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Khudhur FWK, MacDonald JM, Daly L, Macente A, Spruženiece L, Griffin S, Wilson C. Microstructural analysis of slag properties associated with calcite precipitation due to passive CO 2 mineralization. Micron 2023; 174:103532. [PMID: 37683551 DOI: 10.1016/j.micron.2023.103532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/21/2023] [Accepted: 08/28/2023] [Indexed: 09/10/2023]
Abstract
CO2 mineralization in slag has gained significant attention since it occurs with minimal human intervention and energy input. While the amount of theoretical CO2 that can be captured within slag has been quantified based on slag composition in several studies, the microstructural and mineralogical effects of slag on its ability to capture CO2 have not been fully addressed. In this work, the CO2 uptake within legacy slag samples is analyzed through microstructural characterization. Slag samples were collected from the former Ravenscraig steelmaking site in Lanarkshire, Scotland. The collected samples were studied using X-ray Computed Tomography (XCT) to understand the distribution and geometry of pore space, as well as with scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) to visualize the distribution of elements within the studied samples. Electron backscatter diffraction (EBSD) was used to study the minerals distribution. The samples were also characterized through X-ray diffraction (XRD) and X-ray fluorescence (XRF), and the amount of captured CO2 was quantified using thermogravimetric analysis (TGA). Our results demonstrate that CO2 uptake occurs to the extent of ∼9-30 g CO2/ kg slag. The studied samples are porous in nature, with pore space occupying up to ∼30% of their volumes, and they are dominated by åkermanite-gehlenite minerals which interact with the atmospheric CO2 slowly at ambient conditions. EDS and EBSD results illustrate that the precipitated carbonate in slag is calcite, and that the precipitation of calcite is accompanied by the formation of a Si-O-rich layer. The provided analysis concludes that the porous microstructure as well as the minerals distribution in slag should be considered in forecasting and designing large-scale solutions for passive CO2 mineralization in slag.
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Affiliation(s)
- Faisal W K Khudhur
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK.
| | - John M MacDonald
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Luke Daly
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK; Australian Centre for Microscopy and Microanalysis, University of Sydney, Sydney 2006, NSW, Australia; Department of Materials, University of Oxford, Oxford OX1 3PH, UK
| | - Alice Macente
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK; Department of Civil and Environmental Engineering, University of Strathclyde, Glasgow G1 1XJ, UK; School of Civil Engineering, University of Leeds, Leeds LS2 9JT, UK
| | - Liene Spruženiece
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK; Geoanalytical Electron Microscopy and Spectroscopy (GEMS) Laboratory, University of Glasgow, Glasgow G12 8QQ, UK
| | - Sammy Griffin
- School of Geographical and Earth Sciences, University of Glasgow, Glasgow G12 8QQ, UK
| | - Claire Wilson
- School of Chemistry, University of Glasgow, Glasgow G12 8QQ, UK
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Ivanova TK, Kremenetskaya IP, Marchevskaya VV, Slukovskaya MV, Drogobuzhskaya SV. Magnesium Silicate Binding Materials Formed from Heat-Treated Serpentine-Group Minerals and Aqueous Solutions: Structural Features, Acid-Neutralizing Capacity, and Strength Properties. MATERIALS (BASEL, SWITZERLAND) 2022; 15:ma15248785. [PMID: 36556591 PMCID: PMC9786796 DOI: 10.3390/ma15248785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/29/2022] [Accepted: 12/05/2022] [Indexed: 05/27/2023]
Abstract
The influence of structural features of three serpentine-group minerals (antigorite, chrysotile, and lizardite) on the hydration of heat-treated materials and the formation of magnesium silicate binder has been studied. Initial serpentine samples have been fired in the interval 550-800 °C with a step of 50 °C; acid neutralization capacity (ANC) values have been determined for all samples. Antigorite samples (SAP) have exhibited a maximum reactivity at a temperature of 700 °C (ANC 7.7 meq/g). We have established that the acid-neutralizing capacity of chrysotile and lizardite samples in the temperature range of 650-700 °C differ slightly; the capacity varied in the interval of 19.6-19.7 meq/g and 19.6-19.7 meq/g, respectively. The samples obtained at optimal temperatures (antigorite-700 °C, lizardite, and chrysotile-650 °C) have been studied. Heat-treated serpentines have interacted with water vapor for a year; serpentine hydration has been investigated. The strength characteristics of the resulting binder agents were studied after 7, 28, 180, and 360 days. Upon hardening within 7 days, the strengths of the SAP and SCH samples have been almost the same (2.2 MPa), whereas this indicator for the SLH and SLK samples has been significantly lower (0.5 MPa). After hardening for over a year, the chrysotile sample SCH had the highest strength (about 8 MPa), whereas the strength of antigorite SAP was 3 MPa. The samples of initial, heat-treated, and hydrated heat-treated serpentines have been studied using XRD, differential scanning calorimetry, and surface texture analysis. The serpentine structure is crucial in destroying the mineral crystal lattice during heat treatment. In contrast to heat-treated chrysotile and lizardite, antigorite did not adsorb water. Structural features of chrysotile provided the highest compressive strength of the binding agent compared with antigorite and lizardite. The acid-neutralizing ability of lizardite was noticeably higher than antigorite, whereas its compressive strength was lower due to the layered mineral structure and impurities. We have established that the minerals' structural features are crucial for the hydration of heat-treated serpentines; the structure determines material utilization in various environmental technologies.
