ABSTRACT Carbon capture and storage (CCS) can reduce carbon dioxide (CO 2 ) emissions from energy and industrial activities, but its regional air quality and health implications depend on the capture technology, transport configuration, and associated energy requirements. This study assessed six CCS configurations in the Po Valley, Northern Italy, using the MAQ integrated assessment model. Monoethanolamine‐based post‐combustion capture was applied to natural gas (NG) combustion activities in the energy sector (MS1) at 60%, 85%, and 90% CO 2 removal rates. Oxy‐fuel combustion was applied to NG industrial furnaces in the industrial combustion sector (MS3) and kept constant across scenarios. Captured CO 2 from MS1 was transported either by road tankers or pipeline, whereas the MS3 CO 2 stream was assumed to be transported by pipeline. Gross CO 2 captured, transported, and stored ranged from 121.952 to 127.946 MtCO 2 /year. After accounting for road‐transport emissions, CO 2 conditioning, and electricity demand for oxygen production, net CO 2 reductions ranged from 105.744 MtCO 2 /year for Truck‐60 to 111.925 MtCO 2 /year for Pipeline‐90. Pipeline transport provided a higher net CO 2 reduction than tanker transport at the same capture rate. All scenarios reduced domain‐average PM2.5 and NO 2 concentrations relative to the CLE2020 baseline. Mean cell‐level reductions ranged from 0.063 to 0.075 µg/m 3 for PM2.5 and from 0.234 to 0.293 µg/m 3 for NO 2 , with statistically significant differences after false‐discovery‐rate correction. Estimated avoided attributable deaths ranged from 162 to 186 deaths/year for PM2.5 and from 175 to 215 deaths/year for NO 2 . Pipeline configurations achieved the greatest air‐quality and health benefits because they avoided additional road‐transport emissions. These findings show that CCS can provide substantial net climate mitigation and modest local air‐quality co‐benefits, provided that the full energy and transport chain is explicitly accounted for.
ABSTRACT CO 2 injection into depleted gas reservoirs can operate close to the vapor–liquid equilibrium envelope because post‐depletion pore pressure is often much lower than in saline‐aquifer storage. This study applies a one‐dimensional transient two‐phase mixture solver with a Lee‐type evaporation–condensation source closure, hybrid Peng–Robinson/Span–Wagner CO 2 properties, transient radial heat transfer, and an injectivity‐coupled sandface boundary to a 1500‐m tapered‐completion CO 2 injector. The base case injects pure CO 2 at 30 kg/s into a depleted reservoir at 9.0 MPa. Three shut‐in durations (1, 10, and 30 min) and three restart durations (10, 30, and 60 min) are evaluated; selected shut‐in cases are benchmarked against RELAP5‐3D under matched conditions. The two solvers agree within approximately 1.7°C on the minimum wellhead temperature. Shut‐in collapses the frictional pressure contribution and leaves the upper wellbore below the local saturation pressure. The resulting vapor‐rich upper section absorbs latent heat and cools by more than 17°C in the upper 300 m. Modeled minimum wellhead temperatures range from −19.1°C for emergency shut‐in to −8.7°C for 30‐min controlled shut‐in. Restart can create a second flash‐cooling event; the 60‐min restart is not necessarily the thermally safest option because it prolongs the subsaturation flashing window. For this case, the 30‐min shut‐in and 30‐min restart give the best balance among low‐temperature response, flashing‐window closure, and ramp severity of the three shut‐in and three restart ramp durations tested. This recommendation is scenario‐specific, not a universal operating limit, and should be supported by sensitivity analysis before material qualification or field approval.
ABSTRACT The infiltration and flow expansion in coal seams have long remained a critical challenge in coal mining. This study introduces an innovative method employing ultrasound‐assisted supercritical CO 2 (ScCO 2 ) for coal modification, utilizing custom‐designed experimental apparatus. By synergistically combining the chemical dissolution capacity of ScCO 2 with ultrasonic cavitation and mechanical vibration, the technique enables multiscale active intervention within the coal matrix—from macroscopic fractures to nanopores. This technology effectively addresses the efficiency constraints of conventional single‐phase supercritical fluid methods. Experimental results revealed a substantial improvement in coal pore structure after ultrasound‐assisted ScCO 2 treatment, with the total pore volume and porosity reaching 0.2166 mL/g and 23.93%, respectively, and the macropore volume accounting for 93.35% of the total pore volume. In addition, the pore fractal dimension and structural complexity decreased. Permeability tests showed a strong positive correlation between treatment duration and enhancement, with increases of 733.33%, 872.92%, and 1157.29% observed after 4, 7, and 10 days, respectively. These findings provide a promising pathway toward more efficient coalbed methane extraction.
ABSTRACT CO 2 methanation shows advantages in power‐to‐gas technologies using renewable energy. The kinetic and thermal analysis enables to exactly evaluate methanation activity and avoid temperature shifts assigned to exotherm. In this article, Ru‐doped 30%Ni/Ce 0.9 Zr 0.1 O 2 catalyst is prepared using one‐pot hydrolysis method. The results indicate that the activity is significantly enhanced at temperature over 300°C, leading to higher catalyst temperature than controlled temperature. The kinetic analysis obtains low activation energy of 63.8 kJ/mol than reported for Ni‐based catalysts for different models. The adsorption of H 2 and CO 2 is important for CO 2 methanation, and the activation energy is estimated as 61.6 kJ/mol when considering only H 2 and CO 2 adsorption. Significant hot spots are observed in a model tube reactor due to exothermal methanation according to the kinetic equation. The addition of CH 4 in the feed gas is considered an alternative way to decrease the temperature of hot spot.
ABSTRACT Scaling geological CO 2 storage requires simultaneously controlling plume migration, pressure buildup, geomechanical integrity, and monitoring cost under deep subsurface uncertainty. Yet early‐stage assessments often treat these elements in isolation, obscuring the decision‐critical couplings between pressure‐defined regulatory exposure and storage economics. Here, we present a verified reduced‐complexity integrated assessment workflow that couples (i) analytical, superposed pressure solutions for confined, leaky, and bounded aquifers, (ii) a plume‐coupled trapping model tracking mobile, residual, dissolved, and mineralized CO 2 , (iii) probabilistic geomechanical screening using slip tendency and Coulomb stress proxies, and (iv) a techno‐economic analysis in which monitoring cost scales explicitly with the computed pressure‐based area of review (AoR). Applied uniformly to seven benchmark projects and a Gulf of Suez case (Hammam Faraun [HF] Member, Egypt), the framework reveals a consistent bifurcation of limiting constraints: High‐transmissivity open systems tend to be plume/monitoring‐footprint limited, whereas semi‐closed or compartmentalized systems are pressure‐ and integrity‐limited. For HF, deterministic simulations indicate modest well overpressure, but Monte Carlo propagation yields a heavy‐tailed AoR distribution with probability of 0.84 during operations, showing that regulatory exposure can be dominated by basin‐scale hydraulic uncertainty rather than plume size. Trapping evolves from injection‐era mobility to postinjection immobilization dominated by dissolution, and mineral trapping remains negligible over 100‐year horizons. By explicitly coupling AoR uncertainty to monitoring obligations, we show that regulatory footprint is a first‐order driver of risk‐adjusted levelized storage cost and portfolio ranking, providing a computational bridge from sparse site data to decision‐relevant probabilities and design trade‐offs.
