Mineral Sequestration Research Articles

Numerical Modeling Study on Mineral Alteration and Sealing Performance for CO2 Geological Sequestration with Enhancing Water Recovery in Hydraulic Fractured Shale Reservoirs

Abstract Recently, CO2 geological sequestration combined with enhancing deep saline water/brine recovery is regarded as a potential strategic choice for reduction of CO2 emissions. This technology not only achieves the relatively secure storage of CO2 which was captured during industrial processes but also can enhance the recovery of water for drinking, industrial, and agricultural utilization. However, the impact of CO2-water-rock reactions on the shale reservoir in the system is unclear and the sealing performance of mudstone caprock has not been investigated. For analyzing the mechanism of mineral alteration in the shale reservoir, a three-dimensional injection-production model in the double-fractured horizontal well pattern is established according to actual parameters of shale and mudstone layers. In addition, mineral alteration was characterized and caprock sealing performance was also assessed. Numerical results showed that the presence of CO2 can lead to the dissolution of k-feldspar, oligoclase, chlorite, and dolomite and the precipitation of clay minerals such as kaolinite, illite, and smectite (Ca-smectite and Na-smectite). Due to positive ion released by dissolved primary minerals, the precipitation of secondary carbonate occurs including ankerite and dawsonite, which induces the mineral sequestration capacity of the shale reservoir. The amount of CO2 sequestration by mineral is 51430.96 t after 200 years, which equals 23.47% of the total injection (219145.34 t). Besides, the height of the sealing gas column is used for evaluating the sealing performance of the shale-mudstone interface. Results show that the height of the sealing gas column at the interface above the injection well is lower but the maximum value of CO2 gas saturation is only 0.00037 after 200 years. The height of the sealing gas column at the interface is greater than 800 m, which can be classified as level II and guarantee the security of the CO2 storage. The analysis results provide reliable guidance and reference for the site selection of CO2 geological sequestration.

Thermal decomposition process of dypingite Mg5(CO3)4(OH)2·5H2O

Dypingite is one of the most common phases of crystalline magnesium carbonate hydrates, which are considered potential targets for CO2 mineral sequestration. Ex-situ high-temperature X-ray diffraction and ex-situ high-temperature synchrotron X-ray scattering experiments with pair distribution function analysis were used to explore the thermal transformation process of dypingite. Dypingite transformed to hydromagnesite until 100 °C, but its local structure remained unchanged. At the temperature range from 250 °C to 350 °C, where the amorphous phase was predominant, the second and third coordination spheres were continuously modified and crystallized to MgO at 400 °C. Although the local structure of dypingite was as that of hydromagnesite, dypingite exhibited a different thermal transformation pathway from hydromagnesite.

CO2 Mineral Sequestration and Faujasite Zeolite Synthesis by Using Blast Furnace Slag: Process Optimization and CO2 Net-Emission Reduction Evaluation

CO₂ Mineral Sequestration and Faujasite Zeolite Synthesis by Using Blast Furnace Slag: Process Optimization and CO₂ Net-Emission Reduction Evaluation

Numerical simulation of CO2 mineral sequestration in basalt reservoir through an abandoned oil well: a case study in Xujiaweizi area, Northeast China

Numerical simulation of CO2 mineral sequestration in basalt reservoir through an abandoned oil well: a case study in Xujiaweizi area, Northeast China

Analysis of the Process of Mineral Sequestration of CO2 with the Use of Fluidised Bed Combustion (FBC) Fly Ashes

There is a current focus on replacing the generally accepted conventional power generation technologies with more advanced ones that will better protect the natural environment. The need to limit CO2 emissions from power generation plants presents a problem that must be solved in many countries that use coal or lignite as basic fuels. One potential option is mineral sequestration performed using side products of fossil fuel combustion, such as fluidised bed combustion (FBC) fly ashes. Fluidised bed combustion (FBC) lignite fly ashes are characterised by a high storage capacity of 15.7%. Research conducted with the most commonly used method of direct mineral sequestration—CO2 trapping with fluidised bed combustion (FBC) ash in water suspension—has indicated a very high level of carbonation of CO2, reaching 11%. Calcite was the basic product of carbonation. The calcite content increased from 2% to 12% in the suspension subjected to treatment with CO2. Furthermore, CO2 reduced the pH and limited the leaching of impurities, such as Zn, Cu, Pb, Ni, As, Hg, Cd, Cr, Cl, and SO4. The fly ash suspensions subjected to CO2 treatment can be used in industry in the final stage of carbon capture and utilisation (CCU) technology, which will further contribute to the implementation of the circular economy.

