CO2 Stream Research Articles

Effects of impurities N2 and O2 on CO2 storage efficiency and costs in deep saline aquifers

Carbon capture and storage (CCS) is one of the key technologies for reducing CO2 emissions, but it has suffered from the high costs for the purification of captured CO2 streams. Storing CO2 with two major impurities (i.e., N2 and O2) in geological formations would be more economical; however, the cost savings might be offset by the reduced CO2 storage efficiency. To understand the relationships between the reduced CO2 storage efficiency and the CO2 storage costs in deep saline aquifers, the effects of impurities N2 and O2 on the CO2 storage efficiency and CO2 storage costs in deep saline aquifers are evaluated. We established a 2D model by developing a new module incorporated into TOUGH2, to simulate the migration and dissolution of CO2-N2-O2 mixtures in aquifers based on the hydrogeological conditions of the Shenhua CCS site in China. It is found that the partitioning between CO2 and the impurities during migration can reduce CO2 storage efficiency by raising impurity concentrations in gas phase. But higher pressure and temperature in reservoirs can alleviate the reduction of CO2 storage efficiency, while retaining the benefit of the impurities on the CO2 dissolution efficiency. With 10 mol% N2, the CO2 storage efficiency is decreased by at least 32%, while the CO2 storage cost in saline aquifers is increased less than 0.01 US$/t CO2.

Advanced petroleum coke oxy‐combustion power generation with carbon capture and sequestration: Part I—Design and techno‐economic analysis

AbstractThis study presents a first‐of‐its‐kind design and economic analysis of a petroleum coke oxy‐combustion electric power generation technology operated with and without carbon capture and sequestration. In this work, we examined three petroleum coke oxy‐combustion designs: petcoke oxy‐combustion, petcoke oxy‐combustion operated with carbon capture and sequestration (CCS), and petcoke oxy‐combustion with CO2 purification by distillation and CCS. The technical and economic performance of the designs were assessed based on thermal efficiency, CO2 capture rate, pipeline CO2 purity, CO2 emissions, and levelized cost of electricity (LCOE). The results of our assessments yielded a base‐case LCOE of $84.24/MWh for the petcoke oxy‐combustion design, $90.94/MWh for the petcoke oxy‐combustion design operated with CCS, and $102.8/MWh for petcoke oxy‐combustion with CO2 purification by distillation and CCS. Although the design that employed CO2 purification had higher LCOE than the other designs, its captured CO2 stream meets pipeline standards. Therefore, this design was selected for the proposed petroleum coke oxy‐combustion technology. Further analysis carried out includes the cradle‐to‐customer gate life‐cycle environmental impact assessment of the petcoke oxy‐combustion power plant which is presented in Part II of this work. Thus, this work represents the first study to present the eco‐technoeconomic and life‐cycle analysis that considered the impacts of O2 removal from CO2 captured from oxy‐combustion exhaust via cryogenic distillation for solid fuels in general.

Carbon Storage Potential of North American Oil & Gas Produced Water Injection with Surface Dissolution

Carbon dioxide (CO2) geological storage traditionally involves capturing a CO2 stream from a point source such as a power station or from cement, steel, or natural gas processing plant, transporting it and compressing it, prior to injection as a supercritical phase into a suitable geological reservoir overlain by a cap-rock or seal. One of the main perceived risks in CO2 geological storage is migration or leakage of the buoyant CO2 stream through the seal, via faults or fractures, or other migration out of the storage complex. Injection of CO2 dissolved in water may be one solution to mitigate the leakage risk. This approach could take advantage of large volumes of wastewater already being reinjected into saline aquifers worldwide but particularly in North America, thus reducing costs. This study examines the potential to “piggyback” off the existing wastewater injection industry as a novel carbon storage option.

Carbamate intermediates over mesoporous carbon nitrides in CO2 mediated oxidation reaction

Utilization of CO2 as an oxygen atom donor in the catalytic oxidation of organic compounds has gained much attention due to the potential capability of CO2 use as soft oxidant. Investigations were performed for the in-situ formation of carbamates over mesoporous carbon nitrides synthesized by different carbon and nitrogen sources urea-formaldehyde (UF-MCN), melamine-glyoxal (MG-MCN) and melamine (MS-MCN) under the CO2 stream in the infrared cell for the first time using diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). The capabilities of these carbamates were studied by in-situ DRIFTS as oxidation intermediates for “O” atom transfer to oxygen acceptor organic molecules like benzaldehyde. The formation of carbamate over mesoporous carbon nitrides was explored by Density functional theory (DFT) calculation as a first step towards new mechanistic insights for CO2 activation over metal-free catalyst involving “O” atom transfer. The catalytic potential of the mesoporous carbon nitrides for “O” atom transfer using CO2 were demonstrated by benzene to phenol and benzaldehyde to benzoic acid transformation reactions.

