storage, and insufficient investment in new well exploration. These challenges necessitate multistakeholder collaboration, the development of a supportive regulatory environment, and investment in extensive site characterization campaigns. Addressing these barriers is fundamental to realizing the country's CCS potential and contributing to global decarbonization efforts. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.

This study examines the potential of Midcontinent Rift rocks to facilitate long-term CO₂ sequestration by providing the necessary Ca and Mg for carbonate mineralization. Surface samples were collected from the Oronto and Bayfield-Jacobsville Groups around Lake Superior and used for petrography and X-ray diffraction to determine their mineral composition. Also, X-ray fluorescence was also used to assess their bulk chemical composition. The samples were then exposed to CO₂ and deionized water in Teflon-lined vessels at 90°C, and the resulting leachate fluids were analyzed for the cation released during the testing. SEM microscopy was used to examine the samples for potential mineralization of carbonate minerals. The Oronto Group sediments consist primarily of feldspathic to feldspathic lithic arenites with a chlorite-dominated matrix, and the primary porosity is blocked by calcite and hematite cement. The Bayfield–Jacobsville sequences are porous quartz arenites to feldspathic quartz arenites that do not contain significant accumulation of Ca-, Mg-, and Fe-bearing minerals. The leachate fluids obtained from Oronto Group samples exhibit a maximum Ca release rate (5.2 × 10⁻⁴ mole/cm².day), indicating rapid calcite cement dissolution and increased porosity and permeability. SEM/EDS microanalysis revealed areas where pore-filling calcite was preferentially dissolved. Longer-term rock-water reactions resulted in induced carbonate mineralization, as evidenced by calcite crystals observed in a sample reacted for 102 days. © 2024 Society of Chemical Industry and John Wiley & Sons, Ltd.