Experimental study and kinetics on CO2 mineral sequestration by the direct aqueous carbonation of pepper stalk ash

While carbon capture, utilization, and storage (CCUS) is recognized as a highly promising technology for large-scale CO2 reduction from power and chemical industries, there have not been many investigative efforts on CCUS using biomass feedstock such as pepper stalk ash (PSA). Therefore, in this study, the direct carbonation of incinerated PSA via an aqueous route was studied under low-medium pressure conditions in an autoclave reactor. To optimize the reaction conditions in order to achieve the maximum carbonation efficiency, the complex effects of various operating parameters, such as the reaction temperature, liquid–solid (L/S) ratio, reaction time, pressure, and reaction gas, on the CO2 sequestration characteristics were systematically investigated. Under the theoretical framework of the shrinking core model (SCM) and assuming that the diffusion coefficient is a function of time, a new kinetic equation was proposed to provide a more precise fit to the experimental data of the heterogeneous direct carbonation. In addition to solid carbonates, PSA carbonation yielded dry residues from liquid products, which included 58.03 wt% potassium oxide and hence can potentially be used as feedstock for potassium fertilizers.

Modeling Kinetics of CO2 (Carbon Dioxide) Mineral Sequestration in Heterogeneous Aqueous Suspensions Systems of Cement Dust

The necessity to reduce CO2 emission in the environment has encouraged people to search for solutions for its safe capture and storage. Known methods for carbon dioxide mineral sequestration are based primarily on the use of its binding reaction with metal oxides, mainly earth metals. Increasingly important, due to the availability and price, are processes based on the suspension of various wastes such as fly ash, cement dust or furnace slag. Due to the complexity of the mineral sequestration of CO2 in water-waste suspensions, an important issue is to determine the reaction mechanisms. This applies mainly to the initial period of the transformation phase of mineral wastes, and consequently with the occurrence of a number of transition states of ionic equilibria. The mechanisms and reaction rates in the various stages of the process of CO2 mineral sequestration in heterogeneous systems containing selected wastes are defined herein. This paper presents a method of modeling kinetics of this type of process, developed on the basis of the results of the absorption of CO2 thanks to the aqueous suspension of fly ash and cement dust. This allowed for the transfer of obtained experimental results into the mathematical formula, using the invariant function method, used to describe the processes.

A review on ex situ mineral carbonation.

The increased CO2 quantities in the environment have led to many harmful effects. Therefore, it is very important to decrease the CO2 levels in the environment. CO2 capture along with safe and permanent storage using mineral CO2 sequestration method can play an important role to reduce carbon emissions into the environment. Mineral sequestration is a stable storage method that provides long-term storage and an appropriate substitute for the more popular geological storage method. The process is most suited for places where there is a lack of underground cavities for underground geological storage. Minerals rich in Ca and Mg are used predominantly in carbonation reactions. In addition, those alkaline wastes that are rich in Mg and Ca such as cement waste, steel slag and many process ashes can also be employed in CO2 sequestration. Mineral carbonation could be used for the sequestration of billions of tonnes of CO2 every year. However, various drawbacks related to mineral carbonation still need to be addressed, such as resolving the slow rate of reactions, necessity of large amounts of feedstock, decreasing the high overall cost of CO2 sequestration and reducing the huge energy requirements to accelerate the carbonation reaction. This study explores a number of carbonation methods, parameters that control the process and future potential applications of carbonated products.

