CO2 sequestration

The mineral carbonation, a process of converting CO 2 into stable minerals (mineralization), has been studied extensively to capture and store CO 2. However, most of the mineral carbonation studies have been largely investigated at lab scale. Preliminary and pilot scale studies for accelerated mineral carbonation (AMC) were conducted at one of the largest coal-fired power plants (2120 MW) in the USA by reacting flue gas with fly ash particles in a fluidized bed reactor. In the preliminary experiments, flue gas CO 2 and SO 2 concentrations decreased from 13.0 to 9.6% and from 107.8 to 15.1 ppmv, respectively during the first 2 min. of reaction. The flue gas treatment increased mercury (Hg) concentration in fly ash (0.1 to 0.22 mg/kg) suggesting that fly ash particles also mineralized flue gas Hg. From these results, we designed and developed pilot scale process skid consisting-a moisture reducing drum (MRD) (0.9 m ĭ × 1.8 m), a heater/humidifier (0.9 m ĭ × 1.8 m), and a fluidized bed reactor (FBR) (0.9-1.2 m ĭ × 3.7 m) to capture and mineralize flue gas CO 2. Flue gas was withdrawn from the stack and was fed to the MRD at about 0.094 m 3 /s. The MRD and the heater/humidifier pretreat flue gas before it enters the FBR. The MRD captures droplets of water entrained in the flue gas to protect the blower placed between the MRD and the heater/humidifier. The heater/humidifier enables control of flue gas moisture and temperature. Approximately 100-300 kg of fresh fly ash was collected from the electrostatic precipitator through ash hopper and placed in the fluidized-bed reactor. The fly ash particles were fluidized by flow of flue gas through a distributor plate in the FBR. The pilot scale studies were conducted at a controlled pressure (115.1 kPa) by controlling the flue gas moisture content. The flue gas was continuously monitored to measure flue gas CO 2 , SO 2 and NO x concentrations by an industrial grade gas analyzer, while the fresh and spent fly ashes were analyzed for calcium carbonate (CaCO 3), sulfur (S), and mercury (Hg) content. The pilot scale study results suggest that an appreciable amount of flue gas CO 2 and significant amounts of SO 2 and Hg can be directly captured (without separation) and mineralized by the fly ash particles.

One promising avenue for reducing CO2 emissions is through the use of carbon capture, utilization, and storage (CCU|S) technologies, which necessitate capital-intensive capture stage implementation. This study proposes implementing a cluster-based approach to its organization, which enables cost reduction through economies of scale achieved by integrating stationary emission sources into a single network with a shared infrastructure. To evaluate the economic effects of this organizational framework, an optimization model was developed utilizing algorithms (SLSQP, Nelder-Mead method, etc.) that account for: spatial distribution of emission sources, emission volumes, CO2 partial pressure in flue gas streams. The model was tested using data from 533 Russian industrial enterprises in the energy, cement, and ferrous metallurgy sectors, with aggregate annual emissions exceeding 0.5 billion tons of CO2. For a preliminary analysis of the spatial and technological data of these enterprises, a methodical approach was developed (based on the DBSCAN algorithm), which made it possible to identify 94 geographical areas of their increased concentration. Information about industrial enterprises forming six largest regions was utilized for modeling 90 configurations of carbon capture and transportation projects with shared infrastructure. The results demonstrated that the cluster-based approach reduced the cost of capture in the considered examples by 6.44-13.51 %, depending on the maximum radius of a cluster. An additional reduction in transportation costs due to the use of joint gas pipelines averaged 37.26 and 57.01 % for a 200 and 500 km distances, respectively. Under the same distances and with a maximum cluster radius of no less than 20 km, the average reduction in aggregate costs across the evaluated configurations amounted to 17.81 %. The results obtained confirm the importance of organizational solutions for scaling up CCU|S projects and establishing novel crosssectoral technological chains. The proposed methodologies can be effectively employed to identify promising areas for the implementation of CCU|S pilot projects and to design highly efficient local networks for CO2 capture and transportation with shared infrastructure.

Strategic target commodity, Production trend, Hanging roof, Technical and financial support Due to poor agricultural production in Malawi, mining is the promising economic driver with coal as the strategic target commodity. The mining sector is in its infancy stage compared to other sub-Saharan countries. The paper discusses coal production trends and contributions to the overall economy of Malawi. Following analysis of problems in coal mines, a research investigating the effect of humidity on the strength properties of coal bearing rocks in Malawi is introduced. The aim is to improve the status of safety and risk management issues in underground coal mines. Method involves in-situ measurement of humidity, collection of rock samples and conduction of a multistage triaxial test for strength properties. The expected results are humidity variations in the sublevels, a weakening effect in the existing rupture surfaces in hanging roof and collapse. A conclusion can be drawn that technical and financial support brought to coal mines correlates with productivity.

Effective CO2 sequestration (SC) in rehabilitated tropical forest depends heavily on species performance and competition dynamics. This study evaluates SC potential and interspecific competition of native lowland forest tree species in Bedegung Biodiversity Park, South Sumatra, Indonesia―an area rehabilitated since 2014 through collaboration between the South Sumatra Provincial Environmental Service, National Gas Company, and IPB University. Despite the rehabilitation efforts, early planting did not consider the planting distances (Lij), impacting tree density (Dx) and individual competition index (CIi)―factors directly influencing SC. From 2020 to 2023, monitoring of tree diameter, height, and Lij data collected within a 60 × 20 m permanent plot revealed a decline in Dx from 900 ind ha–1 in 2020 to 725 ind ha–1 in 2023, primarily due increased competition. The site’s average SC reached 69.91 tCO2 ha–1 y–1, lower than mature tropical forests due to stand age. Among all species, Bayur (Pterospermum javanicum) exhibited superior SC performance, sequestering 10.02 ± 6.98 tCO2 ind–1 y–1―well above the mean―and showing increased resilience, indicated by 1/CIi from 0.62 to 4.38. These results highlight Bayur’s exceptional role in SC under competitive pressure. For enhanced SC outcomes, management interventions such as thinning, fertilization, remove the weeds, and removing dead trees are urgently recommended. Prioritizing species with high SC potential and adaptive performance, like Bayur, is essential for optimizing carbon gains in forest rehabilitation programs.

