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Wennebro, J., Vikström, T., Reinsdorf, O. & Wiinikka, H. (2025). Influence of Feedstock Water Content on Renewable Carbon Black Production Through High-Temperature Pyrolysis of Upgraded Bio-Oils. Energy & Fuels, 39(16), 7805-7814
Open this publication in new window or tab >>Influence of Feedstock Water Content on Renewable Carbon Black Production Through High-Temperature Pyrolysis of Upgraded Bio-Oils
2025 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 39, no 16, p. 7805-7814Article in journal (Refereed) Published
Abstract [en]

Pyrolysis oil (PO) derived from biomass has the potential to serve as a renewable feedstock for future carbon black (CB) production. However, its composition is significantly different from the fossil feedstocks currently used for CB manufacturing, as it contains higher concentrations of oxygen and water that might influence the yield and nanostructure of CB. In this article, we examine how the water content in PO affects the production of CB at high-temperature pyrolysis (1400-1600 °C) in an electrically heated entrained flow reactor. The main objective was to investigate the influence of water content on the yield and quality of the CB produced from upgraded PO with varying inherent water contents (0-20 wt %). The experiments in this work were performed with model compounds to simulate an upgraded PO. The produced CB was characterized by using several analytical techniques, including elemental composition, powder X-ray diffraction, transmission electron microscopy, and nitrogen physisorption. The results show a clear correlation between the water content in the PO feedstock and the output of CB, showing a reduced yield of CB as the water content increases. These results highlight the crucial role of feedstock composition in making PO a viable renewable feedstock for CB production.

Place, publisher, year, edition, pages
American Chemical Society, 2025
Keywords
Pyrolysis; Bio-oils; Elemental compositions; Entrained Flow Reactor; High-temperature pyrolysis; Influence of water; Model compound; Pyrolysis oil; Renewable feedstocks; Renewables; X- ray diffractions; Water content
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-78460 (URN)10.1021/acs.energyfuels.5c00308 (DOI)2-s2.0-105002740938 (Scopus ID)
Note

The authors gratefully acknowledge FORMAS (grant no 2020-01992) for financial support

Available from: 2025-05-21 Created: 2025-05-21 Last updated: 2025-05-21Bibliographically approved
Thorin, E., Sepman, A., Carlborg, M., Wiinikka, H. & Schmidt, F. M. (2025). Oxy-fuel combustion of softwood in a pilot-scale down-fired pulverized combustor – Fate of potassium. Fuel, 381, Article ID 133485.
Open this publication in new window or tab >>Oxy-fuel combustion of softwood in a pilot-scale down-fired pulverized combustor – Fate of potassium
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2025 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 381, article id 133485Article in journal (Refereed) Published
Abstract [en]

