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Stumps as fuel

the influence of handling method on fuel quality

Anerud, Erik (2012). Stumps as fuel. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2012:85
ISBN 978-91-576-7732-7
[Doctoral thesis]

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Wood fuels make a key contribution to renewable energy sources in the Nordic countries. The growing demand for forest biomass can be partly met by utilising energy-rich stumps left after clear cutting. As fuel, stump wood is commonly associated with a high presence of contaminants, resulting in high ash content. The concentration of contaminants depends on factors such as soil type, weather conditions, harvesting method, storage duration and other handling operations. The high ash content is a major drawback when using stump wood as fuel. Handling methods that could improve fuel quality are therefore highly desirable. To produce a fuel of acceptable quality, i.e. with low moisture and ash content and high energy value, the
above-mentioned factors require evaluation and quantification. In this thesis, various handling methods within the supply chain for Norway spruce stump and their effects on the biomass as fuel are evaluated. The following handling processes are dealt with: harvesting technique, pre-treatments including stump splitting/fractionation and
cleaning using vibration or sieving, storage methods and storage duration. Choice of stump harvesting head proved to have an impact on fuel quality, as splitting of stumps
during extraction allowed better drying during storage. Such stumps could be stored directly in windrows, since no difference could be established between this method and
storage in heaps prior to windrow storage. In general, storage improved fuel quality. Changes in fuel quality parameters do not reflect the whole picture, however, since dry matter losses occur during storage, and therefore the storage period should be kept as short as possible. During winter months, when demands for fuel are highest, stump ash
content can be high, since frozen contaminants are difficult to detach from stumps during transport. To achieve acceptable fuel quality during high demand periods, long storage duration or a pre-treatment involving additional stump cleaning is required. Fuel quality was clearly improved by vibration-based cleaning before the comminution of stumps or by sieving stump wood after crushing. These methods can allow stump wood fuel of acceptable quality to be supplied within a harvesting season.

Authors/Creators:Anerud, Erik
Title:Stumps as fuel
Subtitle:the influence of handling method on fuel quality
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :October 2012
Number of Pages:60
I.Anerud, E., Jirjis, R., Nordfjell. T. (2012). Softwood stumps as fuel – a review of the supply chain from harvesting to end-user including major environmental issues. Submitted to Renewable & Sustainable Energy Reviews in 2010.
II.Anerud, E., Jirjis, R. (2011). Fuel quality of Norway spruce stumps – influence of harvesting technique and storage method. Scandinavian Journal of Forest Research 26, 257-266.
III.Anerud, E., Jirjis, R., Gebresenbet, G. (2012). Evaluation of the performance of a three-dimensional vibrating test rig for cleaning stumps. Australian Journal of Agricultural Engineering 3(2), 51-58.
IV.Anerud, E., Jirjis, R., Gebresenbet, G. (2012). Cleaning of harvested Norway spruce stumps using a vibration-based method. Accepted for publication in International Journal of Forest Engineering.
V.Von Hofsten, H., Anerud, E. Fogdestam, N., Granlund, P., Eliasson, L. (2012). An alternative supply system for stump biomass – coarse grinding combined with sieving of the produced hog fuel (manuscript).
Place of Publication:Uppsala
Publisher:Inst. för energi och teknik, Sveriges lantbruksuniversitet
ISBN for printed version:978-91-576-7732-7
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:J Handling, transport, storage and protection of agricultural products > J12 Handling, transport, storage and protection of forest products
K Forestry > K01 Forestry - General aspects
K Forestry > K11 Forest engineering
P Natural resources > P06 Renewable energy resources
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Forest Science
Agrovoc terms:picea abies, stumps, fuelwood, handling, storage, quality, moisture content, ash content, evaluation
Keywords:biofuel, bioenergy, contaminant reduction system, forest fuel, fuel quality, procurement system, harvesting, storage, stump wood, vibration
Permanent URL:
ID Code:9153
Department:(NL, NJ) > Dept. of Energy and Technology
External funders:Swedish Energy Agency
Deposited By: Erik Anerud
Deposited On:24 Oct 2012 06:23
Metadata Last Modified:02 Dec 2014 10:52

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