This study examines the impact of hysteresis effects on oil recovery during CO₂-Water Alternating Gas (WAG) injection, a widely applied enhanced oil recovery (EOR) technique with significant implications for carbon capture, utilization, and storage (CCUS). Hysteresis, which describes the cyclic variations in relative permeability during alternating imbibition and drainage cycles, plays a critical role in accurately modeling multiphase flow in porous media. However, its effects on CO₂-WAG efficiency remain underexplored in many reservoir simulations. To address this gap, a sector model was developed to simulate CO₂-WAG injection, incorporating hysteresis effects to assess their influence on oil recovery and CO₂ trapping. The results reveal that considering hysteresis leads to a 0.9% increase in the oil recovery factor, demonstrating its role in enhancing residual oil mobilization. Moreover, hysteresis significantly contributes to greater CO₂ retention within the reservoir, improving long-term sequestration potential and reducing gas production rates. The findings underscore the necessity of incorporating hysteresis in CO₂-WAG simulations to improve the accuracy of EOR performance predictions and optimize CCUS strategies. Neglecting hysteresis can lead to an underestimation of both oil recovery and CO₂ trapping potential, impacting reservoir management decisions. This study highlights the importance of precise relative permeability modeling in CO₂-WAG injection to ensure reliable performance forecasts and efficient field implementation.

Optimizing oil recovery from mature reservoirs remains a key challenge in the petroleum industry. This study evaluates the efficiency of CO 2-WAG injection compared to continuous CO 2 and water flooding using a sector model of the X Oil Field. A compositional reservoir simulator was employed to analyze oil recovery under water-wet and mixed-wet conditions, incorporating three-phase relative permeability and wettability effects. The results show that continuous CO 2 flooding yields the highest oil recovery, with water-wet systems outperforming mixed-wet reservoirs. CO 2-WAG injection provides a balanced approach, enhancing recovery while enabling CO 2 sequestration, but remains less effective than continuous CO 2 flooding. Water flooding, though the least efficient in terms of oil recovery, demonstrates long-term production stability. The gas-oil ratio (GOR) is notably higher in CO 2-WAG, indicating gas breakthrough challenges. These findings emphasize the significant role of wettability in enhanced oil recovery (EOR) and suggest that continuous CO 2 flooding is the most effective technique for maximizing production in heterogeneous reservoirs. This study contributes valuable insights for optimizing injection strategies, improving hydrocarbon recovery, and supporting sustainable reservoir management.

One of the major challenges facing the energy sectors in practically all developing countries worldwide is clean cooking. In Sierra Leone, only 1% of the population has access to clean cooking, making it one of the worst among the developing countries with clean cooking problems. Many people are switching to improved biomass cookstoves (IBCs), but the unprecedented production of charcoal-based IBCs and varied designs, particularly ceramic linings, make it dif icult for users to choose the right size. The study surveyed major IBC production and sales centres in Sierra Leone's western regions between 2021 and 2023, examining temperature pro iles of the metal stove (MS) and wonder stove (WS). The data showed that an average of 3352 MS and 1833 WS were produced and sold between 2021 to 2023. A water boiling test was adopted for IBCs testing and Testo 310 flue gas analyzer was used to track the temperature pro iles of the chosen IBCs. The indings suggest that WS could be able to generate and retain heat more quickly and sustainably than MS. Additionally, the recorded temperatures and timings of all IBCs were also subjected to a systematic correlational analysis. A simulation of the various temperatures and times was also plotted to ascertain the temperature-time graph differences. These results are relevant and could aid in the analysis of IBC emissions and thermal ef iciency. Thus, the results of the study could be utilized to offer policy recommendations for IBC production and sales centres in Sierra Leone and other developing countries.

This work investigates CO 2 dissolution and migration in a homogeneous aquifer through a vertical well at different water injection rate and ascertains the amount of CO 2 sequestered into the subsurface. Numerical simulation was done with Computer Modelling Group (CMG) simulator and builder used to write the dataset and validated with GEM.WINPROP was used to predict the thermodynamics properties using the Peng-Robinson 1978 EOS and sensitivity studies carried out with three different water injection rate (25, 50 and 75m 3 /day) and compared to a base condition of no water injection. Result indicates that after 196 years, mobile CO 2 gas cap formation was at the top of the formation with a saturation of 0.99 and length of 558.4753m, 75604384 moles of CO 2 dissolved and 18547034 moles of CO 2 trapped without water injection above the CO 2 injector. For 25m 3 /day of water injected, there was a 54 % decrease in the length of gas cap saturation, 17% decrease in the CO 2 dissolved and 28% decrease in the CO 2 trapped when compared with the base case model without water injection. 50m 3 /day scenario of water injected had 93% decrease in the length of gas cap saturation, 39% decrease in the CO 2 dissolved, and 63% decrease in the CO 2 trapped. Also, 75m 3 /day of water injected above the CO 2 injector shows no zone of mobile supercritical CO 2 formed at the top of the structure with 50% decrease in the CO 2 dissolved and 64% decrease in the CO 2 trapped .Result reveals that most of the injected CO 2 were completely dissolved in water and less trapped at different rate of water injection.