Oxy-fuel biomass combustion can facilitate carbon capture in heat and power plants and enable negative carbon dioxide (CO2) emissions. We demonstrate oxy-fuel combustion (OFC) of softwood powder in a 100-kW atmospheric down-fired pulverized combustor run at a global oxidizer-fuel equivalence ratio of around 1.25. The simulated oxidizer was varied between oxygen (O2)/CO2 mixtures of 23/77, 30/70, 40/60 and 54/46, and artificial air. The concentrations of the main gaseous potassium (K) species: atomic K, potassium hydroxide (KOH) and potassium chloride (KCl), were measured at two positions in the reactor core using photofragmentation tunable diode laser absorption spectroscopy (PF-TDLAS). Major species were quantified by TDLAS in the reactor core and with Fourier transform infrared spectroscopy and mass spectrometry at the exhaust. Flue gas particles were collected at the exhaust employing a low-pressure impactor and analyzed by X-ray powder diffraction and scanning electron microscopy. The measured individual K species concentrations in the reactor core agreed with predictions by thermodynamic equilibrium calculations (TEC) within one order of magnitude and the sum of K in the gas phase agreed within a factor of three for all cases. Atomic K was underpredicted, while the dominating KOH and KCl were slightly overpredicted. The ratios of measured to predicted total K were similar in artificial air and OFC, but the distributions of the individual species differed at the upper reactor position. The gaseous K species and fine particle concentrations in the flue gas were directly proportional to the O2 content in the oxidizer. The crystalline phase compositions of the coarse mode particles were rich in K- and calcium-containing species. The fine mode particles, which contained most of the K, consisted mainly of K2SO4 (94%) and K3Na(SO4)2, which is in excellent agreement with TECs of gas phase condensation. As supported by the solid phase analysis, complete sulfation of K species was achieved for all studied cases. A CO2 purity (dry) of up to 94% was achieved for OFC. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2025
Keywords
Antiknock compounds; Bioremediation; Bottoming cycle systems; Coal; Explosives detection; Fourier transform infrared spectroscopy; Liquid chromatography; Photoelectron spectroscopy; Photolysis; Potassium chloride; Pulse repetition rate; Radioactivation analysis; Steam; Supersonic aerodynamics; Wood fuels; X ray powder diffraction; Biomass combustion; Heat and power plants; Oxy-fuels; Oxyfuel combustion; Pilot scale; Potassium (K); Potassium chloride; Pulverized combustions; Scale-down; Sulphation; Potassium hydroxide
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-76169 (URN)10.1016/j.fuel.2024.133485 (DOI)2-s2.0-85207600325 (Scopus ID)
Note

The authors acknowledge financial support from the Swedish Energy Agency and the Kempe Foundations. The long-term support from the Swedish Strategic Research Environment Bio4Energy for our activities is highly appreciated.

Available from: 2024-11-22 Created: 2024-11-22 Last updated: 2024-11-22Bibliographically approved
Johansson, A., Fernberg, J., Sepman, A., Colin, S., Wennebro, J., Normann, F. & Wiinikka, H. (2024). Cofiring of hydrogen and pulverized coal in rotary kilns using one integrated burner. International journal of hydrogen energy, 90, 342-352
Open this publication in new window or tab >>Cofiring of hydrogen and pulverized coal in rotary kilns using one integrated burner
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2024 (English)In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 90, p. 342-352Article in journal (Refereed) Published
Abstract [en]

The grate-kiln process for iron-ore pellet induration utilizes pulverized coal fired burners. In a developed infrastructure for H2, it might be desirable to heat the existing rotary kilns with renewably produced H2. Technical challenges of H2 heating of grate-kilns include high emissions of NOX and maintaining sufficient heat transfer to the pellet bed. This article examined cofiring (70% coal/30% H2) in 130 kW experiments using two different integrated burner concepts. Compared to pure coal combustion, cofiring creates a more intense, smaller flame with earlier ignition and less fluctuations. The process temperature and heat transfer are enhanced in the beginning of the kiln. The co-fired flames emit 32% and 78% less NOX emissions compared to pure coal and H2 combustion, respectively. We can affect the combustion behavior and NOX emissions by the burner design. H2/coal cofiring using integrated burners is probably an attractive solution for emission minimization in rotary kilns.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Coal, Coal combustion, Coal fueled furnaces, Iron ore pellets, Pulverized fuel, Co-firing, Combustion behaviours, Emission, Hydrogen combustion, Pellet induration, Process heat, Process temperature, Pulverized coal fired burner, Pulverized coals, Technical challenges, Rotary kilns
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-76031 (URN)10.1016/j.ijhydene.2024.09.327 (DOI)2-s2.0-85205469308 (Scopus ID)
Funder
Swedish Energy Agency, P2022-00196
Note

The authors gratefully acknowledge Luossavaara-Kiirunavaara AB (LKAB), the Swedish Energy Agency and the European Union (EU) for the financial support of this work (P2022-00196). Additionally, all experimental support provided from our colleagues Niklas Mörtlund, Therese Vikström, Sandra Lundström and others at RISE, Piteå is greatly appreciated.