Effects of diffuse groundwater discharge, internal metabolism and carbonate buffering on headwater stream CO2 evasion

Groundwater discharge to headwater streams and concomitant terrestrially derived CO2 input play a key role in stream CO2 evasion. However, previous studies rarely examined the transport and transformation of terrestrially derived CO2 in headwater streams, thereby limiting our understanding of stream CO2 evasion. Here, we firstly used a numerical flow model to quantify groundwater discharge rates along a 43 km headwater stream (semiarid northwest China) by combining stream flow rate, radon-222 isotopic data, and then estimated internal metabolism through a reach-scale dissolved O2 mass balance and carbonate buffering through carbon budget for the stream. Modeling results indicate that groundwater discharge rates were highly variable (2.17–7.03 m2 d−1, mean ± 1 standard deviation: 4.48 ± 1.25 m2 d−1). Groundwater was supersaturated with CO2 at all sites (5.45 ± 3.87 mg C L−1). Our results also show that diffuse groundwater discharge was a major control on terrestrial carbon input to the stream. Terrestrial CO2 input (3.92 ± 2.03 g C m−2 d−1) contributed more CO2 to the stream than internal metabolism (1.74 ± 2.33 g C m−2 d−1). However, most terrestrially derived CO2 was transformed into HCO3− through carbonate buffering after entering the stream, inhibiting stream CO2 evasion. This carbonate buffering process depends on the hydrochemistry and proportion of mixing waters. Overall, our study provides a bottom-up and holistic perspective to understand the transport and transformation of terrestrially derived CO2 in headwater streams.

Prediction of CO2 Minimum Miscibility Pressure Using an Augmented Machine-Learning-Based Model

Summary Minimum miscibility pressure (MMP) is one of the key design parameters for gas injection projects. It is a physical parameter that is a measure of local displacement efficiency while subject to some constraints due to its definition. Also, the MMP value is used to tune compositional models along with proper fluid description constrained with other available basic phase behavior data, such as bubble point pressure and volumetric properties. In general, carbon dioxide (CO2) and hydrocarbon gases are the most common gases used for (or screened for) gas injection processes, and because of recent focus, they are used to screen for the coupling of CO2-sequestration and CO2-enhanced oil recovery (EOR) projects. Because the CO2/oil phase behavior is quite different than the hydrocarbon gas/oil phase behavior, researchers developed specialized correlations for CO2 or CO2-rich streams. Therefore, there is a need for a tool with expanded range capabilities for the estimation of MMP for CO2 gas streams. The only known and widely accepted measurement technique for MMP that is coherent with its formal definition is the use of a slimtube apparatus. However, the use of slimtube restricts the amount of data available, even though there are other alternative techniques presented over the last three decades, which all have various limitations (Dindoruk et al. 2021). Due to some of the complexities highlighted in Dindoruk et al. (2021) and time and resource requirements, there have been a number of correlations developed in the literature using mostly classical regression techniques with relatively sparse data using various combinations of limited input data (Cronquist 1978; Lee 1979; Yellig and Metcalfe 1980; Alston et al. 1985; Glaso 1985; Jaubert et al. 1998; Emera and Sarma 2005; Yuan et al. 2005; Ahmadi et al. 2010; Ahmadi and Johns 2011). In this paper, we present two separate approaches for the calculation of the MMP of an oil for CO2 injection: analytical correlation in which the correlation coefficients were tuned using linear support vector machines (SVMs) (Press et al. 2007; MathWorks 2020; RDocumentation 2020b; Cortes and Vapnik 1995) and using a hybrid method (i.e., superlearner model), which consists of the combination of random forest (RF) regression (Breiman 2001) and the proposed analytical correlation. Both models take the compositional analysis of oils up to heptane plus fraction, molecular weight of oil, and the reservoir temperature as input parameters. Based on statistical and data analysis techniques in combination with the help of corresponding crossplots, we showed that the performance of the final proposed method (hybrid method) is superior to all the leading correlations (Cronquist 1978; Lee 1979; Yellig and Metcalfe 1980; Alston et al. 1985; Glaso 1985; Emera and Sarma 2005; Yuan et al. 2005) and supervised machine-learning (Metcalfe 1982) methods considered in the literature (Altman 1992; Chambers and Hastie 1992; Chapelle and Vapnik 2000; Breiman 2001; Press et al. 2007; MathWorks 2020). The proposed model works for the widest spectrum of MMPs from 1,000 to 4,900 psia, which covers the entire range of oils within the scope of CO2 EOR based on the widely used screening criteria (Taber et al. 1997a, 1997b). NOTE: A correction notice has been issued for this paper and is available under the Supplementary Data section.