Simultaneous Co2 Mineral Sequestration and Rutile Beneficiation by Using Titanium-Bearing Blast Furnace Slag: Process Description and Optimization

Simultaneous Co2 Mineral Sequestration and Rutile Beneficiation by Using Titanium-Bearing Blast Furnace Slag: Process Description and Optimization

Mineral sequestration of CO2 from Vernasca Ca-looping demo system: scale up to a pilot

In recent years, carbon sequestration into thermodynamically stable carbonates has been developed as a promising carbon capture, utilization and storage (CCUS) method, especially, when alkaline industrial wastes are used as sorbents. The use of industrial wastes to sequester CO2 plays a dual role in environment protection, creating opportunities not only for capture and disposal of CO2 but also for recycling of wastes and promoting the transition to circular economy. The CLEANKER project (Horizon 2020 Project Clean clinker production by Calcium looping process) aims to build a CO2 mineralization pilot incorporated into Ca-looping demo system in Vernasca cement plant and use the re-carbonated wastes in concrete applications. Different types of wastes such as burnt oil shale (BOS) from Eesti, Balti and Auvere power plants as well as from Enefit280 oil producing unit in Estonia, concrete demolition wastes (CDW), cement by-pass dust (CBD) from Robilante, Italy, blast furnace slag (NSF) from Bremen, Germany were tested first in laboratory scale via dry and wet direct carbonation routes under the conditions of CO2-rich model gas flow of 70 – 100% CO2, simulating the Ca-looping system. The results show that selected types of BOS and cement wastes could be used as efficient binders in both dry and wet CO2 mineralization systems with binding capacities up to 0.18 kg of CO2 per kg of BOS and up to 0.24 kg of CO2 per kg of CBD. The activating effect of hydration as a pre-treatment method showed that at lower operating temperatures, the same level of CO2 capture can be achieved, thereby rendering the carbonization processes of similar industrial wastes more energy efficient. Moreover, the CO2 mineralization tests with BOS in a 46 L concrete mixer confirmed the applicability of wet carbonization process also in larger scale. Based on the results, the most promising materials, BOS and CBD, were selected for in the proposed CO2-mineralization process in wet conditions at ambient temperature. The pilot (200 L) was designed based on a commercially available concrete mixer integrated into CLEANKER Ca-looping demo system and equipped with CO2 inlets and outlets, as well as CO2, temperature and moisture sensors to detect the reaction progress. The re-carbonated wastes will be tested via concrete casting in order to demonstrate the quality of the commercial product in the following stages of the project.

Separation of Products from Mineral Sequestration of CO2 with Primary and Secondary Raw Materials

Rising levels of greenhouse gases (GHG) in our atmosphere make it necessary to find pathways to reduce the amount of GHG, especially emissions of CO2. One approach is carbon capture and utilization by mineralization (CCUM). With this technology, it is possible to bind CO2 chemically from exhaust gas streams in magnesium or calcium silicates. Stable products of this exothermic reaction are carbonates and amorphous silica. Being amongst the biggest emitters of CO2, the cement industry has to find ways to reduce emissions. Geological mapping in Europe has been carried out to find suitable feedstock material, mainly olivines but also slags, to perform lab‑scale carbonation tests. These tests, conducted in a 1.5 L autoclave with increased pressure and temperature, have been scaled up to a 10 L and a 1000 L autoclave. The outcomes of the carbonation are unreacted feed material, carbonate, and amorphous silica, which have to be separated to produce substitutes for the cement industry as pozzolanic material (amorphous silica) or a value‑added product for other applications like paper or plastics (magnesite/calcite with bound anthropogenic CO2). Therefore, a process for the separation of ultrafine carbonation product was developed, consisting mainly of classification and flotation.

Numerical Simulation of Effects of Microbial Action on CO2 Geological Storage in Deep Saline Aquifers

