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Trubetskaya, A., Timko, M. T. & Umeki, K. (2020). Prediction of fast pyrolysis products yields using lignocellulosic compounds and ash contents. Applied Energy, 257, Article ID 113897.
Open this publication in new window or tab >>Prediction of fast pyrolysis products yields using lignocellulosic compounds and ash contents
2020 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 257, article id 113897Article in journal (Refereed) Published
Abstract [en]

The effects of lignocellulosic biomass composition on product yields and distributions were studied under high-temperature pyrolysis conditions (800–1250 °" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; display: inline; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; position: relative;">°°C) in a drop tube reactor. Several types of biomass were studied along with xylan, cellulose, and two types of lignin as model feeds. Among the model feeds, soot yields obtained from lignin pyrolysis were greater than those obtained from cellulose or xylan. Cellulose pyrolysis produced mostly gaseous products, along with small amounts of tars. Impregnation of lignin with alkali metals greatly reduced tar and soot formation, simultaneously increasing the hydrogen content of the syngas product. An empirical model predicted with reasonable accuracy trends in the product yields obtained from pyrolysis of whole biomass samples using as input data obtained from model feeds composition data and the pyrolysis temperature. Reaction temperature and ash content both have a strong influences on char yield, whereas gas yields were mostly affected by the reaction temperature.

Place, publisher, year, edition, pages
Elsevier, 2020
Keywords
Fast pyrolysis, Lignin, Potassium, Residence time, Modeling
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-76607 (URN)10.1016/j.apenergy.2019.113897 (DOI)2-s2.0-85073997898 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-11-04 (johcin)

Available from: 2019-11-04 Created: 2019-11-04 Last updated: 2019-11-19Bibliographically approved
Kreitzberg, T., Phounglamcheik, A., Haugen, N. E., Kneer, R. & Umeki, K. (2019). A Shortcut Method to Predict Particle Size Changes during Char Combustion and Gasification under regime II Conditions. Combustion Science and Technology
Open this publication in new window or tab >>A Shortcut Method to Predict Particle Size Changes during Char Combustion and Gasification under regime II Conditions
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2019 (English)In: Combustion Science and Technology, ISSN 0010-2202, E-ISSN 1563-521XArticle in journal (Refereed) Epub ahead of print
Abstract [en]

In most industrial applications, combustion and gasification of char progresses under regime II conditions. Unlike in other regimes, both particle size and density change simultaneously in regime II due to non-uniform consumption of carbon inside the particles. In this work, mathematical predictions of diameter changes in regime II were made by a one-dimensional simulation tool, where transient species balances are resolved locally inside the particle. This simulation is computationally expensive and usually not appropriate for the implementation in comprehensive CFD simulations of combustion or gasification processes. To overcome this restraint, an alternative shortcut method with affordable computation time has been developed and validated against the detailed model. This method allows the calculation of diameter changes during combustion and gasification from precalculated effectiveness factors. Additionally, the change of particle size has been investigated experimentally in a single particle converter setup. Therein, particles are fixed on a sample holder placed in the hot flue gas of a flat flame burner. Size and temperature trends are optically assessed by a 3CCD camera.

Place, publisher, year, edition, pages
Taylor & Francis, 2019
Keywords
combustion, gasification, char conversion, biomass, particle size change
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-76792 (URN)10.1080/00102202.2019.1678919 (DOI)000492714600001 ()
Available from: 2019-11-20 Created: 2019-11-20 Last updated: 2019-11-21
Trubetskaya, A., Souihi, N. & Umeki, K. (2019). Categorization of tars from fast pyrolysis of pure lignocellulosic compounds at high temperature. Renewable energy, 141, 751-759
Open this publication in new window or tab >>Categorization of tars from fast pyrolysis of pure lignocellulosic compounds at high temperature
2019 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 141, p. 751-759Article in journal (Refereed) Published
Abstract [en]