Life Cycle Analysis of Electrofuels: Fischer-Tropsch Fuel Production from Hydrogen and Corn Ethanol Byproduct CO2.

Electrofuels from renewable H2 and waste CO2 streams are of increasing interest because of their CO2 emissions reduction potentials compared to fossil counterparts. This study evaluated the well-to-wheel (WTW) greenhouse gas (GHG) emissions of Fischer-Tropsch (FT) fuels from various electrolytic H2 pathways and CO2 sources, using various process designs (i.e., with and without H2 recycle) and system boundaries. Two systems with different boundaries were considered: a stand-alone plant (with CO2 from any source) and an integrated plant with corn ethanol production (supplying CO2). The FT fuel synthesis process was modeled using Aspen Plus, which showed that 45% of the carbon in CO2 can be fixed in the FT fuel, with a fuel production energy efficiency of 58%. Using nuclear or solar/wind electricity, the stand-alone FT fuel production from various plant designs can reduce WTW GHG emissions by 90-108%, relative to petroleum fuels. When integrating the FT fuel production process with corn ethanol production, the WTW GHG emissions of FT fuels are 57-65% lower compared to petroleum counterparts. This study highlights the sensitivity of the carbon intensity of FT fuels to the system boundary selection (i.e., stand-alone vs integrated), which has different implications under various GHG emission credit frameworks.

Effects of CO2 binary mixtures on pipeline performance for Carbon Capture and Storage

Captured CO2 from the manufacturing industries and power generation sources are not pure and may contain usually some amount of impure components, which affect the flow dynamics of the CO2 in the pipelines. Major component of impurities includes N2, H2, H2S, O2, Ar etc., depending on the capture technology used for the removal of CO2 [1]. To design efficient CO2 pipeline transportation systems, it is imperative to understand the effect of these impure components on the flow behaviour. The simulation of the effect of CO2 binary mixture on pipeline performance is carried out in this study. The steady-state flow in pipeline is described by a set of parabolic mass, momentum and energy conservation equations. To solve the set of equations subject to the boundary and the inlet conditions of the pipeline, the nonlinear algebraic solver library DNSQE in Fortran is used to study the behaviour of 90 vol % CO2, and 10 vol % single impure component (N2, H2, H2S, O2 and Ar). The pertinent fluid properties are calculated using the Peng-Robinson (PR) equation of state. The presence of impure components changed the properties of the flowing fluid. From the results, H2 shows the most significant impact on the performance of CO2 pipeline as the highest pressure drop has smaller density and greater flow velocity against other CO2 streams. The results also show that Ar had the mildest effect followed by O2, N2 and CO. In the case of H2S, the flow parameters are found to be nearly identical to those for pure CO2.

Computational discovery of metal oxides for chemical looping hydrogen production

Summary Chemical looping hydrogen (CLH) production is a promising pathway that can offer both use of renewable resources and efficient CO2 capture capabilities. Here, we use the CALculation of PHase Diagrams (CALPHAD) thermodynamic database to study the water conversion capability of metal oxides (MOx) for CLH. We report the discovery of iron-based oxides with theoretical hydrogen yields up to 8 times higher than those of state-of-the-art oxides (e.g., ceria and ferrites). More specifically, Fe0.4Co0.6Ox is found to have a theoretical conversion efficiency capability > 50% at 700°C. Experimental results are presented, and a technoeconomic model quantifies the importance of MOx oxygen capacity and water conversion in this process. This reflects the potential of CLH production with a hydrogen cost of $1.25 ± $0.38/kg at a scale of 50 tons per day. This is comparable to steam methane reforming but with the added benefit of producing a stream of pure CO2.

