• Environmental Engineering Research
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• v.22 no.3
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• pp.320-328
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• 2017

This paper describes the non-isothermal pyrolysis of wood pellet and saw dust, and their blends with bituminous coal. The blends showed the distinct, two peaks in thermogravimetric curves, and the first peak came from the biomass pyrolysis and the second one came from the coal pyrolysis. The interaction in the blend was evaluated in terms of the maximum rate of weight loss, characteristic temperatures, char yields, and the calculated and experimental thermogravimetric curves. The activation energies and frequency factors for the blends were obtained with the multi-stage, Coats and Redfern method. The respective activation energies of 73 and 67 kJ/mol and the frequency factors of 725,100 and $65,262min^{-1}$ were obtained for the present wood pellet and saw dust samples. The thermogravimetric study shows that there is no significant interaction between the present biomass and coal in the blends, and the pyrolysis behavior can be described with the additive rule.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.4
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• pp.32-42
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• 2012

Wood biomass including forest residues, waste wood, and construction residuals has been widely generated in Korea, but forest biomass from the National Forest Management Operation Project plays a big role in generating wood biomass. Unfortunately the promotion policy of woody energy organized by the Forest Service in Korea concentrates more on demand creation rather than on supply expansion. Therefore, in order to utilize insufficient wood resources effectively, it is greatly required to develop uses for maximizing their added value. In particular, more attention to the use of the second generation biomass has been paid in foreign countries because there is a threshold that the first generation biomass cannot produce enough biofuel without threatening food supplies and biodiversity. In Korea, wood pellets are regarded as the alternative clean fuels to oils and coals that emit green house gases into the atmosphere. However, using wood as pellet raw materials can not be an economic way because the value of wood disappears right after burning in the boiler in spite of its contribution to the decrease of carbon emission. Differently from wood pellets, kraft pulping process using woody biomass produces black liquor as a by-product which can be used to generate electricity, bioenergy and biochemicals through gasification. Thus, it can be more economical to make a torrefaction of lignocellulosic biomass such as low-quality wood and agricultural leftovers as raw materials of pellets.

• Journal of Forest and Environmental Science
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• v.25 no.2
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• pp.127-130
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• 2009

This study has been carried out to investigate the characteristics of the commercial wood pellets such as moisture content, heating value, ash content, and chemical component. The wood pellets from national forestry cooperatives federation and China were evaluated to see if they can be 1st or 2nd class of Korea standard. Indonesian pellet was estimated to be a 3rd class because of the heating value and high ash content. It is considered that there is a quality difference in wood pellets in accordance with the production nations. It could be originated from the difference of raw materials produced in different region.

• Journal of the Korean Wood Science and Technology
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• v.42 no.3
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• pp.318-326
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• 2014

This study was conducted to investigate the potential of non-used forest biomass residues as raw materials for making wood pellets with additives such as wood tar and starch and to evaluate fuel characteristics of the pellets. Wood tar, a by-product provided from the carbonization process of wood, could be a suitable additive for wood pellet production due to its higher calorific value and lower hazardous heavy metals, such as cadmium and mercury, compared to woody biomass. When the wood tar (10 wt%) was added, the calorific value was increased from 4,630 kcal/kg (wood pellet without additive) to 4,800 kcal/kg (wood pellet with additive). With the increase of additive amount into wood pellet, the length and individual density of wood pellet increased. In addition, bulk density of the pellets was increased, whereas the fine content was decreased. Consequently the overall productivity of wood pellets was improved by adding 2 w% additives into wood pellets; the percentage of productivity increase was 5.9% and 4.9% for adding starch and wood tar, respectively.