This study presents how the yields of different tar compounds from pure lignocellulosic compounds respond to the change in temperature and residence time. Experiments were carried out with a drop tube furnace in the temperature range from 800 to 1250 °C. The tar composition was characterized by gas chromatography with a flame ionization detector and mass spectrometry using a dual detector system. Longer residence time and higher heat treatment temperatures increased the soot formation and decreased the tar yields. Soot yields from lignin samples were greater than soot yields from holocellulose pyrolysis. The dominating products in tars from pyrolysis of all lignocellulosic compounds were benzene and toluene. Cellulose and hemicellulose pyrolysis produced greater amount of oxygenates in tars, whereas lignin tar was rich in phenols, polycyclic hydrocarbons and naphthalenes. Simultaneous reduction of tar and soot was achieved by impregnation of lignin from wheat straw with alkali metals. The OPLS-DA model can accurately explain the differences in tar composition based on the experimental mass spectrometry data.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Fast pyrolysis, Lignocellulosic compounds, Potassium, Tar, Principal component analysis
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73691 (URN)10.1016/j.renene.2019.04.033 (DOI)000472241100065 ()
Note

Validerad;2019;Nivå 2;2019-05-03 (johcin)

Available from: 2019-04-17 Created: 2019-04-17 Last updated: 2019-08-15Bibliographically approved
Lotfian, S., Ahmed, H., Umeki, K. & Samuelsson, C. (2019). Conversion Characteristics of Alternative Reducing Agents for the Bath Smelting Processes in an Oxidizing Atmosphere. Journal of Sustainable Metallurgy, 5(2), 230-239
Open this publication in new window or tab >>Conversion Characteristics of Alternative Reducing Agents for the Bath Smelting Processes in an Oxidizing Atmosphere
2019 (English)In: Journal of Sustainable Metallurgy, ISSN 2199-3823, Vol. 5, no 2, p. 230-239Article in journal (Refereed) Published
Abstract [en]

The amount of plastic-containing materials, such as shredder residue material, which is generated after the processing of electronic equipment waste, is increasing. One interesting option for the sustainable management of these materials, instead of incineration or landfilling, is recycling through injection in a bath smelting process, such as zinc fuming. In this way, the plastic material could partially substitute coal as a reductant in the process. In such processes, shredder residue material is injected alongside air into the furnace at temperatures up to 1250 °C. Once the material is injected, it undergoes several conversion steps, including ignition, devolatilization, and char oxidation. In this study, the conversions of shredder residue material and other pure plastic materials were investigated using a drop tube furnace and an optical single-particle burner. The effect of particle size on the conversion time of each material was studied. The conversion time of the particles increases as the particle size increases, although the relationship is not linear. The results indicate that plastic materials with a particle size range of 1–7 mm have a considerably longer conversion time than that of coal used in the conventional processes.

Place, publisher, year, edition, pages
New York: Springer, 2019
Keywords
Shredder residue materials, Thermal conversion, Oxidizing conditions, Drop tube furnace, Optical single- particle burner
National Category
Metallurgy and Metallic Materials Energy Engineering
Research subject
Process Metallurgy; Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73269 (URN)10.1007/s40831-019-00217-x (DOI)000471200800009 ()2-s2.0-85062709413 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-07-01 (johcin)

Available from: 2019-03-20 Created: 2019-03-20 Last updated: 2019-07-01Bibliographically approved
Bach-Oller, A., Fursujo, E. & Umeki, K. (2019). Effect of potassium impregnation on the emission of tar and soot from biomass gasification. Paper presented at The 10th International Conference on Applied Energy (ICAE2018), August 22-25, 2018, Hong Kong, China; Innovative Solutions for Energy Transitions; Edited by Jinyue Yan, Hong-xing Yang, Hailong Li, Xi Chen.. Energy Procedia, 158, 619-624
Open this publication in new window or tab >>Effect of potassium impregnation on the emission of tar and soot from biomass gasification
2019 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 158, p. 619-624Article in journal (Refereed) Published
Abstract [en]

Entrained flow gasification of biomass has the potential to generate synthesis gas as a source of renewable chemicals, electricity, and heat. Nonetheless, formation of tar and soot is a major challenge for continuous operation due to the problems they cause at downstream of the gasifier. Our previous studies showed the addition of alkali in the fuel can bring significant suppression of such undesirable products.