BIFoR FACE: Water–soil–vegetation–atmosphere data from a temperate deciduous forest catchment, including under elevated CO2

AbstractThe ecosystem services provided by forests modulate runoff generation processes, nutrient cycling and water and energy exchange between soils, vegetation and atmosphere. Increasing atmospheric CO2 affects many linked aspects of forest and catchment function in ways we do not adequately understand. Global levels of atmospheric CO2 will be around 40% higher in 2050 than current levels, yet estimates of how water and solute fluxes in forested catchments will respond to increased CO2 are highly uncertain. The Free Air CO2 Enrichment (FACE) facility of the University of Birmingham's Institute of Forest Research (BIFoR) is the only FACE in mature deciduous forest. The site specializes in fundamental studies of the response of whole ecosystem patches of mature, deciduous, temperate woodland to elevated CO2 (eCO2). Here, we describe a dataset of hydrological parameters – seven weather parameters at each of three heights and four locations, shallow soil moisture and temperature, stream hydrology and CO2 enrichment – retrieved at high frequency from the BIFoR FACE catchment.

Selective and High Current CO2 Electro-Reduction to Multicarbon Products in Near-Neutral KCl Electrolytes.

Reducing CO2 to value-added multicarbon (C2+) fuels and chemicals using renewable energy is a viable way to circumvent CO2 buildup in the atmosphere and facilitate closing the carbon cycle. To date it remains a challenge to achieve high product selectivity and long-term stability of electrocatalytic carbon dioxide reduction reaction (CO2RR) especially at practically relevant high current levels >100 mA cm-2. Here, we report a simple electrodeposited Cu electrocatalyst on a hydrophobic porous gas-diffusion layer (GDL) electrode affording stable and selective CO2RR to C2+ products in near-neutral KCl electrolytes. By directing the CO2 stream to fully submerged hydrophobic GDLs in a H-cell, high C2+ partial current densities near 100 mA cm-2 were achieved. In a flow-cell setup, the Cu/GDL cathode in 2 M KCl afforded stable CO2RR superior to that in widely used KOH electrolytes. We found that Cu etching/corrosion associated with trace oxygen played a role in the catalyst instability in alkaline media under cathodic CO2RR conditions, a problem largely suppressed in near-neutral electrolyte. A two-electrode CO2 electrolyzer was constructed with a Cu/GDL cathode in KCl catholyte and an anode comprised of nickel-iron hydroxide on nickel foam (NiFe/NF) in a KOH anolyte separated by Nafion membrane. By periodically adding HCl to the KCl catholyte to compensate the increasing pH and remove accumulated (bi)carbonates, we observed little decay over ∼30 h in flow-cell CO2RR activity and selectivity at 150 mA cm-2 with a high Faradaic efficiency (FE) of ∼75% and energy efficiency of 40% for C2+ products.

Design of a Multi-user Intermediate Storage Facility in the Grenland Region of Norway

This paper describes a design and pre-feasibility study of a multi-user intermediate CO2 storage facility in the Grenland region of Norway considering upstream and downstream issues. The study focuses on the principles for design and installation of a generic hub facility, so the results can be utilised at other sites. The pre-feasibility study found that design pressures of 7 and 15 bar pressures are feasible transport conditions; moreover, showed that economies of scale might reduce the total cost for a CO2 network. It is recognised that cooperation across the chain is crucial in the management of impurities, due to the likely diverse sources of CO2 stream composition. An intermediate storage facility can support the continuous supply of CO2 via a pipeline system for reservoir injection, therefore improving the integrity of the injection well and equipment and the reservoir performance. A mixed integer linear programming optimisation model has been developed for sizing and costing two intermediate storage HUBs of CO2 in Grenland and Kollsnes and shipping connection between them. The model considers a flow of 2 mtpa of CO2 for 27 years. The 7 bar design pressure has shown lower total costs when compared with the 15 bar scenario. This is due to the higher costs for shipping and intermediate storage when operating at higher pressure, which is larger than the cost reduction from liquefying CO2 to a higher pressure and higher temperature than those required for a 7 bar scenario. The estimated levelised costs were 11.7 €/tonne at 7 bar pressure and 13.2 €/tonne at 15 bar pressure.

