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- Gunarathne, Duleeka S., et al.
(författare)
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Performance of an effectively integrated biomass multi-stage gasification system and a steel industry heat treatment furnace
- 2016
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 170, s. 353-361
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Tidskriftsartikel (refereegranskat)abstract
- The challenges of replacing fossil fuel with renewable energy in steel industry furnaces include not only reducing CO2 emissions but also increasing the system energy efficiency. In this work, a multi-stage gasification system is chosen for the integration with a heat treatment furnace in the steel powder industry to recover different rank/temperature waste heat back to the biomass gasification system, resulting higher system energy efficiency.A system model based on Aspen Plus was developed for the proposed integrated system considering all steps, including biomass drying, pyrolysis, gasification and the combustion of syngas in the furnace. Both low temperature (up to 400 °C) and high temperature (up to 700 °C) heat recovery possibilities were analysed in terms of energy efficiency by optimizing the biomass pretreatment temperature.The required process conditions of the furnace can be achieved by using syngas. No major changes to the furnace, combustion technology or flue gas handling system are necessary for this fuel switching. Only a slight revamp of the burner system and a new waste heat recovery system from the flue gases are required.Both the furnace efficiency and gasifier system efficiency are improved by integration with the waste heat recovery. The heat recovery from the hot furnace flue gas for biomass drying and steam superheating is the most promising option from an energy efficiency point of view. This option recovers two thirds of the available waste heat, according to the pinch analysis performed. Generally, depending on the extent of flue gas heat recovery, the system can sustain up to 65% feedstock moisture content at the highest pyrolysis temperature studied.
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- Hulme-Smith, Christopher, 1989-, et al.
(författare)
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Spreadability Testing of Powder for Additive Manufacturing
- 2020
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Ingår i: Berg- und Huttenmännische Monatshefte (BHM). - : Springer Nature. - 0005-8912 .- 1613-7531. ; 166:1, s. 9-13
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Tidskriftsartikel (refereegranskat)abstract
- The spreading of powders into thin layers is a critical step in powder bed additive manufacturing, but there is no accepted technique to test it. There is not even a metric that can be used to describe spreading behaviour. A robust, image-based measurement procedure has been developed and can be implemented at modest cost and with minimal training. The analysis is automated to derive quantitative information about the characteristics of the spread layer. The technique has been demonstrated for three powders to quantify their spreading behaviour as a function of layer thickness and spreading speed.
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| 6. |
- Liu, Hao, et al.
(författare)
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A thermodynamic study of hot syngas impurities in steel reheating furnaces : Corrosion and interaction with oxide scales
- 2014
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Ingår i: Energy. - : Elsevier BV. - 0360-5442 .- 1873-6785. ; 77, s. 352-361
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Tidskriftsartikel (refereegranskat)abstract
- Environmental concerns lead industries to implement gasified biomass (syngas) as a promising fuel in steel reheating furnaces. The impurities of syngas as well as a combination with iron oxide scale form complex mixtures with low melting points, and might cause corrosion on steel slabs. In this paper, the effects of syngas impurities are thermodynamically investigated, when scale formation on the steel slabs surface simultaneously takes place. A steel reheating furnace can be divided into preheating, heating, and soaking zones where the temperature of a steel slab changes respectively. Therefore, the thermodynamic calculation is performed at different temperatures to predict the fate of impurities. Then, the stable species are connected with respective zones in a reheating furnace. It is concluded that reactions due to alkali compounds, chloride, and particulate matter could take place on steel slabs. In the low temperature range, interaction of sodium chloride occured with pure iron prior to scale formation. Then, at high temperature the reactions of impurities are notable with iron oxides due to scale growing. Furthermore, the multicomponent reactions with syngas impurities showed that most of alkali contents evaporate at first stages, and only small amounts of them remain in slag at high temperature.
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| 7. |
- Marchetti, Lorenzo, et al.
(författare)
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On Metal Powder Tribocharging and Humidity Adsorption
- 2022
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Ingår i: World PM 2022 Congress Proceedings. - : European Powder Metallurgy Association (EPMA).
