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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
Thorin, E., Sepman, A., Ögren, Y., Ma, C., Carlborg, M., Wennebro, J., . . . Schmidt, F. M. (2023). Quantitative real-time in situ measurement of gaseous K, KOH and KCl in a 140 kW entrained-flow biomass gasifier. Proceedings of the Combustion Institute, 39(1), 1337-1345
Open this publication in new window or tab >>Quantitative real-time in situ measurement of gaseous K, KOH and KCl in a 140 kW entrained-flow biomass gasifier
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2023 (English)In: Proceedings of the Combustion Institute, ISSN 1540-7489, E-ISSN 1873-2704, Vol. 39, no 1, p. 1337-1345Article in journal (Refereed) Published
Abstract [en]

Photofragmentation tunable diode laser absorption spectroscopy (PF-TDLAS) was used to simultaneously measure the concentrations of gas phase atomic potassium (K), potassium hydroxide (KOH) and potassium chloride (KCl) in the reactor core of a 140 kWth atmospheric entrained-flow gasifier (EFG). In two gasification experiments at air-to-fuel equivalence ratio of 0.5, the EFG was first run on forest residues (FR) and then on an 80/20 mixture of FR and wheat straw (FR/WS). Combustion at air-to-fuel equivalence ratio of 1.3 was investigated for comparison. A high K(g) absorbance was observed in gasification, requiring the photofragmentation signals from KOH(g) and KCl(g) to be recorded at a fixed detuning of 7.3 cm-1 from the center of the K(g) absorption profile. In combustion, the fragments recombined instantly after the UV pulse within around 10 μs, whereas in gasification, the K(g) fragment concentration first increased further for 30 μs after the UV pulse, before slowly decaying for up to hundreds of μs. According to 0D reaction kinetics simulations, this could be explained by a difference in recombination kinetics, which is dominated by oxygen reactions in combustion and by hydrogen reactions in gasification. The K species concentrations in the EFG were stable on average, but periodic short-term variations due to fuel feeding were observed, as well as a gradual increase in KOH(g) over the day as the reactor approached global equilibrium. A comparison of the average K species concentrations towards the end of each experiment showed a higher total K in the gas phase for FR/WS, with higher K(g) and KCl(g), but lower KOH(g), compared to the FR fuel. The measured values were in reasonable agreement with predictions by thermodynamic equilibrium calculations. © 2022 The Author(s). 

Place, publisher, year, edition, pages
Elsevier Ltd, 2023
Keywords
Biomass, Entrained-flow gasification, Photofragmentation, Potassium (K), Tunable diode laser absorption spectroscopy (TDLAS), Absorption spectroscopy, Combustion, Fuels, Gases, Gasification, Potassium hydroxide, Reaction kinetics, Semiconductor lasers, Entrained flow gasification, Entrained flow gasifiers, Equivalence ratios, Forest residue, Gas-phases, Potassium chloride, Tunable diode laser absorption spectroscopy, Chlorine compounds
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-61456 (URN)10.1016/j.proci.2022.07.180 (DOI)2-s2.0-85139508080 (Scopus ID)
Note

 Funding details: 36160-1, 50470-1; Funding details: Energimyndigheten; Funding details: Kempestiftelserna, JCK-1316; Funding details: Horizon 2020, 637020; Funding text 1: The authors acknowledge financial support from the Swedish strategic research program Bio4Energy, the Kempe Foundations ( JCK-1316 ), and the Swedish Energy Agency through both the Swedish Gasification Centre and projects no. 50470-1 and 36160-1 . The fuels were received from a project which received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 637020 - Mobile Flip.

Available from: 2022-12-07 Created: 2022-12-07 Last updated: 2023-07-06Bibliographically approved
Sepman, A., Thorin, E., Ögren, Y., Ma, C., Carlborg, M., Wennebro, J., . . . Schmidt, F. (2022). Laser-based detection of methane and soot during entrained-flow biomass gasification. Combustion and Flame, 237, Article ID 111886.
Open this publication in new window or tab >>Laser-based detection of methane and soot during entrained-flow biomass gasification
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2022 (English)In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 237, article id 111886Article in journal (Refereed) Published
Abstract [en]

