• Clean Technology
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• v.23 no.3
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• pp.331-342
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• 2017

To estimate the combustion characteristics of sewage sludge and wood pellet, thermogravimetric analysis (TGA) was conducted. As TGA results, combustion characteristics of sewage sludge was worse than wood pellet. In ash fusion temperature (AFT) analysis, slagging tendency of sewage sludge is very high compared to wood pellet. And also, the bubbling fluidized bed reactor with a inner diameter 400 mm and a height of 4300 mm was used for experimental study of combustion characteristics fueled by sewage sludge and wood pellet. The facility consists of a fluidized bed reactor, preheater, screw feeder, cyclone, ash capture equipment and gas analyzer. The thermal input of sewage sludge cases were $54.5{\sim}96.5kW_{th}$, in case of wood pellet experiment, it was $96.1kW_{th}$. As experiment results, the $NO_x$ emission of sewage sludge was averagely about 10 times the $NO_x$ emission of wood pellet. And also CO emission of sewage sludge is about 3.5 times of wood pellet. Lastly as a result of analysis of captured ash in cyclone, the combustion efficiency of all cases were over 99%, but the potential for slagging/fouling was high at all cases by component analysis of ash.

• Journal of the Korean Wood Science and Technology
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• v.30 no.2
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• pp.79-86
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• 2002

Anatomical characteristics of Mulpurenamu (Korean ash, Praxmus rhynchopbylla), Deulmaenamu (Manshurican ash, Fraxinus mandsburica) and Sheamulpure (Sieboldiana ash, Fraxinus sieboldiana) grown in Korea were examined by an optical microscopy and an image analysis. Some characteristics such as boundary of annual rings, shape and size of vessel elements, arrangement of axial parenchyma cells in cross section, and cell volumetric composition showed significant differences between the sample species. In radial variation of elements, fiber length and vessel size increased from the pith for about 10 to 15 years and then reached a more or less constant. The results of this study can be used for identification of wood and indices of wood quality in Fraxinus spp.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.419-423
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• 1990

This study was carried out to investigate the cause of pith-damaged wood formation, the state of growth, and difference of chemical composition of Japanese Larix(L. leptolepis Gorden). 1. Larix grew normaly to 10 years, and the volume increment was 32.4%. But it was gradually decreased to 19.4% from 11 to 13 years that the heartwood damage was occurred. Therefore, the volume increment was decreased 13%. The decayed wood was formed from fire wound portion of bark by forest fire. The volume loss from pith-dagmaged wood occurred by forest fire was more than 20%. 2. On the ash content, heartwood(0.05%) and pith-damaged wood(0.08%) was lower than sapwood(0.29%). The difference of extractive contents are considered the reason. It is considered that this ash content difference is depend upon the extractive contents among sap, heart and decayed wood parts. Holocellulose contents were from 54.3% to 59.3% and there were no difference among heartwood, pith-damaged wood, and sapwood, On the pentosan contents, heartwood(6.3%) and pith-damaged wood(6.6%) were higher than sapwood. Lignin contents of pith-damaged wood was tower than heartwood (34.4%). This seems to weaken all kinds of wood strength.

• Journal of the Korean Wood Science and Technology
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• v.28 no.2
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• pp.66-74
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• 2000

Wood of black locust(Robinia pseudoacacia) and bark of poplar(Populus alba x glandulosa), ash(Fraxinus rhynchophylla) and elm(Ulmus davidiana var. japonica) trees were collected, extracted with acetone-$H_2O$(7:3. v/v), fractionated with hexane, chloroform, ethylacetate and $H_2O$. then freeze dried to get some dark brown powder for bioactive tests. Decay-resistant activity was tested using wood block specimens from the hardwood trees and expressed by weight loss rate. Black locust specimens indicated the best anti-decaying property and poplar blocks were the worst. Antimicrobial and antioxidant activities were also investigated against each wood or bark extractives. Antifungal and antibacterial activities did not indicate any significant differences among the tested fractions. In antioxidant activity. ${\alpha}$-tocopherol one of natural antioxidants. and BHT, one of synthetic antioxidants, were used as references to compare with the antioxidant activities of the extracted fractions. Ethylacetate fraction of ash bark indicated the highest activity besides BHT in this test and all fractions of black locust extractives also indicated higher activities compared with the other fractions.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.221-224
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• 2008

