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Mutadza I, Ikiensikimama SS, Joel OF. Geo-mechanical and geo-morphology characterisation of the cap rocks in the Niger Delta for potential carbon capture and storage. Heliyon 2024; 10:e31206. [PMID: 38803952 PMCID: PMC11128909 DOI: 10.1016/j.heliyon.2024.e31206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 05/03/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024] Open
Abstract
The world has been battling climate change which is caused by an excessive amount of carbon dioxide in the atmosphere. Carbon sequestration in geological sinks was identified as one of the major methods to curb and reduce the amount of carbon dioxide in the atmosphere. The carbon dioxide stored in the geological formations must not escape back into the atmosphere. Characterisation of potential reservoirs for geological sequestration is pertinent for injectivity, capacity, and most importantly containment of carbon dioxide. The cap rock is one of the most important factors determining carbon sequestration success. This study focuses on the preliminary characterisation of the caprocks for evaluating potential subsurface storage of carbon dioxide based on their petrophysical characteristics. X-ray Diffraction and X-ray Fluorescence provided the mineralogical composition and geochemical data of the cap rocks while Scanning Electron Microscopy-EDS was used to identify the qualitative information on the micromorphological textural structure of the cap rocks in the Niger Delta. Conventional Triaxial experiments were used to determine the elastic and geo-mechanical strength of the caprocks. It was identified that the grain skeleton of caprocks in the region is predominated by Quartz, Albite, and Muscovite. The ratio of the tectosilicate and phyllosilicate minerals indicates that the cap rocks are silicate shale. The peak strength of the caprocks ranged from 48.85 to 80.50 MPa and are classified as strong rocks. The cap rocks showed a quasi-elastic behaviour after being subjected to compressive axial force. The elastic modulus of the caprocks was also observed. The characteristics exhibited by the shale caprock at the rock matrix level are highly favourable for sealing carbon dioxide and hence indicate capability for use in carbon sequestration.
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Affiliation(s)
- Itai Mutadza
- University of Port Harcourt, East-West Road, Port Harcourt, Nigeria
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2
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Cao TD, Snyder SW, Lin YI, Lin YJ, Negi S, Pan SY. Unraveling the Potential of Electrochemical pH-Swing Processes for Carbon Dioxide Capture and Utilization. Ind Eng Chem Res 2023; 62:20979-20995. [PMID: 38107749 PMCID: PMC10722509 DOI: 10.1021/acs.iecr.3c02183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/27/2023] [Accepted: 09/28/2023] [Indexed: 12/19/2023]
Abstract
Global warming, driven by the accumulation of anthropogenic greenhouse gases, particularly CO2, in the atmosphere, has garnered significant attention due to its detrimental environmental impacts. To combat this critical issue, the deployment of CO2 capture and utilization (CCU) strategies has been considered as one of the technology-based solutions, leading to extensive scientific and engineering research. Electrochemical pH-swing (EPS) processes offer a promising approach to diverse CCU pathways, such as the delivery of pure CO2 gas, the delivery of bicarbonate (e.g., for microalgae cultivation), and the formation of carbonate minerals. In this study, we discuss several CCU pathways using EPS and provide an in-depth analysis of its mechanisms and potential applications, outlining its limitations from both thermodynamic and kinetic standpoints. The EPS process has demonstrated remarkable capabilities, achieving a CO2 capture efficiency of over 90% and unlocking valuable opportunities for CCU applications. We also develop an initial techno-economic assessment and provide the perspectives and challenges for future development and deployment of EPS. This study sheds light on the integration of EPS with CCU, closing the carbon cycle by effectively utilizing the products generated through the process, such as carbonate minerals and bicarbonate solution. For instance, the bicarbonate product can serve as a viable feedstock for bicarbonate-based microalgae production systems, with the added benefit of reducing costs by 40-80% compared to traditional gaseous CO2 delivery approaches. By integration of electrochemical technologies with CCU methods, this study underscores the immense potential for mitigating CO2 emissions and advancing sustainable practices to combat global warming. This study not only addresses the urgent need for effective solutions but also paves the way for a greener and more sustainable future.