Methane is one of the main gas species produced during biomass gasification and may be a desired or undesired product. Syngas CH4 concentrations are typically >5 vol-% (when desired) and 1–3 vol-% even when efforts are made to minimize it, while thermochemical equilibrium calculations (TEC) predict complete CH4 decomposition. How CH4 is generated and sustained in the reactor core is not well understood. To investigate this, accurate quantification of the CH4 concentration during the process is a necessary first step. We present results from rapid in situ measurements of CH4, soot volume fraction, H2O and gas temperature in the reactor core of an atmospheric entrained-flow biomass gasifier, obtained using tunable diode laser absorption spectroscopy (TDLAS) in the near-infrared (1.4 µm) and mid-infrared (3.1 µm) region. An 80/20 wt% mixture of forest residues and wheat straw was converted using oxygen-enriched air (O2>21 vol%) as oxidizer, while the global air-fuel equivalence ratio (AFR) was set to values between 0.3 and 0.7. Combustion at AFR 1.3 was performed as a reference. The results show that the CH4 concentration increased from 1 to 3 vol-% with decreasing AFR, and strongly correlated with soot production. In general, the TDLAS measurements are in good agreement with extractive diagnostics at the reactor outlet and TEC under fuel-lean conditions, but deviate significantly for lower AFR. Detailed 0D chemical reaction kinetics simulations suggest that the CH4 produced in the upper part of the reactor at temperatures >1700 K was fully decomposed, while the CH4 in the final syngas originated from the pyrolysis of fuel particles at temperatures below 1400 K in the lower section of the reactor core. It is shown that the process efficiency was significantly reduced due to the C and H atoms bound in methane and soot. © 2021 The Authors

Place, publisher, year, edition, pages
Elsevier Inc., 2022
Keywords
Biomass, Entrained-flow reactor, Gasification, Methane, Soot, Tunable diode laser absorption spectroscopy (TDLAS), Absorption spectroscopy, Atmospheric movements, Atmospheric temperature, Dust, Infrared devices, Reaction kinetics, Semiconductor lasers, Surface reactions, Synthesis gas, Air/fuel equivalence ratio, Biomass Gasification, CH 4, Entrained flow, Entrained Flow Reactor, Equilibrium calculation, Syn gas, Thermochemical equilibrium, Tunable diode laser absorption spectroscopy
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-57326 (URN)10.1016/j.combustflame.2021.111886 (DOI)2-s2.0-85120458898 (Scopus ID)
Note

 Funding details: 50470-1; Funding details: Energimyndigheten; Funding details: Horizon 2020, 637020; Funding text 1: The authors acknowledge financial support from the Swedish strategic research program Bio4Energy and the Swedish Energy Agency through both the Swedish Gasification Centre and project no. 50470-1. The fuels were received from a project, which received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement no. 637020 - Mobile Flip.

Available from: 2021-12-16 Created: 2021-12-16 Last updated: 2023-05-19Bibliographically approved
Sepman, A., Ögren, Y., Wennebro, J. & Wiinikka, H. (2022). Simultaneous diagnostics of fuel moisture content and equivalence ratio during combustion of liquid and solid fuels. Applied Energy, 324, Article ID 119731.
Open this publication in new window or tab >>Simultaneous diagnostics of fuel moisture content and equivalence ratio during combustion of liquid and solid fuels
2022 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 324, article id 119731Article in journal (Refereed) Published
Abstract [en]

The precise control of bio-based combustion is challenging due to the varying composition and moisture content of the fuels, difficulties in achieving stable fuel feeding, and complex underlying thermochemical processes. We present simultaneous online diagnostics of two combustion parameters, the equivalence ratio and fuel moisture content, in a pilot-scale environment. The parameters were evaluated by analysing the H2O and CO2 concentrations. These were measured using a Fourier transform infrared (FTIR) spectrometer (exhaust) and tuneable diode laser (TDL) absorption spectroscopy (combustion chamber) in pilot-scale diesel and pulverized biomass combustion. Liquid H2O was added into the combustion chamber to represent fuel moisture. The equivalence ratio of diesel and wood combustion was varied by adjusting the flows of combustion air in a staged manner or by using rapid periodic variations (on the order of seconds). The moisture fuel levels calculated using the measured fuel and water flow rates (flow method) and the FTIR and TDL H2O and CO2 concentrations agree within 3% (absolute) for both fuels. The TDL and FTIR equivalence ratios agreed quantitatively for both diesel and biomass combustion. However, close to stoichiometry, the TDL values for biomass are up to 15% lower than the FTIR values, indicating ongoing combustion at the location of the TDL measurements. © 2022 The Authors

