| 1. |
- Hochstöger, Daniel, et al.
(författare)
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Experiences from commissioning and first operation of a 1 mw demonstration-scale dual fluidized bed gasification plant
- 2023
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Ingår i: European biomass conference and exhibition proceedings. - : ETA-Florence Renewable Energies. ; , s. 594-599
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Konferensbidrag (refereegranskat)abstract
- The use of biomass, whether wood or waste materials, represents an opportunity to reduce dependence on fossil fuels. Using dual fluidized bed (DFB) steam gasification technology for conversion of biomass, biogenic residues and waste is a possible approach to exploit this potential. A demonstration-scale 1 MW gasification plant with subsequent product gas and flue gas cleaning has been constructed at the Syngas Platform Vienna. The performance of this plant during its first continuous operation was evaluated in this study by analyzing temperature and pressure profiles recorded over a period of nearly 6 hours of continuous operation and by evaluating various performance indicators, such as steam-to-fuel ratio, gasification temperatures, and product gas composition. The resulting data sets were compared with existing results from the 100 kW pilot plant at TU Wien. The discrepancies found and their avoidance is discussed. In addition, this paper highlights the mechanical challenges encountered during commissioning, such as high temperatures at the fabric filter and additional condensate drain in steam supply pipes, and identifies potential challenges during the installation and operation of future gasification plants.
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| 2. |
- Kuba, Matthias, et al.
(författare)
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A review on bed material particle layer formation and its positive influence on the performance of thermo-chemical biomass conversion in fluidized beds
- 2021
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Ingår i: Fuel. - : Elsevier. - 0016-2361 .- 1873-7153. ; 291
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Forskningsöversikt (refereegranskat)abstract
- Bed material particle layer formation plays a significant role in thermo-chemical conversion of biomass. The interaction between biomass ash and bed material in fluidized bed conversion processes has been described for a variety of different applications and spans from fundamental research of formation mechanisms to effects of this layer formation on long-term operation in industrial-scale. This review describes the current state of the research regarding the mechanisms underlying layer formation and the positive influence of bed material particle layer formation on the operation of thermo-chemical conversion processes. Thus, the main focus lies on its effect on the catalytic activity towards gasification reactions and the impact on oxygen transport in chemical looping combustion. The review focuses on the most commonly investigated bed materials, such as quartz, feldspar or olivine. While the most relevant results for both the underlying mechanisms and the subsequently observed effects on the operation are presented and discussed, knowledge gaps where further research is necessary are identified and described.
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| 3. |
- Kuba, Matthias, et al.
(författare)
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Deposit build-up and ash behavior in dual fluid bed steam gasification of logging residues in an industrial power plant
- 2015
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Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 139, s. 33-41
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Tidskriftsartikel (refereegranskat)abstract
- A promising way to substitute fossil fuels for production of electricity, heat, fuels for transportation and synthetic chemicals is biomass steam gasification in a dual fluidized bed (DFB). Using lower-cost feedstock, such as logging residues, instead of stemwood, improves the economic operation. In Senden, near Ulm in Germany, the first plant using logging residues is successfully operated by Stadtwerke Ulm. The major difficulties are slagging and deposit build-up. This paper characterizes inorganic components of ash forming matter and draws conclusions regarding mechanisms of deposit build-up. Olivine is used as bed material. Impurities, e.g., quartz, brought into the fluidized bed with the feedstock play a critical role. Interaction with biomass ash leads to formation of potassium silicates, decreasing the melting temperature. Recirculation of coarse ash back into combustion leads to enrichment of critical fragments. Improving the management of inorganic streams and controlling temperature levels is essential for operation with logging residues. (C) 2015 Elsevier B.V. All rights reserved.
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| 4. |
- Kuba, Matthias, et al.
(författare)
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Surface characterization of ash-layered olivine from fluidized bed biomass gasification
- 2021
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Ingår i: Biomass Conversion and Biorefinery. - : Springer. - 2190-6815 .- 2190-6823. ; 11:1, s. 29-38
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Tidskriftsartikel (refereegranskat)abstract
- The present study aims to present a comprehensive characterization of the surface of ash-layered olivine bed particles from dual fluidized bed gasification. It is well known from operation experience at industrial gasification plants that the bed material is activated during operation concerning its positive influence on gasification reactions. This is due to the built up of ash layers on the bed material particles; however, the chemical mechanisms are not well understood yet. Olivine samples from long-term operation in an industrial-scale gasification plant were investigated in comparison to fresh unused olivine. Changes of the surface morphology due to Ca-enrichment showed a significant increase of their surface area. Furthermore, the Ca-enrichment on the ash layer surface was distinctively associated to CaO being present. The presence of CaO on the surface was proven by adsorption tests of carbon monoxide as model compound. The detailed characterization contributes to a deeper understanding of the surface properties of ash layers and forms the basis for further investigations into their influence on gasification reactions.
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| 5. |
- Kuba, Matthias, et al.