We made densified wood pellet by hemp woody core as replacing wood resource. Hemp was separated into the bast fiber and the woody core by hot steaming treatment. The hemp woody core had a similar lignin content and carbohydrate composition with hardwood. Also, the hemp had a low ash content, which resulted in a low ash formation in pellet burning. Heating value of the hemp pellet had a very similar to the pellet made by hardwoods. The hemp woody core can replace hardwood for densified wood pelletmaking.

• Journal of the Korea Furniture Society
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• v.27 no.3
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• pp.253-262
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• 2016

Woodcraft activity is inseparable with our ordinary life and its relevant research should be consistently maintained because it has significant educational value to blossoming students. These days, which interest in woodcraft is rapidly expanding from early childhood to old age, this study was done to provide images to those who work in this field or who have interest. Out of the 43 jewelry and gift boxes used in this study, species of white which has low proportion of packing materials consists of species of Fir (Abies spp), Birch (Betula spp) and Amercia basswood (Tilia americana Linnaeus) and the higher proportion species of Mahogany (Swietenia macrophylla), Bayor (Pteorospermum diversifolium Bl), Snakewood (Piratinera guianensis aubl.) and Bintangor (Calophhyllum spp.) were used in valuable products. It was showed that out of 56 works selected from '400 Wood Boxes', the species of Walnut (Juglans regia), Cherry (Prunus serotina), Wenge (Milletia laurentii De. wild), Ebony (Diospyros spp.), Ash (Fraxinus spp.) and Cocobolo (Dallbergia cultrata Grah.) were frequently used.

• Journal of Korean Society of Forest Science
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• v.58 no.1
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• pp.23-26
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• 1982

The chemical components in sap and heart wood of Q. variabilis and Q.serrate grown in Mt. Jiri were analyzed Q. variabilis ash contents were 0.57%, in sap wood portion and 1.00% in heart wood. Of the extractives cold water extractives were 5.74% in sap wood and 4.77% in heart wood. Hot water extractives were 6.33% in sap, 6.30% in heart wood portion. 1% caustic soda extractives were 15.52% in sap wood and 15.63% in heart wood. Alcohol-benzol extractives were 4.89% in sap wood and 2.96% in heart wood Holocellulose contents were 73.19% in sap wood, 78.83% in heart wood. Lignin contents were 21.76% in sap wood and 18.14% in heart wood portion. In pentosan contents there were 15.92% in sap wood and 26.50% in heart wood. In Q serrata ash contents were 0.26% in sap wood and 0.27% in heart wood. Cold water extractives were 2.81% in sap wood and 2.04% in heart wood. Hot water extractives were 5.32% in sap wood and 7.08% in heart wood portion. 1%-C austic soda extractives were 15.73% in sap wood and 16.55% in heart wood. Alcohol-benzol extractives were 3.93% in sap wood and 3.51% in heart wood. Holo celluloe contents were 74.21% and 74.84% in sap and heart wood portion respectively. Lignin contents were 14.11% in sap wood and 19.19% in heart wood. Of the pentosan contents there were 20.75% and 21.44% in sap and heart wood respectively. In conclution ash, holocellulose, lignin and pentosan contents showed always consistent differences between sap and heart wood in Q.variabilis, but in Q.serrata only lignin content showed slight difference between sap and heart wood.