Place, publisher, year, edition, pages
Elsevier Ltd, 2022
Keywords
Biomass, Entrained flow reactor, Equivalence ratio, Fuel moisture content, tuneable diode laser absorption spectroscopy (TDLAS), Absorption spectroscopy, Carbon dioxide, Combustion, Combustion chambers, Diesel engines, Flow of water, Fourier transform infrared spectroscopy, Fuels, Moisture determination, Semiconductor lasers, Spectrometers, Biomass combustion, CO 2 concentration, Diode-laser, Equivalence ratios, Fourier transform infrared, Pilot scale, Tuneable diode laser absorption spectroscopies, Tuneable diode laser absorption spectroscopy
National Category
Fusion, Plasma and Space Physics
Identifiers
urn:nbn:se:ri:diva-59893 (URN)10.1016/j.apenergy.2022.119731 (DOI)2-s2.0-85134966967 (Scopus ID)
Note

Correspondence Address: Sepman, A.; RISE AB, Box 726, Sweden; email: alexey.sepman@ri.se; Funding details: Energimyndigheten; Funding text 1: We gratefully acknowledge financial support from the Swedish Energy Agency through the 50470-1 project.

Available from: 2022-08-11 Created: 2022-08-11 Last updated: 2023-05-19Bibliographically approved
Fooladgar, E., Brackmann, C., Mannazhi, M., Ögren, Y., Bengtsson, P.-E., Wiinikka, H. & Tóth, P. (2021). CFD modeling of pyrolysis oil combustion using finite rate chemistry. Fuel, 299, Article ID 120856.
Open this publication in new window or tab >>CFD modeling of pyrolysis oil combustion using finite rate chemistry
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2021 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 299, article id 120856Article in journal (Refereed) Published
Abstract [en]

This paper reports the first Computational Fluid Dynamics (CFD) model developed for biomass pyrolysis oil spray combustion using Finite-Rate Chemistry (FRC) approach. To make the CFD calculations feasible, a reduced mechanism for modeling the combustion of biomass Fast Pyrolysis Oil (FPO) based on the POLIMI 1412 mechanism and a model for eugenol oxidation was developed. The reduced mechanism consisted of 200 reactions and 71 species. This level of complexity was found to be a good tradeoff between predictive power and computational cost such that the reduced model could be used in CFD modeling. The predictive power of the reduced mechanism was demonstrated via 0D (adiabatic, premixed, constant pressure reactor), 1D (laminar counterflow flame) and 3D (CFD of a methane-air flat-flame piloted FPO spray flame) calculations. Results from CFD were compared against experimental data from non-intrusive optical diagnostics. The reduced model was successfully used in CFD calculations—the computational cost was approximately 2 orders of magnitude higher than that of a simplified model. Using the reduced mechanism, the concentration of pollutants, minor combustion products, and flame radicals could be predicted—this is added capability compared to already existing models. The CFD model using the reduced mechanism showed quantitative predictive power for major combustion products, flame temperature, some pollutants and temperature, and qualitative predictive power for flame radicals and soot. © 2021 The Authors

Place, publisher, year, edition, pages
Elsevier Ltd, 2021
Keywords
Biomass, Chemical kinetics, Computational Fluid Dynamics, Fast Pyrolysis Oil, Finite-Rate Chemistry, Laser diagnostics, Spray combustion
National Category
Energy Engineering
Identifiers
urn:nbn:se:ri:diva-53008 (URN)10.1016/j.fuel.2021.120856 (DOI)2-s2.0-85105060454 (Scopus ID)
Note

Funding details: Energimyndigheten; Funding details: Energimyndigheten, EM 44110-1; Funding text 1: The financial support of the Swedish Energy Agency (Energimyndigheten) through the project “Computational Optimization of Gas Turbine Combustors Firing Biomass Fast Pyrolysis Oil” (EM 44110-1) and the Swedish Government through Bio4Energy program is greatly acknowledged