Role of CCS for Emission Reduction from Fertiliser and Cement Industry

Role of CCS for Emission Reduction from Fertiliser and Cement Industry

Corrosion Study on Wellbore Materials for the CO2 Injection Process

For reliability and safety issues of injection wells, corrosion resistance of materials used needs to be determined. Herein, representative low-cost materials, including carbon steel X70/1.8977 and low alloyed steel 1.7225, were embedded in mortar to mimic the realistic casing-mortar interface. Two types of cement were investigated: (1) Dyckerhoff Variodur commercial Portland cement, representing a highly acidic resistant cement and (2) Wollastonite, which can react with CO2 and become stable under a CO2 stream due to the carbonation process. Exposure tests were performed under 10 MPa and at 333 K in artificial aquifer fluid for up to 20 weeks, revealing crevice corrosion and uniform corrosion instead of expected pitting corrosion. To clarify the role of cement, simulated pore water was made by dispersing cement powder in aquifer fluid and used as a solution to expose steels. Surface analysis, accompanied by element mapping on exposed specimens and their cross-sections, was carried out to trace the chloride intrusion and corrosion process that followed.

Design and evaluation of a novel system for the flue gas compression and purification from the oxy-fuel combustion process

The process of flue gas compression and purification is essential for oxy-fuel combustion, because of its significance in determining the quality of the CO2 product. Based on the difference of dew points between CO2 and acid contaminants, a novel system, which integrated the partial CO2 recirculation with the flue gas purification, was proposed and evaluated in this study. The simulation results confirmed that a CO2 stream with a purity of 99.9% could be achieved, and the distillate after treatment in SO2 and NO absorbers could be directly recycled back to the boiler. The performance of CO2 recovery was enhanced by elevating the condensing pressure to 3.0–4.0 MPa. Besides, there was a critical ratio between the recycled CO2 liquid and the raw flue gas for the abatement of contaminants, which was 11.0 L/m3. Furthermore, the performances of SO2 and NO removal were investigated. The efficiencies of SO2 and NO abatement could be more than 99% when the reaction pressures were 0.5 MPa and 1.5 MPa separately. Besides, a critical molar ratio of SO2 to NO in the raw feeding flue gas was determined, and the removal of SO2 was restrained when the SO2/NO molar ratio increased over the critical point. As for the NO abatement, the continuous re-oxidation of NO released from the dissociation of HNO2 was dominant in the NO absorber, and the performance of NO removal was dramatically enhanced with the presence of NO pre-oxidation at low reaction pressures.

Towards Defining Reasonable Minimum Composition Thresholds – Impacts of Variable CO2 Stream Compositions on Transport, Injection and Storage

The collaborative project “Impacts of impurities in CO2 streams captured from different emitters in a regional cluster on transport, injection and storage (CLUSTER)” aimed to set up recommendations on how to define “reasonable minimum composition thresholds” that CO2 streams should meet when accessing CO2 transport pipeline networks. Within CLUSTER, we investigated potential impacts of CO2 streams with different and temporally variable compositions and mass flow rates along the whole CCS chain. Investigations included, amongst others, impacts on: • corrosion of pipeline steel, • pipeline network design and related transport costs, • alteration of well bore cements, • pressure development and rock integrity, • geochemical reactions, and • petrophysical and geomechanical rock properties. All investigations are based on a generic CCS chain scenario. In this scenario, CO2 streams are captured from a spatial cluster of eleven emitters and collected in a regional pipeline network. Emitters comprise seven fossil fuel-fired power plants equipped with different capture technologies, two cement plants, one refinery and one integrated iron and steel plant. In total, 19.78 Mio t CO2 (including impurities) are captured in the emitter cluster annually. The combined CO2 stream is transported in a trunk line with a length of 400 km (100 km of these offshore) and is injected into five generic storage structures. The storage reservoirs are saline aquifers of the Buntsandstein. The investigations revealed beneficial and deteriorating impacts of different impurities and combinations thereof. Overall, no fundamental technical obstacles for transporting, injecting and storing CO2 streams of the modelled variable compositions and mass flow rates were observed. Based on the results, the CLUSTER project team recommends not to define “minimum composition thresholds” for CO2 streams as strict threshold values for each individual impurity in the stream. Instead, CO2 stream compositions and variabilities for specific CCS projects should be constrained with regard to a set of parameters including i) the overall CO2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of CO2 stream composition, and iv) impurity combinations to be avoided.

