CO2 In Aqueous Phase Research Articles

Enhanced hydrogen sequestration through hydrogen foam generation with SDS Co-Injection in subsurface formations

Inherent obstacles of hydrogen injection encompass preferential channeling through larger pathways, hampering microscopic sweep efficiency within porous media. This work pioneers hydrogen foam generation via co-injection with aqueous sodium dodecyl sulfate (SDS) to enhance subsurface hydrogen trapping capacity. SDS addition substantially reduces hydrogen-water interfacial tension and enhances viscoelasticity. In contrast to robust hydrogen foam stability, CO2 foams display compromised integrity, stemming from surfactant aggregation and ensuing infiltration channels that permit aqueous phase CO2 dissolution. Hydrogen foams conversely sustain uniform surfactant films, forestalling hydrogen ingress into water. Synergetic microfluidic and pore-scale simulations visualise mechanisms underlying intensified hydrogen capture and mobility reduction attributed to deformation and flow resistance when traversing constricted pores. Introducing the amphiphilic SDS surfactant considerably promotes hydrogen adsorption through its hydrophobic tail. Core flooding experiments quantify over 2 times hydrogen storage ratio amplification with SDS relative to sole hydrogen injection. The framework contributes pragmatic strategies to harness high-efficiency hydrogen foam for scalable clean energy storage.

Photocatalytic reduction of CO2 in aqueous phase using amino-functionalized MOFs loaded with hydroxy-functionalized graphene quantum dots

Hydroxy-functionalized graphene quantum dots (OH-GQDs) were loaded onto NH2-MIL-101(Fe) to prepare a novel binary OH-GQDs/NH2-MIL-101(Fe) (OGNM) composite with a simple solvothermal method. The obtained catalysts were characterized by SEM, TEM, XRD, FI-IR, XPS and BET to analyze the morphology, elemental composition, and specific surface area of the composite material. Notably, the morphology and micro-structures of OGMM-3 exhibited that OH-GQDs evenly dispersed on the surface of hexagonal micropillar NH2-MIL-101(Fe). The nanocomposite catalysts were tested in a photocatalytic CO2 reduction system using water and acetonitrile as solvents, without additional sacrificial agents. OGNM-3 composite possessed the optimum photoreduction CO2 activity, with a CO yield of 128.68 μmol·g−1 within 10 h, which was 5.3 times higher than that of pure NH2-MIL-101(Fe). After three cycles of reuse, the catalyst still maintained catalytic activity without any significant changes in its crystal structure, morphology or functional groups. In summary, this study proposed a design for synthesizing binary OGNM photocatalysts, offering useful insights for cost-effectively address CO2 emissions in greenhouse gas emissions.

Chemical‐Mechanical Impacts of CO2 Intrusion Into Heterogeneous Caprock

AbstractThe potential economic benefits offered by CO2‐enhanced oil recovery (CO2‐EOR) and storage, including increasing oil production and mitigating CO2 storage cost, make it an attractive approach for reducing CO2 emissions. Sealing formation (caprock) integrity is considered a key risk factor, because of the potential for leaked CO2 or brine migrating into shallow groundwater formations. The primary purpose of this research is to evaluate general caprock sealing efficiency and integrity under typical CO2‐EOR conditions, by assessing the influence of hydrological and mineralogical heterogeneity, possible mineralogical alteration, and potential failure of rock due to hydrological and mineralogical changes. An active CO2‐EOR project at the Farnsworth Unit (FWU) in the northern Texas is selected as a case study. A coupled reactive‐transport‐geomechanics model of the FWU caprock (the Morrow Shale and the Thirteen Fingers Limestone) was developed based on site‐specific geological data. Key results suggest that the Thirteen Fingers Limestone is an effective caprock. After 5,000 years, effectively no supercritical CO2 penetrates this formation, and the penetration depth of dissolved CO2 in aqueous phase does not exceed 10 m. Because of mineral precipitation in the Morrow Shale, maximum porosity decreases ~25% at the reservoir‐caprock interface, suggesting increased caprock sealing efficiency. Geomechanical response of the caprock due to CO2 intrusion and mineral alteration suggests low risk of induced fractures. This study provides a refined evaluation of long‐term caprock integrity as a function of coupled hydrological, chemical, and geomechanical processes and is intended to support future assessment of feasibility and safety of geologic CO2 sequestration.