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Affiliation(s)
- Tatiana K. Ivanova
- I.V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
- Laboratory of Nature-inspired Technologies and Environmental Safety of the Arctic, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
| | - Irina P. Kremenetskaya
- I.V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
| | | | - Marina V. Slukovskaya
- I.V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
- Laboratory of Nature-inspired Technologies and Environmental Safety of the Arctic, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
| | - Svetlana V. Drogobuzhskaya
- I.V. Tananaev Institute of Chemistry and Technology of Rare Elements and Mineral Raw Materials, Kola Science Centre, Russian Academy of Sciences, 184209 Apatity, Russia
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Onutai S, Sato J, Osugi T. Possible pathway of zeolite formation through alkali activation chemistry of metakaolin for geopolymer–zeolite composite materials: ATR-FTIR study. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2022.123808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Benhelal E, Shamsaei E, Rashid MI. Challenges against CO 2 abatement strategies in cement industry: A review. J Environ Sci (China) 2021; 104:84-101. [PMID: 33985750 DOI: 10.1016/j.jes.2020.11.020] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 11/11/2020] [Accepted: 11/13/2020] [Indexed: 06/12/2023]
Abstract
Cement industry is an intensive source of fuel consumption and greenhouse gases (GHGs) emissions. This industry is responsible for 5% of GHGs emissions and is among the top industrial sources of carbon dioxide (CO2) emissions. Therefore, CO2 emissions reduction from cement production process has been always an appealing subject for researches in universities and industry. Various efforts have been carried out to mitigate the huge mass of CO2 emissions from the cement industry. Although, majority of these strategies are technically viable, due to various barriers, the level of CO2 mitigation in cement industry is still not satisfactory. Among numerous researches on this topic, only a few have tried to answer why CO2 abatement strategies are not globally practiced yet. This work aims to highlight the challenges and barriers against widespread and effective implementation of CO2 mitigation strategies in the cement industry and to propose practical solutions to overcome such barriers.
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Affiliation(s)
- Emad Benhelal
- Department of Chemical Engineering, The University of Newcastle, New South Wales 2287, Australia.
| | - Ezzatollah Shamsaei
- Department of Civil Engineering, Monash University, Clayton 3800, Victoria, Australia
| | - Muhammad Imran Rashid
- Chemical, Polymer and Composite Materials Engineering Department, University of Engineering and Technology, Lahore (New Campus) 39021, Pakistan
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Rashid M, Benhelal E, Farhang F, Oliver T, Stockenhuber M, Kennedy E. Application of concurrent grinding in direct aqueous carbonation of magnesium silicates. J CO2 UTIL 2021. [DOI: 10.1016/j.jcou.2021.101516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ostovari H, Müller L, Skocek J, Bardow A. From Unavoidable CO 2 Source to CO 2 Sink? A Cement Industry Based on CO 2 Mineralization. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:5212-5223. [PMID: 33735574 DOI: 10.1021/acs.est.0c07599] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The cement industry emits 7% of the global anthropogenic greenhouse gas (GHG) emissions. Reducing the GHG emissions of the cement industry is challenging since cement production stoichiometrically generates CO2 during calcination of limestone. In this work, we propose a pathway towards a carbon-neutral cement industry using CO2 mineralization. CO2 mineralization converts CO2 into a thermodynamically stable solid and byproducts that can potentially substitute cement. Hence, CO2 mineralization could reduce the carbon footprint of the cement industry via two mechanisms: (1) capturing and storing CO2 from the flue gas of the cement plant, and (2) reducing clinker usage by substituting cement. However, CO2 mineralization also generates GHG emissions due to the energy required for overcoming the slow reaction kinetics. We, therefore, analyze the carbon footprint of the combined CO2 mineralization and cement production based on life cycle assessment. Our results show that combined CO2 mineralization and cement production using today's energy mix could reduce the carbon footprint of the cement industry by 44% or even up to 85% considering the theoretical potential. Low-carbon energy or higher blending of mineralization products in cement could enable production of carbon-neutral blended cement. With direct air capture, the blended cement could even become carbon-negative. Thus, our results suggest that developing processes and products for combined CO2 mineralization and cement production could transform the cement industry from an unavoidable CO2 source to a CO2 sink.