Aqueous phase salinity has a major effect on the quantity of carbon
dioxide trapped by solubility trapping and may also affect mineral
dissolution and precipitation. While carbon dioxide storage through
structural, residual, dissolution and partly mineral trapping modes have
a wide investigation, the mineral trapping potential and its influencing
factors have not been explored. In this work, the effects of variable aqueous
phase salinity on carbon dioxide mineralization were investigated.
Numerical simulations were done using a geochemical simulator and
three-dimensional homogeneous aquifer model of dimensions 30×30×10
(9000 grid blocks) and block width of 70 m was built. The generated grid
was populated with petrophysical, grid and rock properties .Four models
with similar rock and fluid characteristics were simulated for pure water
and different salinity of 0.01 wt (10000 ppm), 0.015 wt (15000 ppm) and
0.02 wt (20000 ppm) respectively. Result shows a decrease in the moles of
carbon dioxide solubilized with an increase in brine salinity level. Increase in
brine salinity decreases the moles of carbon dioxide converted to aqueous
ions and dissolution in resident brine. There was an increase in the rate of
Kaolinite precipitation, Calcite precipitation and a decrease in the rate of
Anorthite dissolution with increase in duration of carbon dioxide injection.
The mineral mole changes for Anorthite increases with level of salinity and
decreases with duration of carbon dioxide injection. Moreover, Calcite
and Kaolinite mineral moles changes decreases with level of salinity and
with duration of carbon dioxide injection. Calcite and Kaolinite decreases
as aqueous phase salinity increases. This work has shown that formation
minerals has different reactivity to salinity concentration which decides
carbon dioxide trapping and storage capacity

This work investigates the performance of two numerical solubility models for CO2 dissolution and trapping. Two geological models were developed for Li-Nghiêm's and Harvey's solubility models. Visualization of the CO2 plume's spatial distribution was conducted for 10-year injection period and plume migration monitored for 190 years under natural gradients. Both models successfully simulate the lateral migration of injected CO2 during the injection phase, followed by upward migration due to its lower density relative to formation water. The onset of the solubility trapping mechanism results in a greater concentration of CO2 at the bottom of the aquifer. There was structural trapping during the injection phase, followed by a slight increase and subsequent decline during the post-injection phase due to solubility trapping. Both models predict substantial CO2 solubility in water during injection, but Li-Nghiêm's model have higher solubility than Harvey's model.CO2 solubility trapping mechanisms increased the concentration of CO2 in the brine in the postinjection phase. it is evident that the choice of solubility model impact predictions of CO2 solubility and migration and should be evaluated for any CO2 storage Project. Hence, the selection should consider site-specific geological and fluid conditions.

Adequate geological storage of carbondioxide in saline aquifers is a function of several factors that requires understanding and examination. Previous works have argue that solubility of carbondioxide in brine decreases as the salinity of the brine increases, but it is unclear in the literature the impact of salinity on carbondioxide (CO 2) trapping during sequestration. This work adopt a simulation based approach to determine CO 2 dissolution and trapping at different salinities. A dataset was written and validated with CMG's greenhouse gases simulator and the thermodynamics properties calculation carried out with Peng-Robinson equation of state. Four sensitivity analyses was conducted with brines of no salinity (pure water), salinity of 100000ppm, 200000ppm and 300000ppm and model outputs compared for CO 2 sequestration. The result shows that CO 2 solubilised in water with zero level salinity, and a lower gas cap size was formed at the top of the structure. Later, gas cap size increases as the salinity level increases at the top of the structure. Also, the moles soluble in water decreases as the salinity level increases with the least moles for zero water salinity. Alternatively to the moles solubilised, the number of moles of CO 2 trapped increases with the salinity level. CO 2 storage in deep saline aquifers is the best storage techniques but its injection into aquifer of high salinity reduced its solubility.

In this work, a compositional simulator (CMG-GEM) was employed to model the flow behavior of two components (CO2 and H2O) in the context of carbondioxide(CO2) sequestration within a saline aquifer with infinite extent. A fluid model was built with the Peng Robinson EOS in a WINPROP and a base case model of limited extent aquifer with a range of volume modifiers assigned to boundary grid blocks as infinite was simulated. The amount of CO2 trapped, its maximum migration distance, and CO2 saturation distribution were analyzed for each of the aquifer volume considered.Pore volume modifiers of 10 3 , 10 4 , and 10 5 were sensitized. Results shows that saline aquifer of infinite extents complements the structural trapping of supercritical CO2 by limiting the ultimate migration distance of CO2 gravity currents. The quantity of trapped CO2 exhibited a rise as the pore volume of the boundary blocks increased from 10 0 (base case) to 10 3 , 10 4 , and 10 5 .For the base case,volume multiplier of 10 3 , 10 4 , and 10 5 , the amount of CO2 trapped were 59502925moles,88120568moles ,96803000moles, and 101404776moles showing an increase in moles as the volume increases. The base case model shows a CO2 lateral migration distance of 525ft along the aquifer length while pore volume of 10 3 , 10 4 , and 10 5 gives a lateral migration distance of 884ft, 985ft and 985ft respectively. The results indicate that the infinite volume effects have caused a dispersed distribution of CO2 trapped, contrasting with a concentrated distribution of mobile CO2 in a limited aquifer.