Available from: 2021-05-26 Created: 2021-05-26 Last updated: 2023-05-19Bibliographically approved
Sepman, A., Fredriksson, C., Ögren, Y. & Wiinikka, H. (2021). Laser-Based, Optical, and Traditional Diagnostics of NO and Temperature in 400 kW Pilot-Scale Furnace. Applied Sciences, 11(15), Article ID 7048.
Open this publication in new window or tab >>Laser-Based, Optical, and Traditional Diagnostics of NO and Temperature in 400 kW Pilot-Scale Furnace
2021 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 11, no 15, article id 7048Article in journal (Refereed) Published
Abstract [en]

A fast sensor for simultaneous high temperature (above 800 K) diagnostics of nitrogen oxide (NO) concentration and gas temperature (T) based on the spectral fitting of low-resolution NO UV absorption near 226 nm was applied in pilot-scale LKAB’s Experimental Combustion Furnace (ECF). The experiments were performed in plasma and/or fuel preheated air at temperatures up to 1550 K, which is about 200 K higher than the maximal temperature used for the validation of the developed UV NO sensor previously. The UV absorption NO and T measurements are compared with NO probe and temperature measurements via suction pyrometry and tuneable diode laser absorption (TDL) using H2O transitions at 1398 nm, respectively. The agreement between the NO UV and NO probe measurements was better than 15%. There is also a good agreement between the temperatures obtained using laser-based, optical, and suction pyrometer measurements. Comparison of the TDL H2O measurements with the calculated H2O concentrations demonstrated an excellent agreement and confirms the accuracy of TDL H2O measurements (better than 10%). The ability of the optical and laser techniques to resolve various variations in the process parameters is demonstrated.

Keywords
NO UV absorption, temperature, TDLAS, pilot-scale furnace
National Category
Atom and Molecular Physics and Optics
Identifiers
urn:nbn:se:ri:diva-55657 (URN)10.3390/app11157048 (DOI)
Available from: 2021-08-05 Created: 2021-08-05 Last updated: 2023-05-19Bibliographically approved
Weiland, F., Lundström, S. & Ögren, Y. (2021). Oxygen-blown gasification of pulp mill bark residues for synthetic fuel production. Processes, 9(1), Article ID 163.
Open this publication in new window or tab >>Oxygen-blown gasification of pulp mill bark residues for synthetic fuel production
2021 (English)In: Processes, ISSN 2227-9717, Vol. 9, no 1, article id 163Article in journal (Refereed) Published
Abstract [en]

Synthetic fuel production via gasification of residual biomass streams from the pulp and paper industry can be an opportunity for the mills to enable improved resource utilization and at the same time reduce the production of excess heat. This paper summarizes initial oxygen-blown gasification experiments with two bark residues from a European pulp and paper mill, i.e., a softwood bark and a hardwood bark. The gasification process was characterized by measuring syngas yields and process efficiency to find optimum operating conditions. In addition, impurities in the syngas and ash behavior were characterized. Maximum yields of CO and H2 were obtained from softwood bark and amounted to approximately 29 and 15 mol/kg fuel, respectively. Optimum cold gas efficiency was achieved at an oxygen stoichiometric ratio of λ = 0.40 and was approximately 76% and 70% for softwood bark and hardwood bark, respectively. Increased λ had a reducing effect on pollutants in the syngas, e.g., higher hydrocarbons, NH3, HCl, and soot. The situation for sulfur species was more complex. Evaluation of the bark ashes indicated that slag formation could start already from 800◦C. Furthermore, a non-intrusive laser diagnostics technique gave rapid feedback on the millisecond scale. Measured syngas temperature and water content were in good agreement with the applied reference methods. © 2021 by the authors. 

Place, publisher, year, edition, pages
MDPI AG, 2021
Keywords
Bark residues, Gasification, Online TDLAS process measurement, Oxygen blown, Pulp mill, Syngas
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-52222 (URN)10.3390/pr9010163 (DOI)2-s2.0-85099947248 (Scopus ID)
Note

Funding details: Horizon 2020; Funding details: Energimyndigheten; Funding details: 818011; Funding text 1: This is exactly the combination of processes that are being studied in the European Pulp & Fuel project within which this work has been performed, i.e., oxygen-blown gasification of bark residues in combination with SCWG of black liquor aiming for synthetic fuel production. The Pulp & Fuel project received funding from the European Union’s Horizon 2020 research and innovation program and consists of ten partners from four European countries. The project addresses the thermochemical conversion of industrial wastes produced at a pulp and paper mill into biofuel.; Funding text 2: Funding: The Pulp&Fuel project, within which this work was mainly carried out, received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 818011. The TDLAS method, for temperature and water concentration measurements, was developed within the Bio4Gasification (B4G) and Swedish Gasification Center (SFC), financed by the Swedish Energy Agency together with academia and industry partners.