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Konferensbidrag (refereegranskat)abstract
- In this work, three characterization techniques were applied to a set of alloys in fine powder form (TiAl6V4, AlSi10Mg, AlSi7, 316L, ferritic stainless steel, martensitic stainless steel and WC-Co-mixes). We sought deeper understanding of response to humidity and flowability as a result of the powder alloy. Slight tribo-charging (induced and measured using a GranuCharge setup) against metal surfaces was found to occur for all alloys. Although the accumulated charge was small and dissipated quickly. Greater charging occurs if the environment is humid, and if the powder slides against plastic surfaces. Dynamic Vapor Sorption (DVS) was employed to understand the adsorption capacity of powders. It showed that WC-Co-mixes adsorbed much more humidity than the other materials. Some alloys retained some of the adsorbed mass when humidity returned to normal conditions. RPA was tested on powders during exposure to 20-98% RH, which above 80% RH caused declining flowability.
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| 8. |
- Mellin, Pelle, et al.
(författare)
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A proposed Swedish national standard and best practice for detection of Ar in PM hip material
- 2018
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Ingår i: Euro PM 2018 Congress and Exhibition. - : European Powder Metallurgy Association (EPMA). - 9781899072507
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Konferensbidrag (refereegranskat)abstract
- Ar in metal is present as gaseous voids which affect the material performance; most notably the mechanical properties. In agreement with literature findings, our investigation confirms this for 316L steel produced by PM HIP. Detecting the Ar is possible by microscopy, but more reliably with inert gas fusion followed by gas chromatography or mass spectrometry. The users of these techniques have accumulated experience over the years and consider them robust, especially in terms of distinguishing a presence or absence of Ar. Since consensus has emerged, a standard is now possible. We propose firstly a national standard. It may be used as a quality agreement between the purchaser and provider of the PM HIP service. The proposed standard considers the distinctiveness of PM HIP. For example that Ar tends to segregate in PM HIP cans. In fact, consensus has also been reached on how to reliably sample from PM HIP cans. © European Powder Metallurgy Association (EPMA).
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- Mellin, Pelle, 1985-, et al.
(författare)
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Accuracy and Potential Use of a Developed CFD-pyrolysis Model for Simulating Lab-scale Bio Oil Production
- 2012
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Ingår i: The 20th EU BC&E Online Proceedings 2012. - 9788889407547 ; , s. 953-959
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The paper describes development of a CFD¬pyrolysis model using an Eularian-Eularian framework with an implemented pyrolysis reaction model. The CFD¬pyrolysis model is used to simulate the bubbling fluidized bed reactor integrated in a new experimental fast pyrolysis process for bio oil production. The model is compared to experiments in aspect of outlet gas composition, temperature and bed height. Tar behavior and yield of bio oil are illustrated and a parametric study investigates impact of flow rate and temperature on bio oil yield. The results show a tolerable fit compared to measurements and reasonable tendencies in the parametric study.
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| 10. |
- Mellin, Pelle, et al.
(författare)
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An Euler–Euler approach to modeling biomass fast pyrolysis in fluidized-bed reactors – Focusing on the gas phase
- 2013
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Ingår i: Applied Thermal Engineering. - : Elsevier BV. - 1359-4311 .- 1873-5606. ; 58:1-2, s. 344-353
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Tidskriftsartikel (refereegranskat)abstract
- A developed 3D Euler–Euler CFD model, with an integrated pyrolysis model, is proposed as a way of predicting vapor phase dynamics and product distributions in the fluidized bed process for biomass fast pyrolysis. The main interest in this work is the gases resulting from the pyrolysis mixed with the fluidizing gas. We propose therefore a simple rendering of the solid material while directing attention to the vapor phase. At the same time the required computational resources for reaching stabilized conditions in the reactor are reduced. Temperature profile, velocity profile and pyrolysis products are predicted and globally verified by a series of parallel cases, which are compared to experimental measurements and known trends of liquid, solid and gas yields. The comparison of experimental measurements and model predictions satisfy the accuracy of the model and on a quantitative basis, the product yields agree with commonly known trends of bio oil versus temperature and residence time.
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