• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.11
• /
• pp.1102-1110
• /
• 2008

This research was performed to analyze the characteristics of wood wastes from origin and to suggest grade-classification for them. Korean proximate analysis was conducted, and heating value, heavy metals and Cl concentrations were analyzed for gradeclassification. Wood wastes were sampled from forest, living, construction and demolition, and industrial areas with origin. Moisture content of most wood wastes was ranged in 5$\sim$10%. VS (volatile solids) and ash contents of them showed > 95% and < 5%, respectively. Most wood wastes except wood for growing mushroom permitted the standard (low heating value $\geq$ 3,500 kcal/kg) for refusederived fuel. CCA (Cr, Cu, As) concentration of wood wastes used in bench, wasted fishing boat, and railroad crosstie was higher than that of the other ones. Cl content showed approximately 1.3% in wood box for fish and $\leq$ 0.2% in the other wood wastes. Cl content of all wood wasted used in this research permitted the standard (Cl $\leq$ 0.2%, dry weight basis) for refuse-derived fuel. If the wood wastes were classified in 3-grade, plywoods would be in 2nd grade, and MDF (medium density fiber), wooden bench, painted electric wire drum, wasted fishing boat, and railroad crosstie be in 3rd grade.

• Korean Chemical Engineering Research
• /
• v.57 no.6
• /
• pp.874-882
• /
• 2019

In this study, the gasification characteristics of four types of unused woody biomass and one waste wood in a lab-scale bubbling fluidized bed gasifier (Diameter: 0.11 m, Height: 0.42 m) were investigated. Effect of equivalence ratio (ER) of 0.15-0.3 and gas velocity of $2.5-5U_0/U_{mf}$ are determined at the constant temperature of $800^{\circ}C$ and fuel feeding rate of 1 kg/h. The silica sand particle having an average particle size of $287{\mu}m$ and olivine with an average particle size of $500{\mu}m$ were used as the bed material, respectively. The average product gas composition of samples is as follows; $H_2$ 3-4 vol.%, CO 15-16 vol.%, $CH_4$ 4 vol.% and $CO_2$ 18-19 vol.% with a lower heating value (LHV) of $1193-1301kcal/Nm^3$ and higher heating value (HHV) of $1262-1377kcal/Nm^3$. In addition, it was found that olivine reduced most of C2 components and increased $H_2$ content compared to silica sand, resulting in cracking reaction of tar. The non-condensable tar decreases by 72% ($1.24{\rightarrow}0.35g/Nm^3$) and the condensable tar decreases by 27% ($4.4{\rightarrow}3.2g/Nm^3$).

• Korean Chemical Engineering Research
• /
• v.54 no.5
• /
• pp.687-692
• /
• 2016

Biomass has been concerned as one of the alternative energy resources because it is renewable, abundant worldwide, eco-friendly, and carbon neutral. Quercus variabilis has been studied to understand pyrolysis reaction characteristics, and to evaluate the efficiency of bio-energy production from fast pyrolysis. Quercus variabilis were fast pyrolyzed in a bubbling fluidized bed reactor at various reaction conditions. The effects of pyrolysis temperature between $400^{\circ}C$ and $550^{\circ}C$ on product yields were investigated. The yield of bio-oil was changed between 36.98 wt% and 39.14 wt%, and those of gas yield was 33.40 and 36.96 wt% with increasing reaction temperature. The higher heating value (HHV) of bio-oil at $500^{\circ}C$ ($3.0{\times}U_{mf}$) was 20.18 MJ/kg. The gas compositions were similar for all reaction conditions such as CO, $CO_2$ and $CH_4$, and $CO_2$ selectivity was the highest (37.16~50.94 mol%). The bio-oil has high selectivities for furfural, phenol and their derivatives such as 1-hydroxy-2-propanone, 2-methoxy-phenol, 1,2-benzendiol, 2,6-dimethoxy-phenol.