Available from: 2021-02-09 Created: 2021-02-09 Last updated: 2023-05-16Bibliographically approved
Toth-Pal, Z., Ögren, Y., Sepman, A., Gren, P. O. & Wiinikka, H. (2020). Combustion behavior of pulverized sponge iron as a recyclable electrofuel. Powder Technology, 373, 210-219
Open this publication in new window or tab >>Combustion behavior of pulverized sponge iron as a recyclable electrofuel
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2020 (English)In: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 373, p. 210-219Article in journal (Refereed) Published
Abstract [en]

In this work, the combustion behavior of pulverized sponge iron (PSI), a practical-grade iron product that was proposed as a potential candidate in the metal fuel cycle, was observed directly using high-magnification shadowgraphy and other optical diagnostics techniques. The PSI was combusted in a laboratory-scale, McKenna flat-flame burner. Results suggest that, in agreement with theoretical models, PSI combusted heterogeneously, with most of the particle mass converting to an intact, solid oxide. However, in contrast with previous hypotheses, the formation of a microflame of combusting aerosol that was attached to the particle surface was observed. Results from quantitative shadowgraphy indicated near-instantaneous melting and complex behavior—we attempted to explain these based on the Fe–O phase diagram. The analysis of micron- and nano-sized combustion products confirmed that the PSI combusted heterogeneously and a gaseous sub-oxide was formed. Combustion under high excess oxygen was hypothesized to reduce the formation of these oxides.

Place, publisher, year, edition, pages
Elsevier B.V., 2020
Keywords
Energy carrier, Energy vector, Iron combustion, Metal combustion, Metal fuels, Zero‑carbon, Combustion, Sponge iron, Combustion behavior, Combustion products, Excess oxygen, Flat flame burner, High magnifications, Optical diagnostics technique, Particle mass, Particle surface, Pulverized fuel, fuel, iron, oxygen, pulverized sponge iron, unclassified drug, Article, calibration, controlled study, digital imaging, measurement accuracy, particle size, pyrometry, scanning electron microscopy, shadowgraphy, surface property, theoretical model, velocity
National Category
Engineering and Technology
Identifiers
urn:nbn:se:ri:diva-45373 (URN)10.1016/j.powtec.2020.05.078 (DOI)2-s2.0-85087108013 (Scopus ID)
Note

Funding details: Energimyndigheten, EFOP-3.6.1-16-00011, 45374-1; Funding details: European Social Fund, ESF; Funding details: European Commission, EC; Funding text 1: The authors thank Jonas Persson for his assistance in carrying out the experiments. This work has been financed by the Swedish Energy Agency , project number 45374-1 . Pal Toth was partly financed by the project EFOP-3.6.1-16-00011 that was implemented in the framework of the Szechenyi 2020 program of Hungary . Financial support was provided by the European Union , co-financed by the European Social Fund .

Available from: 2020-07-22 Created: 2020-07-22 Last updated: 2023-05-19Bibliographically approved
Wiinikka, H., Sepman, A., Ögren, Y., Lindblom, B. & Nordin, L.-O. (2019). Combustion Evaluation of Renewable Fuels for Iron-Ore Pellet Induration. Energy & Fuels, 33(8), 7819-7829
Open this publication in new window or tab >>Combustion Evaluation of Renewable Fuels for Iron-Ore Pellet Induration
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2019 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 33, no 8, p. 7819-7829Article in journal (Refereed) Published
Abstract [en]

Induration (or sintering) of iron-ore pellets requires high temperature (∼1300 °C), which today is generated by burning fuel oil in the firing zone of the straight-grate plant (SG) or coal in the rotary kiln of grate-kiln (GK) plants. In this study, ∼150 kWth combustion experiments were used to investigate the opportunity of totally replacing fuel oil with H2 or pyrolysis oil and replacing coal with wood pellets or black pellets powder. For SG plants, the fuel oil can probably be replaced with either H2 or pyrolysis oil without any major concerns, except for slightly or much higher NOx emissions in the case of pyrolysis oil and H2, respectively. For GK induration machines, it is probably challenging to replace coal entirely with biomass since the temperature profile will be different, and there is a risk for increased ash related operational problems. For both SG and GK plants, the slightly lower O2 concentration in the flue gas observed during biomass combustion (pyrolysis oil, wood pellets, and black pellets) may, however, be negative for the induration process, and this needs to be clarified in future research.