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Affiliation(s)
- Hesam Ostovari
- Institute of Technical Thermodynamics, RWTH Aachen University, 52062 Aachen, Germany
| | - Leonard Müller
- Institute of Technical Thermodynamics, RWTH Aachen University, 52062 Aachen, Germany
| | - Jan Skocek
- Global R&D, HeidelbergCement AG, Oberklamweg 2-4, 69181 Leimen, Germany
| | - André Bardow
- Institute of Technical Thermodynamics, RWTH Aachen University, 52062 Aachen, Germany
- Institute of Energy and Climate Research - Energy Systems Engineering (IEK-10), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
- Energy & Process Systems Engineering, ETH Zurich, Tannenstrasse 3, 8092 Zurich, Switzerland
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Rim G, Roy N, Zhao D, Kawashima S, Stallworth P, Greenbaum SG, Park AHA. CO 2 utilization in built environment via the PCO2 swing carbonation of alkaline solid wastes with different mineralogy. Faraday Discuss 2021; 230:187-212. [PMID: 34042933 DOI: 10.1039/d1fd00022e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbon mineralization to solid carbonates is one of the reaction pathways that can not only utilize captured CO2 but also potentially store it in the long term. In this study, the dissolution and carbonation behaviors of alkaline solid wastes (i.e., waste concrete) was investigated. Concrete is one of the main contributors to a large carbon emission in the built environment. Thus, the upcycling of waste concrete via CO2 utilization has multifaceted environmental benefits including CO2 emission reduction, waste management and reduced mining. Unlike natural silicate minerals such as olivine and serpentine, alkaline solid wastes including waste concrete are highly reactive, and thus, their dissolution and carbonation behaviors vary significantly. Here, both conventional acid (e.g., hydrochloric acid) and less studied carbonic acid (i.e., CO2 saturated water) solvent systems were explored to extract Ca from concrete. Non-stoichiometric dissolution behaviors between Ca and Si were confirmed under far-from-equilibrium conditions (0.1 wt% slurry density), and the re-precipitation of the extracted Si was observed at near-equilibrium conditions (5 wt% slurry density), when the Ca extraction was performed at a controlled pH of 3. These experiments, with a wide range of slurry densities, provided valuable insight into Si re-precipitation phenomena and its effect on the mass transfer limitation during concrete dissolution. Next, the use of the partial pressure of CO2 for the pH swing carbon mineralization process was investigated for concrete, and the results were compared to those of Mg-bearing silicate minerals. In the PCO2 swing process, the extraction of Ca was significantly limited by the precipitation of the carbonate phase (i.e., calcite), since CO2 bubbling could not provide a low enough pH condition for concrete-water-CO2 systems. Thus, this study showed that the two-step carbon mineralization via PCO2 swing, that has been developed for Mg-bearing silicate minerals, may not be viable for highly reactive Ca-bearing silicate materials (e.g., concrete). The precipitated calcium carbonate (PCC) derived from waste concrete via a pH swing process showed very promising results with a high CO2 utilization potential as an upcycled construction material.