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Enhanced gas recovery methods such as foamed CO 2 are recommended for depleted gas reservoirs. Viscoelastic surfactant (VES) is a form of a surfactant used for forming CO 2 foam. In this study, the impact of VES on CH 4 and CO 2 retention and adsorption in calcite rock samples was studied. Crushed samples of Indiana limestone rocks of average particle size (125-250 μm) were used in the static adsorption experiments. To study the effect of VES on CH 4 and CO 2 adsorption, 50% of the crushed samples were conditioned in a solution of NaCl of 0.1 vol % surfactant. X-ray diffraction shows that the rock samples are 99.99% calcite and traces of quartz. The gas adsorption experiments were performed at different temperatures; namely; 50, 100, and 150 °C and at a pressure of 45 bar. At 50 °C, the plain calcite samples adsorbed more CH 4 and CO 2 compared to that treated with VES. However, at 100 and 150 °C, the plain sample adsorbed much less CH 4 and CO 2 than the treated sample. This means that at higher temperatures (100 and 150 °C) VES enhanced the adsorption of both CO 2 and CH 4 on the rock surface. Thermodynamic investigations showed that the process of gas adsorption in the plain samples was exothermic with ΔH ads of -13.5 and -16.7 kJ/mol for CO 2 and CH 4 , respectively, and at 50 °C the adsorption was spontaneous with ΔG ads of -0.425 for CH 4 and -2.599 for CO 2 . In contrast, at higher temperatures (100 and 150 °C), the adsorption of CO 2 and CH 4 on surfactant treated sample was spontaneous and endothermic with corresponding ΔH ads of 36.2 and 60.1 kJ/mol and ΔG ads of -4.701 and -0.581 for CO 2 and CH 4 , respectively. The adsorption of CO 2 was three times that of CH 4 because of the high affinity of calcite to CO 2 . Because of the multilayer adsorption on both samples, Freundlich isotherm was found to be the best model that fits the experimental data of calcite with both CO 2 and CH 4 at different temperatures. Dynamic adsorption experiments were carried out using gas coreflooding system with the same calcite cores used in the static adsorption experiments. The results of this study showed that carbonate rock samples conditioned in the surfactant solution have great adsorption potential for CO 2 and are excellent candidates for CO 2 sequestration. However, surfactant promoted high CH 4 adsorption at 100 and 150 °C, and this will reduce the natural gas recovery. In contrast, using viscoelastic surfactant at low-temperature reservoirs (50 °C) reduced CH 4 adsorption by blocking the active adsorption sites in the carbonate rock samples, and this will increase the gas recovery.

Sandstone oil reservoirs consist of different clay minerals such as kaolinite, illite, and chlorite. These clay minerals highly affect the formation damage during enhanced oil recovery (EOR) and well stimulation operations in these reservoirs. No attention was paid to investigate the effect of these clay minerals on the formation damage during different reservoir processes. In addition, no solution was introduced to mitigate the effect of clay minerals on the formation damage in sandstone reservoirs. In this study, the effect of clay mineral contents and type on the formation damage was studied in detail by injecting water and HCl as damaging fluids. Bandera grey, Berea, and Bandera brown sandstone rocks with various clay mineral contents were studied. XRD was used to characterize the sandstone rocks to determine the clay type and content in each rock. Two core plugs from each rock were selected for HCl and water injection. Core flooding experiments were performed to measure the initial and final permeability. In the core flooding experiments, fluids were injected into the cores at 25 °C and at a backpressure of 1000 psi. SEM was carried out before and after flooding for the tested rocks to locate the change in the clay distribution inside the rocks. The NMR analysis of core samples was done before and after flooding with the damaging fluid to quantify the formation damage and to find the possible damaging mechanism. NMR was used to locate the damage inside the rock due to the migration of clay minerals. Based on the core flooding, SEM, and NMR analysis, the maximum damage by the fresh water took place in Berea sandstone core due to fine migration and clay swelling. The illite clay mineral and chlorite can cause the formation damage on HCl injection. Illite can break down and migrates in the cores during the acid injection. In sandstone acidizing, chlorite clay mineral caused iron hydroxide precipitation inside the cores during treatment with mud acid. NMR showed that clay minerals plugged the pore throats of the rocks and reduced the rock permeability during the injection of fresh water.

During cooling and permanence outside, the solidified slag involved in the refinement process taking place in the steelmaking ladles suffers attack by environmental components such as water vapor and gaseous CO 2 (weathering). The reactions involved are hydration and carbonation, and as a consequence, the pulverization of the slag occurs. In the present paper, the results of a study of the degradation of a typical steelmaking ladle slag over a period of eighteen weeks (126 days) are reported. To monitor the slag evolution, several experimental techniques were used, some of them rarely employed in this context, after dividing the initial slag batch in four granulometric fractions between > 7.2 mm and < 1.4 mm: granulometry by sieving, X-ray fluorescence (XRF), X-ray diffraction (XRD), and thermogravimetric (TGA) and thermal differential (DTA) analyses. As was already known, the main elements responsible for the slag degradation are free lime, followed by calcium aluminates and magnesia. It was also found that anhydrous and hydrated calcium aluminates are concentrated in the finest granulometric fractions and contribute to the generation of fines mainly during the final stage of hydration. The high percentage of particles smaller than 1.4 mm, with cementitious properties provided mainly by the presence of anhydrous calcium aluminates, are promising characteristics for alternative reusing of the studied ladle slag. Furthermore, slag weathering mechanisms are critical for understanding other steelmaking processes in which the slag is deeply involved, such as the protective role of the remaining thin slag layer against decarburation of ladle or converter working lining refractory bricks.

The volumetric changes in the coal matrix (Coal Shrinkage) and permeability properties under various gas environment conditions were studied in the laboratory. The shrinkage and permeability of coal were examined with respect to changing gas type and confining pressures. The shrinkage tests were carried out in high -pressure bombs while the permeability study was conducted in a specially constructed high pressure chamber. Methane (CH4), carbon dioxide(CO2), nitrogen (N 2) and a 50% mixture of CO2/CH4 gas were used in the study. The tests showed that under different pressure levels gas type affected permeability and shrinkage characteristics of coal.

The storage of CO 2 in unused coal mines is a viable option for reducing emissions of CO 2 , whose accumulation in the atmosphere is one of the main contributors to global warming. Understanding CO 2 behaviour and storage capacity of the coal is an important first step before injecting the CO 2 . We used experimental equipment to extract coal from a mine and to obtain a representative sample of both its internal structure (in terms of cleats, macropores, mesopores and micropores) and occluded gases. Storage capacity was studied in terms of variations in gas pressure. The adsorption isotherm was experimentally obtained applying a procedure specifically designed to avoid altering the coal. An unused coal bed was selected to determine how much CO 2 it could adsorb and to study the feasibility of storing power plant CO 2 in this kind of mine.

