Industrial supply chains and production machinery of forest chips in Finland

Kärhä, Kalle

doi:10.1016/j.biombioe.2010.11.016

Cited by 62 publications

(46 citation statements)

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“…Although increases in smalldiameter forest stands are feasible, based on different scenarios, a number of problematic issues tied to operational environment and supply chain operations exist when producing forest chips for energy production. The primary supply chains in the production of wood chips from small-diameter forest stands in Finland include: Terrain chipping, roadside chipping, terminal chipping, and chipping at plant with the primary differences between the system is the location of comminution and transportation of material as either uncomminuted or comminuted wood chips (Kärhä 2011a). Terrain chipping entails comminution at the harvesting site; Roadside chipping by either separate chipper and chip truck for transportation, or an integrated chipper and chip truck occurs along roadside forest landings where forest chips are then transported to the energy plant; Terminal chipping comminutes whole-trees or delimbed stemwood at a selected terminal and utilizes a selected mode of transportation (truck, train, or barge) in transporting the forest chips to the energy plant; Chipping at plant utilizes truck transportation of raw material as whole-trees or delimbed stemwood to the energy plant for comminution (Kärhä 2011a).…”

Section: Development Of Energy Wood Supply Chains and Harvesting Of Smentioning

confidence: 99%

Opportunities for cost mitigation and efficiency improvements through rationalization of small-diameter energy wood supply chains

Petty¹

2014

Diss. For.

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To be presented, with the permission of the faculty of Agriculture and Forestry of the University of Helsinki, for public criticism in the Walter Auditorium of the EE-building (Agnes Sjöbergin katu 2) on April 4 th , 2014, at 12 o'clock noon. ABSTRACTThe production of energy wood from small-diameter (DBH < 9 cm) forests in Finland through separate energy wood and integrated energy wood and pulpwood production often face cost pressures that inhibit economic viability of many operations. Systemic factors, such as small stem sizes, limited removals, and high density of young forest stands limit the efficiency of many operations resulting in low productivity and high operating costs, particularly within cutting operations. Within the study, means to increase efficiency and mitigate costs of small-diameter energy wood and integrated energy wood and pulpwood operations by identifying optimal methods, technologies, and policy that may be applied were identified. Studies of integrated and delimbed stemwood cutting methods including the use of multi-tree handling and combined timber assortments in forest stands with stem size (DBH) of removals varying between 5-17 cm were investigated and compared against separate pulpwood production. Findings suggest that the methods provide increases in productivity and decreases in costs, particularly in < 11 cm DBH conditions. Crane scale measuring was investigated as a technical solution in timber logistics to be applied in energy wood and industrial roundwood procurement. The measuring method, used as a basis of payment, was found to provide a reliable, accurate, and cost effective method when compared with a manual timber pile measurement system. Policies, in the form of financial incentives were investigated to determine the effects of applicable subsidies on the profitability of energy wood production based on stem size of removal, finding possibilities for profitable operations with reduction in subsidies, however, with stem sizes (DBH) of removal 7 cm incentives played an important role in increasing profitability.Cost reductions were identified through: The utilization of integrated and delimbed stemwood harvesting methods with multi-tree handling, decreasing harvesting costs by 0.1-52.4% dependent on stem size (DBH) of removal between 7-17 cm when compared to a traditional pulpwood harvesting method; Combining timber assortments providing harvesting cost reductions between 1.5-8.0% between 5-17 cm; Crane scale measurement use provided increased accuracy and a 18.2-45.5% reduction in costs when compared to a manual timber pile measurement system when dependent on estimated working volumes between 20,000-30,000 m 3 ; Financial incentives under the PETU system were applied increasing profit margins of integrated supply chain operations by 3.8-19.9% dependent on stem size of removal, particularly with stem size of removals between 5-7 cm.Through rationalization of supply chains, harvesting methods, technologies, and policy which exhibit the ability to reduce costs and should be...

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Section: Development Of Energy Wood Supply Chains and Harvesting Of Smentioning

confidence: 99%

Opportunities for cost mitigation and efficiency improvements through rationalization of small-diameter energy wood supply chains

Petty¹

2014

Diss. For.

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“…Laitila et al 2008). Heavy-duty (operating weight around 20 tonnes) tracked excavators are primarily used for the lifting of stumps (Kärhä 2009(Kärhä , 2011a(Kärhä , 2011b. Approximately 200 excavators are currently used for stump lifting in Finland (Kärhä 2011c).…”

Section: Introductionmentioning

confidence: 99%

“…It is estimated that the proportion of stump wood chips and chips out of the small-sized thinning wood consumed by energy plants will increase significantly in the future (Kärhä 2007(Kärhä , 2011a.…”

Section: Introductionmentioning

confidence: 99%

Comparison of two stump-lifting heads in final felling Norway spruce stand

Kärhä¹

2012

Silva Fenn.

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The use of stump and root wood chips has increased very rapidly in the 21st century in Finland: in the year 2000, the total consumption of stump wood chips for energy generation was 10 GWh, while in 2010 it was approximately 2 TWh. Metsäteho Oy and TTS Research evaluated two stump-lifting devices for the lifting of Norway spruce (Picea abies) stumps. The productivity and costs of stump lifting were determined. There was one base machine with one operator in the time study. When lifting stumps with a diameter of 30 cm, the effective hour productivity of stump lifting was 11.2 m 3 solid over bark (sob)/E 0 (4.8 ton D /E 0 ) without site preparation using a Väkevä Stump Processor, and when lifting spruce stumps with a diameter of 40 cm, the productivity was 14.9 m 3 sob/E 0 (6.5 ton D /E 0 ). When the site preparation (mounding) was integrated into lifting work, the stump-lifting productivity decreased 21-27%. The stump-lifting productivity of the other lifting head (Järvinen) was lower than that of the Väkevä Stump Processor. Some development suggestions for the Järvinen lifting head were presented and discussed. The cost calculations showed that stump-lifting costs are extremely high when stump diameter is less than 20 cm. Therefore, the study recommended a change in the current stump-harvesting guidelines of Finland: The study suggested that all the stumps with a diameter less than 20 cm should be left on the harvesting site.

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“…Harvesting of delimbed stems is a promising way to simplify procurement operations (Laitila 2012), and it has been estimated that the role of comminuting at the plant in the production of chips from small-sized thinning wood will increase in the future (Kärhä 2011). Compared to fuel chips made of logging residues or stumps, the quality of thinning wood chips is significantly higher.…”

Section: Procurement Of Stumps and Delimbed Stems For Fuelmentioning

confidence: 99%

The cost competitiveness of conifer stumps in the procurement of forest chips for fuel in Southern and Northern Finland

Laitila¹,

Ranta²,

Asikainen³

et al. 2015

Silva Fenn.

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• 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. AbstractThe 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.

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Industrial supply chains and production machinery of forest chips in Finland

Cited by 62 publications

References 0 publications

Opportunities for cost mitigation and efficiency improvements through rationalization of small-diameter energy wood supply chains

Opportunities for cost mitigation and efficiency improvements through rationalization of small-diameter energy wood supply chains

Comparison of two stump-lifting heads in final felling Norway spruce stand

The cost competitiveness of conifer stumps in the procurement of forest chips for fuel in Southern and Northern Finland

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