Changes in the Composition and Surface Properties of Torrefied Conifer Cones
The paper investigated the torrefaction of cones from three tree species: Scots pine (<i>Pinus sylvestris</i> L.), Norway spruce (<i>Picea abies</i> L.), and European larch (<i>Larix decidua</i> Mill.). The objective was to determine the effects of torrefaction te...
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MDPI AG
2020-12-01
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| Online Access: | https://www.mdpi.com/1996-1944/13/24/5660 |
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| author | Monika Aniszewska Arkadiusz Gendek Štěpán Hýsek Jan Malaťák Jan Velebil Barbora Tamelová |
| author_facet | Monika Aniszewska Arkadiusz Gendek Štěpán Hýsek Jan Malaťák Jan Velebil Barbora Tamelová |
| author_sort | Monika Aniszewska |
| collection | DOAJ |
| description | The paper investigated the torrefaction of cones from three tree species: Scots pine (<i>Pinus sylvestris</i> L.), Norway spruce (<i>Picea abies</i> L.), and European larch (<i>Larix decidua</i> Mill.). The objective was to determine the effects of torrefaction temperature on the properties of cones with a view to their further use as a renewable energy source. Torrefaction was conducted at 200, 235, 275, and 320 °C for 60 min under an inert gas atmosphere. Elemental composition, ash content, and lower heating value (LHV) were measured for the original and torrefied samples. Torrefaction performance was evaluated using formulas for solid yield, higher heating value (HHV), HHV enhancement factor, as well as energy yield. Scanning electron microscopy (SEM) was used to assess elemental composition and structural changes at the surface of the torrefied material. For all the studied conifer species, the higher the torrefaction temperature, the greater the carbon and ash content and the higher the LHV (a maximum of 27.6 MJ·kg<sup>−1</sup> was recorded for spruce and larch cones torrefied at 320 °C). SEM images showed that an increase in process temperature from 200 to 320 °C led to partial decomposition of the scale surface as a result of lignin degradation. Cone scales from all tree species revealed C, O, N, Mg, K, and Si at the surface (except for pine scales, which did not contain Si). Furthermore, the higher the temperature, the higher the enhancement factor and the lower the energy yield of the torrefied biomass. Under the experimental conditions, spruce cones were characterized by the lowest weight loss, the highest HHV, and the highest energy yield, and so they are deemed the best raw material for torrefaction among the studied species. |
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| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T14:08:25Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-0358a8cdd08b48739ed48ed7738fe04d2023-11-21T00:23:04ZengMDPI AGMaterials1996-19442020-12-011324566010.3390/ma13245660Changes in the Composition and Surface Properties of Torrefied Conifer ConesMonika Aniszewska0Arkadiusz Gendek1Štěpán Hýsek2Jan Malaťák3Jan Velebil4Barbora Tamelová5Department of Biosystems Engineering, Institute of Mechanical Engineering, Warsaw University of Life Sciences—SGGW, Nowoursynowska 164, 02-787 Warsaw, PolandDepartment of Biosystems Engineering, Institute of Mechanical Engineering, Warsaw University of Life Sciences—SGGW, Nowoursynowska 164, 02-787 Warsaw, PolandDepartment of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamycka 129, Prague 6, 165 00 Prague, Czech RepublicDepartment of Technological Equipments of Buildings, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, Prague 6, 165 21 Prague, Czech RepublicResearch Institute of Agricultural Engineering, Drnovska 507, Prague 6, 161 01 Prague, Czech RepublicDepartment of Technological Equipments of Buildings, Faculty of Engineering, Czech University of Life Sciences Prague, Kamycka 129, Prague 6, 165 21 Prague, Czech RepublicThe paper investigated the torrefaction of cones from three tree species: Scots pine (<i>Pinus sylvestris</i> L.), Norway spruce (<i>Picea abies</i> L.), and European larch (<i>Larix decidua</i> Mill.). The objective was to determine the effects of torrefaction temperature on the properties of cones with a view to their further use as a renewable energy source. Torrefaction was conducted at 200, 235, 275, and 320 °C for 60 min under an inert gas atmosphere. Elemental composition, ash content, and lower heating value (LHV) were measured for the original and torrefied samples. Torrefaction performance was evaluated using formulas for solid yield, higher heating value (HHV), HHV enhancement factor, as well as energy yield. Scanning electron microscopy (SEM) was used to assess elemental composition and structural changes at the surface of the torrefied material. For all the studied conifer species, the higher the torrefaction temperature, the greater the carbon and ash content and the higher the LHV (a maximum of 27.6 MJ·kg<sup>−1</sup> was recorded for spruce and larch cones torrefied at 320 °C). SEM images showed that an increase in process temperature from 200 to 320 °C led to partial decomposition of the scale surface as a result of lignin degradation. Cone scales from all tree species revealed C, O, N, Mg, K, and Si at the surface (except for pine scales, which did not contain Si). Furthermore, the higher the temperature, the higher the enhancement factor and the lower the energy yield of the torrefied biomass. Under the experimental conditions, spruce cones were characterized by the lowest weight loss, the highest HHV, and the highest energy yield, and so they are deemed the best raw material for torrefaction among the studied species.https://www.mdpi.com/1996-1944/13/24/5660torrefactionweight losslower heating valueelemental compositionSEM |
| spellingShingle | Monika Aniszewska Arkadiusz Gendek Štěpán Hýsek Jan Malaťák Jan Velebil Barbora Tamelová Changes in the Composition and Surface Properties of Torrefied Conifer Cones Materials torrefaction weight loss lower heating value elemental composition SEM |
| title | Changes in the Composition and Surface Properties of Torrefied Conifer Cones |
| title_full | Changes in the Composition and Surface Properties of Torrefied Conifer Cones |
| title_fullStr | Changes in the Composition and Surface Properties of Torrefied Conifer Cones |
| title_full_unstemmed | Changes in the Composition and Surface Properties of Torrefied Conifer Cones |
| title_short | Changes in the Composition and Surface Properties of Torrefied Conifer Cones |
| title_sort | changes in the composition and surface properties of torrefied conifer cones |
| topic | torrefaction weight loss lower heating value elemental composition SEM |
| url | https://www.mdpi.com/1996-1944/13/24/5660 |
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