Article
Chemistry, Multidisciplinary
Chunxia Jia, Hao Yu, Hongpeng Liu, Hong Qin, Qing Wang
Summary: The temperature and heating rate were found to have significant effects on the pyrolysis products of Indonesian oil sand. Fourier transform infrared spectroscopy revealed the presence of four functional group bands in the oil sand. Additionally, the study showed that temperature influenced the total pore volume and specific surface area of char, while the heating rate did not significantly affect the development of pore structure. This research provides a theoretical foundation for the effective exploitation and economical application of oil sand.
Article
Engineering, Chemical
Tiit Kaljuvee, Igor Stubna, Tomas Hulan, Mai Uibu, Marve Einard, Rainer Traksmaa, Mart Viljus, Jekaterina Jefimova, Andres Trikkel
Summary: The thermal behavior of clay samples from Hungary and Estonia was studied using thermal and thermo-dilatometric analysis methods. The results showed that water and other compounds were released at different temperatures, and oxidation, dehydroxylation, and decomposition were the main mechanisms involved. The addition of new types of oil shale ashes and cement bypass dust affected the thermal behavior of the clays.
Article
Energy & Fuels
Mais Baqain, Can Rustu Yoruk, Dmitri Nesumajev, Oliver Jarvik, Alar Konist
Summary: The CO2-intensive oil shale power industry in Estonia produces a significant amount of ash, which is mainly disposed of in landfills. Switching to oxy-fuel technology with CO2 storage can help reduce carbon footprint. However, there are expected differences in ash formation under oxy-fuel conditions, leading to additional challenges in ash handling and environmental concerns.
Article
Thermodynamics
Hendrik Nicolai, Paulo Debiagi, Xu Wen, Louis Dressler, Anna Massmeyer, Johannes Janicka, Christian Hasse
Summary: This work introduces a new approach based on Large-Eddy Simulation (LES) coupled with a flamelet description of the gas-phase and seamless detailed solid-fuel kinetics, and applies it to a self-sustained oxy-fuel coal combustion chamber. The approach enables a detailed description of the turbulent flow field, mixing, and heat transfer, including thermal radiation and the radiative transport equation. The flamelet description of the gas phase allows for accurate and computationally efficient representation of turbulence-chemistry interactions. Coupled with a solid-fuel kinetic mechanism, it allows for seamless simulation of the particle conversion process.
COMBUSTION AND FLAME
(2022)
Article
Energy & Fuels
Hendrik Nicolai, Paulo Debiagi, Johannes Janicka, Christian Hasse
Summary: Oxy-fuel combustion combined with carbon capture technologies has the potential to rapidly reduce CO2 emissions in coal-fired power plants. However, the combustion of solid fuels in an oxygen-carbon dioxide environment is not fully understood. This study aims to analyze the impact of oxygen content on thermo-chemical conversion by applying a recently developed approach to a range of oxy-fuel swirl flames.
Article
Thermodynamics
Mustafa Versan Kok, Mikhail A. Varfolomeev, Danis K. Nurgaliev, Jayaraman Kandasamy
Summary: The thermal characteristics and model free kinetics of four different oil shale samples were investigated using TGA-MS analysis. The reactions regions, peak temperatures, mass loss, and residue of the samples were determined. The main volatile products and compounds produced during oil shale combustion were identified. Model free kinetics methods were applied to determine the activation energy, which ranged from 91.8 to 154.1 kJ mol(-1) depending on the type and origin of the oil shale.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)
Article
Energy & Fuels
Mohamed Amine Ifticene, Chengdong Yuan, Ameen A. Al-Muntaser, Yaroslav V. Onishchenko, Dmitrii A. Emelianov, Mikhail A. Varfolomeev
Summary: In this study, the conversion/combustion behavior and kinetics of oil shale and its components were investigated using TG-FT-IR. The results showed significant differences in the reaction stages among bitumen, kerogen, and oil shale. The thermal-oxidative decomposition of kerogen was found to be complex and influenced by the mineral matrix in oil shale.
Article
Geochemistry & Geophysics
Tiit Kaljuvee, Mai Uibu, Can Rustu Yoruk, Marve Einard, Andres Trikkel, Rein Kuusik, Olev Trass, Igor Stubna, Tomas Hulan, Valli Loide, Jekaterina Jefimova
Summary: The research focused on the thermooxidative decomposition of Estonian oil shale samples from different deposits and the utilization of oil shale ashes formed during combustion. The study found that the differences in thermal behavior of oil shale samples are due to variations in organic matter, chemical and mineralogical composition, and sample morphology. Additionally, grinding and water treatment of oil shale ashes improved SO2 binding efficiency, while post-granulation treatment conditions affected the strength and leachability of granulated oil shale ashes, enhancing their soil neutralizing ability.