Available from: 2024-11-01 Created: 2024-11-01 Last updated: 2024-11-01Bibliographically approved
Ögren, Y., Sepman, A., Fooladgar, E., Weiland, F. & Wiinikka, H. (2024). Development and evaluation of a vision driven sensor for estimating fuel feeding rates in combustion and gasification processes. Energy and AI, 15, Article ID 100316.
Open this publication in new window or tab >>Development and evaluation of a vision driven sensor for estimating fuel feeding rates in combustion and gasification processes
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2024 (English)In: Energy and AI, ISSN 2666-5468, Vol. 15, article id 100316Article in journal (Refereed) Published
Abstract [en]

A machine vision driven sensor for estimating the instantaneous feeding rate of pelletized fuels was developed and tested experimentally in combustion and gasification processes. The feeding rate was determined from images of the pellets sliding on a transfer chute into the reactor. From the images the apparent area and velocity of the pellets were extracted. Area was determined by a segmentation model created using a machine learning framework and velocities by image registration of two subsequent images. The measured weight of the pelletized fuel passed through the feeding system was in good agreement with the weight estimated by the sensor. The observed variations in the fuel feeding correlated with the variations in the gaseous species concentrations measured in the reactor core and in the exhaust. Since the developed sensor measures the ingoing fuel feeding rate prior to the reactor, its signal could therefore help improve process control. 

Place, publisher, year, edition, pages
Elsevier B.V., 2024
Keywords
Combustion, Fuel feeding, Gasification, Image processing, Neural network, Process monitoring, Feeding, Image segmentation, Pelletizing, Process control, Combustion pro-cess, Feeding rate, Gasification process, Images processing, Machine-learning, Machine-vision, Neural-networks, Segmentation models, Transfer chutes
National Category
Environmental Engineering
Identifiers
urn:nbn:se:ri:diva-71916 (URN)10.1016/j.egyai.2023.100316 (DOI)2-s2.0-85181658798 (Scopus ID)
Funder
Swedish Energy Agency, 50470-1Swedish Research Council FormasVinnovaEU, Horizon 2020, 818011
Note

Correspondence Address: Y. Ögren; RISE AB, Piteå, Box 726 SE-941 28, Sweden; . The Bio4Energy, a strategic research environment appointed by the Swedish government and the SwedishCenter for Gasification financed by the Swedish Energy Agency and member companies. The RE:source program finance by the Swedish Energy Agency, Vinnova and Formas. The Pulp&Fuel project financed by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 818011 and the TDLAS-AI project (Swedish energy agency project 50470-1). 

Available from: 2024-02-22 Created: 2024-02-22 Last updated: 2024-02-22Bibliographically approved
Sepman, A., Wennebro, J., Fernberg, J. & Wiinikka, H. (2024). Following fuel conversion during biomass gasification using tunable diode laser absorption spectroscopy diagnostics. Fuel, 374, Article ID 132374.
Open this publication in new window or tab >>Following fuel conversion during biomass gasification using tunable diode laser absorption spectroscopy diagnostics
2024 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 374, article id 132374Article in journal (Refereed) Published
Abstract [en]

The efficiency of the gasification process and product quality largely depend on the degree of fuel conversion. We present the real-time in-situ tunable diode laser measurements of main carbon and oxygen-containing species in the hot reactor core of a pilot-scale entrained flow biomass gasifier (EFG). The concentrations of CO, CO2, CH4, C2H2, H2O, soot, and gas temperature were measured during the air and oxygen-enriched gasification of stem wood at varying equivalence ratios. The experiments were made at the upper and lower optical ports inside a 4 m long, ceramic-lined, atmospheric EFG, allowing to access the degree of the fuel conversion inside the reactor. The exhaust composition was measured by micro-GC, FTIR, and low-pressure impactor. There was a good agreement between the data measured inside the reactor and at the exhaust for oxygen-enriched gasification implying that the chemical reactions are practically frozen downstream the optical ports. For air, the data indicated that the gasification reactions are still active at the measurement locations. Significant concentrations of C2H2, up to 5000 ppm, were found inside the reactor. 