The present work investigated, in a drop tube furnace, the effect of potassium on tar and soot formation (as well as on its intermediates) for three different types of fuels: an ash lean stemwood, a calcium rich bark and a silicon rich straw. The study focused on an optimal method for impregnating the biomass with potassium. Experiments were conducted for different impregnation methods; wet impregnation, spray impregnation, and solid mixing to investigate different levels of contact between the fuel and the potassium.

Potassium was shown to catalyze both homogenous and heterogeneous reactions. Wet and spray impregnation had similar effects on heterogeneous reactions (in char conversion) indicating that there was an efficient molecular contact between the potassium and the organic matrix even if potassium was in the form of precipitated salts at a micrometer scale. On the other hand, potassium in the gas phase led to much lower yields of C2 hydrocarbons, heavy tars and soot. These results revealed that potassium shifted the pathways related to tar and soot formation, reducing the likelihood of carbon to end up as soot and heavy tars by favouring the formation of lighter compounds such as benzene. A moderate interaction between the added potassium and the inherent ash forming elements were also observed: Potassium had a smaller effect when the fuel was naturally rich in silicon.

The combined results open the door to a gasification process that incorporates recirculation of naturally occurring potassium to improve entrained flow gasification of biomass.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Biomass, gasification, tar, soot, alkali catalyst, potassium
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-75272 (URN)10.1016/j.egypro.2019.01.164 (DOI)000471031700101 ()
Conference
The 10th International Conference on Applied Energy (ICAE2018), August 22-25, 2018, Hong Kong, China; Innovative Solutions for Energy Transitions; Edited by Jinyue Yan, Hong-xing Yang, Hailong Li, Xi Chen.
Note

Konferensartikel i tidskrift

Available from: 2019-07-10 Created: 2019-07-10 Last updated: 2019-07-10Bibliographically approved
Bach-Oller, A., Furusjö, E. & Umeki, K. (2019). On the role of potassium as a tar and soot inhibitor in biomass gasification. Applied Energy, 254, Article ID 113488.
Open this publication in new window or tab >>On the role of potassium as a tar and soot inhibitor in biomass gasification
2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 254, article id 113488Article in journal (Refereed) Published
Abstract [en]

The work investigates in a drop tube furnace the effect of potassium on carbon conversion for three different types of fuels: an ash lean stemwood, a calcium-rich bark and a silicon-rich straw. The study focuses on an optimal method for impregnating the biomass with potassium. The experiments are conducted for 3 different impregnation methods; wet impregnation, spray impregnation, and dry mixing to investigate different levels of contact between the fuel and the potassium. Potassium is found to catalyse both homogenous and heterogeneous reactions. All the impregnation methods showed a significant effect of potassium on heterogeneous reactions (char conversion). The fact that dry mixing of potassium in the biomass shows an effect reveals the existence of a gas-induced mechanism that supply and distributes potassium on the char particles. Concerning the effect of potassium on homogenous reactions, it is found that potassium in the gas phase leads to much lower yields of C2 hydrocarbons, heavy tars and soot. The results indicate that potassium reduces the likelihood of light aromatic to progress toward heavier polyaromatic hydrocarbons clusters, thereby inhibiting the formation of soot-like material. A moderate interaction between the added potassium and the inherent ash forming elements is also observed: Potassium has a smaller effect when the fuel is naturally rich in silicon. The combined results are of interest for the design of a gasification process that incorporates recirculation of naturally occurring potassium to improve entrained flow gasification of biomass.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Potassium, Biomass, Gasification, Alkali, Soot, Tar
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-75762 (URN)10.1016/j.apenergy.2019.113488 (DOI)2-s2.0-85070904380 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-08-29 (johcin)

Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2019-09-09Bibliographically approved
Jayawickrama, T. R., Haugen, N. E., Babler, M. U., Chishty, M. A. & Umeki, K. (2019). The effect of Stefan flow on the drag coefficient of spherical particles in a gas flow. International Journal of Multiphase Flow, 117, 130-137
Open this publication in new window or tab >>The effect of Stefan flow on the drag coefficient of spherical particles in a gas flow
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2019 (English)In: International Journal of Multiphase Flow, ISSN 0301-9322, E-ISSN 1879-3533, Vol. 117, p. 130-137Article in journal (Refereed) Published
Abstract [en]

Particle laden flows with reactive particles are common in industrial applications. Chemical reactions inside the particle can generate a Stefan flow that affects heat, mass and momentum transfer between the particle and the bulk flow. This study aims at investigating the effect of Stefan flow on the drag coefficient of a spherical particle immersed in a uniform flow under isothermal conditions. Fully resolved simulations were carried out for particle Reynolds numbers ranging from 0.2 to 14 and Stefan flow Reynolds numbers from (-1) to 3, using the immersed boundary method for treating fluid-solid interactions. Results showed that the drag coefficient decreased with an increase of the outward Stefan flow. The main reason was the change in viscous force by the expansion of the boundary layer surrounding the particle. A simple model was developed based on this physical interpretation. With only one fitting parameter, the performance of the model to describe the simulation data were comparable to previous empirical models.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Drag coefficient, Stefan flow, Boundary layer, multiphase reactive flow
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-73836 (URN)10.1016/j.ijmultiphaseflow.2019.04.022 (DOI)000474496000010 ()2-s2.0-85065836366 (Scopus ID)
Note

Validerad;2019;Nivå 2;2019-06-11 (oliekm)

Available from: 2019-05-03 Created: 2019-05-03 Last updated: 2019-08-16Bibliographically approved
Phounglamcheik, A. & Umeki, K. (2018). Change in size and density of a biomass char during heterogeneous reactions. In: : . Paper presented at 25th International conference on Chemical Reaction Engineering, Florence, Italy, 20-23 May 2018.
Open this publication in new window or tab >>Change in size and density of a biomass char during heterogeneous reactions
2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Chemical Engineering Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-70426 (URN)
Conference
25th International conference on Chemical Reaction Engineering, Florence, Italy, 20-23 May 2018
Available from: 2018-08-15 Created: 2018-08-15 Last updated: 2018-08-16Bibliographically approved
Trubetskaya, A., Kling, J., Umeki, K., Attard, T. M., Budarin, V. L. & Hunt, A. J. (2018). Effect of supercritical extraction on the soot nanostructure and gasification product yields. In: : . Paper presented at 37th International Symposium on Combustion, Dublin, Ireland, 29 July-3 August, 2018.
Open this publication in new window or tab >>Effect of supercritical extraction on the soot nanostructure and gasification product yields
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2018 (English)Conference paper, Poster (with or without abstract) (Refereed)
National Category
Chemical Engineering Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-70170 (URN)
Conference
37th International Symposium on Combustion, Dublin, Ireland, 29 July-3 August, 2018
Available from: 2018-07-27 Created: 2018-07-27 Last updated: 2018-08-08Bibliographically approved
Phounglamcheik, A., Wang, L., Romar, H., Broström, M., Ramser, K., Skreiberg, Ø. & Umeki, K. (2018). Effects of pyrolysis oil recycling and reaction gas atmosphere on the physical properties and reactivity of charcoal from wood. In: : . Paper presented at 22nd International Symposium on Analytical and Applied Pyrolysis, Kyoto, Japan, 3-8 June 2018.
Open this publication in new window or tab >>Effects of pyrolysis oil recycling and reaction gas atmosphere on the physical properties and reactivity of charcoal from wood
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2018 (English)Conference paper, Oral presentation with published abstract (Refereed)
National Category
Bioenergy Renewable Bioenergy Research Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-70428 (URN)
Conference
22nd International Symposium on Analytical and Applied Pyrolysis, Kyoto, Japan, 3-8 June 2018
Available from: 2018-08-15 Created: 2018-08-15 Last updated: 2018-08-16Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6081-5736

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