Article
Energy & Fuels
P. Debiagi, C. Ontyd, S. Pielsticker, M. Schiemann, T. Faravelli, R. Kneer, C. Hasse, V. Scherer
Summary: This work investigates pyrolysis and char oxidation of a high-volatile Colombian bituminous coal, developing a kinetic model based on experimental data. The model accounts for devolatilization and heterogeneous char reactions, accurately simulating experimental results and highlighting the features and limitations of the model.
Article
Engineering, Environmental
Xieyuan Wu, Zebin Wei, Jingyong Liu, Zihong Chen, Fatih Evrendilek, Wenxiao Huang
Summary: This study compared the combustion characteristics of different parts of Sedum alfredii in different atmospheres, finding that the aboveground part had better combustion performance at the same heating rate. It also found high deposition risk for both samples and consistent temperature dependency of gas emissions in both atmospheres.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Thermodynamics
Mustafa Versan Kok, Berk Bal, Mikhail A. Varfolomeev, Danis K. Nurgaliev
Summary: This research investigates the non-isothermal thermogravimetric analysis and kinetics of oil shale samples at different heating rates and in the air atmosphere. The results show that the decomposition of oil shale samples follows two successive reaction stages, combustion and mineral decomposition, in different temperature intervals. The study determines the reaction intervals, peak temperature, mass loss, and derivative mass loss rate values of oil shale samples. It also calculates the combustibility indices and activation energy values using various model-free methods. Kinetic models are validated by comparing experimental and simulated conversion curves.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2023)
Article
Thermodynamics
Peng Jiang, Yang Meng, Ashak Mahmud Parvez, Xin-yue Dong, Xin-yun Wu, Meng-xia Xu, Cheng Heng Pang, Cheng-gong Sun, Tao Wu
Summary: The combustion characteristics and ash fusion behaviours of Qinghai coal and Fushun oil shale, as well as their blends, were studied. It was found that the blends exhibited good combustion performance in terms of ignition and burnout indices, with combustion temperature having the most significant impact on thermogravimetric mass loss. The addition of oil shale was shown to mitigate slagging and fouling tendencies in Qinghai coal combustion.
Article
Engineering, Chemical
Shaolong Gao, Baofeng Wang, Fengling Yang, Kai Zhang, Fangqin Cheng
Summary: This study found that increasing oxygen concentration can improve the combustion performance of coal gangue, while high oxygen content atmosphere is unfavorable for combustion. Gasification reaction accelerates overall carbon consumption, and kinetic analysis shows different combustion laws under different atmospheres and oxygen concentrations.
ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING
(2021)
Article
Green & Sustainable Science & Technology
Artjom Saia, Dmitri Neshumayev, Aaro Hazak, Priit Sander, Oliver Jarvik, Alar Konist
Summary: This study conducts a comparative techno-economic analysis of adding CO2 capture technologies to existing oil shale power plants in Estonia. The results show that oxy-fuel combustion capture performs better than post-combustion capture, but it leads to a reduction in power plant efficiency. The feasibility of CO2 capture in Estonian oil shale power plants depends on long-term trends in the electricity market and CO2 emissions trading system, and it may require state aid, which could reduce the overall competitiveness of the Estonian economy.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Thermodynamics
Zhichao Chen, Yanyu Qiao, Xiaolan Wu, Yu Zheng, Jiawei Li, Zhenhua Yuan, Zhengqi Li
Summary: This study investigated the physical, chemical, and combustion characteristics of semi-coke (SC) and demineralized semi-coke (De-SC) under oxy-fuel conditions. The results showed that compared to SC, De-SC exhibited lower ignition and burnout temperatures, higher combustion rates, and distinct homogeneous and heterogeneous combustion stages. Demineralization resulted in a less developed pore structure, lower alkali metal and volatile content, and increased reactivity of De-SC. The combustion of De-SC primarily occurred on the particle surface, with a combination of surface and internal combustion at specific conditions. De-SC had lower activation energy and higher pre-exponential factor compared to SC under different atmospheres. These findings provide a theoretical basis for the application of De-SC in oxy-fuel combustion.
Article
Energy & Fuels
Can Rustu Yoruk, Tonis Meriste, Serkan Sener, Rein Kuusik, Andres Trikkel
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2018)
Article
Biochemistry & Molecular Biology
Kaia Tonsuaadu, Michel Gruselle, Frieda Kriisa, Andres Trikkel, Patrick Gredin, Didier Villemin
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
(2018)
Article
Thermodynamics
Can Rustu Yoruk, Mai Uibu, Mustafa Cem Usta, Tiit Kaljuvee, Andres Trikkel
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2020)
Correction
Thermodynamics
Can Rustu Yoruk, Mai Uibu, Mustafa Cem Usta, Tiit Kaljuvee, Andres Trikkel
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2020)
Article
Geochemistry & Geophysics
Mustafa Cem Usta, Can Rustu Yoruk, Tiina Hain, Peeter Paaver, Ruben Snellings, Eduard Rozov, Andre Gregor, Rein Kuusik, Andres Trikkel, Mai Uibu
Article
Geochemistry & Geophysics
Tiit Kaljuvee, Mai Uibu, Can Rustu Yoruk, Marve Einard, Andres Trikkel, Rein Kuusik, Olev Trass, Igor Stubna, Tomas Hulan, Valli Loide, Jekaterina Jefimova
Summary: The research focused on the thermooxidative decomposition of Estonian oil shale samples from different deposits and the utilization of oil shale ashes formed during combustion. The study found that the differences in thermal behavior of oil shale samples are due to variations in organic matter, chemical and mineralogical composition, and sample morphology. Additionally, grinding and water treatment of oil shale ashes improved SO2 binding efficiency, while post-granulation treatment conditions affected the strength and leachability of granulated oil shale ashes, enhancing their soil neutralizing ability.