CO2 geological storage (CGS) is a crucial strategy for meeting CO2 emission reduction targets. However, the effect of microbial action on CGS in deep saline aquifer is unclear. In this paper, numerical simulations based on previous experimental data were conducted to investigate CO2 solubility-trapping and mineral-trapping by microbial-mediated process in CGS demonstration base in Ordos, north of China. The simulation results reveal that the presence of a microbial community has a positive influence on CGS, mainly in terms of the amount of CO2 that can be injected and the manner by which it is stored. With the effect of microbial action, the amount of injected CO2 was increased by 23.33% and the CO2 mineral sequestration increased from 1.12 to 2.05%. In addition, microbial action plays different roles at different stages of CGS. In the initial stage of CO2 injection, the microbial action promotes dissolution of calcite, oligoclase and clay minerals such as chlorite and kaolinite, providing a favorable condition (more K+, Ca2+, Na+, Mg2+, Fe2+ and HCO3−) for CO2 mineral-trapping. In the following stage of CGS, microbial action accelerates the precipitation of carbon-fixing minerals such as calcite and siderite, enhancing the CO2 storage security in deep saline aquifer. As such, secondary minerals such as ferroan dolomite and dawsonite were observed in advance in microbially mediated CO2–saline–sandstone interactions, further indicating that microbes play a positive role in CO2 mineral-trapping. Consequently, the microbial action can promote mineral capture of CO2 and increase the CO2 storage security in deep saline aquifer. These conclusions can provide a reference and basis for the suitability assessment of CGS in such deep saline aquifer like Erdos, China.

CO2 mineral sequestration by using blast furnace slag: From batch to continuous experiments

CO2 mineral sequestration is a promising strategy to combat global warming. Indirect CO2 mineral sequestration was proposed in our previous study by using blast furnace slag as feedstock. As the continuity of this research, the continuous experiment process was carried out in a self-designed rotary kiln, and the results were compared with those of the batch experiment. The results showed that several problematic situations, such as the formation of kiln rings, insufficient mass, and heat transfer, occurred in the continuous experiment. A “returning charge” operation by adding an inert component into the feedstock was suggested for the prevention of ring formation and achieved good results. The reaction conditions for the continuous experiment were harsher than those of the batch experiment due to the scale-up effects. Preliminary analysis of CO2 net-emission reduction was conducted based on the continuous experimental results. It was shown that the net reduction of CO2 emissions amounted to 36 kg for 1000 kg of blast furnace slag processed. The results demonstrated in this study can act as guidance for pilot- or industrial-scale applications of indirect CO2 mineral sequestration technologies, especially for process parameter optimization and equipment design.

Mechanism of Nickel, Magnesium, and Iron Recovery from Olivine Bearing Ore during Leaching with Hydrochloric Acid Including a Carbonation Pre-Treatment

This work continues on from previous studies showing that mineral sequestration by carbonation of magnesium or calcium silicates under high pressure and high temperature can be successfully carried out by processing in an autoclave. The paper is focused on the influence of experimental parameters on avoiding scale formation during pre-treatment in an autoclave and a subsequent leaching. Amorphous silica and magnesite, respectively, were the main reaction products in a carbonation of olivine under high pressure conditions in an autoclave. In addition, the examined peridotites may be accompanied by small to medium amounts of nickel or other metals, the recovery of which will be investigated in the present study: Extraction of metals such as nickel, iron, and magnesium from olivine bearing ore using hydrochloric acid under atmospheric pressure was studied between 50 and 90 °C in 1 h. The obtained results have shown maximal leaching efficiency of about 35% for Ni, Fe, and Mg under atmospheric pressure, in comparison to more than 60% obtained under the same conditions after a carbonation pre-treatment in an autoclave. Silica gel was formed during leaching without a pre-treatment of peridotite blocking the leaching process, which is not the case for the pre-treated material. The influence of temperature, reaction time, particle size and pre-treatment of peridotite in an autoclave during carbonation at 175 °C and 71.5 bar was studied. A new mechanism model for metal extraction from olivine-bearing ore by avoiding silica gel formation during leaching with hydrochloric acid including a carbonation pre-treatment is proposed. This study explains additionally a behavior of metals such as nickel, magnesium, and iron during a carbonation of olivine bearing ore and leaching of a carbonated solid product.