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Affiliation(s)
- Thanh
Ngoc-Dan Cao
- Department
of Bioenvironmental Systems Engineering, College of Bioresources and
Agriculture, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan ROC
| | - Seth W Snyder
- Energy
and Environment Science & Technology, Idaho National Laboratory, Idaho Falls 83415, Idaho United States
| | - Yu-I Lin
- Department
of Bioenvironmental Systems Engineering, College of Bioresources and
Agriculture, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan ROC
| | - Yupo J Lin
- Applied
Materials Division, Argonne National Laboratory, Lemont, Illinois 60439, United Statesa
| | - Suraj Negi
- Department
of Bioenvironmental Systems Engineering, College of Bioresources and
Agriculture, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan ROC
| | - Shu-Yuan Pan
- Department
of Bioenvironmental Systems Engineering, College of Bioresources and
Agriculture, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan ROC
- Agricultural
Net-Zero Carbon Technology and Management Innovation Research Center,
College of Bioresources and Agriculture, National Taiwan University, Taipei City, 10617 Taiwan, ROC
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3
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Zhu P, Wu ZY, Elgazzar A, Dong C, Wi TU, Chen FY, Xia Y, Feng Y, Shakouri M, Kim JYT, Fang Z, Hatton TA, Wang H. Continuous carbon capture in an electrochemical solid-electrolyte reactor. Nature 2023; 618:959-966. [PMID: 37380692 DOI: 10.1038/s41586-023-06060-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 04/06/2023] [Indexed: 06/30/2023]
Abstract
Electrochemical carbon-capture technologies, with renewable electricity as the energy input, are promising for carbon management but still suffer from low capture rates, oxygen sensitivity or system complexity1-6. Here we demonstrate a continuous electrochemical carbon-capture design by coupling oxygen/water (O2/H2O) redox couple with a modular solid-electrolyte reactor7. By performing oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) redox electrolysis, our device can efficiently absorb dilute carbon dioxide (CO2) molecules at the high-alkaline cathode-membrane interface to form carbonate ions, followed by a neutralization process through the proton flux from the anode to continuously output a high-purity (>99%) CO2 stream from the middle solid-electrolyte layer. No chemical inputs were needed nor side products generated during the whole carbon absorption/release process. High carbon-capture rates (440 mA cm-2, 0.137 mmolCO2 min-1 cm-2 or 86.7 kgCO2 day-1 m-2), high Faradaic efficiencies (>90% based on carbonate), high carbon-removal efficiency (>98%) in simulated flue gas and low energy consumption (starting from about 150 kJ per molCO2) were demonstrated in our carbon-capture solid-electrolyte reactor, suggesting promising practical applications.
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Affiliation(s)
- Peng Zhu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Zhen-Yu Wu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Ahmad Elgazzar
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Changxin Dong
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA
| | - Tae-Ung Wi
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Feng-Yang Chen
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Yang Xia
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Yuge Feng
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Mohsen Shakouri
- Canadian Light Source Inc., University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jung Yoon Timothy Kim
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Zhiwei Fang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - T Alan Hatton
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Haotian Wang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX, USA.
- Department of Chemistry, Rice University, Houston, TX, USA.
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4
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Gupta AK, Gautam A, Mondal MK. Experimental, modeling and RSM optimization of CO2 loading for an aqueous blend of diethylenetriamine and 3-dimethyl amino-1-propanol. KOREAN J CHEM ENG 2023. [DOI: 10.1007/s11814-022-1300-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
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5
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Kamolov A, Turakulov Z, Rejabov S, Díaz-Sainz G, Gómez-Coma L, Norkobilov A, Fallanza M, Irabien A. Decarbonization of Power and Industrial Sectors: The Role of Membrane Processes. MEMBRANES 2023; 13:130. [PMID: 36837633 PMCID: PMC9964316 DOI: 10.3390/membranes13020130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/11/2023] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
Carbon dioxide (CO2) is the single largest contributor to climate change due to its increased emissions since global industrialization began. Carbon Capture, Storage, and Utilization (CCSU) is regarded as a promising strategy to mitigate climate change, reducing the atmospheric concentration of CO2 from power and industrial activities. Post-combustion carbon capture (PCC) is necessary to implement CCSU into existing facilities without changing the combustion block. In this study, the recent research on various PCC technologies is discussed, along with the membrane technology for PCC, emphasizing the different types of membranes and their gas separation performances. Additionally, an overall comparison of membrane separation technology with respect to other PCC methods is implemented based on six different key parameters-CO2 purity and recovery, technological maturity, scalability, environmental concerns, and capital and operational expenditures. In general, membrane separation is found to be the most competitive technique in conventional absorption as long as the highly-performed membrane materials and the technology itself reach the full commercialization stage. Recent updates on the main characteristics of different flue gas streams and the Technology Readiness Levels (TRL) of each PCC technology are also provided with a brief discussion of their latest progresses.