• Clean Technology
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• v.27 no.4
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• pp.325-331
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• 2021

In this study, bio-carbons were produced by activation process from unused biomass (Grade 3 wood pellet and spent coffee grounds) to determine the removal performance of formaldehyde and acetaldehyde. The activation experiments were conducted in a fixed bed reactor using CO₂ as an activation agent. The temperature of the activation reactor and input of CO₂ were 900 ℃ and 1 L min^-1 for all the experiments. The maximum BET surface area of about 788 m² g^-1 was obtained for bio-carbon produced from Grade 1 wood pellet, whereas about 544 m² g^-1 was achieved with bio-carbon produced from spent coffee grounds. In all the experiments, the bio-carbons produced were mainly found to have micro-porous nature. A lower ash amount in raw material was favored for the high surface area of bio-carbons. In the removal test of formaldehyde and acetaldehyde, the bio-carbon produced from spent coffee grounds showed excellent adsorption performance compared with woody biomass (Grade 1 wood pellet and Grade 3 wood pellet). In addition, the comparative experiment of commercial impregnated activated carbon and bio-carbon produced from spent coffee grounds was conducted. In terms of formaldehyde removal performance, the commercial impregnated bio-carbon was excellent, while bio-carbon produced from spent coffee grounds was excellent in acetaldehyde removal.

• Korean Journal of Medicinal Crop Science
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• v.21 no.1
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• pp.7-19
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• 2013

This study was carried out to select new pelleting binder and material for seeds from Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. The optimum treatments of the various concentrations and species of priming agents to improve seed germination of both woody medicinal plants were also estimated. Germinability was increased when the seeds of Fraxinus rhynchophylla Hance was soaked in -1.0 MPa of PEG6000 solution at $15^{\circ}C$ for 4 days significantly, the optimum treatment for improving germination of Alnus sibirica Fisch. ex Turcz was observed when the tested seeds was soaked in 100 mM of KCl at $15^{\circ}C$ for 4 days. The influence of physical and chemical properties of pelleting solid materials, the mixture of gypsum, diatomaceous earth, dalma ceramic and vermicuolite (6:1:1:1 ratio) were found as the best pelleting materials for Fraxinus rhynchophylla Hance and Alnus sibirica Fisch. ex Turcz. seeds. To satisfy the requirements of absorption and compatibility for multi-layer seed pelleting, SGPA (Starch-grafted cross-linked polyacrylates) hydrogel was prepared using starch, acrylonitrile, ceric ammonium nitrate, nitric acid, methyl alcohol and potassium hydroxide. The resulting SGPA hydrogel showed high water absorption but not plant compatibility. It suggested that seed pelleting using pelleting materials and SGPA hydrogel (multi-layer coating) after priming agent treatment is to increase germinability and seedling growth and it can reduced irrigation labours and can also save seed.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.783-791
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• 2015

A fluidized-bed reactor with an inside diameter of 0.1 m and a height of 1.2 m was used to study the effect of steam and catalyst additions to air-blown biomass gasification on the production of producer gas. The equipment consisted of a fluidized bed reactor, a fuel supply system, a cyclone, a condenser, two receivers, steam generator and gas analyzer. Silica sand with a mean particle diameter of $380{\mu}m$ was used as a bed material and calcined dolomite ($356{\mu}m$), which is effective in tar reduction and producer gas purification, was used as the catalyst. Both of Korea wood pellet (KWP) and a pellet form of EFB (empty fruit bunch) which is the byproduct of Southeast Asia palm oil extraction were examined as biomass feeds. In all the experiments, the feeding rates were 50 g/min for EFB and 38 g/min for KWP, respectively at the reaction temperature of $800^{\circ}C$ and an ER (equivalence ratio) of 0.25. The mixing ratio (0~100 wt%) of catalyst was applied to the bed material. Air or an air-steam mixture was used as the injection gas. The SBR (steam to biomass ratio) was 0.3. The composition, tar content, and lower heating value of the generated producer gas were measured. The addition of calcined dolomite decreased tar content in the producer gas with maximum reduction of 67.3 wt%. The addition of calcined dolomite in the air gasification reduced lower heating value of the producer gas. However The addition of calcined dolomite in the air-steam gasification slightly increased its lower heating value.

