International Journal of Greenhouse Gas Control最新文献

This study presents the application of an efficient and robust Dynamic Pore-Network Modeling (DPNM) framework for accurate prediction of carbon dioxide (CO₂) trapping behavior under the dynamic flow conditions prevalent in subsurface applications. Residual trapping of CO₂ is crucial in the context of geological sequestration, serving as a constitutive relationship that controls relative permeability hysteresis and thereby determining the magnitude of CO₂ trapping within formations over varying timescales. Utilizing our DPNM framework, we study the complexities of residual trapping in miniature-core-sized digital replicate of a sandstone. We systematically conduct series of two-phase flow simulations to examine the relationships between total residual CO₂ amount, trapping efficiency, and initial saturations across a spectrum of capillary numbers and wettability states. Dynamic simulation results lead to a simple power-law scaling equation correlating CO₂ trapping efficiency with initial saturation across various capillary numbers. Further analysis explores the morphological and topological characteristics of fluids during primary drainage and various imbibition displacements within the pore network. This work contributes an essential tool and deepens our understanding of CO₂ trapping dynamics, driving progress towards more effective and safer strategies for carbon capture and storage.

Aqueous ammonia is one of the most promising solvents to conventional amine for capturing CO₂ from flue gas and other industrial emissions owing to its high CO₂ loading capacity, low-cost, less corrosive, and low vulnerability to degradation. However, due to the slow absorption rate of CO₂, the industrial application of ammonia is restricted. The present review mainly focused on the current developments of the aqueous ammonia-based carbon capture process (AAP) and its enhancement technologies to improve the absorption rate performance. The reaction between aqueous ammonia and CO₂, including reaction mechanism, reaction intermediates, reaction products, and influence of different operational parameters on the absorption performance, are presented. The enhancement technologies, mass transfer coefficients, and perspectives for each potential technology in AAP are reviewed. Furthermore, the recent advances in the potential of ammonia for combined removal of several flue gas components such as; NO_x, SO_x, CO₂, and other pollutants are discussed. Finally, in light of recent advancements and obstacles of AAP, this study provides views and highlights in which future prospective investigation is necessary to improve the absorption rate of aqueous ammonia.

The installed capacity of thermal power plants has been increasing in Brazil. Consequently, harmful emissions are also rising due to the increasing consumption of conventional fuels. More stringent environmental regulations and concerns regarding climate change have led to joint efforts towards using low-carbon energy generation technologies. Adopting carbon capture and storage technologies could help mitigate these emissions. However, a comprehensive analysis of their suitability for the application is necessary, depending on numerous factors. This study investigates the strengths, weaknesses, opportunities, and threats for exploiting carbon capture technologies in Brazilian thermal power plants by conducting a SWOT analysis. The study presents environmental, economic, social, policy and legal aspects of applying CCS technologies for emission mitigation. The recommendation based on this analysis provides a future framework for assessing and implementing CCS technologies for thermal power plants in Brazil.

Several promising CO₂ capture technologies, like oxy-combustion, adsorption and membranes, feature a purity of the captured CO₂ stream which is insufficient for the storage site or the transport system. In these cases, a CO₂ Purification Unit (CPU) is required to lower the concentrations of O₂, N₂ and Ar at the limits allowed by the storage site/transport system. In this work, the available CO₂ Purification processes have been reviewed and the six main schemes have been simulated in Aspen Plus and optimized. Their performance have been ranked based on six selected key performance indicators: total annual cost, Specific cost per ton of captured CO₂, specific energy consumption, recovery, purity, and O₂ concentration in the purified CO₂. The techno-economic optimization is repeated for different carbon tax values and for three different feed streams compositions. The results of the optimization show that flash-based CPUs cannot meet the requirements for CO₂ storage due to a high concentration of O₂ (>1000 ppm) but they feature a low specific cost (5.8–25.9 €/tonCO₂ depending on the feedgas and plant size), low specific energy consumption (124.9–436.1 kJ/tonCO₂) and acceptable recovery (94.60–99.46 %). The distillation-based CPU can meet the requirements for CO₂ storage, but these CPUs have the highest cost (52–112 % higher than flash-based CPU) and the lowest recovery. The optimal CPUs are the ones which combine both distillation column and flash separation. These CPUs meet the oxygen requirements for CO₂ storage (<10 ppm) while providing the highest purity (99.997–99.999 %), high recovery (90.61–99.32 %) at a limited cost (6.1–36.0 euro/tonCO₂).