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Affiliation(s)
- Azizbek Kamolov
- Department of IT, Automation, and Control, Tashkent Chemical-Technological Institute, Tashkent 100011, Uzbekistan
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
| | - Zafar Turakulov
- Department of IT, Automation, and Control, Tashkent Chemical-Technological Institute, Tashkent 100011, Uzbekistan
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
| | - Sarvar Rejabov
- Department of IT, Automation, and Control, Tashkent Chemical-Technological Institute, Tashkent 100011, Uzbekistan
| | - Guillermo Díaz-Sainz
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
| | - Lucia Gómez-Coma
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
| | - Adham Norkobilov
- Department of IT, Automation, and Control, Tashkent Chemical-Technological Institute, Tashkent 100011, Uzbekistan
- Department of Engineering Technologies, Shahrisabz Branch of Tashkent Chemical-Technological Institute, Shahrisabz 181306, Uzbekistan
| | - Marcos Fallanza
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
| | - Angel Irabien
- Department of Chemical and Biomolecular Engineering, University of Cantabria, 39005 Santander, Spain
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6
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Teymouri M, Behfarnia K, Shabani A, Saadatian A. The Effect of Mixture Proportion on the Performance of Alkali-Activated Slag Concrete Subjected to Sulfuric Acid Attack. MATERIALS (BASEL, SWITZERLAND) 2022; 15:6754. [PMID: 36234095 PMCID: PMC9571105 DOI: 10.3390/ma15196754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Long-term deterioration and durability concerns in harsh environments with acidic attacks are considered as the weaknesses of ordinary Portland cement (OPC) concrete. Although the performance of alkali-activated slag concrete (AASC) has been reported to be superior in acidic environments, there is a poor understanding regarding the impacts of diverse mix design parameters on AASC durability in an acidic environment. This research aims to understand the impact of mix design parameters on the durability of AASC in the sulfuric acid (H2SO4) environment with pH = 3. The type of alkaline solution, the molarity of alkaline solutions, the weight ratio of alkaline solutions to slag, and the weight ratio of NaOH to Na2SiO3 are mix design parameters investigated in this study. The compressive strength reduction and weight loss were monitored from early ages up to 180 days. Moreover, an OPC concrete sample was produced as a reference.
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Affiliation(s)
- Mohammad Teymouri
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - Kiachehr Behfarnia
- Department of Civil Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Amirhosein Shabani
- Department of Civil Engineering and Energy Technology, Oslo Metropolitan University, Pilestredet 35, 0166 Oslo, Norway
| | - Armin Saadatian
- Department of Construction Management, Colorado State University, Fort Collins, CO 80523, USA
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7
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CO2 Emission and Cost Optimization of Concrete-Filled Steel Tubular (CFST) Columns Using Metaheuristic Algorithms. SUSTAINABILITY 2021. [DOI: 10.3390/su13148092] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Concrete-filled steel tubular columns have garnered wide interest among researchers due to their favorable structural characteristics. To attain the best possible performance from concrete-filled steel tubular columns while reducing the cost, the use of optimization algorithms is indispensable. In this regard, metaheuristic algorithms are finding increasing application in structural engineering due to their high efficiency. Various equations that predict the ultimate axial load-carrying capacity (Nu) of concrete-filled steel tubular columns are available in design codes as well as in the research literature. However, most of these equations are only applicable within certain parameter ranges. To overcome this limitation, the present study adopts a recently developed set of equations for the prediction of Nu that have broader ranges of applicability. Furthermore, a newly developed metaheuristic algorithm, called the social spider algorithm, is introduced and applied in optimizing the cross-section of circular concrete-filled steel tubular columns. The improvement of the structural dimensioning under the Nu constraint is demonstrated. The objective underlying the optimization presented here is to minimize the CO2 emission and cost associated with the fabrication of concrete-filled steel tubular stub columns. In this context, the relationships between the cross-sectional dimensioning of circular concrete-filled steel tubular columns and the associated CO2 emissions and cost are characterized and visualized.