Terigi Ciccone held a lengthy discussion in June 2025 with AI Bot Grok 3 (Grok) to investigate ongoing questions concerning the causes and extent of climate change, as presented by the United Nations Intergovernmental Panel on Climate Change (UN IPCC). The discussion centered on six significant points of disagreement. A summary of these six items was provided by Grok and is presented in Annex B with final comments added by the authors. However, the subject of this article is to discuss only the sixth issue, the Residual CO2 Imbalance in the atmosphere. The goal is to quantify and assess the potential impact that human-produced CO2 may have on weather, climate, and the Earth's biosphere. Specifically, the analysis presented in this article focuses solely on refuting the assumption on the extent and impact of the alleged accumulation of human-made carbon dioxide (CO2) in the atmosphere.

A CO 2 monitoring pilot was initiated at the Penn West Energy Trust CO 2 EOR operations within the Cardium formation of the Pembina Field. The Penn West Pembina-Cardium CO 2 EOR Monitoring research program focused on well integrity, local/ regional geology and hydrology, extensive monitoring of CO 2 and short and long predictive modeling. The geochemical modelling program of the Penn West Monitoring Project quantified the chemical reactions that occur between the gas -oil-water -rock within the reservoir prior to, during, and following CO 2 injection. An equilibrium speciation geochemical model was used to examine the field produced water compositions . M any of the produced waters are undersaturated with respect to calcite. This is most easily explained when mixtures of waters o f quite different chemical compositions are produced from a single producing well. This observation has important implications for the interpretation of produced water compositions and demonstrates that flow within the reservoir must be understood to fully interpret the chemistry signatures. A reaction mass transfer model was used to evaluate the chemical processes in the reservoir (short and long term) and to evaluate the thermodyn amic data base. It established that the dominant reaction controlling the short term water composition was ion exchange reactions, coupled with calcite dissolution and CO 2 transfer from the oil phase. It was also used as a predictive tool to estimate the m ineralogical reactions which will ultimately be responsible for the long term trapping of the injected CO 2. GEM -GHG was used to calculate the chemical processes occurring during the various phases of hydrocarbon recovery, including the predicted evolution of produced water compositions, and th e results compared to field measurements. Discrepancies between the modeled and the measured field data can be used to refine the model, improving our understanding of chemical processes in the reservoir. The geochemic al models allow an assessment of the amount of CO 2 trapping in each of the major units in the reservoir. There are large uncertainties in the absolute value of the amounts, but they allow a direct comparison between trapping mechanisms and a direct comparison between the trapping in each reservoir unit . This work represents a first study to demonstrate the potential of using geochemical sampling and measurements and integrating them with reservoir models for secondary and tertiary oil recovery.

八耳俊文：マンハッタン計画と水俣病―戦後20年日本地球化学史― ・・・・・・・・・・ 3
矢島道子：日本の古生物学の歩みをふりかえる ・・・・・・・・・・・・・・・・・・・ 11
Maddalena Napolitani: Earth science's visual culture in 19th century Europe ・・・・・・・・・・・ 14
原 郁夫：四国中央部三波川帯構造地質学の現在―論争の終焉 ・・・・・・・・・・・・・ 24
会田信行：寺田寅彦の日本海拡大説と松山基範 ・・・・・・・・・・・・・・・・・・・ 32
山田俊弘：ニコラウス・ステノ『サメの頭部の解剖』(1667)の翻訳と研究(その6) ・・・・ 36

Enhanced Oil Recovery (EOR) techniques are vital for maximizing oil production while addressing sustainability and geomechanical considerations. CO₂ injection is particularly effective in heavy oil reservoirs, reducing viscosity, inducing oil swelling, and enhancing mobility. Integrating Carbon Capture and Storage (CCS) with CO₂ injection boosts oil recovery and facilitates carbon sequestration, contributing to climate change mitigation efforts. However, pressure buildup during injection poses risks such as caprock failure or fault reactivation, highlighting the need for rigorous monitoring and geomechanical modelling to maintain reservoir integrity. Continuous CO₂ flooding achieves high recovery rates, but demands significant energy and CO₂ volumes, making it resource-intensive. The Water Alternating Gas (WAG) process is a major step forward. By alternating between water and CO₂ injections, it reduces overall CO₂ consumption, enhances recovery, and optimizes sweep profiles. This approach addresses economic and environmental challenges head-on. Water injection is less effective in recovery optimisation, but it helps maintain reservoir pressure and prepares reservoirs for future carbon storage. Integrating these techniques with thorough geomechanical evaluations establishes a robust framework for enhancing recovery, maintaining reservoir stability, and supporting sustainable energy production.

India's urban infrastructure faces a critical gap in pedestrian and non-motorized transport facilities. While Concrete Paver Blocks (CPBs) are commonly used for this purpose, their production has significant environmental impacts. This investigation examines geopolymer concrete as a viable, sustainable substitute for conventional paver blocks. Geopolymer Paver Blocks (GPBs) are synthesized utilizing fly ash, Ground Granulated Blast furnace Slag (GGBS), and an alkaline activating agent. Reclaimed Asphalt Pavement (RAP) aggregates were integrated to augment sustainability further as a substitute for traditional aggregates. The study evaluated the mechanical, durability, and abrasion properties of the developed GPBs, comparing them to traditional CPBs. Incorporating Reclaimed Asphalt Pavement (RAP) aggregates contributed to a decrease in the workability of freshly mixed concrete. Empirical investigations demonstrated that integrating RAP aggregates led to a deterioration in the mechanical strength characteristics of Geopolymer Binders (GPBs); however, they still adhered to the requirements as per IS 15658: 2021. Notably, GPBs exhibited enhanced durability attributes compared to traditional concrete. Moreover, the research found that the abrasion loss of GPBs was less than that of CPBs, although an increase in RAP content was associated with heightened abrasion loss. The insights gained from this study reinforce the potential of incorporating RAP into GPBs as a significant step toward sustainable infrastructure development, thereby reducing the carbon footprint associated with conventional cement-based materials.