Storage resource estimates are part of the foundation for Carbon Capture and Storage (CCS) policy, project development and pipeline routing. Multiple generations of such estimates have found that hundreds and even thousands of gigatons of storage are available in basins around the world. However, these estimates have largely been based on basin-scale static capacity calculations that assume pore space is accessible to CO₂, because basins have open boundaries that allow water to be displaced and avoid pressure build-up. However, as we now consider large-scale injection that stresses the system capacity, limitations to the flow of CO₂ and displaced brine must be considered. These limits include pressure interactions among multiple projects, physical lateral discontinuities such as faults and facies changes, overpressure, juxtaposition with impermeable basement, and regulatory requirements that require protection of freshwater. We present here a simple algorithm to estimate the total pressure-limited storage resource. Applying it to the example of the Texas coastal Miocene results in a significantly lower storage resource over our previous static capacity estimates (assuming no water production). Based on this assessment, we find that CCS is still unlikely to be capacity-limited, but effective regulation, land valuation and project development will require recalibration and consideration of all projects in pressure communication. We conclude that depth-dependent and geomechanically-limited pressure space, not pore space, is the key subsurface commodity.

The storage of CO₂ in deeply buried geological formations provides a contribution to mitigate hard-to-abate CO₂ emissions from industry. Robust geological models and capacity estimations are crucial for the successful planning and implementation of safe storage projects. This study focuses on the CO₂ storage potential of the Middle Buntsandstein Subgroup within the Exclusive Economic Zone of the German North Sea. We have mapped a total of 71 potential storage sites based on existing 3D models, seismic and well data. Static CO₂ capacities are calculated for each structure using Monte Carlo simulations with 10,000 iterations to account for uncertainties. All potential reservoirs are evaluated based on their potential capacity, burial depth, top seal integrity and trap type. We have identified 38 potential storage sites with burial depths between 800 m and 4500 m, reservoir capacities (P50) above 5 Mt CO₂ and suitable sealing units. The estimated cumulative static storage capacity percentiles of these structures range between P10 = 902.08 Mt and P90 = 5508.93 Mt, with P50 = 2554.10 Mt. We expect the best storage conditions on the West Schleswig Block, where salt-controlled anticlines with moderate burial depths, large reservoir capacities and limited lateral flow barriers are the dominant trap types. Relatively poor storage conditions can be expected for small (P50 < 5 Mt CO₂), deeply buried (> 4500 m) and structurally complex potential storage sites in the Horn and Central Graben. Our study highlights the most prolific reservoirs and discusses the most suitable locations for further exploration.

Carbon Capture and Storage (CCS) is a pre-requisite to decarbonize CO₂ emissions from industrial sectors and as an industry capable of compensating for hard-to-abate emissions in a net zero scenario. A method was developed to evaluate the geomechanical constraints and safe operating envelope as function of pore pressure and temperature. The probability of failure was estimated from uncertain input stiffness and strength data, and as cooling and re-pressurization shifts the in-situ effective stresses, the safe operating envelope was determined, here given by pressure and temperature.

Onshore storages nearby industrial clusters enable energy and cost-effective handling of CO₂. In the South-Eastern European region, onshore depleted oil and gas fields located nearby high-emitting industries may developed into CO₂ storages. This paper describes a method for determining maximum fluid pressure as function of temperature from geomechanical restrictions. The method was employed on a practical example used to evaluate the safe operation envelope for a pilot CO₂ injection site into a depleted onshore naturally fractured carbonate oil and gas field. The tool uses Monte Carlo simulations to perform geomechanical stability analyses by sampling from the inherent uncertainty of the input parameters to probability of failure as function of pressure and temperature. The risk of re-opening natural fractures, induced fracturing and fault reactivation are evaluated so the safe operating envelope can be obtained. The uncertainty of the input parameters is thus directly reflected in the safe operating envelope – thus providing an effective communication of value information to external stake holders when maturing a CO₂ storage pilot.