• Journal of Bio-Environment Control
• /
• v.22 no.1
• /
• pp.35-41
• /
• 2013

This study was conducted to provide data necessary for reducing the condensation on greenhouse covering in winter season. The variation of VPD (Vapor Pressure Deficit) and condensation flux was analyzed in experimental tomato greenhouse. VPD values in experimental plastic greenhouse were greater than 0.2 kPa of disease prevention threshold, and lower than 0.5 kPa of threshold for dehumidification. The surface temperature of inside covering was slightly higher than the average temperature of outside and above curtain, and changed according to outside temperature. The humidity above curtain was nearly 100% and good condition for condensation. The humidity below curtain was 75~90% and comparatively stable condition for growing. The condensation flux value in experimental greenhouse corresponded with result of Seginer and Kantz (1986).

• Resources Recycling
• /
• v.19 no.2
• /
• pp.45-53
• /
• 2010

During the biomass gasification, tar generation is typically accompanied, which causes many problems, such as pipe plugging and equipment fouling. In the experiments, activated carbon was applied to the upper reactor of the two-stage gasifier in order to remove the tar generated during gasification. In addition, the effects of the upper-reactor temperature and equivalence ratio on the producer gas characteristics (composition, tar content and lower heating value) were investigated. To investigate the effect of the upper reactor-temperature, experiments were performed at 743, 793, $838^{\circ}C$, respectively. To examine the influence of the equivalence ratio, a comparison experiment was carried out at a equivalence ratio of 0.17. In all experiments, tar contents in the producer gases were below $2mg/Nm^3$. The maximum LHV of the producer gas was above $10MJ/Nm^3$, which is much higher than the typical LHV($3\sim6MJ/Nm^3$) in the air gasification of biomass.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.7
• /
• pp.749-755
• /
• 2011

The performance and emission characteristics of a CNG (compressed natural gas) engine were experimentally investigated under different natural gas compositions. The engine specifications were as follows: 6606 cc, turbo, lean-burn-type; its ignition timing was fixed for the fuel gas with a HHV (higher heating value) of 10454 kcal/$Nm^3$. The experimental results showed that when the HHV of the fuel gas was changed from 10454 kcal/$Nm^3$ to 9811 kcal/$Nm^3$ and 9523 kcal/$Nm^3$, the average power reductions were 3.2 % and 3.4 % (1.5 % and 2.1 %, respectively, with A/F control switched off), respectively, and the average thermal-efficiency reductions were 1.1 % and 1.5 % (1.5 % and 2.1%, respectively, with A/F control switched off), respectively. The emissions of $CO_2$, CO, and $NO_x$ decreased as the HHV of the fuel gas was lowered. On the other hand, the emissions of THC (total hydrocarbon) were not consistent, and the extent of change in their emissions was small.

• Microbiology and Biotechnology Letters
• /
• v.44 no.3
• /
• pp.400-407
• /
• 2016

A unicellular green alga, Chlorella vulgaris KNUA027, was isolated from the roots of Panax ginseng seedlings and its biotechnological potential was investigated. The results of GC/MS analysis showed that C. vulgaris KNUA027 was rich in nutritionally important polyunsaturated fatty acids (PUFAs) such as alpha-linolenic acid (C_18:3 ω3, 45.8%, 50.8 mg/g) and hexadecatrienoic acid (C_16:3 ω3, 11.8%, 13.1 mg/g). Therefore, this Korean indigenous microalga may have potential as a source of omega-3 PUFAs. It was also found that the saturated palmitic acid (C_16:0, 37.1%, 41.2 mg/g), which is suitable for biodiesel production, was one of the major fatty acids produced by strain KNUA027. The proximate analysis showed that the volatile matter content was 88.5%, and the ultimate analysis indicated that the higher heating value was 19.8 MJ/kg. Therefore, the results from this research with C. vulgaris KNUA027 may provide the basis for the production of microalgae-based biofuels and biomass feedstock.