Understanding the effects of geochemistry and mineral composition on geomechanical characteristics is critical in the design and optimization of hydraulic fracturing necessary for shale gas reservoir production. Fundamental information is still missing in experimental methodologies used to evaluate the influence of geochemical parameters and mineral composition on geomechanical properties of shale gas reserves. This paper provided an in-depth assessment of the various experimental methodologies and their applications in the relationship between the geomechanical and geochemical features of the Longmaxi shale formation. The limits of these methodologies were recognized, comparative analyses on experimental data and geomechanical parameters were performed, and recommendations for improved geomechanical assessments were provided. This review will contribute to fundamental understanding and will guide future experimentally-based geochemical and geomechanical investigations on shale gas reserves.

This study investigates the optimization of self-compacting mortar (SCM) properties incorporating cement kiln dust (CKD) and glass powder (GP) as partial replacements for ordinary Portland cement (OPC). Slump, flow, compressive strength, flexural strength, and porosity were studied by central composite design (CDD) to investigate the impact of CKD and GP (0-25% each). Material variability was understood using statistical models developed from SCM property prediction (R 2 = 0.92-0.95). In the case of CKD, the workability generally increased, whereas the workability decreased in the case of GP, especially at the higher levels. Both materials reduced compressive and flexural strengths, with CKD being the most significant contributor. Higher CKD and GP contents increased porosity, proportional to strength losses. The optimum formulation of 7.22% CKD and 5.26% GP, which showed the highest desirability of 0.97, was identified as the optimum formulation with a balance between fresh and hardened properties through the desirability approach. The optimized mixture resulted in a slump (22.98 cm), flow time (11.55 secs), compressive strength (54.33 MPa), flexural strength (8.4 MPa), and porosity (14.49%). The optimized formulation demonstrates significant environmental and economic benefits, reducing CO₂ emissions by 68.15 kgCO₂/t (12.39%) and decreasing material costs by $5/ton (12.4%) compared to the control SCM. This study demonstrates the possibility of integrating CKD and GP in SCM, offering a sustainable alternative to traditional cement-based mortars without significant performance loss.

A combination of experiments and extensive modelling, including a chemical kinetics analysis, was performed for a CO2/H2O plasma in a dielectric barrier discharge. This provides a better understanding of the mechanisms related to the reactivity of the plasma and of the conversions into value-added products, such as methanol.

A combination of experiments and extensive modelling, including a chemical kinetics analysis, was performed for a CO$_2$/H$_2$O plasma in a dielectric barrier discharge. This provides a better understanding of the mechanisms related to the reactivity of the plasma and of the conversions into value-added products, such as methanol.

The provincial authority set the value of 6,000 μS/cm of electrical conductivity as the aquifer protection level. A hydrogeological assessment of the Barrancas oilfield was carried out to determine the depth of protection. To map the Cenozoic formations and adjust the conceptual hydrogeological model, open-well electrical logging and cutting descriptions of oil and gas wells were used. To estimate the conductivity of the formation water, the Archie equation was employed first, using the cutting description as a support of petrophysics. The lithological complexity initially suggested that Archie's formula was not the most appropriate to determine the EC of the aquifers, so the alternative of SP log combined with the salinity of the drilling mud was applied. After the analysis, depth contour line maps were created for 6,000 μS/cm.
To verify the results, groundwater samples were taken from the aquifers present in the Mogotes, Serie Amarilla and La Pilona formation. After calibrating the petrophysical estimates with the laboratory results, it was verified that both indirect methodologies are appropriate for the quantification of the EC, highlighting that the Archie equation is the one that fits best, despite the first hypothesis.

Carbon capture and storage (CCS) is proved to be effective measure for reducing CO 2 emissions. whilst the world still highly depends on the use of fossil fuel energy, this method is necessary for reaching the world's 1.5 °C goal. Saline aquifers among all possible underground formations are most common targeted ones for CO 2 storage due to their frequent presence, and large storage capacity. However, this storage option suffers from sufficient well injectivity to inject large volumes of CO 2 at acceptable rates through a minimum number of wells. The injectivity impairment/reinforcement happens through mineral dissolution, fine particle movement, salt precipitation and hydrate formation (known so far). Each of these mechanisms will be more dominant in injectivity alteration at different distance from the injection point depending on reservoir pressure and temperature, formation water salinity, rock mineralogy, and flow rate of CO 2 injection as well as its dryness. In this study we have chosen a commercial software Eclipse 300 together with an open-source code to investigate the impact of formation characteristics, CO 2-Brine-Rock interaction, pressure, temperature as well as injection rate on injectivity alteration. The goal for this work is to provide a workflow which can help predicting injectivity alteration using the existing tools. Simulation results show that permeability is affected severely by salt precipitation during CO 2 injection. Combined static and dynamic parameter study demonstrate that the injection rate plays a crucial role in size and expansion of CO 2 plume as well as growth rate of dry out zone length, amount of salt precipitation and length of equilibrium region. The higher the injection rate, the quicker activation of the capillary and gravity force which leads to drag more brine to near well-bore resulting in higher volume fraction of salt precipitation. However, low injection rate could result in smaller CO 2 plume, shorter dry out zone and longer equilibrium region in term of distance from injection point. Thus, optimizing the injection rate regarding reservoir parameters i.e., temperature, pressure and in-situ salinity, will lead to higher storage capacity as well as well performance and maintenance.