Most climate change mitigation scenarios rely on negative emissions technologies like bioenergy with carbon capture and storage (BECCS). However, little is known about public support for BECCS. This paper gauges Danes’ willingness to pay (WTP) for biomass with carbon capture and storage and examines factors influencing it. Denmark is a suitable case study given its reliance on biomass and negative emissions to achieve climate targets. Results from a questionnaire-based survey indicate a mean WTP of 3072 DKK (412 EUR) per household per year. This correspondents to a 12% increase in heat and electricity expenses. The need for negative emissions is the main stated reason for WTP. This may be interpreted as reflecting either support for, or reluctant acceptance of, BECCS. Results show that being younger, being concerned about climate change and believing that it is mainly caused by human activity, and believing in the mitigation potential of biomass and that sustainability is a precondition of its use have a significant effect on WTP. Public views on BECCS are complex but must be acknowledged if discussion of the role of BECCS in the decarbonisation agenda is to move forward.

The article presents a new setup for the accurate measurements of the phase behaviour of CO₂ mixtures relevant to CCS as well as a CO₂-H₂O working fluid for EGS, designed to cover the temperature range from -60 to 200 °C and up to 100 MPa in pressure. Included in the article are a description of the experimental setup, methodology, and results of the experimental campaign conducted in the SINTEF Energy Research labs for the EnerGizerS project. Phase equilibrium of the CO₂-water system has been investigated at the temperature of 50 °C and pressures between 1 and 17.5 MPa, using the analytical isothermal technique. These measurements are compared and verified against the existing data, followed by a presentation of the fit of GERG-2008/EOS-CG for CO₂ and H₂O. The maximum mole fraction of water in the CO₂H₂O mixture at measured conditions should not exceed 0.35 % and even less than 0.3481 % at 7.8 MPa to maintain the vapour phase of the mixture. The accuracy with respect to GERG-2008/EOS-CG varies from 1.044 % to 10.683 % near the critical values of sCO₂. The estimated uncertainty of the setup is 31 mK for temperature measurements, from 0.4 to 2.5 kPa for pressure measurements and from 0.2 to 2.1 % of total combined relative uncertainty as regards the mole fraction. Despite the fact that the EGS reservoir could reach conditions above 150 °C and 50 MPa, lower values were adopted to validate the setup at 50 °C. Knowledge gaps at higher pressure and temperature values are still in dire need of filling.

The corrosion behavior of A3 carbon steel in 30 wt.% MEA and AMP-MEA (2:1) blended amine solutions, two typical CO₂ capture solvents for chemical absorption processes, was investigated. The inhibition effects of imidazoline, sodium metavanadate (NaVO₃), and phosphoric acid, triethanolamine salt (P-TEA) were evaluated using various electrochemical testing techniques and immersion corrosion experiments. Results showed that NaVO₃ exhibited the highest corrosion inhibition effect at a concentration level of 1000 ppm, while imidazoline showed limited effectiveness. Both NaVO₃ and P-TEA significantly increased solution resistance and charge transfer resistance, thereby enhancing corrosion inhibition. Additionally, AMP-MEA blends exhibited improved corrosion performance compared to MEA, with the formation of a denser protective layer on the surface of A3 carbon steel. Furthermore, experimental results revealed that NaVO₃ and P-TEA, instead of forming protective oxide or carbonate layers, formed complexes or chelates with iron ions in the solution. These compounds adsorbed onto the carbon steel surface, effectively preventing further corrosion. These findings provide valuable insights into the corrosion behavior of A3 carbon steel in amine-CO₂H₂O systems and underscore the potential of NaVO₃ and P-TEA as effective corrosion inhibitors. This knowledge is crucial for developing enhanced corrosion control strategies in related industrial applications.