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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
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
Hardi, F., Imai, A., Theppitak, S., Kirtania, K., Furusjö, E., Umeki, K. & Yoshikawa, K. (2018). Gasification of Char Derived from Catalytic Hydrothermal Liquefaction of Pine Sawdust under a CO2 Atmosphere. Paper presented at 2nd International Conference on the Sustainable Energy and Environmental Development (SEED), Krakow, Poland, Nov 14-17 2017. Energy & Fuels, 32(5), 5999-6007
Open this publication in new window or tab >>Gasification of Char Derived from Catalytic Hydrothermal Liquefaction of Pine Sawdust under a CO2 Atmosphere
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2018 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 32, no 5, p. 5999-6007Article in journal (Refereed) Published
Abstract [en]

The integration between K2CO3 catalytic hydrothermal liquefaction (HTL) and gasification is explored to improve the gasification process. In this study, the CO2 gasification characteristics and the activation energies of the chars derived from four kinds of HTL products, black liquor (BL), and virgin pine sawdust (PS) are investigated non-isothermally using a thermogravimetric analyzer. The complete conversion of BL char and HTL product chars was achieved at lower temperatures (1150 K) than that of PS char (1300 K). BL char showed the highest derivative thermogravimetric (DTG) peak, an indicator of high reactivity, followed by HTL product chars and PS char. HTL liquid product chars exhibited the lowest DTG peak temperature (1023–1058 K), which is advantageous for the low-temperature gasification. The activation energies were calculated isoconversionally using the Kissinger–Akahira–Sunose (KAS), Flynn–Wall–Ozawa (FWO), and Starink approximations. On the basis of the KAS method, the range of the activation energy for the HTL aqueous product char sample was 127–259 kJ/mol, which was wider than that for BL char (171–190 kJ/mol). The HTL process can improve the gasification feedstock reactivity, and the use of the HTL liquid product allows for the gasification at a low temperature.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-68549 (URN)10.1021/acs.energyfuels.8b00589 (DOI)000432754700035 ()
Conference
2nd International Conference on the Sustainable Energy and Environmental Development (SEED), Krakow, Poland, Nov 14-17 2017
Note

Konferensartikel i tidskrift;2018-06-07 (andbra)

Available from: 2018-04-30 Created: 2018-04-30 Last updated: 2018-06-07Bibliographically approved
Phounglamcheik, A., Wretborn, T. & Umeki, K. (2018). Increasing efficiency of charcoal production with bio-oil recycling. Energy & Fuels, 32(9), 9650-9658
Open this publication in new window or tab >>Increasing efficiency of charcoal production with bio-oil recycling
2018 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 32, no 9, p. 9650-9658Article in journal (Refereed) Published
Abstract [en]

Charcoal from biomass is a promising alternative for fossil coal. Although its quality increases at high pyrolysis temperature, charcoal yield decreases, meaning lower economic performances of charcoal production processes. This work aims at demonstrating potential methods to increase charcoal yield while keeping its quality at satisfying levels. We suggested the recycling of bio-oil from pyrolysis process as a primary measure. In addition, we also investigated in detail the consequence of utilizing CO2 instead of N2 as reaction media under practical conditions (i.e. thick particles). An experimental investigation was carried out in a macro-thermogravimetric (macro-TG) reactor. Sample (woodchips, bio-oil, and woodchips embedded with bio-oil) was exposed to the reaction temperature either instantaneously (isothermal condition) or by slow heating (slow pyrolysis) in controlled gas flows of N2 and CO2. The results showed that char yield increases with the bio-oil recycling on wood chips at all pyrolysis temperatures (300–700 °C). By 20% of bio-oil embedding on wood chips, charcoal yield increased by 18.3% on average. The increase of charcoal yield was not only because of the increase in reactants, but also due to the synergetic effect between bio-oil and wood chips upon physical contact. Bio-oil recycling had negligible effects on the property of charcoal, such as carbon content and heating value. Although CO2 did not affect primary pyrolysis, it had effects on mass transfer processes. As a result, significantly higher char yield was obtained from pyrolysis in CO2 than in N2 by ensuring a good contact of volatiles and solid surface (i.e. usage of thick particles and slow heating). This study suggests that we can achieve high charcoal yield while maintaining the similar charcoal property by bio-oil recycling, CO2 purging, use of thick particles, and slow heating.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
National Category
Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-70583 (URN)10.1021/acs.energyfuels.8b02333 (DOI)000445711700071 ()2-s2.0-85052873835 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-10-15 (johcin) 

Available from: 2018-08-24 Created: 2018-08-24 Last updated: 2018-10-24Bibliographically approved
Trubetskaya, A., Hofmann Larsen, F., Shchukarev, A., Ståhl, K. & Umeki, K. (2018). Potassium and soot interaction in fast biomass pyrolysis at high temperatures. Fuel, 225, 89-94
Open this publication in new window or tab >>Potassium and soot interaction in fast biomass pyrolysis at high temperatures
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2018 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 225, p. 89-94Article in journal (Refereed) Published
Abstract [en]

his study aims to investigate the interaction between potassium and carbonaceous matrix of soot produced from wood and herbaceous biomass pyrolysis at high heating rates at 1250°C in a drop tube reactor. The influence of soot carbon chemistry and potassium content in the original biomass on the CO2 reactivity was studied by thermogravimetric analysis. The XPS results showed that potassium incorporation with oxygen-containing surface groups in the soot matrix did not occur during high temperature pyrolysis. The potassium was mostly found as water-soluble salts such as KCl, KOH, KHCO3 and K2CO3 in herbaceous biomass soot. The low ash-containing pinewood soot was less reactive than the potassium rich herbaceous biomass soot, indicating a dominating role of potassium on the soot reactivity. However, the catalytic effect of potassium on the reactivity remained the same after a certain potassium amount was incorporated in the soot matrix during pyrolysis. Raman spectroscopy results showed that the carbon chemistry of biomass soot also affected the CO2 reactivity. The less reactive pinewood soot was more graphitic than herbaceous biomass soot samples with the disordered carbon structure.

Place, publisher, year, edition, pages
Elsevier, 2018
National Category
Engineering and Technology Energy Engineering
Research subject
Energy Engineering
Identifiers
urn:nbn:se:ltu:diva-68116 (URN)10.1016/j.fuel.2018.03.140 (DOI)000432922400011 ()2-s2.0-85044460207 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-04-03 (andbra)

Available from: 2018-04-02 Created: 2018-04-02 Last updated: 2018-06-07Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0001-6081-5736

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