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Absorption spectroscopy, Biomass, Fourier transform infrared spectroscopy, Laser diagnostics, Oxygen, Semiconductor lasers, Biomass Gasification, Biomass gasifier, Entrained flow, Fuel conversion, Gasification process, Gasification products, Optical ports, Oxygen-enriched, TDLAS, Tunable diode laser absorption spectroscopy, Gasification
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-74710 (URN)10.1016/j.fuel.2024.132374 (DOI)2-s2.0-85197599780 (Scopus ID)
Funder
Swedish Energy Agency, 50470-1
Note

We gratefully acknowledge financial support from the Swedish Energy Agency through 50470-1 project.

Available from: 2024-08-08 Created: 2024-08-08 Last updated: 2024-08-08
Weiland, F., Jacobsson, D., Wahlqvist, D., Ek, M. & Wiinikka, H. (2024). Inorganic Chemistry during Pyrolysis, Gasification, and Oxyfuel Combustion of Kraft Pulping Black Liquor. Energy & Fuels, 38(6), 5279-5287
Open this publication in new window or tab >>Inorganic Chemistry during Pyrolysis, Gasification, and Oxyfuel Combustion of Kraft Pulping Black Liquor
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2024 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 38, no 6, p. 5279-5287Article in journal (Refereed) Published
Abstract [en]

Changed utilization of black liquor in the pulp and paper industry has the potential to offer simplified carbon capture and, thus, negative net emissions from these large point sources. This can be achieved either by adapting existing recovery boilers to oxyfuel combustion or by replacing them with black liquor gasification technology. In this work, the chemistry during black liquor conversion was therefore studied in detail under different atmospheres relevant for pyrolysis, gasification, and oxyfuel combustion. Experiments were performed using environmental scanning transmission electron microscopy (ESTEM) and thermogravimetric analysis (TGA), supported with thermodynamic equilibrium calculations (TECs) to understand and interpret the results. Black liquor conversion was found to be generally similar in air and oxyfuel atmospheres containing approximately 20-25 mol % oxygen. The results however indicated that there was a higher probability of forming carbonates in the melt at higher carbon dioxide (CO2) partial pressures, which in addition was found to be associated with potentially higher sulfur loss during black liquor conversion. Both of these characteristics can negatively affect the chemical recycling at the pulp mill by increasing the need for lime and makeup chemicals.

Place, publisher, year, edition, pages
American Chemical Society, 2024
Keywords
Combustion; Gasification; Gravimetry; Lime; Pyrolysis; Scanning Electron Microscopy; Sulfur Dioxide; Thermal Analysis; Combustion; Gasification; High resolution transmission electron microscopy; Indicators (chemical); Kraft pulp; Lime; Paper and pulp industry; Pyrolysis; Scanning electron microscopy; Sulfur dioxide; Thermogravimetric analysis; Black liquor; Black liquor gasification; Inorganic chemistry; Oxyfuel combustion; Point-sources; Pulp and paper industry; Pulping black liquor; Pyrolysis combustions; Pyrolysis gasifications; Recovery boilers; Carbon dioxide
National Category
Mechanical Engineering
Identifiers
urn:nbn:se:ri:diva-72825 (URN)10.1021/acs.energyfuels.3c05031 (DOI)2-s2.0-85187342372 (Scopus ID)
Funder
Swedish Energy Agency, P2020-90041
Note

This work was made possible through funding from the Swedish Energy Agency’s initiative “The Industrial Leap”, project P2020-90041.