• Korean Journal of Environmental Agriculture
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• v.18 no.3
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• pp.265-271
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• 1999

The direct seeding of seeds or the pellets of three native tree species (Pinus densiflora, Parthenocissus tricuspidata and Rhus chinensis) was tried on the rock cut-slope revegetation bed established by construction of mechanical excavation or erosion break with artificially enriched soil medium. The seed $pellet(1{\sim}2\;cubic\;cm)$ made by coating seeds(treated with proper previous pregermination treatments) with the mixture of peatmoss, clay, chemical absorbant(3.5:1.0:0.2, v/v) showed about twice better percent germination than the control seeds. The percent germination and the survival rate of the germinated seedlings were higher in the spring direct seeding than the summer or the fall. The soil medium containing the compost showed extremely low percent $germination(0{\sim}3%)$ which presumably attributed to the compost inducing damping-off disease. The survival rates were affected mainly by shading of natural herbaceous vegetation invading from outside to the revegetation bed. The planting of two year old container seedlings of P. densiflora and P. tricuspidata on August 2, 1998 was successful indicating that it could be an alternative revegetation method in case the summer direct seeding is unfavorable.

• Clean Technology
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• v.26 no.4
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• pp.239-250
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• 2020

Biomass is an abundant renewable energy resource that can replace fossil fuels for the reduction of greenhouse gas (GHG). Indonesia has a large number of cheap biomass feedstocks, such as reforestation (waste wood) and palm residues (empty fruit bunch or EFB). In general, raw biomass contains more than 20% moisture and lacks calorific value, energy density, grindability, and combustion efficiency. Those properties are not acceptable fuel attributes as the conditions currently stand. Recently, torrefaction facilities, especially in European countries, have been built to upgrade raw biomass to solid fuel with high quality. In Korea, there is no significant market for torrefied solid fuel (co-firing) made of biomass residues, and only the wood pellet market presently thrives (~ 2 million ton yr-1). However, increasing demand for an upgraded solid fuel exists. In Indonesia, torrefied woody residues as co-firing fuel are economically feasible under the governmental promotion of renewable energy such as in feed-in-tariff (FIT). EFB, one of the chief palm residues, could replace coal in cement kiln when the emission trading system (ETS) and clean development mechanism (CDM) system are implemented. However, technical issues such as slagging (alkali metal) and corrosion (chlorine) should be addressed to utilize torrefied EFB at a pulverized coal boiler.

• Journal of the Korean Wood Science and Technology
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• v.43 no.3
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• pp.374-380
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• 2015

The quality characteristics of the woodpellet manufactured from two domestic pines (Pinus densiflora S. et Z. and Pinus rigida Mill.) were investigated for the efficient energy use of woody biomass resources. Properties of woodpellets such as moisture content, heating value, ash content, apparent density and durability were determined by using the standard test method of woodpellets of Korea Forest Research Institute (KFRI) and elemental analysis. The results of elemental analysis for C, H, O and N showed 61.42% carbon, 5.56% hydrogen, 32.87% oxygen, and 0.15% nitrogen for Pinus densiflora S. et Z. and 61.03% carbon, 5.96% hydrogen, 32.83% oxygen, and 0.18% nitrogen for Pinus rigida Mill. No significant difference between Pinus densiflora S. et Z. and Pinus rigida Mill was observed on elemental analysis. Heating values of each woodpellet were ranged from 19.00 to 19.42 MJ/kg which satisfied the first grade quality standard (${\geq}18.0MJ/kg$) by KFRI. The ash contents of woodpellet were slightly different between Pinus densiflora S. et Z. and Pinus rigida Mill., and satisfied the first grade quality standard (${\leq}0.7%$) by KFRI. Apparent density of woodpellet (Pinus densiflora S. et Z.) was passed the first grade standard level (${\geq}640kg/m^3$), and woodpellets from Pinus rigida Mill. satisfied the second grade quality of the standard. The moisture contents of each woodpellet were satisfied by the first grade quality standard (${\leq}10%$). The durability of woodpellet (Pinus densiflora S. et Z.) was passed the third grade level (${\geq}95%$), but Pinus rigida Mill. woodpellet was insufficient to satisfy the quality standard.