After $\text{CO}_2$ is sequestrated into deep saline aquifers, it dissolves into underlaying brine, with extensive precipitation reactions emerging. Whether and how precipitation reactions impact $\text{CO}_2$ dissolution is still an open question that affects the evaluation of sequestration safety and efficiency.
We conduct visualized experiments in a visible chamber. Calcium hydroxide...
Two experimental studies focused on understanding the reactive transport properties of CO2 in cement-based materials are discussed. In the first study, we investigate the kinetics of water sorption into air-entrained mortar specimens when purged with different gas phases CO2, CH4, and N2. The rate of water sorption in the presence of different gases was measured using an engineered flow system...
Carbon capture and storage (CCS) gains much attention as it contributes to mitigating climate change. However, during CCS, the periodic injection of pressurized CO2 leads to strong thermal cycling and shocks in the subsurface, due to the endothermic expansion of pressurized CO2 upon injection. Under these temperature variations, the wellbore and subsurface formations cyclically contract and...
Geologic CO2 sequestration is a promising means of reducing atmospheric CO2 emissions. At the interface between the scCO2 and formation brine, CO2 will dissolve into formation brine, lowering formation pH and creating conditions favorable for mineral reactions. These reactions may alter the porosity, permeability, and stiffness of the formation, impacting injectivity and reservoir security....
Low natural gas recovery factors from shale reservoirs have stimulated interest in Enhanced Shale Gas Recovery (ESGR) using CO$_2$ injection. This process seeks to exploit the preferential adsorption of CO$_2$ in shale’s nanometric pores, so as to enhance desorption of CH$_4$ and to promote geological sequestration of CO$_2$. To facilitate the design of this process, an integrated experimental...
The use of the subsurface for low-carbon energy-related activities, such as geothermal energy, geologic carbon storage and underground energy storage, will intensify during the transition towards a carbon-neutral society. Such intensification requires managing induced seismicity to avoid the cancellation of projects like the Underground Gas Storage (UGS) project of Castor, Spain, which implied...
Geothermal fluids often contain significant amounts of minerals and gasses such as CO2 and N2. As these fluids are extracted, a change in pressure and temperature will occur in or near the production well. These changes disturb the equilibrium the water is in with its dissolved minerals and gases and can result in degassing, that is, the formation of free gas bubbles. These bubbles take up...
- Introduction
Of the viable strategies outlined by the Intergovernmental Panel on Climate Change (IPCC) for atmospheric emission reduction strategies and technologies, geological storage of CO2 holds an enormous promise with the potentials to have significant impacts on emission and atmospheric CO2 reduction. Predicting the behavior of CO2-brine in the complex heterogeneous porous...
Underground Hydrogen Storage (UHS) has the potential to play an important role in the transition towards renewable energy resources [1,2]. In many industrial applications, initially a mixture of hydrogen (H2) and methane (CH4) will be introduced to the grid and storage facilities [3]. Secure and efficient UHS requires accurate characterization of the cyclic movement of the H2-CH4 gas mixture...
Hydrogen energy is poised to play a pivotal role in the global efforts to achieve net-zero targets and the planned transition from traditional fossil fuels to clean energy sources. While there has been increasing interest in the use of green hydrogen, the massive amount needed for future demand would require new storage facilities. Underground storage of hydrogen, e.g., in saline aquifers and...
The energy transition efforts have given rise to the demand for energy storage. Due to its desirable characteristics, hydrogen is a favorable medium for storing the excess low-carbon electricity. Subsurface porous formations provide the solution for large storage capacities required to facilitate the energy transition. A successful storage project requires accurate modeling of the hydrogen...
Geological CO$_2$ storage can be successfully implemented in deep saline aquifers that have sufficient storage efficiency and are overlain by a competent sealing caprock. Constitutive functions that govern macroscale capillary pressure and relative permeability are central in constraining both storage efficiency of the formation and sealing properties of the caprock. Capillary pressure and...
A major challenge for geological carbon storage is increasing confidence in storage security. The ability to model and predict trapping in complex geological systems is essential to minimise risks and ensure the permeance of geological carbon storage. Capillary trapping is a key mechanism shown to improve storage security by immobilising a significant proportion of the CO2 plume [1]. Current...
Field-data-based numerical simulations of CO2 injection and plume migration are carried out to investigate competing impacts of geo-heterogeneity, top-seal topography, and flow rate on the shape of the evolving injection plume and the ensuing CO2 saturation distribution. The presented sensitivity analysis is performed on cylinder-shaped well-spot models, which capture property distributions...
Injecting CO2 for storage into deep saline formations is a promising technology for minimizing the amount of released greenhouse gas released into the atmosphere, contributing to global warming. The pressure build-up in the storage formation during an injection can affect the caprock integrity, leading to pressure-driven leakage of native brine or CO2, posing a contamination risk in shallow...
Gas diffusion layers in fuel cells need to allow the simultaneous flow of gases and water. Empirically this is achieved by coating the naturally hydrophilic carbon fibres with a hydrophobic coating, usually PTFE. We have used high-resolution X-ray imaging to observe the configuration of water within gas diffusion layers with different degrees of PTFE coating, and to quantify curvature and...
A fuel cell (FC) directly converts chemical energy from the oxidation-reduction reaction during which a transfer of electrons takes place between two chemical species into electrical energy. The powering off FC is supplied by continuous injection of hydrogen at the anode, and oxygen at the cathode. Continuous electrical energy is then available at the battery terminals. We will only focus on...
Solar-driven thermochemical fuel production cycle is one of important route for effective conversion and storing dilute and fluctuation solar energy into value-added fuels. The performance of a thermochemical reactor is largely dependent on the porous media design. The reacting porous media should simultaneously facilitate heat and mass transfer, provide reaction sites, as well as maintain...
The solar thermochemical fuel synthesis method utilizes concentrated solar radiation to drive a series of reduction/oxidation (RedOx) reactions for splitting the abundant CO2/H2O into CO/H2 known as syngas. In the following, the syngas will be catalytically converted into solar fuels through a commercially proven process such as Fischer–Tropsch. However, the commercialization of the process...
The presence of pollutants in the air is becoming an area of significant interest and there has been an increasing concern about air quality and its impact on health due to the presence of volatile organic compounds (VOC) in the air. VOC molecules include toluene, formaldehyde, methylene chloride, tetrachloroethylene, xylene, acetone and benzene which may appear in different forms as in...
The mobilization of oil in porous media is a function of capillary number (Nca), i.e. the ratio of viscous to capillary forces. With foam injection, Nca increases considerably, a result of the combined effects of an increase in pressure gradient (∇p) due to gas-mobility reduction by foam and reduction in oil/water interfacial tension (IFT) by foaming surfactant. However, the relative...
Surfactant-Alternating-Gas (SAG) (also known as FAWAG) is the most common method of injection for foam EOR. Injectivity is a key factor of a foam EOR process for both process economics and diversion. We have examined liquid injectivity after a period of gas injection. During gas injection following foam, a bank of collapsed, or greatly weakened, foam propagates slowly from the inlet. During...