CO2 Hydrogenation to Formate by Palladium Nanoparticles Supported on N-Incorporated Periodic Mesoporous Organosilica

Development of a heterogeneous catalyst capable of selective transformation of CO2 to valuable products still remains a challenge. In this article, we account for the surfactant-directed synthesis of a new framework-incorporated nitrogen-containing periodic mesoporous organosilica nanosphere (NPMO). A thoroughly characterized N-incorporated hybrid PMO was utilized as a platform for stabilizing well-dispersed and easily accessible Pd nanoparticles (Pd-NPMO) without using any stabilizing agents or expensive dendrimers. Further, this bifunctional hybrid catalyst has been demonstrated to heterogeneously catalyze aqueous phase CO2 hydrogenation (CO2/H2 ratio 1:3) for the direct synthesis of formate under 4 MPa pressure and at 100 °C. To validate the superior performance of the Pd-NPMO catalyst, we compared the activity with Pd-SBA-15 catalysts, and the results showed a 10-fold increase in turnover frequency of 108 h–1 using Pd on NPMO which envisaged the crucial role of nitrogen sites in this catalyst to boost the CO2 valorization to formate.

Swelling behavior of heavy crude oil in carbonated water at the presence of Na2SO4 and Mg2SO4

Carbonated water (CW) and low salinity (LS) injection processes are among the most widely investigated method during the past decade due to their unique advantages. Although the results revealed rather efficiency of these two methods, it is reported that using the combination of these two methods can introduce new insight about the smart and newly developed enhance oil recovery processes. Respect to these facts, the current work is aimed to investigate the swelling behavior of heavy crude oil in carbonated water at the presence of Na2SO4 and Mg2SO4. In this way, one of the main effective mechanisms through the carbonated water injection which is swelling factor is examined in the presence of two different salts, namely, Na2SO4 and Mg2SO4, under different pressures (500–4000 psi) and temperatures (30–80 °C). The results obtained in this investigation are compared with the previously reported results regarding the carbonated brine (CB) solutions consisted of different salts such as KCl, NaCl, CaCl2, and MgCl2 with the same concentration of 15,000 ppm. The results not only reveal the possible mechanism behind the swelling factor variation, but also reveal that crude oil and ion type as well as temperature besides the solubility of CO2 in aqueous phase can introduce tremendous influence on the mobility of CO2 molecules and their partitioning from aqueous phase towards the oil phase. Also, the obtained results reveal that the presence of divalent ions can directly affect the crossover pressure toward lower values.

Effect of brine type and pH on the interfacial tension behavior of carbonated brine/crude oil

Although carbon dioxide (CO2) injection is an efficient tool to enhance the oil recovery, deposition of asphaltenes, extensive gas consumption, rapid breakthrough of CO2, etc. faced it with serious challenges. As a solution for these disadvantages, the injection of dissolved CO2 in water instead of direct CO2 injection is proposed during the past decade. Respect to this fact, in the current investigation, the dynamic interfacial tension (IFT) values of carbonated brines/acidic crude oil are measured to examine synergetic or antagonistic effect of CO2 and aqueous solution consisted of sulfate anions i.e. 15000 ppm of MgSO4 and Na2SO4 in a wide range of temperatures (30–80 °C) and pressures (500–4000 psi). The sulfate anion based salts are considered in the current investigation wince it has been well established that sulfate anion can introduce more profound effects on the dynamic IFT variation. Considering the obtained results and comparing them with the previously published studies, one can conclude that the variation of IFT of crude oil/carbonated brine as a function of temperature and pressure is completely different compared to IFT of crude oil/brine due to lower pH resulted regarding the dissolution of CO2 in aqueous phase, dominant effect of CO2 at higher pressures and more diffusivity of CO2 at higher temperatures.

Reactive transport modeling of mineral carbonation in unaltered and altered basalts during CO2 sequestration