This document quantitatively analyzes the interaction of greenhouse gases (GHGs), specifically 2 0 8 2 carbon dioxide (CO) and water vapor, with infrared radiation emitted by the Earth's surface. Using fundamental physical principles, the rates of infrared energy absorption by these gases and their 2 0 8 2 contribution to the global energy balance were calculated. The results reveal that both CO and water vapor absorb an extremely small fraction of total infrared radiation: approximately

Vertical profile of CO2 production (Ps) and transport, as well as their isotopic discrimination (13CO2/12CO2) should be considered to improve the soil CO2 efflux (Fs) mechanistic understanding and especially its short-term temporal variations. In this context, we propose a new methodology able to measure continuously and simultaneously Fs, the vertical soil CO2 concentration ([CO2]) profile and their respective isotopic signature (�Fs and �CO2) [1]. The Ps of the different soil layers and their isotopic signature (�Ps) can then be determined from these measurements by an approach considering diffusion as the only gas transport. A field campaign was conducted with this device at the Scots Pine Hartheim forest (Germany). The results [2] show (i) a Ps dependence on local temperature specific for each layer, (ii) an enrichment of �Ps with soil drought, (iii) Fs and [CO2] large intra-day fluctuations non explained by the soil temperature and moisture. These fluctuations can be generated ...

Increased construction activities, leads in deficiency of conventional building materials. To overcome the problem now a day’s different techniques have been used to benefit industrial by-products which are available in large quantities. Manufacturing of artificial lightweight aggregates by pelletization method is one important technique to substitute natural aggregates in concrete. The present study examines the manufacturing of twenty one (21) different types of artificial aggregates from industrial by-products with the addition of glass fibers at a fixed 17min pelletization time, along with 28% of water content. Manufactured fresh pellets were air-dried for 24 hours and later hardening of aggregates through cold-bonding technique (Water Curing) at room temperature for 28 days and tested with different aggregate properties. The study results that the highest individual aggregate compressive strength of 48.1MPa was observed for 12mm F21 aggregate. The lowest impact strength of 13.3...

In today's business environment, where the insourcing of software development and cross-organizational code sharing are becoming increasingly critical, the concept of "InnerSource"-applying open-source development methodologies within a corporate setting-has garnered significant attention. The purpose of this study is to elucidate both the process of introducing InnerSource and the manner in which it evolves within companies. First, a comparative analysis of Japanese and global enterprises highlights differences in the state of software sharing, perceptions of its importance, and barriers to implementation. In particular, delayed insourcing and organizational silos-commonly observed in Japanese firms-are extracted and empirically verified as factors that hinder early InnerSource adoption. Next, this study demonstrates that InnerSource adoption involves multi-layered, topological evolution beyond conventional staged models of program evolution. The research proposes three theoretical frameworks: InnerSource Topologies, which conceptualizes collaborative structures and categorizes internal collaboration levels; the Multi-layered Incentive Model, which combines monetary and non-monetary rewards at individual and project levels; and the InnerSource Circumplex Model, which helps organizations define InnerSource forms based on their specific needs. By mapping InnerSource evolution as a circumplex rather than simple staged progression, leaders can better adjust their focus during implementation. These frameworks help refine the previously ambiguous concept of InnerSource from the perspectives of sharing scope and community growth. These findings reaffirm that successful InnerSource adoption requires the parallel pursuit of top-down program structuring and bottom-up voluntary collaboration. They also contribute to fostering a sustainable innovation culture and enhancing software-sharing practices within enterprises. Furthermore, the newly proposed frameworks, particularly the Circumplex Model, offer versatile guidelines for organizations of varying cultural backgrounds and scales, enabling them to flexibly redefine and introduce InnerSource. This research is thus expected to advance corporate software sharing and spur innovation in diverse industrial contexts.

Methane is activated at ambient conditions in a dielectric barrier discharge (DBD) plasma reactor packed with Pd/γ-alumina catalyst containing different loadings of Pd (0.5, 1, 5 wt%). Results indicate that the presence of Pd on γ-alumina substantially abates the formation of deposits, leads to a notable increase in the production of alkanes and olefins and additionally improves the energy efficiency compared to those obtained for the non-packed reactor and the bare γ-alumina packed reactor. A low amount of Pd (0.5 and 1 wt%) favors achieving a higher production of olefins (mainly C2H4 and C3H6) and a higher yield of H2. Increasing Pd loading to 5 wt% promotes the interaction of H2 and olefins, which consequently intensifies the successive hydrogenation of unsaturated compounds, thus incurring a higher production of alkanes (mainly C2H6 and C3H8). The substantial abatement of the deposits is ascribed to the role of Palladium in moderating the strength of the electric and shifting th...

Spectral conversion of light and production of more useful photons for the photosynthesis process increases the growth of photosynthetic microorganisms including microalgae. Many researches have been done in this field, but due to the geometry of the cultivation system, the location of the light source, the failure to return photons into the system, etc., an accurate assessment of the effect of the spectral conversion on the growth of microalgae has not been provided. In this research, the effect of spectral conversion on the growth rate of microalgae Chlorella sp. has been evaluated using a more accurate method than other studies. For this purpose, a white LED lamp was placed inside a double-walled transparent tube as a light source, and the space between the walls was filled with Rhodamine 6G solution as a spectral converter. The whole above system was placed in the middle of a culture flask, in order to distribute the light homogeneously. In addition, the outer surface of the culture flask was covered with aluminum foil in order to minimize the photons leaving the flask and returning them inside. The results showed that in this method, the biomass productivity of Chlorella sp. microalgae increased up to 220%. The amount of this increase in more light intensity has been significantly less. In addition, the amount of light photons used in biomass production also increased up to 4 times.