Article
Thermodynamics
Sanoop Kumar Puthiya Veetil, Kaarel Rebane, Can Rustu Yoruk, Margus Lopp, Andres Trikkel, Michael Hitch
Summary: The study evaluated the development of a Ca-based CO2 capture sorbent from a limestone-rich mine waste via aqueous mineral carbonation. It was found that optimal dissolution and carbonation of calcium occurred at 2.5% pulp density, resulting in the production of pure calcite during the process. The promising CO2 uptake capacity of the developed sorbent suggests its potential for direct CO2 capture.
Article
Engineering, Chemical
Tiit Kaljuvee, Igor Stubna, Tomas Hulan, Mai Uibu, Marve Einard, Rainer Traksmaa, Mart Viljus, Jekaterina Jefimova, Andres Trikkel
Summary: The thermal behavior of clay samples from Hungary and Estonia was studied using thermal and thermo-dilatometric analysis methods. The results showed that water and other compounds were released at different temperatures, and oxidation, dehydroxylation, and decomposition were the main mechanisms involved. The addition of new types of oil shale ashes and cement bypass dust affected the thermal behavior of the clays.
Article
Chemistry, Multidisciplinary
Siim Link, Patrik Yrjas, Daniel Lindberg, Andres Trikkel
Summary: This study investigated the ash melting behavior of a blend of reed and wheat straw using various laboratory methods. The results showed that the melting started at 660-680 degrees C and the liquid mass fraction was 13.8% at this temperature, indicating the blend could become sticky. Intensive melting occurred in the temperature range of 800-980 degrees C, with rapid melting between 950 and 980 degrees C caused by the melting of SiO2 and K2MgSi5O12.
Article
Energy & Fuels
Siim Link, Patrik Yrjas, Daniel Lindberg, Andres Trikkel, Valdek Mikli
Summary: This study investigated the melting behavior of fuel ash blends of reed, pine wood pellets and Douglas fir wood chips. Various methods were used to examine the morphology and composition of the ash samples at different temperatures. The results revealed different reactions and gas releases during the melting process.
Article
Geochemistry & Geophysics
Mustafa Cem Usta, Can Rustu Yoruk, Mai Uibu, Tiina Hain, Andre Gregor, Andres Trikkel
Summary: In this study, fly ash compacts were prepared by accelerated carbonation using locally available ashes in Estonia. Various variables such as compaction pressure, curing temperature, CO2 concentration, and pressure were investigated to understand their influence on CO2 uptake and strength development. The porous surface structure of the compacts changed after carbonation, with an increase in CO2 uptake levels observed under higher temperature, gas pressure, and CO2 concentration.
Article
Engineering, Chemical
Tiit Kaljuvee, Kaia Tonsuaadu, Marve Einard, Valdek Mikli, Eliise-Koidula Kivimae, Toivo Kallaste, Andres Trikkel
Summary: In this study, the thermal behavior of Estonian graptolite-argillite samples was investigated, revealing the complex mechanism of their thermal decomposition. The samples were found to have high proportions of orthoclase and quartz, and lower proportions of muscovite, jarosite, and pyrite. The thermal decomposition of the samples occurred in multiple steps.
Article
Chemistry, Inorganic & Nuclear
Kaia Tonsuaadu, Juha Kallas, Rein Kuusik, Gizem Hacialioglu-Erlenheim, Andres Trikkel
Summary: The study investigated the kinetics of apatite dissolution in diluted acids using thermodynamic calculations and experiments, and found that the dissolution rate can be tracked by changes in pH values.
Article
Energy & Fuels
Mai Uibu, Kadriann Tamm, Regiina Viires, Janek Reinik, Peeter Somelar, Lembi Raado, Tiina Hain, Rein Kuusik, Andres Trikkel
Summary: The modernisation of the oil shale industry in Estonia has led to significant changes in the composition and binding properties of the ash generated, impacting its environmental impact. Sample collection from various points along different combustion plants can aid in optimizing deposition conditions and guiding utilization-recycling processes for the changing oil shale characteristics. Mapping out the properties of oil shale ash is crucial in developing circular economy aspects of oil shale utilisation.