Basalt formation is a new promising CO2 sink for providing secure long-term carbon storage via trapped CO2 in mineral phases. When water enters into the crystal structures of the divalent cation-bearing unaltered basalt, the rock is altered and serpentinized. The serpentinization of the unaltered basalt occurs widely around the world. To evaluate the mineral carbonation efficiency of unaltered and altered basalt over a longer time frame, a predictive modeling frame is established in TOUGHREACT based on data from core-scale static batch experiments and the field-scale Carbfix project. Results indicate that unaltered basalt has higher carbonation efficiency than altered basalt both in the carbonation rate and extent due to serpentine kinetic limitations for aqueous phase CO2 injection, and the carbonates mineralization extent and rate increase with the content of olivine minerals in basalt. Furthermore, under these conditions, the longer CO2 migration distance from the injection site enhances the chance for mineral carbonation in the serpentinized basalt. In addition, rapid aqueous phase CO2 injection may limit mineral carbonation and cause porosity reduction near wellbores in the basaltic reservoir, and this effect is more pronounced in case of unaltered basalt than in the altered basalt. Compared to the injection rate, the impact of reservoir conductivity is found to be significant on mineral carbonation in both the unaltered basalt and altered basalt; higher conductivity is more advantageous for CO2 mineralization under certain circumstances. In combination, the injectivity rate should be carefully assessed at sites based on the reservoir conductivity and whether the basalt is altered or unaltered and the extent of alteration.

Swelling behavior of heavy crude oil during injection of carbonated brine containing chloride anion

Carbonated brine (CB) injection, known as one of the effective enhanced oil recovery processes, is highly dependent on the reservoir conditions (i.e. temperature and pressure) as well as the type of dissolved salt in aqueous solution. This study is aimed to investigate the influential parameters on the swelling of crude oil as the most important mechanism during CB injection. The swelling of crude oil in the presence of different CB solutions consisted of different salts such as KCl, NaCl, CaCl2 and MgCl2 with constant concentration of 15,000 ppm is studied using a high-pressure, high-temperature visual cell which measures the volume of drop using image processing software based on Young-Laplace method. Also, the Δ Bond number of crude oil is examined to more reliably find out the mechanisms. According to the results, it can be concluded that the solubility of CO2 in aqueous phase is not the only parameter affecting the swelling behavior, and that the crude oil and ion type as well as temperature have remarkable effect on the mobility of CO2 molecules and their partitioning from aqueous phase toward oil phase.

Delaminated CoAl‐Layered Double Hydroxide@TiO2 Heterojunction Nanocomposites for Photocatalytic Reduction of CO2

AbstractPhotocatalytic reduction offers an attractive route for CO2 utilization as a chemical feedstock for solar fuels production but remains challenging due to the poor efficiency, instability, and/or toxicity of current catalyst systems. Delaminated CoAl‐layered double hydroxide nanosheets (LDH‐DS) combined with TiO2 nanotubes (NTs) or nanoparticles (NPs) are promising nanocomposite photocatalysts for CO2 reduction. Heterojunction formation between visible light absorbing delaminated CoAl nanosheets and UV light absorbing TiO2 nanotubes greatly enhances interfacial contact between both high aspect ratio components relative to their bulk counterparts. The resulting synergic interaction confers a significant improvement in photoinduced charge carrier separation, and concomitant aqueous phase CO2 photocatalytic reduction, in the absence of a sacrificial hole acceptor. CO productivity for a 3 wt% LDH‐DS@TiO2‐NT nanocomposite of 4.57 µmol gcat‐1 h‐1 exhibits a tenfold and fivefold increase over that obtained for individual TiO2 NT and delaminated CoAl‐LDH components respectively and is double that obtained for 3 wt% bulk‐LDH@TiO2‐NT and 3 wt% LDH‐DS@TiO2‐NP catalysts. Synthesis of delaminated LDH and metal oxide nanocomposites represents a cost‐effective strategy for aqueous phase CO2 reduction.

Probabilistic analysis of CO2 storage mechanisms in a CO2-EOR field using polynomial chaos expansion