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8
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Abstract
CO2-derived methanol and dimethyl ether can play a very important role as fuels, energy carriers, and bulk chemicals. Methanol production from CO2 and renewable hydrogen is considered to be one of the most promising pathways to alleviate global warming. In turn, methanol could be subsequently dehydrated into DME; alternatively, one-step CO2 conversion to DME can be obtained by hydrogenation on bifunctional catalysts. In this light, four oxide catalysts with the same Cu and Zn content (Cu/Zn molar ratio = 2) were synthesized by calcining the corresponding CuZnAl LDH systems modified with Zr and/or Ce. The fresh ex-LDH catalysts were characterized in terms of composition, texture, structure, surface acidity and basicity, and reducibility. Structural and acid–base properties were also studied on H2-treated samples, on which specific metal surface area and dispersion of metallic Cu were determined as well. After in situ H2 treatment, the ex-LDH systems were tested as catalysts for the hydrogenation of CO2 to methanol at 250 °C and 3.0 MPa. In the same experimental conditions, CO2 conversion into dimethyl ether was studied on bifunctional catalysts obtained by physically mixing the ex-LDH hydrogenation catalysts with acid ferrierite or ZSM-5 zeolites. For both processes, the effect of the Al/Zr/Ce ratio on the products distribution was investigated.
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9
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Faridmehr I, Nehdi ML, Nikoo M, Huseien GF, Ozbakkaloglu T. Life-Cycle Assessment of Alkali-Activated Materials Incorporating Industrial Byproducts. MATERIALS 2021; 14:ma14092401. [PMID: 34063038 PMCID: PMC8125601 DOI: 10.3390/ma14092401] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/17/2021] [Accepted: 05/03/2021] [Indexed: 11/25/2022]
Abstract
Eco-friendly and sustainable materials that are cost-effective, while having a reduced carbon footprint and energy consumption, are in great demand by the construction industry worldwide. Accordingly, alkali-activated materials (AAM) composed primarily of industrial byproducts have emerged as more desirable alternatives to ordinary Portland cement (OPC)-based concrete. Hence, this study investigates the cradle-to-gate life-cycle assessment (LCA) of ternary blended alkali-activated mortars made with industrial byproducts. Moreover, the embodied energy (EE), which represents an important parameter in cradle-to-gate life-cycle analysis, was investigated for 42 AAM mixtures. The boundary of the cradle-to-gate system was extended to include the mechanical and durability properties of AAMs on the basis of performance criteria. Using the experimental test database thus developed, an optimized artificial neural network (ANN) combined with the cuckoo optimization algorithm (COA) was developed to estimate the CO2 emissions and EE of AAMs. Considering the lack of systematic research on the cradle-to-gate LCA of AAMs in the literature, the results of this research provide new insights into the assessment of the environmental impact of AAM made with industrial byproducts. The final weight and bias values of the AAN model can be used to design AAM mixtures with targeted mechanical properties and CO2 emission considering desired amounts of industrial byproduct utilization in the mixture.