The Status and Challenges of CO <sub>2</sub> Shipping Infrastructures

The Status and Challenges of CO <sub>2</sub> Shipping Infrastructures

Corrosion of carbon steel in simulated CCS streams

It is expected that Carbon capture and storage (CCS) may involve a large network with many sources, transportation systems and storage sites. Depending on factors like flue gas source, capturing technique and process parameters, the captured CO2 may contain various types and concentrations of other components. These components are expected to be present at low concentrations (in the ppm range) and are therefore commonly referred to as impurities. It is well known that some impurities may react and produce species that are corrosive to carbon steel. Long transport pipelines will be made of carbon steel due to cost considerations, and it is therefore essential to avoid formation of corrosive species. In the present work, corrosion of carbon steel was tested in a CO2 stream containing low levels of water and the impurities H2S, SO2, NO2 and O2 at a temperature of 25 °C and a pressure of 99 bar. The experiment was carried out in a custom-made autoclave with transparent windows that allowed for in-situ observation of any chemical reactions or corrosion processes. Each impurity, including water, was pre-mixed with CO2 at a high concentration (impurity stock solutions) and continuously injected through individual feed lines into the autoclave. This ensured that all impurities were injected fully dissolved in the CO2 phase and that no reactions could take place before the impurities were mixed inside the autoclave. The impurity injection rate was adjusted relative to the to the total CO2 rate, to get the desired impurity concentration in the autoclave. Exhaust CO2 was continuously removed from the autoclave and analysed for impurity content by laser spectroscopy. Comparison of the injected and exhaust impurity concentration made it possible to identify chemical reactions as concentration changes. The experiment demonstrated that there were no corrosion reactions when the impurities were at the target concentrations. However, chemical reactions between the impurities did take place. An episode with clogging of the vent line, which resulted in a temporarily increase of the impurity concentrations, resulted in formation of a separate liquid phase containing sulfuric and nitric acid formed. This also started corrosion of the carbon steel coupon.

Experimental based CO2 transport specification ensuring material integrity

Material choice has a large impact on the total cost of the transport system for carbon capture and storage (CCS). Cost-considerations make carbon steel the preferred candidate for the pipelines. As carbon steel will corrode if aqueous phases are present, it is important to control the CO2 composition and operate the system such that formation of water containing phases is avoided. There are many suggested specifications and recommendations for the type and concentration of impurities to be allowed in the CO2 stream. These impurity limits are often set from a health, safety, and environmental point of view and due to lack of knowledge are not so much based on material integrity issues. This gap of knowledge makes it difficult to make a specification that will ensure safe operation and long-term integrity. The present paper summarises the results of a large research project that systematically tested CO2 with various combinations and concentrations of potentially reactive impurities (H2O, NO2, SO2, H2S, O2). It was clearly shown that many impurity combinations were basically inert, while other resulted in chemical reactions and some combinations even resulted in formation of a separate aqueous phase that contained high concentrations of sulfuric and nitric acid as well as elemental sulphur. This aqueous phase was corrosive to carbon steel. Corrosion was also observed in certain situations even if a separate aqueous phase was not observed visually. It is important to avoid precipitation of solid products since it may cause problems at the injection point and in the reservoir. The present work demonstrated that the types and combination of impurities that are present is important for the maximum impurity concentration that can be allowed to prevent chemical reactions and corrosion from occurring. The concentration limit for each impurity should be below 20 ppmv if NO2, SO2, H2S, O2 are present together.

Toward Probabilistic Modeling of Halite Nucleation and Growth during Carbon Storage Process: Pore Scale Modeling

To maximize safety and cost-efficiency of CO2 storage, it is necessary to understand how a high permeability in the near-well region is maintained. Nucleation and growth of salt crystals driven by the evaporation of formation water into under-saturated (dry) super-critical CO2 stream results in the changes in the porosity and permeability of the near well-bore area. Permeability reduction is the main reason of the injectivity loss in the context of CO2 storage in saline aquifers. According to recent studies, during CO2 storage, salt crystals form in two different forms: 1) single, large crystals in the aqueous phase, and 2) aggregates of micrometer size salt crystals in the gas phase. All the previous numerical studies at pore-scale addressed the formation of single, large crystals in the aqueous phase. In this work, we developed a 3D pore-scale reactive transport solver (a D3Q19 advection-diffusion Lattice-Boltzmann model) and took nucleation process into account via a new probabilistic approach to simulate the formation of micro-meter size salt crystals in the gas phase and their effect on changes in pore morphology and permeability for the first time. Comparing the results of porosity-permeability relation with some of the well-known clogging models, confirms the need for a new clogging model to capture the permeability reduction caused by salt aggregates.