• Food Science of Animal Resources
• /
• v.24 no.1
• /
• pp.37-43
• /
• 2004

The "Ginseng Pork" produced by feeding ginseng by-products can be a compatible product in the sense of increasing pork consumption and developing functional food in the international pork market. This experiment was conducted to produce "Ginseng Pork" with emphasis on growth performance and meat quality. Experiments were conducted in which 30 Landrace heads were fed with bark of ginseng root(BGR) or heating extracts ginseng leaves and stem(HEG). WB-shear force was not different among the treatment groups until 15 days of ageing, but pork fed with the 6% BGR showed a higher shear force at 20 day of storage at 4$^{\circ}C$. Cooking loss showed lower value for the 9% BGR group compared with the control group. At 15 day, the 3% and 9% BGR groups showed lower cooking losses than control. Pork groups fed HEG showed a significantly(p<0.05) lower TBARS values after 5 days of storage. As for VBN analysis, the feeding groups of 9% BGR and 5.5% HEG had significantly lower values at 5 and 20 days when compared to the other treatment groups. It might be concluded that the accumulation of ginseng saponin in the pork resulted in retarding the ageing and inhibiting the oxidation.

• Journal of Conservation Science
• /
• v.24
• /
• pp.13-22
• /
• 2008

The identification of species, hygroscopic property, and ability of ethylene gas absorption of 23 ancient charcoals excavated from wooden coffin burials and roof-tile kilns of Chudong-ri cultural site were investigated. All of the 12 charcoals excavated from wooden coffin burials were broad-leaved trees. Among the total 12 samples, 9 samples were Lepidobalanus and others were Celtis spp.. On the other hand, other 11 charcoals from roof-tile kilns were needle-leaved tree, Pinus spp.(hard pine). The broad-leaved tree charcoals from wooden coffin burials showed a higher moisture absorption capacity than needle-leaved tree charcoals from roof-tile kilns. The ethylene gas absorption was greater in the Lepidobalanus charcoal than that of Celtis spp. and Pinus spp. (hard pine) charcoal. The broad-leaved tree charcoal having high absorption ability of substances was due to a large microporous and specific surface area. Therefore, it was estimated that broad-leaved tree charcoals were filled in order to make favorable condition in tomb. The wood quality of pine is soft and easy to burn because of low specific gravity, as well as high calorific value by resin in wood. We could assume that the pine wood was used as fuel for roof-tile kilns because of easy control of heating and thermal power.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.43 no.2
• /
• pp.93-99
• /
• 2010

This study was conducted to prepare canned salmon frame and to characterize its food components. In the preparation of high-quality canned foods, the boiling water generated in the pre-heating process should be removed, and then the pre-treated canned salmon frame should be sterilized for an $F_0$ value of 12 min. The proximate composition of the canned salmon frame prepared under optimal conditions (CSFP) was 58.4% moisture, 15.7% protein, 21.4% lipid, and 3.5% ash. Based on the results of volatile basic nitrogen and microbiological tests, the CSFP was acceptable. The sensory score for the color of CSFP was 4.1 points, which was higher than that of commercial canned salmon frame (CCSF). However, there were no significant differences in the sensory scores for flavor and taste between CSFP and CCSF. The total amino acid content of CSFP was 14.58 g/100 g, which was 4.9% lower than that of CCSF. The major amino acids in CSFP were aspartic acid (11.0%), glutamic acid (14.8%), and lysine (10.6%), which accounted for 36.4% of the total amino acid content. The CSFP was high in calcium and phosphorus, while it was low in magnesium and zinc. The major fatty acids in CSFP were 16:0 (15.2%), 18:1n-9 (17.0%), 18:2n-6 (16.7%), 20:5n-3 (9.3%), and 22:6n-3 (8.8%). Based on the results, CSFP is a high-quality canned food in terms of hygiene and nutrition.