Title
Carbon Mineralization Technology of Solid Wastes (Waste Treatment Technology)
Code
SP2025/004
Summary
The storage of hazardous solid waste will cause serious environmental pollution (https://doi.org/10.1016/j.jcou.2023.102502), so the proper treatment of solid waste is related to the well-being of people around the world and the long-term development of the global economy. In compliance with the EU communication COM/2014/398 “Towards a circular economy: A zero waste program for Europe”, which introduces the main objectives and measures in the field of circular economy, the landfilling of recyclable waste will not be allowed from the year 2025, and it will be completely prohibited from the year 2050. In the context of addressing climate change, if a special treatment technology can be used to sequester carbon dioxide in solid wastes, on the one hand, it will effectively solve a series of problems caused by the stockpiling of solid wastes and absorb carbon dioxide. On the other hand, the reaction products can also be applied to the field of cement-based materials, which will help reduce carbon emissions from cement production and promote the transformation of the construction industry towards a low-carbon model.
The project aims to deeply and systematically analyze the reactivity of solid wastes , such as coal gangue (https://doi.org/10.1144/qjegh2016-007) and fly ash (https://doi.org/10.1016/j.atmosenv.2022.119556) in the Ostrava-Karviná district (https://dx.doi.org/10.1088/1755-1315/92/1/012060), and yellow phosphorus slag with carbon dioxide under specific process conditions, and accurately determine the optimal combination of key parameters like temperature, pressure, and catalyst, thus laying a solid theoretical and data foundation for subsequent large-scale industrial applications.
1. Analysis of the Physicochemical Properties of Solid Wastes in Ostrava:
Wastes containing elements such as calcium (Ca) and magnesium (Mg) can undergo chemical reactions with carbon dioxide to form stable carbonates such as CaCO3 and MgCO3, thereby fixing carbon dioxide. Although there have been numerous studies on the carbon sequestration reactions of many different solid wastes, such as steel slag and slag. However, the solid wastes generated in the Ostrava region have complexity and particularity (https://doi.org/10.21203/rs.3.rs-3866533/v1). Therefore, it is necessary to select typical solid wastes such as coal gangue and fly ash for analyzing their carbon sequestration potential and screening, which has practical guiding significance for the subsequent carbon sequestration application of local solid wastes.
Considering the distribution of waste piles and the ease of utilization, 2 to 3 waste piles with the largest occupied volume and relatively uniform tailings accumulation are selected for sampling analysis. Samples are extracted from different depths of each waste pile (grouped at 2 m intervals) and pretreated. Utilize advanced instruments such as X-ray fluorescence spectroscopy (XRF), scanning electron microscope (SEM), specific surface area analyzer, and laser particle size analyzer to comprehensively detect the chemical compositions, mineral compositions, microscopic morphologies, and pore structure characteristics of coal gangue and fly ash. By doing so, we can accurately grasp the intrinsic properties of the wastes, predict the potential reaction sites and difficulties when they react with carbon dioxide, and provide crucial references for subsequent experimental parameter settings.
The contents of CaO and MgO in the XRF results will be key indicators of focus. Solid wastes with carbon sequestration potential will be screened out, and the standard is tentatively set as a theoretical CO2 uptake of more than 10%. The calculation of Theoretical CO2 uptake refers to relevant literature. (https://doi.org/10.3989/mc.1957.v07.i079.2151).
2. Exploration of the Wet Carbon Sequestration Technology
Regarding the research on carbonization reactions, the traditional dry carbon sequestration method mainly involves the direct reaction between solid wastes and carbon dioxide gas. This method has a low efficiency, and its reaction parameters are uncontrollable, making it difficult to achieve rapid and large-scale carbon sequestration. Therefore, it is necessary to develop new and efficient carbon sequestration technology, the wet carbon sequestration technology. This technology can not only significantly improve the carbon sequestration efficiency but also adjust the reaction parameters according to the characteristics of solid wastes in the Ostrava region, thus achieving a comprehensive optimization of the carbon sequestration rate and efficiency.
Set up a basic solid-liquid-gas three-phase reaction apparatus so that parameters such as reaction temperature, carbon dioxide gas velocity/pressure, solid-liquid ratio, and catalyst can be flexibly adjusted. For each type of solid waste with carbon sequestration potential, single-variable control is carried out to adjust the process parameters one by one to different values within a certain range. Reaction products are extracted at regular intervals, and then the degree of carbon sequestration reaction under different parameters and the rate of carbon sequestration reaction under the same parameter are analyzed and explored. The reaction degree and reaction rate of each sample are characterized based on their actual carbon dioxide absorption amount. Thermal gravimetric measurements of the samples were obtained using a thermogravimetric analyzer. The calculation of Actual CO2 uptake refers to the literature (https://doi.org/10.1016/j.cemconcomp.2023.105307). Eventually, determine the key parameter combination that maximizes reaction efficiency and optimizes product quality, and prepare it for subsequent experiments.