Oil fields are already used for storing carbon via CO2-enhanced-oil-recovery (CO2-EOR). Such storage is an outcome of CO2-EOR, albeit not necessarily by design. A next step would be intentional storage via post-EOR CO2 injection. Trapping mechanisms in such post-EOR operations would include the same mechanisms as in CO2-EOR, including and especially hydrostratigraphic trapping and oil/aqueous dissolution. Forecasting the nature of trapping and the ultimate CO2 distribution in a reservoir is hindered by uncertainty in reservoir properties. The purpose of this study is to develop and apply reduced order models (ROMs) integrated with Monte Carlo simulations to quantify oil solubility trapping (oil phase), aqueous solubility trapping (aqueous phase), and hydrodynamic trapping (CO2 in supercritical phase). The case study site for this analysis is the SACROC unit in western Texas. A Polynomial Chaos Expansion (PCE) technique was used to develop the ROMs. The sources of uncertainty considered are porosity and permeability. Model results of interest include dissolved mass of CO2 in oil phase, mass of CO2 in supercritical phase, dissolved mass of CO2 in aqueous phase, and oil saturation in the rock formation. Reduced order models are developed for all cells in five selected layers of the model, which are adjacent to injection wells, at three specific time points of interest, including the end of a simulated CO2-EOR period, the end of a post-EOR continuous CO2 injection period, and the end of a post-injection monitoring period. Results of regression fit and validation analysis yield high R2 values and low NRMSE values, indicating that the ROMs derived from PCE are capable of meaningful predictions (compared to conventional reservoir models) and effectively represent relationships between model parameters (inputs) and model results (outputs) of interest. Results of 1000 Monte Carlo simulations indicate a dominantly upward transport of CO2 during injection, driven by buoyancy, and a dominantly downward transport of dissolved CO2 after injection stops, caused by increases in both oil and brine density. At the end of the 100-year simulation of the SACROC case study, the results forecast that the storage layers of interest store between 54% and 61% of total trapped CO2 in the entire domain in the oil phase, between 21% and 24% in the supercritical phase, and between 11% and 15% in the aqueous phase. These layers are forecasted to store between 89% and 98% of total trapped CO2 in the field by the end of simulation.

A linear fluorescence-quenching response in an amidine-functionalised solid-state sensor for gas-phase and aqueous CO2 detection.

An amidine-functionalised metal-organic framework (MOF) was shown to be an effective chemosensor in the presence of gaseous and aqueous phase CO2 by virtue of a quenched fluorescence response. This work demonstrates how multifunctional MOFs with high selectivity for CO2 may be exploited to develop CO2 chemosensors.

Fracture-based modeling of complex flow and CO2 migration in three-dimensional fractured rocks

The fractures and pores in rock formations are the fundamental units for flow and contaminant-transport simulations. Modeling and meshing a fractured rock system are challenging tasks because mesh generations of fractured networks typically involve complex procedures in conducting topological transformations, and the modeling of such a complex mesh system is computationally expensive. The objective of this study was to develop a three-dimensional (3D) discrete fracture network (DFN) model and an associated unstructured mesh generation (UMG) model to simulate flow and transport for fractured rock systems. This study employed coupled multicomponent, multiphase fluids in a 3D porous and fractured media simulator (the TOUGH2/ECO2N model) to analyze flow and CO2 migration in fracture formations. The developed DFN and UMG models were first tested using a single and horizontal fracture plate to evaluate the results based on various mesh types. The models were then implemented in multiple DFN realizations to assess the behavior of equivalent permeability of a rock block influenced by various fracture intensities. By exploiting the well-developed TOUGH2/ECO2N model, the developed DFN and UMG models were applied to problems of flow and CO2 migration in fracture formations. The simulation results showed that the developed models can capture behaviors of the flow and transport in fractured formations. Different types of mesh led to slight variations in pressure distribution near injection wells. However, such pressure variations can be reduced with refined mesh around the injection wells. The results based on 52 DFN realizations indicated that the value of equivalent permeability for the simulated rock block shows three to four orders of magnitudes lower than the value of the specified fracture permeability. The injection of supercritical CO2 exhibited a rapid migration of gaseous and aqueous phase CO2 along connected fractures.

ジオリアクター：地熱を利用したCO2 固定化研究

This paper is a short review of a new technology, “Georeactor”, which sequesters and fixes CO2 into geothermal fields by carbonate mineralization. In countries such as Japan, where have many active volcanic areas, one possibility is to sequester CO2 into hydrothermal regions. The chemical reaction rates between CO2-saturated water and rocks are usually faster than those at room temperature. For example, the following reaction (alteration reaction forming kaolinite from plagioclase): CaAl2Si2O8 (plagioclase)+H++HCO3-+H2O=CaCO3 (calcite)+Al2Si2O5(OH)4 (kaolinite) is a good example that gives rise the carbonate precipitation. This reaction moves towards the right-hand side with increasing temperatures and CO2 in aqueous phase (or HCO3- as a soluble species), suggesting a potential of CO2 sequestration. The calcite- and kaolinite (clay)-rich rock produced through the reaction is expected to form a cap rock for the geothermal reservoir, with increasing storage safety. Furthermore, the high temperature of a geothermal field is favourable for immediate mineral carbonation, which would also contribute to the storage safety. In Japan, total rock volume in geothermal fields is estimated to be 4900 km3. The CO2 storage capacity is calculated to be about 20 billion tons CO2 (∼17 times Japan's total annual CO2 emissions).