• Journal of Korean Society of Forest Science
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• v.104 no.2
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• pp.198-205
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• 2015

The aim of this study was to provide the basic design parameters for developing logging residue compression machines by investigating compressive deformation characteristics of different types of logging residues. To achieve these objectives, Pinus rigida, Pinus koraensis and Quercus mongolica were selected as specimens, and compression-deformation tests by UTM(universial testing machine) were conducted. The experimental dataset were used to set up the model based on the compression-deformation ratio in the form of exponential function. The results showed that stress coefficient in terms of mechanical properties of logging residues was decreased, whereas strain coefficient tended to be increased as the number of compression increased at target density of $350kg/m^3$ and $400kg/m^3$. The model presented that the required stress was decreased as the number of compression increased, and the stress growth rate was swelled compared to the change of the deformation rate. Therefore, it showed that proper initial compression force was a significant variable in order to achieve the target density of logging residue.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.81-89
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• 2013

Nowadays, excessive using of fossil fuel contributes to global warming. Also, this phenomenon increases steadily. Therefore forest biomass from logging residues has received attention. The goal of this study was to determine the sustainability and economic feasibility of forest-biomass energy source. Accordingly, forest biomass resource was calculated, and harvesting and transporting machines which can be used in investing area were chosen, when using forest biomass as energy source. And then through these data, the harvesting cost was decided. The forest biomass resource calculated, thinned trees and logging residues, was 37,330.23 $m^3$ and 14,073.60 ton, respectively. When harvesting timber in each sub-compartment, the average thinned trees yield was 120.73 $m^3$, and tree logging residues was 402.80 ton. The use of tower yarder as harvesting and transporting equipments in study area was 85.4% and 66.7%, respectively, in up hill and down hill yarding. The average harvesting cost of biomass in the possibility area of timber yarding operation was expensive as 81,757 won/$m^3$, 85,434 won/m3 and 50,003 won/ton, respectively, in thinned trees and logging residue. If using data from this research analysis, tree could be felled by choosing sub-compartment.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.375-378
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• 2014

In this study, we carried out torrefaction experiment using PKS(Palm Kernel Shell), and Bagasse as a raw material of oversee of herbaceous biomass and using waste wood and logging residue as a raw material of domestic of woody biomass. And then, by analyzing the physical & chemical properties, we investigated the characteristics as a fuel. By using the result of thermo gravimetric analysis, the biomass residue was torrefied for 30 minutes at a temperature range of $250-350^{\circ}C$ in anaerobic condition. As a result, torrefied materials of moisture content are lower than raw, but of fixed carbon, calorific value and ash are higher than raw.

• Korean Journal of Agricultural Science
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• v.49 no.2
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• pp.317-330
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• 2022

Recently, the policy regarding climate change in Korea and overseas has been to promote the utilization of forest biomass to achieve net zero emissions. In addition, with the implementation of the unused forest biomass system in 2018, the size of the Korean market for manufacturing wood pellets and wood chips using unused forest biomass is rapidly expanding. Therefore, it is necessary to estimate the total amount of unused forest biomass that can be used as an energy source and to identify the capacity that can be continuously produced annually. In this study, we estimated the actual forest area that can be produced of logging residue and the potential amount of unused forest biomass resources based on GT (green ton). Using a forest functions classification map (1 : 25,000), 5th digital forest type map (1 : 25,000), and digital elevation model (DEM), the forest area with a slope of 30° or less and mountain ridges of 70% or less was estimated based on production forest and IV age class or more. The total forest area where unused forest biomass can be produced was estimated to be 1,453,047 ha. Based on GT, the total amount of unused forest biomass potential resources in Korea was estimated to be 117,741,436 tons. By forest type, coniferous forests were estimated to be 48,513,580 tons (41.2%), broad-leaved forests 27,419,391 tons (23.3%), and mixed forests 41,808,465 tons (35.5%). Data from this research analysis can be used as basic data to estimate commercial use of unused forest biomass.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.217-232
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• 2021

This study calculated the productivity and cost of extraction and processing of logging residues by cut-to-length (CTL) and whole-tree (WT) harvesting methods. In addition, the comparative analysis of the characteristics of wood chip fuel to examine whether it was suitable for the fuel conditions of the energy facility. In the harvesting and processing system to produce the wood chips of logging residues the system productivity and cost of the CTL harvesting system were 1.6 Gwt/SMH and 89,865 won/Gwt, respectively. The productivity and cost of the WT harvesting system were 2.9 Gwt/SMH and 72,974 won/Gwt, respectively. The WT harvesting productivity increased 1.3times while harvesting cost decreased by 18.7% compared to the CTL harvesting system. The logging residues of wood chips were not suitable for CTL wood chips based on International Organization for Standardization (ISO 17225-4:2021) and South Korea standard (NIFoS, 2020), but the quality (A2, Second class) was improved through screening operation. The WT-unscreened wood chips conformed to NIFoS standard (second class) and did not conform to ISO but were improved through screening operation (Second class). In addition to the energy facility in plant A, all wood chips except CTL-unscreened wood chips were available through drying processing. The WT-unscreened wood chips were the lowest at 99,408 won/Gwt. Plants B, C, and D had higher moisture content than plant A, so WT-unscreened wood chips without drying processing were the lowest at 57,204 won/Gwt. Therefore, the production of logging residues should improve with operation methods that improve the quality of wood chips required for applying the variable biomass and energy facility.