Utilize tests such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) to analyze the composition, microscopic morphology, and chemical structure of the reaction products, so as to further analyze the corresponding reaction mechanisms.
3. Construction of Cement Composite System Based on Carbonized Products and Application Expansion:
The production of cement generates a large amount of carbon dioxide. There have been a great number of studies on the replacement of cement clinker with ordinary solid wastes. Among them, the replacement of cement with solid wastes such as fly ash and slag has already been put into practical production applications. However, studies on the replacement of cement with solid wastes after carbon sequestration are rarely mentioned. This part of the research is helpful to provide guidance for building materials with carbon sequestration.
Incorporate the slurry prepared in item 2 directly into cement clinker to prepare composite cement paste and composite cement mortar (https://doi.org/10.1016/j.spc.2024.01.020). Reusing the waste carbonated slurry can reduce the cost of the treatment process and alleviate the environmental problems caused by the wastewater generated during the aqueous carbonation process. By analyzing the fluidity, heat of hydration, compressive strength, hydration products, hydration process, microscopic morphology, and porosity of the composite cement paste, the feasibility of using the carbonated products of the above solid wastes in cement can be evaluated. At the same time, analyze the influence of the doping amount (10%-20%) and the type of carbon sequestration admixture on cement, hoping to obtain the most suitable solid waste for utilization and its optimal doping amount. The full life cycle assessment software is used to simulate carbon emissions from the entire process from raw material mining to the service of building materials, and to quantify the emission reduction benefits. Exploring the further applications of carbonized products and by-products can improve the feasibility of the industrialization and large-scale utilization of solid waste carbonization.
The role of participants in the project solution
Prof. Ing. Bohumir Strnadel, DrSc.
He will coordinate the research activities connected with research topics of PhD study of two students Mr. Panek and Mr. Liu. He will prepare the basic concepts of prepared publications, and participate on conclusions chapters. He will participate on review processes of articles.
Prof. Jin Yang
He will guide the overall implementation of the project tasks, including the experiments, results analysis, etc. He will summarize the experimental results, compare the data with existing references and prepare the article manuscripts.
Ing. Radek Tomášek
He will do the precise screening of suitable waste materials,
He will also analyse the properties of solid waste and carry out basic research on reaction activity.
Ing. Michael Pánek
He will determine the chemical composition of samples using the stoichiometry of the reaction. He will prepare composite samples, all of them according to testing purpose based on ČSN/EN standards. He will develop research collaboration with the Research Institute for Building Materials to explore large-scale industrial applications of developed concrete mixtures.
Mr. Senye Liu
He will work on experimental and theoretical works of prepared articles, analyze experimental results, and formulate partial conclusions. The most important activity of him is to strengthen research results of his PhD study, and to deepen the professional knowledge.
Ing. David Dvořák
He will lead administration of the project, and help with final editing of prepared articles.
7 master's students will be involved in the project as helpers, collecting information, assisting with sample preparation and laboratory testing.
Benefits to the faculty
The proposed project in principal way extends the number of materials field investigation. Silicates with very low toughness provide broad space to improve the relationship between strength and toughness. This access principally extends opportunities for publication in scientific journals with high impact index. There will be broaden cooperation with research institutions providing research on materials engineering, e.g. Research Institute for Building Materials.
BUDGET
The funds will be used to support one researcher (DPP), scholarships for the one foreign student and the purchase of the following goods and services:
Solid waste (200KG);
Cement (PO 42.5 grade, 200KG);
Chemical admixtures (dispersants, solubilizers, catalysts, etc.);
Specialty grinding balls (ceramic balls, etc., 5KG);
Gas (CO2, 10~20KG, N2, 20KG);
Basic consumables (test tubes, beakers, etc.);
Waste pile investigation (measuring the terrain and grasping the surrounding environmental conditions);
Waste pile sampling;
Physicochemical property tests (including X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM), thermogravimetric analysis (TG), etc.);
Set up a basic solid-liquid-gas three-phase reaction apparatus, install and debug various sensors and controllers, and precisely control parameters such as reaction temperature, the flow rate and pressure of carbon dioxide gas, and the solid-liquid ratio;
Site rental and equipment usage (preparation of cement samples);
Transportation and accommodation in Prague/Brno (for exchanges, cementitious material testing, etc.);
Labor costs;
and other materials and services.
Start year
2025
End year
2025
Provider
Ministerstvo školství, mládeže a tělovýchovy
Category
SGS
Type
Specifický výzkum VŠB-TUO
Solver