Available from: 2024-04-29 Created: 2024-04-29 Last updated: 2024-04-29Bibliographically approved
Sepman, A., Malhotra, J. S., Wennebro, J. & Wiinikka, H. (2024). Iron as recyclable electrofuel: Effect on particle morphology from multiple combustion-regeneration cycles. Combustion and Flame, 259, Article ID 113137.
Open this publication in new window or tab >>Iron as recyclable electrofuel: Effect on particle morphology from multiple combustion-regeneration cycles
2024 (English)In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 259, article id 113137Article in journal (Refereed) Published
Abstract [en]

This work describes the morphological and material changes in the iron powder during four regeneration-combustion cycles. The regeneration in H2 and combustion in air experiments were made in a fluidized bed (FB) and an entrained flow reactor (EFR), respectively. The average size of the iron oxide particles more than doubled between the first and fourth combustion cycles, and many of the particles were hollow. The regeneration step did not change the size of the particles but increased their porosity. A mechanism is proposed that describes the formation of large-diameter hollow particles which increases as a function of the regeneration-combustion cycles. The observed increase in particle size and the change in particle morphology complicates the iron fuel concept, as it leads to a degradation of the structural stability of the particle with time.

Place, publisher, year, edition, pages
Elsevier Inc., 2024
Keywords
Fluidized bed combustion; Fluidized beds; Iron oxides; Morphology; Particle size; Air experiments; Average size; Combustion cycle; Entrained Flow Reactor; Iron oxide particles; Material change; Morphological changes; Particle morphologies; Recyclables; Regeneration cycles; Stability
National Category
Energy Engineering Other Environmental Engineering
Identifiers
urn:nbn:se:ri:diva-67706 (URN)10.1016/j.combustflame.2023.113137 (DOI)2-s2.0-85174581752 (Scopus ID)
Available from: 2023-11-06 Created: 2023-11-06 Last updated: 2024-05-17Bibliographically approved
Fooladgar, E., Sepman, A., Ögren, Y., Johansson, A., Gullberg, M. & Wiinikka, H. (2024). Low-NOx thermal plasma torches: A renewable heat source for the electrified process industry. Fuel, 378, Article ID 132959.
Open this publication in new window or tab >>Low-NOx thermal plasma torches: A renewable heat source for the electrified process industry
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2024 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 378, article id 132959Article in journal (Refereed) Published
Abstract [en]

Industrial thermal plasma torches can heat a gas up to 5000–20,000 K, i.e., well above the temperature needed to replace the heat generated from the combustion of traditional fossil fuels (e.g., coal, oil, and natural gas) in large-scale process industry furnaces producing construction materials (e.g., iron, steel, lime, and cement). However, there is a risk for significant NOx emissions when air or N2 are used as plasma-forming gas since the temperature somewhere in the furnace always will be higher compared to the threshold NOx formation temperature of ∼1800 K. Torch NOx forms inside the high temperature region of the plasma torch (>5000 K) when air is used as gas. Process NOx forms instead when the hot gas (when air or nitrogen is used as plasma forming gas) from the plasma torch mixes with process air downstream the torch. By analysing the complex chemistry of both the torch- and process NOx formation with thermodynamic equilibrium and one-dimensional chemical kinetic calculations it was shown that adding H2 to the plasma-forming N2 gas significantly reduces the NOx emissions with more than 90 %. Verifying experiments with air, pure N2, and mixtures of H2 and N2 as plasma-forming gas were performed in a laboratory scale insulated laboratory furnace with different pre-heating temperatures of process air (293, 673, and 1073 K) which the plasma gas mixes with downstream the torch. Depending on the pre-heating temperature the NOx emissions were between 12,000–14,000 mg NO2/MJfuel when air was used as plasma forming gas. Substantial NOx emission reduction occurs both when N2 replaces air, where the NOx emissions was in the span of 8000–11,500 mg NO2/MJfuel and furthermore when H2 was mixed into the N2 gas stream. For the highest degree of H2 mixing (28.6 vol-%), the NOx emissions were between 450–1700 mg NO2/MJfuel depending on the pre-heat temperature of the process air, i.e., a reduction of 88–96 % and 85–94 %, respectively when air or N2 was used as plasma forming gas. The measured NOx emissions are then of the same order of magnitude as would be expected from the combustion of traditional fuels (coal, oil, biomass and pure H2). Finally, by analysing the aerodynamics in an axisymmetric furnace with an experimentally validated computational fluid dynamics (CFD) model using reduced chemistry for the NOx formation (19 species and 70 reactions), further guidelines into the process of NOx reduction from thermal plasma torches are given. 