Place, publisher, year, edition, pages
American Chemical Society, 2019
Keywords
Coal, Fuel oils, Gas plants, Iron ore pellets, Iron ores, Pelletizing, Pyrolysis, Sintering, Biomass combustion, Combustion experiments, High temperature, Operational problems, Pellet induration, Renewable fuels, Straight grate, Temperature profiles, Coal combustion
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39850 (URN)10.1021/acs.energyfuels.9b01356 (DOI)2-s2.0-85070712552 (Scopus ID)
Note

Funding details: Energimyndigheten; Funding text 1: This work has been conducted as part of the HYBRIT research project RP1. We gratefully acknowledge financial support from the Swedish Energy Agency. HYBRIT (Hydrogen Breakthrough Ironmaking Technology) is a joint initiative of the three companies SSAB, LKAB, and Vattenfall with the aim of developing the world’s first fossil-free ore-based steelmaking route. Therese Vikström at RISE ETC is highly acknowledged for performing SEM/EDS analysis of impactor particles and the initial drawings of the experimental facility. Dr. Roger Molinder at RISE ETC is highly acknowledged for the linguistic improvement of the manuscript.

Available from: 2019-08-30 Created: 2019-08-30 Last updated: 2023-05-19Bibliographically approved
Hellström, K., Ögren, Y., da Silva, M., Cristea, M. & Ström, E. (2019). Corrosion behavior of a Mo(Si, Al)2 composite at 1700°C in 95% N2 + 5% H2. Journal of the European Ceramic Society, 39(16), 5197-5203
Open this publication in new window or tab >>Corrosion behavior of a Mo(Si, Al)2 composite at 1700°C in 95% N2 + 5% H2
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2019 (English)In: Journal of the European Ceramic Society, ISSN 0955-2219, E-ISSN 1873-619X, Vol. 39, no 16, p. 5197-5203Article in journal (Refereed) Published
Abstract [en]

A Mo(Si, Al)2 based composite was pre-oxidized to establish an alumina scale on the material surface. Thereafter, the corrosion behavior of the composite was examined at 1700 °C for up to 24 h in 95% N2 + 5% H2. The weight change was followed by recording the material weight before and after exposure. The crystalline corrosion products were analyzed with X-ray diffraction (XRD) and the microstructure of the cross sectioned material was characterized using scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). It was shown that AlN and Al5O6N layers developed on top of the pre-oxidized alumina layer and alumina threads develop out from the specimen surface. The accompanied aluminum consumption converts the substrate Mo(Si,Al)2 into Mo5Si3 immediately below the alumina scale to the extent that the Mo5Si3 becomes porous underneath the alumina scale. Corrosion mechanisms are discussed with the support of thermodynamic calculations.

Place, publisher, year, edition, pages
Elsevier Ltd, 2019
Keywords
Alumina, High temperature corrosion, Mo(Si, Al)2, Molybdenum disiliside, Nitrogen, Aluminum nitride, Aluminum oxide, Corrosive effects, Energy dispersive spectroscopy, III-V semiconductors, Molybdenum compounds, Scanning electron microscopy, Alumina layers, Corrosion behavior, Corrosion mechanisms, Corrosion products, Energy dispersive X ray spectroscopy, Material surface, Specimen surfaces, Thermodynamic calculations, Aluminum corrosion
National Category
Natural Sciences
Identifiers
urn:nbn:se:ri:diva-39849 (URN)10.1016/j.jeurceramsoc.2019.08.017 (DOI)2-s2.0-85070899991 (Scopus ID)
Available from: 2019-08-30 Created: 2019-08-30 Last updated: 2020-01-29Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-6473-7090

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