• Journal of the Korean Wood Science and Technology
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• v.38 no.1
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• pp.49-55
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• 2010

morphologically different Larix Kaemferi Carr sawdust. The pellet characteristics included moisture contents satisfied the first grade (less than 10%) of quality standard of wood pellets announced by Korea Forest Research Institute. Densities were also adequate for the first grade (640kg/$m^3$) on the quality standard and there was no large difference in other characteristics of pellets, however, pellets manufactured with planer shavings had the highest density. Ash contents also passed the first grade (less than 0.7) of quality standard. But bark pellet exceeded the second grade (1.5%) in ash content. Lower absorption ratio of bark pellet showed the effect on hygroscpicity. The heating value of the manufactured wood pellets in this study exceeded the first grade of quality standard(more than 4,300 kcal/kg).

• Journal of the Korean Wood Science and Technology
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• v.51 no.1
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• pp.23-37
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• 2023

One type of biomass that has promising potential for bio pellet production is spent coffee grounds (SCGs). However, previous studies have shown that SCGs in bio pellets cause a lot of smoke. Therefore, they need to be mixed with a material that has a higher calorific value to produce better quality pellets. One material that can be used is pine wood because it has a natural resin content that can increase the calorific value. The aim of this study was to examine the quality of bio pellets produced with SCGs and pine wood charcoal at different particle sizes. The charcoal was ground using either a hammer mill (HM) or a ball mill (BM). Pine wood charcoal was mixed with SCGs at ratios of SCGs to pine wood charcoal of 4:6 and 6:4 by weight, respectively, and the adhesive used a tapioca with a composition ratio 5% of the raw material. The bio pellets were produced using a manual pellet press. The quality of the bio pellets was assessed based on Indonesian National Standard (SNI) 8021-2014, and the physical observations include flame length, burning rate, and compressive strength. The average water content, ash content, and calorific value of the bio pellets were in accordance with SNI 8021-2014, but the density and ash content values were below the standard values. The BM variation of bio pellets had a higher compressive strength than the HM variation, and the 4:6 BM variation had the longest burning time compared with 4:6 HM.

• Journal of the Korean Wood Science and Technology
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• v.43 no.1
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• pp.135-143
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• 2015

This study evaluated fuel properties of composite materials which were prepared by mixing a waste activated carbon from the used purifier filter with torrefied wood powder. Wood species of the raw material of torrefied wood powder are oak wood (Quercus serrata Thunb. ex Murray) and pine wood (Pinus densiflora Siebold & Zucc). And the treatment conditions used for this study were 300 s, 450 s, and 600 s at $200^{\circ}C$ for the wood roaster. Also, the mixing ratios are 5 : 95, 10 : 90, 15 : 85, 20 : 80, 40 : 60, 60 : 40 and 80 : 20 (waste activated carbon : torrefied wood powder). The fuel properties such as highly heating value (HHV), elementary analysis and ash content were evaluated. The results obtained are followings; 1. Despite the same treatment condition of wood roasting, pine wood has higher carbon contents than oak wood. Therefore, pine wood indicated the optimum carbonization at low temperature and short treatment times. 2. The gross calorific value and ash content increased as the mixing ratio of waste activated carbon increased. 3. Mixtures of the waste activated carbon and torrefied wood powder showed greater gross calorific value than those of the mixtures of waste activated carbon and the untreated wood powder. Also, the pine wood resulted in higher heating value that thaose of the oak wood. 4. When composite fuels that were composed waste activate carbon and wood powder are used, higher temperature conditions are required because the combustion is incomplete at $800^{\circ}C$ and 4 hours. 5. The increasing rate of the gross calorific value of mixtures of waste activated carbon and untreated wood powder is higher than does the mixtures of waste activated carbon and torrefied wood powder. Also, this phenomenon is more obvious for pine woods. Therefore, an optimal mixing ratio of waste activated carbon was determined to be between 5% and 10% (wt%). Also, this condition satisfied the requirement of the No.1 grade of wood pellet.