Place, publisher, year, edition, pages
Elsevier Ltd, 2024
Keywords
Catalytic cracking; Coal combustion; Coal industry; Coal oil mixtures; Lignite; Melt spinning; Metal casting; Metal castings; Natural gas wells; Oil shale; Petroleum tar; Pipelines; Plasma welding; Preheating; Putty; Steelmaking furnaces; Wire drawing; Down-stream; Nitrogen oxide emissions; NO 2; NO x; NO x emission; Plasma forming gas; Pre-heating; Process industries; Thermal plasma; Thermal plasma torch; Plasma torches
National Category
Materials Engineering
Identifiers
urn:nbn:se:ri:diva-74989 (URN)10.1016/j.fuel.2024.132959 (DOI)2-s2.0-85202556500 (Scopus ID)
Note

This work was conducted as part of the Hydrogen Breakthrough Ironmaking Technology (HYBRIT) research project RP1. The Swedish Energy Agency is acknowledged for financial support of HYRIT. HYBRIT is a joint initiative of SSAB, LKAB, and Vattenfall with the aim of developing the world’s first fossil-fuel-free ore-based steelmaking route. Sofia Nordqvist (LKAB/HYBRIT), Christian Fredriksson (LKAB), and Fredrik Normann (LKAB/Chalmers Technical University) are also acknowledged for their constructive suggestions

Available from: 2024-09-09 Created: 2024-09-09 Last updated: 2025-04-16Bibliographically approved
Wahlqvist, D., Mases, M., Jacobsson, D., Wiinikka, H. & Ek, M. (2024). Nanocarbon oxidation in the environmental transmission electron microscope - Disentangling the role of the electron beam. Carbon, 218, Article ID 118686.
Open this publication in new window or tab >>Nanocarbon oxidation in the environmental transmission electron microscope - Disentangling the role of the electron beam
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2024 (English)In: Carbon, ISSN 0008-6223, E-ISSN 1873-3891, Vol. 218, article id 118686Article in journal (Refereed) Published
Abstract [en]

Environmental transmission electron microscopy (ETEM) can provide unique insights into nanocarbon oxidation processes through atomic resolution and real time imaging of materials at high temperatures in reactive atmospheres. However, the electron beam can also influence the reaction rates, and even alter the processes entirely, complicating the interpretation of the in situ observations. Many mechanisms have been proposed to account for the impact of the electron beam, predominantly involving ionization of the oxidative gases to form more reactive species. However, these mechanisms have not been critically evaluated and compared to predictions from theory. Here, we evaluate the impact of the electron beam both qualitatively (oxidation mode and spatial extent) and quantitatively (oxidation rates), using high resolution imaging and electron energy loss spectroscopy, at different electron energies and dose rates. We demonstrate that transient defects generated by elastic scattering, forming highly active sites for carbon abstraction by oxygen, is the main mechanism for the enhanced oxidation rates observed in situ. This is evident from an insensitivity to electron energy and saturation of the effects at high electron dose rates. To avoid undue influence of the electron beam in future ETEM studies, we therefore recommend conditions where the intrinsic oxidation dominates over the beam-enhanced oxidation (note that no conditions are completely “safe”) and extensive comparisons with other methods. © 2023 The Author(s)