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Affiliation(s)
- Guanhe Rim
- Department of Earth and Environmental Engineering, USA and Lenfest Center for Sustainable Energy, The Earth Institute, Columbia University, NY 10027, USA. and Department of Chemical Engineering, Columbia University, NY 10027, USA
| | - Noyonika Roy
- Lenfest Center for Sustainable Energy, The Earth Institute, Columbia University, NY 10027, USA. and Department of Chemical Engineering, Columbia University, NY 10027, USA
| | - Diandian Zhao
- Lenfest Center for Sustainable Energy, The Earth Institute, Columbia University, NY 10027, USA. and Department of Civil Engineering and Engineering Mechanics, Columbia University, New York 10027, USA
| | - Shiho Kawashima
- Lenfest Center for Sustainable Energy, The Earth Institute, Columbia University, NY 10027, USA. and Department of Civil Engineering and Engineering Mechanics, Columbia University, New York 10027, USA
| | - Phillip Stallworth
- Department of Physics & Astronomy, Hunter College of the City University of New York, New York, NY 10065, USA
| | - Steven G Greenbaum
- Department of Physics & Astronomy, Hunter College of the City University of New York, New York, NY 10065, USA
| | - Ah-Hyung Alissa Park
- Department of Earth and Environmental Engineering, USA and Lenfest Center for Sustainable Energy, The Earth Institute, Columbia University, NY 10027, USA. and Department of Chemical Engineering, Columbia University, NY 10027, USA
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Weber NH, Stockenhuber SP, Benhelal E, Grimison CC, Lucas JA, Mackie JC, Stockenhuber M, Kennedy EM. Products and mechanism of thermal decomposition of chlorpyrifos under inert and oxidative conditions. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:2084-2094. [PMID: 32909592 DOI: 10.1039/d0em00295j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Chlorpyrifos (CPF) is a widely used pesticide; however, limited experimental work has been completed on its thermal decomposition. CPF is known to decompose into 3,5,6-trichloro-2-pyridinol (TCpyol) together with ethylene and HOPOS. Under oxidative conditions TCpyol can decompose into the dioxin-like 2,3,7,8-tetrachloro-[1,4]-dioxinodipyridine (TCDDPy). With CPF on the cusp of being banned in several jurisdictions worldwide, the question might arise as to how to safely eliminate large stockpiles of this pesticide. Thermal methods such as incineration or thermal desorption of pesticide-contaminated soils are often employed. To assess the safety of thermal methods, information about the toxicants arising from thermal treatment is essential. The present flow reactor study reports the products detected under inert and oxidative conditions from the decomposition of CPF representative of thermal treatments and of wildfires in CPF-contaminated vegetation. Ethylene and TCpyol are the initial products formed at temperatures between 550 and 650 °C, although the detection of HOPOS as a reaction product has proven to be elusive. During pyrolysis of CPF in an inert gas, the dominant sulfur-containing product detected from CPF is carbon disulfide. Quantum chemical analysis reveals that ethylene and HOPOS undergo a facile reaction to form thiirane (c-C2H4S) which subsequently undergoes ring opening reactions to form precursors of CS2. At elevated temperatures (>650 °C), TCpyol undergoes both decarbonylation and dehydroxylation reactions together with decomposition of its primary product, TCpyol. A substantial number of toxicants is observed, including HCN and several nitriles, including cyanogen. No CS2 is observed under oxidative conditions - sulfur dioxide is the fate of S in oxidation of CPF, and quantum chemical studies show that SO2 formation is initiated by the reaction between HOPOS and O2. The range of toxicants produced in thermal decomposition of CPF is summarised.
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Affiliation(s)
- Nathan H Weber
- Faculty of Engineering and Built Environment, Discipline of Chemical Engineering, School of Engineering, University of Newcastle, Callaghan, NSW 2308, Australia.
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Rashid MI, Benhelal E, Rafiq S. Reduction of Greenhouse Gas Emissions from Gas, Oil, and Coal Power Plants in Pakistan by Carbon Capture and Storage (CCS): A Review. Chem Eng Technol 2020. [DOI: 10.1002/ceat.201900297] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Muhammad Imran Rashid
- University of Engineering and Technology (New Campus) Department of Chemical, Polymer and Composite Material Engineering 39021 Lahore Pakistan
- The University of Newcastle Discipline of Chemical Engineering 2308 Newcastle-Callaghan NSW Australia
| | - Emad Benhelal
- The University of Newcastle Discipline of Chemical Engineering 2308 Newcastle-Callaghan NSW Australia
| | - Sikander Rafiq
- University of Engineering and Technology (New Campus) Department of Chemical, Polymer and Composite Material Engineering 39021 Lahore Pakistan
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10
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Affiliation(s)
- José R. Fernández
- Institute of Carbon Science and Technology (INCAR-CSIC), Francisco Pintado Fe 26, 33011 Oviedo, Spain
| | - Susana Garcia
- Research Center for Carbon Solutions (RCCS), School of Engineering & Physical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, United Kingdom
| | - Eloy S. Sanz-Pérez
- Department of Chemical, Energy, and Mechanical Technology, ESCET. Rey Juan Carlos University. C/Tulipán s/n, 28933 Móstoles, Madrid, Spain
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