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Report, 1994

Cold air ventilated and sealed storage of wood-chips from willow : laboratory experiments

de Toro, Alfredo; Jirjis, Raida; Nilsson, Daniel


Two storage methods for chipped willows (Salix spp.), cold air ventilation and sealed storage, were tested at laboratory scale. Fresh chips were stored in six insulated containers for 62 days in a store-room. Temperature development during storage was continuously monitored. Dry matter losses and fungal spore counts, in the central part of the containers, were determined. Two 1.7 m3 containers were continuously ventilated with ambient air (mean temperature 2.7° C) at a rate of 175 m3∙h^-1∙t^-1 dry matter. As a control, a third unventilated identical container was used. To test sealed storage, a similar experiment was conducted using two containers of 0.63 m3. A third, unsealed, container served as a control. These three containers were placed in a room where the average temperature during storage was 14.7° C. In the central part of the ventilated containers, the average temperature of the chips was close to ambient temperature (average 4° C) during most of the storage period while the temperature in the unventilated container averaged at 32.4° C and a maximum of 42° C. The dry matter losses were 5.2% and 13.3% by weight in the ventilated and the control containers respectively. The total number of micro fungal spores increased by 3-5 times in the chips stored in the ventilated containers but, in the control, it increased more than 100 times. The temperature in the central part of the sealed containers was close to ambient (14° C), while the maximum temperature of the control was 59.3° C with an average of 28.8° C. Different dry matter losses were measured in the two sealed containers, 2.7% and 6.0%. However, higher loss of dry matter (8.2%) was determined in the control. The fungal growth in the test containers was less intensive than that in the control. The total number of spores was increased by 3-4 folds in the sealed material compared to 60 times in the control.


storage; sealed; ventilated; cold; willow; wood-chips; bioenergy

Published in

Rapport - Sveriges lantbruksuniversitet, Institutionen för lantbruksteknik
Publisher: Institutionen för lantbruksteknik, Sveriges lantbruksuniversitet

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