The potential of FBC fly ashes to reduce CO2 emissions

The production of electricity and heat in Poland is the reason why the commercial power industry is the largest emitter of CO2. At the same time, significant amounts of solid by-products of combustion, which can be used to bind CO2 by mineral carbonation, are generated during the production processes. The article presents the results of research on mineral sequestration of CO2 (suspension-CO2) using fluidized bed combustion (FBC) fly ashes from hard coal combustion. The analyzed fluidized bed combustion (FBC) fly ashes were characterized by a significant free CaO content (1.7–6.8%) and a high CO2 binding potential ranging from 9.7 to 15.7%. In the case of fluidized bed combustion (FBC) fly ashes suspensions, the basic product of the carbonation process is calcium carbonate, which is clearly indicated by the results of the phase composition determination of solidified suspensions of fluidized bed combustion (FBC) fly ashes. The degree of carbonation, i.e. the degree of CO2 binding, calculated on the basis of the calcium carbonate content, in the analyzed suspensions was up to 1.1%. Mineral carbonation also reduces the leachability of pollutants such as: Zn, Cu, Pb, Ni, As, Hg, Cd, Cr, Cl, and SO42-. The pH is also reduced from about 12 to about 9. Aqueous suspensions of fluidized bed combustion (FBC) fly ashes with introduced CO2 can potentially be used in underground mining. These activities are in line with the concepts of Carbon Capture and Utilization and the idea of circular economy.

Design and evaluation of collagen-inspired mineral-hydrogel nanocomposites for bone regeneration

Bone loss due to trauma and tumors remains a serious clinical concern. Due to limited availability and disease transmission risk with autografts and allografts, calcium phosphate bone fillers and growth factor-based substitute bone grafts are currently used in the clinic. However, substitute grafts lack bone regeneration potential when used without growth factors. When used along with the added growth factors, they lead to unwanted side effects such as uncontrolled bone growth. Collagen-based hydrogel grafts available on the market fail to provide structural guidance to native cells due to high water-solubility and faster degradation. To overcome these limitations, we employed bioinspired material design and fabricated three different hydrogels with structural features similar to native collagen at multiple length-scales. These hydrogels fabricated using polyionic complexation of oppositely charged natural polysaccharides exhibited multi-scale architecture mimicking nanoscale banding pattern, and microscale fibrous structure of native collagen. All three hydrogels promoted biomimetic apatite-like mineral deposition in vitro elucidating crystalline structure on the surface while amorphous calcium phosphate inside the hydrogels resulting in mineral-hydrogel nanocomposites. When evaluated in a non-load bearing critical size mouse calvaria defect model, chitosan - kappa carrageenan mineral-hydrogel nanocomposites enhanced bone regeneration without added growth factors compared to empty defect as well as widely used marketed collagen scaffolds. Histological assessment of the regenerated bone revealed improved healing and tissue remodeling with mineral-hydrogel nanocomposites. Overall, these collagen-inspired mineral-hydrogel nanocomposites showed multi-scale hierarchical structure and can potentially serve as promising bioactive hydrogel to promote bone regeneration. Statement of SignificanceHydrogels, especially collagen, are widely used in bone tissue engineering. Collagen fibrils play arguably the most important role during natural bone development. Its multi-scale hierarchical structure to form fibers from fibrils and electrostatic charges enable mineral sequestration, nucleation, and growth. However, bulk collagen hydrogels exhibit limited bone regeneration and are mostly used as carriers for highly potent growth factors such as bone morphogenic protein-2, which increase the risk of uncontrolled bone growth. Thus, there is an unmet clinical need for a collagen-inspired biomaterial that can recreate structural hierarchy, mineral sequestration ability, and stimulate recruitment of host progenitor cells to facilitate bone regeneration. Here, we propose collagen-inspired bioactive mineral-hydrogel nanocomposites as a growth factor-free approach to guide and enhance bone regeneration.

Utilization of Mineral Sequestration for CO2 Capturing in Car Parks and Tunnels

Decreasing the emissions of CO2 that come from vehicle exhaust, especially in car parking and tunnels, is so vital. CO2 emissions cause corrosion to a reinforcement of concrete. Thus, there is a need to provide a layer that protects the reinforcement from the reach of this harmful gas. This work goals to investigate the efficiency of using board units from Pozzolime concrete and pervious concrete to sequestrate CO2 from the environment and then to convert it into calcium carbonate inside the concrete. The units have dimensions of (200×400×40±5). All specimens were cured in a water tank after about 48 hours after casting. Then paint the sample from all surfaces (three layers) excluding the top surface. The pervious concrete and Pozzolime specimens, at age of 28 days, were put in the chamber, then the gas was supplied to the chamber with concentrations of 15%, 25%, and 50 %, for 24 hours. The efficiency was evaluated through carbonation depth, CO2-uptake, and weight change. The results showed that the maximum CO2 uptake was recorded at the age of 28 days for Pozzolime concrete when exposed to 50% of CO2 concentration.

