Pelletering av tallspån
Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefit...
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| Formato: | Otro |
| Lenguaje: | sueco sueco |
| Publicado: |
2007
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| Materias: | |
| Acceso en línea: | https://stud.epsilon.slu.se/12437/ |
| _version_ | 1855572063098503168 |
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| author | Bergström, Dan |
| author_browse | Bergström, Dan |
| author_facet | Bergström, Dan |
| author_sort | Bergström, Dan |
| collection | Epsilon Archive for Student Projects |
| description | Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity.
Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures. The industrial production of pellets is restricted by accurate control of certain parameters that lead to difficulties when optimising the process.
The purpose of this study was to produce pellets from a selected raw material (pine sawdust) using well known and documented conditions. The characteristics of the pellets were then evaluated from the chosen parameters; type of sawdust, moisture content, compaction pressure and temperature.
During a limited variation of process and raw material parameters pellets were produced in a laboratory scaled press. Density, compression strength and absorption of moisture were evaluated.
Absorption of moisture was shown to be the most important parameter in the process, and many of the results are in agreement with earlier studies on densification of biomass. During the study several questions occurred like, how can pellets as a product be developed, if the composition of wood particles in the raw material is taken into account? |
| format | Otro |
| id | RepoSLU12437 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish swe |
| publishDate | 2007 |
| publishDateSort | 2007 |
| record_format | eprints |
| spelling | RepoSLU124372017-10-30T09:11:47Z https://stud.epsilon.slu.se/12437/ Pelletering av tallspån Bergström, Dan Processing of forest products Wood pellets are an upgraded product of residuals from several wood processing industries, for example saw mills and pulp industries. The pellets are produced by pressing the milled and dried sawdust to cylindrical units with a higher density than the initial raw material. Pellets have great benefits compared to the raw material: high energy per volume, good transport and storage properties and homogeneity. Several parameters collaborate in the whole process, which makes it complex. Wood is a heterogeneous material, chemically and structurally dependent on wood parts, habitat and storage procedures. The industrial production of pellets is restricted by accurate control of certain parameters that lead to difficulties when optimising the process. The purpose of this study was to produce pellets from a selected raw material (pine sawdust) using well known and documented conditions. The characteristics of the pellets were then evaluated from the chosen parameters; type of sawdust, moisture content, compaction pressure and temperature. During a limited variation of process and raw material parameters pellets were produced in a laboratory scaled press. Density, compression strength and absorption of moisture were evaluated. Absorption of moisture was shown to be the most important parameter in the process, and many of the results are in agreement with earlier studies on densification of biomass. During the study several questions occurred like, how can pellets as a product be developed, if the composition of wood particles in the raw material is taken into account? Träpellets är en förädlad restprodukt från sågverk-, trä- och massa industrin. Förädlingen sker genom pressning av den initialt finfördelade och torkade råvaran till små cylindriska enheter med en högre densitet än den ursprungliga råvaran. Den färdiga produktens egenskaper har många fördelar gentemot råvaran: energivärde per volymsenhet, transport- och lagringsegenskaper och homogenitet. I produktionsledet är det många parametrar som samverkar vilket medför att förädlingssteget är relativt komplicerat. Trä/ved är ett komplext material som både till kemisk och strukturell sammansättning varierar med träddel, ståndort och lagringsförfaranden. Den industriella produktionslinjen har begränsningar gällande noggrann kontroll av vissa processparametrar, vilket innebär problem vid styrning av processen. Syftet med detta arbete var att utifrån en given råvara producera pellets i laboratorieskala under kontrollerade betingelser, för att sedan kunna analysera dessa och se hur de använda parametrarna som fukthalt, spåntyp, presstryck och temperatur samverkar och bidrar till slutproduktens egenskaper. Pelleterna testades sedan med avseende på densitet, tryckhållfasthet/hårdhet och fuktabsorption för att samband/trender mellan ingående parametrar och färdig pellets kunde utvärderas. Resultaten visade att råvarans fukthalt är den parameter som till största del styr processen vid pelletering, samt att trender ur försöken överensstämde väl med resultat från liknande parameterstudier vid densifiering av biomassa. Under arbetets gång uppstod nya frågeställningar, t.ex. hur kan en produktutveckling, med avseende på fraktionssammansättning på råvaran, se ut för pellets? 2007-02-05 Other NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/12437/1/bergstrom_d_171030.pdf Bergström, Dan, 2005. Pelletering av tallspån : grundläggande studier. UNSPECIFIED, Umeå. Umeå: (NL, NJ) > Dept. of Silviculture <https://stud.epsilon.slu.se/view/divisions/ANSTI=3A508.html> urn:nbn:se:slu:epsilon-s-8389 swe |
| spellingShingle | Processing of forest products Bergström, Dan Pelletering av tallspån |
| title | Pelletering av tallspån |
| title_full | Pelletering av tallspån |
| title_fullStr | Pelletering av tallspån |
| title_full_unstemmed | Pelletering av tallspån |
| title_short | Pelletering av tallspån |
| title_sort | pelletering av tallspån |
| topic | Processing of forest products |
| url | https://stud.epsilon.slu.se/12437/ https://stud.epsilon.slu.se/12437/ |