本発表では、まず認識論における基礎付け主義への批判であるブートストラップ問題の概要について述べたうえで、問題の成立条件について論じる。そのうえでマイケル  バーグマンによるブートストラップ問題に対する応答を検討する。バーグマンは、ブートストラップ的推論に含まれる認識的循環が許容される状況と許容されない状況に分類することで、基礎付け主義を擁護する。だが、バーグマンによる擁護は、結局のところ基礎付け主義に親和的な直観に依存していることを示す。そのうえで、ブートストラップ問題において二つの直観が衝突していることを論じ、その衝突の中間をとる代替案の可能性について簡単に述べる。

Energy efficiency is crucial for the sustainable operation of industrial and urban sectors. However, practicing engineers seldom have access to open-source tools that can readily evaluate and compare scenarios. In this work, a novel web-based tool called ROSMOSE is developed and proposed for analyzing the energy efficiency of industrial and urban systems and comparing potential process integration options. This optimization framework computes and graphically represents the minimum energy requirements, the pinch temperatures, and the Grand and integrated Carnot composite curves of process systems. Results are used to design utility systems that meet energy demands, while minimizing a specified objective function, such as total cost or environmental impacts. The Quarto environment, in which ROSMOSE is built upon, allows the integration of various open-source software and tools, such as database handling software, process modeling suites, and optimization solvers, along with interactive data visualization and reporting tools. This paper discusses the application of ROSMOSE for the energy integration and total site optimization of a dairy process consisting of milk treatment, and cream and cheese production to demonstrate the tool features. Other integration options, such as the use of heat pumps or solar panels, and the production of soft drinks or biogas as value-added byproducts, are also proposed and evaluated. As a result, from 75 % to 90 % in fuel savings and up to 80 % CO 2 emissions reduction in the dairy plant are identified by optimizing the utility systems integration. Moreover, complete electrification via heat pumps eliminates any fossil fuel needs and it results in 85 % energy savings and up to 96 % CO 2 emissions reduction. The activation of renewable electricity sources, such as solar power, made plausible this fully electrified scenario. Finally, optimized waste management strategies led to in-house fuel production and net export of biogas to the grid, but they also reduce cheese yield by prioritizing the biogas production from whey upgrading process. In this way, decision-makers have access to a clear performance comparison for a list of system configurations to draw informed trade-offs. A similar approach could be adopted to aid decision-making for the design and operation of other industrial and urban energy systems using ROSMOSE.

A negative carbon emission scenario via pyrolysis of three different food waste blends was investigated. A tube reactor was utilized for pyrolysis runs at temperatures of 650 • C, 725 • C, and 900 • C, while the carbon inventory was prepared. The blend of rice and french fries resulted in the highest char yield, being 212 g/kg at 650 • C pyrolysis temperature. In this case, each kg of food waste can correspond to 536 g of captured or removed CO 2 from the air. The blend of roast pork and breaded chicken showed significantly less carbon removal potential of 348 g CO2 /kg sample measured at 650 • C pyrolysis temperature, compared to rice and French fries. A higher pyrolysis temperature resulted in lower char yields, but, on the other side, it resulted in a higher carbon content of char. Additionally, higher pyrolysis temperature resulted in lower carbon capture potential within the temperature range utilized in this study. The heating value of dry pyrolysis gas was between 12.0-16.6 MJ/Nm 3 and 10.3-12.3 MJ/Nm 3 during the heat-up and constant temperature period, respectively. Based on the results, negative CO 2 emission can be reached via pyrolysis of food waste with the benefit of capturing carbon in solid form, and therefore, this method can be considered a promising and alternative method to treat food waste.

Nitrogen oxides released by car traffic affect the health of numerous people located in urban areas. This study shows that concrete doped with activated charcoal can absorb NO2 and could be used to limit the pollution peaks in confined spaces. Samples of cement hydrates and hardened cement paste were exposed to air flows containing hundreds of ppbv of NO2 and the absorption rate was measured. It is shown that pieces of concrete can continue to absorb a significant fraction of the NO2 gas passing over their surfaces for long periods of time due to a reaction with the alkaline cement hydrates. Moreover, the presence of a small fraction of activated charcoal in the cement paste significantly improves and prolongs the adsorption of NO2, especially in the presence of typical atmospheric CO2 levels; and this additive is effective over a the whole range of typical exposure temperatures for concrete. Pilot-scale tests using prototype garages built with activated charcoal concrete confirm th...

Leading to achieve net zero emissions, performing carbon capture and storage (CCS) on a large scale is becoming more necessary, especially for developing countries, which are highly affected by the continuously increasing release of carbon dioxide (CO2). It has also been observed that developing countries does not participate much in the release of CO2 in the atmosphere but are highly influenced by global warming because of geological location. Therefore, addressing challenges of climate changes and its impacts requires high-capacity storage in safe and reliable locations. Depleted oil and gas reservoirs offer a valuable option to store CO2 due to their adequate porosity and permeability. In this research, an effort has been made to provide a simulation study and comprehensive analysis of CO2 storage through reservoir simulation in subsurface oil reservoir. In contrast to prior works, this research article introduces a simulation approach to assess the feasibility of CO2 storage in an oil reservoir. Storage in an oil reservoir was modeled using a commercial compositional simulator. CO2 behavior during injection is examined using gas injection profiles throughout the injection duration and injection rate. Results of the study demonstrate that reservoir pressure changes equally in all layers and grid blocks making the evaluated reservoir suitable for CO2 storage. Bottom hole pressure (BHP) behavior during injection shows the feasibility of CO2 storage. The analysis revealed that continuous injection of CO2 at a rate of 3500 Mscf/day over a period of 10 years led to a successful storage scenario, with the reservoir reaching its space limit and the injection rate dropping to zero. These results suggest the viability and effectiveness of CO2 storage as a means of mitigating greenhouse gas (GHG) emissions.

Cement kiln dust (CKD), a by-product of cement clinker manufacturing, embodies considerable amounts of alkali and alkaline-earth compounds, presenting a potential route for CO2 sequestration. The study aims to clarify
the potential of CKD for CO2 capture and storage. Two experimental  schemes were used: (1) direct carbonation of dry CKD and (2) carbonation of hydrated CKD. Analytical techniques such as XRF, XRD, FT-IR, SEM and DSC/TG
were employed to characterize the mineralogical and morphological transformations of hydratation and carbonation of CKD. The findings reveal that even in the dry state, the CKD has the ability to react with carbon dioxide at normal pressure to form stable mineral phases such as calcite and vaterite. The study confirms that CKD, both in raw and hydrated forms, holds promise for CO2 capture and storage applications.