Soil and geologic formations as antidotes for CO2 sequestration?

AbstractRapid and far‐reaching transitions are required to combat climate change and its impacts. Carbon capture and storage within mineral deposits is a promising solution to remove CO2 from the atmosphere. In‐situ geological storage and ex‐situ mineral sequestration are practically sufficient for sequestering all the anthropogenic CO2. Recent research reports that more than 95% of injected CO2 was mineralized into carbonates in two years by using in‐situ geological approach, and mining wastes and secondary minerals were recycled as resources for ex‐situ CO2 sequestration. However, geological activity is the major risk of in‐situ storage, while high energy consumption and associated cost may limit the application of ex‐situ carbonation. Significant technical breakthroughs of mineral and geological CO2 sequestration are therefore of vital importance to realize a “net‐zero CO2 emissions” and even “carbon‐negative” society.

An efficient methodology to use hydrolysate of phosphogypsum decomposition products for CO2 mineral sequestration and calcium carbonate production

There is an urgent need to find new, improved ways to reduce CO2 emissions and treat phosphogypsum (PG) waste. This research proposes an energy-efficient methodology for the production of pure calcium carbonate and CO2 mineral sequestration (CMS) by hydrolysate of PG decomposition products. The technical feasibility of this process and the influence of process variables on CMS were investigated using online experiments. Pure calcium carbonate was obtained by CO2 separation and mineralization using the hydrolysis solution of PG decomposition products. A carbonization rate greater than 90% was obtained when the liquid phase absorption reached saturation. In addition, lower temperatures and higher CO2 partial pressures favoured CMS. To confirm the operating strategy underlying calcium carbonate crystallization, real-time experiments data obtained from process analytical technologies (PATs) and solutions of population balance equations were used to determine parameters of crystallization kinetic models. The match between model simulation experiments and online experimental results throughout the crystallization process confirms the robustness of our findings.

A Review of CO2 Storage in View of Safety and Cost-Effectiveness

The emissions of greenhouse gases, especially CO2, have been identified as the main contributor for global warming and climate change. Carbon capture and storage (CCS) is considered to be the most promising strategy to mitigate the anthropogenic CO2 emissions. This review aims to provide the latest developments of CO2 storage from the perspective of improving safety and economics. The mechanisms and strategies of CO2 storage, focusing on their characteristics and current status, are discussed firstly. In the second section, the strategies for assessing and ensuring the security of CO2 storage operations, including the risks assessment approach and monitoring technology associated with CO2 storage, are outlined. In addition, the engineering methods to accelerate CO2 dissolution and mineral carbonation for fixing the mobile CO2 are also compared within the second section. The third part focuses on the strategies for improving economics of CO2 storage operations, namely enhanced industrial production with CO2 storage to generate additional profit, and co-injection of CO2 with impurities to reduce the cost. Moreover, the role of multiple CCS technologies and their distribution on the mitigation of CO2 emissions in the future are summarized. This review demonstrates that CO2 storage in depleted oil and gas reservoirs could play an important role in reducing CO2 emission in the near future and CO2 storage in saline aquifers may make the biggest contribution due to its huge storage capacity. Comparing the various available strategies, CO2-enhanced oil recovery (CO2-EOR) operations are supposed to play the most important role for CO2 mitigation in the next few years, followed by CO2-enhanced gas recovery (CO2-EGR). The direct mineralization of flue gas by coal fly ash and the pH swing mineralization would be the most promising technology for the mineral sequestration of CO2. Furthermore, by accelerating the deployment of CCS projects on large scale, the government can also play its role in reducing the CO2 emissions.