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Affiliation(s)
- Iman Faridmehr
- Institute of Architecture and Construction, South Ural State University, Lenin Prospect 76, 454080 Chelyabinsk, Russia;
| | - Moncef L. Nehdi
- Department of Civil and Environmental Engineering, Western University, London, ON N6A 5B9, Canada
- Correspondence:
| | - Mehdi Nikoo
- Young Researchers and Elite Club, Ahvaz Branch, Islamic Azad University, Ahvaz 61349-37333, Iran;
| | - Ghasan Fahim Huseien
- Department of Building, School of Design and Environment, National University of Singapore, Singapore 117566, Singapore;
| | - Togay Ozbakkaloglu
- Ingram School of Engineering, Texas State University, San Marcos, TX 78666-78667, USA;
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10
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Innovative Gas-Liquid Membrane Contactor Systems for Carbon Capture and Mineralization in Energy Intensive Industries. MEMBRANES 2021; 11:membranes11040271. [PMID: 33917973 PMCID: PMC8068349 DOI: 10.3390/membranes11040271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/31/2021] [Accepted: 04/02/2021] [Indexed: 11/16/2022]
Abstract
CO2 mineralization is an alternative to conventional geological storage and results in permanent carbon storage as a solid, with no need for long-term monitoring and no requirements for significant energy input. Novel technologies for carbon dioxide capture and mineralization involve the use of gas-liquid membrane contactors for post-combustion capture. The scope of the present study is to investigate the application of hollow fiber membrane contactor technology for combined CO2 capture from energy-intensive industry flue gases and CO2 mineralization, in a single-step multiphase process. The process is also a key enabler of the circular economy for the cement industry, a major contributor in global industrial CO2 emissions, as CaCO3 particles, obtained through the mineralization process, can be directed back into the cement production as fillers for partially substituting cement in high-performance concrete. High CO2 capture efficiency is achieved, as well as CaCO3 particles of controlled size and crystallinity are synthesized, in every set of operating parameters employed. The intensified gas-liquid membrane process is assessed by calculating an overall process mass transfer coefficient accounting for all relevant mass transfer resistances and the enhanced mass transfer due to reactive conditions on the shell side. The obtained nanocomposite particles have been extensively characterized by DLS, XRD, TGA, SEM, TEM, and FTIR studies, revealing structured aggregates (1–2 μm average aggregate size) consisting of cubic calcite when the contactor mode is employed.
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11
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Lai WH, Hong CY, Tseng HH, Wey MY. Fabrication of waterproof gas separation membrane from plastic waste for CO 2 separation. ENVIRONMENTAL RESEARCH 2021; 195:110760. [PMID: 33493535 DOI: 10.1016/j.envres.2021.110760] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
In this study, waste polystyrene (wPS) plastic was used to prepare gas-separation membranes with hot-pressing technology to reduce the accumulation of plastic waste. Polystyrene is a commonly used polymer for the production of plastic products, and it is also used in the synthesis of membranes for gas separation. Compared to the traditional synthesis process, hot-pressing is environmentally friendly because it does not require organic solvents. The mobility of the polymer chain and the integrity and free volume of the membrane are affected by the temperature, pressure, duration, and annealing environment of the hot-pressing process, thereby altering the performance of the membrane. Additionally, when the wPS contained polybutadiene, the gas separation membranes showed a selectivity of 17.14 for CO2/N2. The membranes also exhibited ideal waterproof performance when the membranes were operated under water pressures of 1-5 bar. Therefore, membranes derived from wPS through hot pressing are waterproof and can be used for gas separation. Furthermore, they are expected to maintain their separation performance in complex environments.
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Affiliation(s)
- Wen-Hsiung Lai
- Department of Environmental Engineering, National Chung Hsing University, Taichung, 402, Taiwan, ROC
| | - Chen-Yao Hong
- Department of Environmental Engineering, National Chung Hsing University, Taichung, 402, Taiwan, ROC
| | - Hui-Hsin Tseng
- School of Occupational Safety and Health, Chung Shan Medical University, Taichung, 402, Taiwan, ROC; Department of Occupational Medicine, Chung Shan Medical University Hospital, Taichung, 402, Taiwan, ROC.
| | - Ming-Yen Wey
- Department of Environmental Engineering, National Chung Hsing University, Taichung, 402, Taiwan, ROC.
