Current issue: 53(2)

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Silva Fennica 1926-1997
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Acta Forestalia Fennica
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Articles containing the keyword 'delimbed stems'.

Category: Research article

article id 1689, category Research article
Juha Laitila, Eeva Lehtonen, Tapio Ranta, Perttu Anttila, Saija Rasi, Antti Asikainen. (2016). Procurement costs of cereal straw and forest chips for biorefining in South-East Finland. Silva Fennica vol. 50 no. 5 article id 1689. https://doi.org/10.14214/sf.1689
Highlights: Procurement cost at the plant was 59 € dry tonne –1 when the annual procurement volume of biomass was 100 000 tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%; Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips due to high baling and transporting costs.

In Finland the increasing use of biofuel in transport presupposes a search for new raw material sources for biorefining. The aim of this study was, at the regional level, to compare the procurement costs of logging residues, stumps, delimbed stems and cereal straw for biorefining. The accumulation and procurement costs of forest chips and cereal straw were estimated within a 100-kilometre transporting distance via existing road network from an end-use-facility located in Kouvola in South-East Finland. The analyses were performed as simulated treatments in thinnings of young stands, cereal fields and regeneration fellings using existing productivity and cost functions and yield calculations based on crop statistics, the forest industry stand data and the sample plots data of the National Forest Inventory of Finland. Accumulation of raw material assortments and costs of production stages were defined per dry tonnes. Subsidies and raw material prices were excluded from consideration in the study. The results indicate that recovering logging residues requires lower costs than utilization of stumps, delimbed stems or cereal straw. Cereal straw represents an important source of biomass in Kouvola but the cost competiveness is poor compared the procurement costs of forest chips. When the annual procurement volume of biomass was 50 000 dry tonnes the cost at the plant was 49 € dry tonne –1 and biomass was comprised totally of logging residues. Procurement cost grew to 59 € dry tonne –1 when the annual procurement volume of biomass was doubled to 100 000 dry tonnes. Of that amount, the proportion of logging residues was 58.4%, stumps 24.3% and delimbed stems 17.3%. First cereal straw dry tonnes were delivered to end-use-facility, when procurement cost grew to 60 € dry tonne –1 and annual procurement volume of biomass was 110 000 dry tonnes.

  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@luke.fi (email)
  • Lehtonen, Natural Resources Institute Finland (Luke), Green Technology, Halolantie 31A, FI-71750 Maaninka, Finland ORCID ID:E-mail: eeva.lehtonen@luke.fi
  • Ranta, Lappeenranta University of Technology, LUT School of Energy Systems, Laboratory of Bioenergy, Lönnrotinkatu 7, FI-50100 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@luke.fi
  • Anttila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: perttu.anttila@luke.fi
  • Rasi, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, Survontie 9A, FI-40500 Jyväskylä ORCID ID:E-mail: saija.rasi@luke.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@luke.fi
article id 1280, category Research article
Juha Laitila, Tapio Ranta, Antti Asikainen, Eero Jäppinen, Olli-Jussi Korpinen. (2015). The cost competitiveness of conifer stumps in the procurement of forest chips for fuel in Southern and Northern Finland. Silva Fennica vol. 49 no. 2 article id 1280. https://doi.org/10.14214/sf.1280
Highlights: Pre-grinding and integrated screening is a way of guaranteeing fuel quality, but, when the stumps’ ash content is six per cent or below, the procurement costs are higher than with grinding of stumps at the plant. Because of high transportation costs, stump harvesting is the most profitable in Southern Finland, where there is greater availability of stumps than in Northern Finland.
The aim of this study was to evaluate cost competitiveness, at regional level, of various systems for stump transportation and grinding, and to compare the results to the procurement costs of delimbed stems from early thinnings at the stand and regional level. The accumulation and procurement costs of stumps and delimbed stems were estimated within a 100-kilometer radius from two power plants located in Kouvola and in Kajaani. The analyses were performed as simulated treatments in clear cuts and thinnings of young stands, using existing productivity and cost functions, alternative ash percentages for stump wood, and yield calculations based on the forest industry regeneration felling stand data and the sample plots data of the National Forest Inventory of Finland. The results were expressed as Euros per solid cubic meter (€ m–3) and Euros per megawatt hour (€ MWh–1). The results highlight the need to improve stump fuel quality and increase the heating value. The procurement cost of stumps was about 1 € MWh–1 lower in Kouvola compared to Kajaani, when using conceivable ash content of 6% for stumps ground at the plant, and ash content of 1.5% for stumps pre-ground at the roadside landing. The procurement costs of stumps were, on average, 0.55 € MWh–1 lower compared to delimbed stems in Kouvola, and on average 0.6 € MWh–1 higher in Kajaani. Pre-grinding and integrated screening is a feasible way to guarantee the fuel quality expressed as ash content already at roadside landings, but the procurement costs are higher compared to grinding stumps at the plant, when the ash content of ground stumps is 6% or less.
  • Laitila, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: juha.laitila@metla.fi (email)
  • Ranta, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: tapio.ranta@lut.fi
  • Asikainen, Natural Resources Institute Finland (Luke), Bio-based Business and Industry, P.O. Box 68, FI-80101 Joensuu, Finland ORCID ID:E-mail: antti.asikainen@metla.fi
  • Jäppinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: eero.jappinen@lut.fi
  • Korpinen, Lappeenranta University of Technology, Sammonkatu 12, FI-50130 Mikkeli, Finland ORCID ID:E-mail: olli-jussi.korpinen@lut.fi

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