(författare)
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Thermal stability of bed particle layers on naturally occurring minerals from dual fluid bed gasification of woody biomass
- 2016
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Ingår i: Energy & Fuels. - Washington : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 30:10, s. 8277-8285
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Tidskriftsartikel (refereegranskat)abstract
- The use of biomass as feedstock for gasification is a promising way of producing not only electricity and heat but also fuels for transportation and synthetic chemicals. Dual fluid bed steam gasification has proven to be suitable for this purpose. Olivine is currently the most commonly used bed material in this process due to its good agglomeration performance and its catalytic effectiveness in the reduction of biomass tars. However, as olivine contains heavy metals such as nickel and chromium, no further usage of the nutrient-rich ash is possible, and additional operational costs arise due to necessary disposal of the ash fractions. This paper investigates possible alternative bed materials and their suitability for dual fluid bed gasification systems focusing on the behavior of the naturally occurring minerals olivine, quartz, and K-feldspar in terms of agglomeration and fracturing at typical temperatures. To this end, samples of bed materials with layer formation on their particles were collected at the industrial biomass combined heat and power (CHP) plant in Senden, Germany, which uses olivine as the bed material and woody biomass as feedstock. The low cost logging residue feedstock contains mineral impurities such as quartz and K-feldspar, which become mixed into the fluidized bed during operation. Using experimental and thermochemical analysis, it was found that the layers on olivine and K-feldspar showed a significantly lower agglomeration tendency than quartz. Significant fracturing of particles or their layers could be detected for olivine and quartz, whereas K-feldspar layers were characterized by a higher stability. High catalytic activity is predicted for all three minerals once Ca-rich particle layers are fully developed. However, quartz may be less active during the buildup of the layers due to lower amounts of Ca in the initial layer formation.
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| 6. |
- Larsson, Anton, 1984, et al.
(författare)
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Steam gasification of biomass – Typical gas quality and operational strategies derived from industrial-scale plants
- 2021
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820. ; 212
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Tidskriftsartikel (refereegranskat)abstract
- Steam gasification enables the thermochemical conversion of solid fuels into a medium calorific gas that can be utilized for the synthesis of advanced biofuels, chemicals or for heat and power production. Dual fluidized bed (DFB) gasification is at present the technology applied to realize gasification of biomass in steam environment at large scale. Few large-scale DFB gasifiers exist, and this work presents a compilation and analysis of the data and operational strategies from the six DFB gasifiers in Europe. It is shown that the technology is robust, as similar gas quality can be achieved despite the differences in reactor design and operation strategies. Reference con-centrations of both gas components and tar components are provided, and correlations in the data are in-vestigated. In all plants, adjusting the availability and accessibility to the active ash components (K and Ca) was the key to control the gas quality. The gas quality, and in particular the tar content of the gas, can conveniently be assessed by monitored the concentration of CH4 in the produced gas. The data and experience acquired from these plants provide important knowledge for the future development of the steam gasification of biomass.
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| 7. |
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| 8. |
- Penthor, Stefan, et al.
(författare)
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The EU-FP7 Project SUCCESS - Scale-up of Oxygen Carrier for Chemical Looping Combustion using Environmentally Sustainable Materials
- 2017
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Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 114, s. 395-406
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Konferensbidrag (refereegranskat)abstract
- The paper gives a high level overview of the work performed in the EU-FP7 funded project SUCCESS (Scale-up of oxygen carrier for chemical looping combustion using environmentally sustainable materials). The project is the most recent one in a series of successful EU-funded research projects on the chemical looping combustion (CLC) technology. Its main objective is to perform the necessary research in order to demonstrate the CLC technology in the range of 10 MW fuel power input. The main focus is on scale-up of production of two different oxygen carrier materials using large scale equipment and industrially available raw materials. This will guarantee availability of oxygen carrier material at tonne scale. The scale-up of the two materials, a Cu and a Mn based, was successful and first tests with the Cu material have already been performed in four different pilot units up to 150 kW where the material showed excellent performance regarding fuel conversion. In addition to technology scale-up, extensive end-user evaluation is performed. This evaluation includes investigations on health, security and environmental impacts (HSE), a life cycle analysis and a techno-economic analysis to compare the CLC technology for steam generation against the current state-of-the-art technologies.
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| 9. |
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| 10. |
- Priščák, Juraj, et al.
(författare)
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Effect of time-dependent layer formation on the oxygen transport capacity of ilmenite during combustion of ash-rich woody biomass
- 2023
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Ingår i: Fuel. - : Elsevier Ltd. - 0016-2361 .- 1873-7153. ; 353
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Tidskriftsartikel (refereegranskat)abstract
- Oxygen carrier aided combustion (OCAC) is a novel technology that aims to enhance combustion of heterogenous fuels by replacing the inert bed material with an active oxygen carrier. One of the promising oxygen carriers is natural ilmenite which shows decent oxygen transport capacity and mechanical stability under OCAC operating conditions. However, interactions between ilmenite and woody biomass ash lead to the formation of a calcium-rich ash layer, which affects the ability of the oxygen carrier (OC) to transfer oxygen throughout the boiler and subsequently decreases the combustion efficiency. This paper focuses on the time-dependent morphological and compositional changes in ilmenite bed particles and the consequence effects on the oxygen transport capacity and reactivity of ilmenite. Ilmenite utilized in this study was investigated in a 5 kW bubbling fluidized bed combustion unit, utilizing ash-rich bark pellets as fuel. A negative effect of iron migration on the oxygen transport capacity was observed in ilmenite bed particles after 6 h of operation in the bubbling fluidized bed reactor. The decrease in the oxygen transport capacity of ilmenite was found to correlate with the increased exposure time in the fluidized bed reactor and was caused by the migration and subsequent erosion of Fe from the ilmenite particles. On the other hand, the older bed particles show an increase in reaction rate, presumably due to the catalytic activity of the calcium-enriched outer layer on the bed particle surface.
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