Place, publisher, year, edition, pages
Elsevier Ltd, 2024
Keywords
Carbon black; Dissociation; Electron beams; Electron energy levels; Electron scattering; Electrons; Energy dissipation; High resolution transmission electron microscopy; Impact ionization; Ionization of gases; Oxidation; Reaction rates; Condition; Dose rate; Electron beam effects; Electron dose; Electron-beam; Electrons energy; Environmental transmission electron microscopes; Environmental transmission electron microscopy; Nanocarbons; Oxidation rates; Electron energy loss spectroscopy
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
urn:nbn:se:ri:diva-68780 (URN)10.1016/j.carbon.2023.118686 (DOI)2-s2.0-85178132166 (Scopus ID)
Funder
Swedish Research Council, 2020-04453Swedish Research Council, 2017-04902
Note

We thank Jens Kling for assistance of, and discussion regarding, the operation of the ETEM at DTU, Vesna Mirosavljevic at Trelleborg AB for supplying CB, and Hugo Selling for assistance with the preliminary quantification of the oxidation rate at low pressures. The authors acknowledge support from NanoLund and funding from the Swedish Research Council (grant numbers 2020-04453 and 2017-04902 ).

Available from: 2024-01-15 Created: 2024-01-15 Last updated: 2024-01-15Bibliographically approved
Mases, M., Jacobsson, D., Wahlqvist, D., Ek, M. & Wiinikka, H. (2024). The oxidation of carbon nanostructures imaged by electron microscopy: Comparison between in-situ TEM and TGA experiments. Applied Surface Science, 672, Article ID 160755.
Open this publication in new window or tab >>The oxidation of carbon nanostructures imaged by electron microscopy: Comparison between in-situ TEM and TGA experiments
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2024 (English)In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 672, article id 160755Article in journal (Refereed) Published
Abstract [en]

The development of a model of carbon oxidation has engaged researchers for decades. Yet many outstanding questions remain due to the inability to experimentally study the details of the oxidation. Today, novel techniques such as environmental transmission electron microscopy (ETEM), allowing for in-situ nanoscale observations of the oxidation process, can help illuminate some of these questions. In this study of few layer graphene (FLG), multi-walled carbon nanotubes (MWCNTs), buckminsterfullerene (C60), and nanodiamonds (NDs) oxidizing in temperatures up to 1100 °C and we analyze the importance of nanostructure for the thermal stability of nanocarbons. The study was complemented with thermogravimetric analysis (TGA) and the experiments were in good agreement with oxidation rates increasing sharply with temperature and the thermal stability of the materials MWCNTs, FLG, C60 and NDs in descending order. Based on the direct nanoscale visualization obtained in the ETEM the materials can be divided into two overall categories: materials with low strain sp2-bonds (FLG and MWCNT); and materials with high strain sp2-bonds (C60) or sp3-bonds (NDs). For materials in the first category, it is possible to identify several different phenomena as their oxidation rate increases as a function of temperatures whereas materials in the second category appear to be more influenced by extrinsic factors such as the electron beam and by structural transformation upon heating. This study clearly shows the value of adding ETEM results to traditional TGA investigations since it gives both a complementary and more detailed information about the dynamic oxidation process.

Place, publisher, year, edition, pages
Elsevier BV, 2024
Keywords
Fullerenes, Graphene, High resolution transmission electron microscopy, Multiwalled carbon nanotubes (MWCN), Nanodiamonds, Oxidation, Thermodynamic stability, C 60, Carbon nano-structures, DSC, Environmental transmission electron microscopy, Few-layer graphene, In-situ TEM, Multi-walled-carbon-nanotubes, Nano scale, Oxidation process, Oxidation rates, Thermogravimetric analysis
National Category
Condensed Matter Physics Materials Chemistry
Identifiers
urn:nbn:se:ri:diva-74729 (URN)10.1016/j.apsusc.2024.160755 (DOI)2-s2.0-85199183947 (Scopus ID)
Funder
Swedish Research Council, 2020-04453
Available from: 2024-08-08 Created: 2024-08-08 Last updated: 2024-08-08
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9395-9928

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