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CO 2 Sequestration in the Production of Portland Cement Mortars with Calcium Carbonate Additions. NANOMATERIALS 2021; 11:nano11040875. [PMID: 33808156 PMCID: PMC8066617 DOI: 10.3390/nano11040875] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 03/25/2021] [Accepted: 03/27/2021] [Indexed: 11/30/2022]
Abstract
The paper presents the obtention and characterization of Portland cement mortars with limestone filler and nano-calcite additions. The nano-calcite was obtained by the injection of CO2 in a nano-Ca(OH)2 suspension. The resulted nano-CaCO3 presents different morphologies, i.e., polyhedral and needle like crystals, depending on the initial Ca(OH)2 concentration of the suspension. The formation of calcium carbonate in suspensions was confirmed by X-ray diffraction (XRD), complex thermal analysis (DTA-TG), scanning electron microscopy (SEM) and transmission electron microscopy (TEM and HRTEM). This demonstrates the viability of this method to successfully sequestrate CO2 in cement-based materials. The use of this type of nano-CaCO3 in mortar formulations based on PC does not adversely modify the initial and final setting time of cements; for all studied pastes, the setting time decreases with increase of calcium carbonate content (irrespective of the particle size). Specific hydrated phases formed by Portland cement hydration were observed in all mortars, with limestone filler additions or nano-CaCO3, irrespective of curing time. The hardened mortars with calcium carbonate additions (in adequate amounts) can reach the same mechanical strengths as reference (Portland cement mortar). The addition of nano-CaCO3 in the raw mix increases the mechanical strengths, especially at shorter hardening periods (3 days).
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13
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Lee YH, Eom H, Lee SM, Kim SS. Effects of pH and metal composition on selective extraction of calcium from steel slag for Ca(OH) 2 production. RSC Adv 2021; 11:8306-8313. [PMID: 35423306 PMCID: PMC8695367 DOI: 10.1039/d0ra08497b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 02/04/2021] [Indexed: 11/21/2022] Open
Abstract
This research article explains the effects of pH and metal composition on the selective calcium extraction from steel slag. The operating parameters including extraction solvent type, solvent concentration, metal composition of steel slag, substance type and pH were investigated. HCl, NH4Cl, NH4OH and NaOH were employed as solvents to extract Ca from steel slag. It has been shown that hydrochloric acid effectively extracts Ca. The high metal content in steel slag reacted sensitively to the solvent concentration, and a specific concentration was derived to selectively extract Ca. The optimal solvent for calcium extraction was 2 M HCl, which induced the extraction of 97% of Ca; 46% of Mg; 35% of Al; and 1% of Si from the steel slag. In order to separate Ca in the leaching solution from other metal ions, various acidic/basic substances were added to regulate the pH. The optimal pH level for removing the impurities without calcium was found to be 9.5. The precipitated impurities were removed by filtration, and the pH was adjusted to 13 or higher for Ca(OH)2(s) production. In conclusion, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) revealed that the Ca content produced through the process was more than 99%. It is expected that high-purity Precipitated Calcium Carbonate (PCC) will be achieved when the generated Ca(OH)2 is used as a source of calcium for mineral carbonation. This research article explains the effects of pH and metal composition on the selective calcium extraction from steel slag.![]()
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Affiliation(s)
- Ye Hwan Lee
- Department of Environmental Energy Engineering, Graduate School of Kyonggi University 94-6 San, Iui-dong, Youngtong-ku Suwon-si Gyeonggi-do 442-760 Korea
| | - Hanki Eom
- Department of Environmental Energy Engineering, Kyonggi University 94-6 San, Iui-dong, Youngtong-ku Suwon-si Gyeonggi-do 442-760 Korea
| | - Sang Moon Lee
- Department of Environmental Energy Engineering, Kyonggi University 94-6 San, Iui-dong, Youngtong-ku Suwon-si Gyeonggi-do 442-760 Korea
| | - Sung Su Kim
- Department of Environmental Energy Engineering, Kyonggi University 94-6 San, Iui-dong, Youngtong-ku Suwon-si Gyeonggi-do 442-760 Korea
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14
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Aghajanian S, Koiranen T. Dynamic modeling and semibatch reactive crystallization of calcium carbonate through CO2 capture in highly alkaline water. J CO2 UTIL 2020. [DOI: 10.1016/j.jcou.2020.02.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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