• Applied Chemistry for Engineering
• /
• v.18 no.5
• /
• pp.415-423
• /
• 2007

Pyrolysis characteristics of sawdust and rice husk as biomass resources in a thermogravimetric analysis were determined. Experiments were carried out with a linear heating rate under inert atmosphere of $N_2$ gas. Pyrolysis of the biomass can be classified as a lower temperature reaction zone where the major component of holocellulose is thermally decomposed and a high temperature reaction zone where lignin is thermally decomposed. The obtained data was analyzed by the two-step consecutive reaction model. Activation energies of sawdust and rice husk are found to be respectively 82.5 kJ/mol and 85.1kJ/mol in the low temperature zone according to the first order reaction model and 19.7 kJ/mol, 22.0 kJ/mol in the high temperature zone according to the three-way transport model. The reaction rate constant with variation of heating rate can be well predicted by the kinetic compensation relation of Gaur-Reed.

• Environmental and Resource Economics Review
• /
• v.29 no.4
• /
• pp.469-497
• /
• 2020

More than one-third of the world's population still has no access to clean cooking facilities despite global interest and efforts to expand the accessibility of clean cooking fuels. They use traditional biomass, i.e., crops, animal dung and firewood, as their cooking fuel, and the health and economic damage from it is severe. As many studies have been conducted to understand the choice and transition of cooking fuel in developing countries, characteristics of household head have been addressed as one of the main fuel determinants. However, decision-making in households is not only made by household head and can vary depending on the relative characteristics of household members. Thus, this study analyses the determinants of cooking fuel choice through the samples of Cambodian couples(household head and his/her spouse) considering both characteristics of husbands and wives. As a result, it is confirmed that the effects of characteristics, such as employment, education levels, and frequency of media use, between husbands and wives on cooking fuel choice were different. This study is expected to contribute to the development of more sophisticated policies to increase clean fuel in Cambodia, given that it takes into account the characteristics of spouses who have not previously been dealt with in analyzing the determinants of cooking fuel choice and that it is difficult to find research on Cambodia.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.4
• /
• pp.532-539
• /
• 2012

This study was carried out to investigate the effect of substrate to inoculum ratio on ultimate methane potential ($B_u$) from piggery wastes. BMP(Biochemical methane potential) assays were executed for the three samples that have different organic characteristics (Filtrate of pig slurry, LF; Thermal hydrolysate of piggery sludge cake, TH; Mixture of LF and TH at the ratio of 4 to 1, Mix), and $B_u$ values obtained from BMP assays were compared with the theoretical methane potential ($B_{th}$) of each samples. While $B_u$ values (0.27, 0.44, and $0.46Nm^3\;Kg^{-1}-VS_{added}$) of TH sample that was pretreated with thermal hydrolysis were below the $B_{th}$ at all S/I ratios (0.1, 0.3, and 0.5), and $B_u$ values of LF (0.64 and $0.53Nm^3\;Kg^{-1}-VS_{added}$ for the S/I ratios of 0.1 and 0.3, respectively) at the lower S/I ratios of 0.1 and 0.3 exceeded the $B_{th}$ values ($0.418Nm^3\;Kg^{-1}-VS_{added}$). And also biodegradability ($B_u/B_{th}$) of LF sample were obtained as 152.07%, 122.67%, and 95.71% at the S/I ratios of 0.1, 0.3, and 0.5, respectively, and unreasonable $B_u/B_{th}$ values were presented at lower S/I ratios of 0.1 and 0.3. $B_u$ and $B_u/B_{th}$ of Mix sample showed a similar tendency with those of LF sample. Therefore, TH sample by thermal hydrolysis pretreatment showed lower anaerobic biodegradability than those of other samples (LF and Mix) and ultimate methane potentials of LF and Mix samples were overestimated in the lower S/I ratio of 0.1 and 0.3.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.2
• /
• pp.36-46
• /
• 2015

Integration of crop-livestock farming has been a problem-solving mode for abatement of environmental pollution and recovery of resources in recent years. The objectives of this study were 1) to suggest the customized integration of crop-livestock farming model reflecting the regional characteristics through in-depth analysis of case study and 2) to analyze the livestock nutrients flow in terms of three primary elements as nitrogen(N), phosphorous(P), and potassium(K). The personal interview and survey were carried out in 2012 for a total of 161 farms from four different regions(NS, NW, JJ, YC) in South Korea. The mass balance analysis was used to suggest and evaluate the models for two sites(JJ and YC). The results showed that NS and NW sites produced relatively more livestock manure than the sites of YC and JJ because of the regional differences in livestock numbers and urbanization. The models were suggested for the site JJ and site YC, and 'two track model(energy and resource recovery)' and 'dispersal type model' were assigned respectively. For the nutrient flows, the releasing P and K with new models had increased up to 7%, while N release had decreased down to 15% in both YC and JJ sites compared to the present treatment system. Estimated value showed that there was oversupply of N (719 ton/yr) and $P_2O_5$ (1,269 ton/yr) in YC and deficiency of N (671 ton/yr) and excessive $P_2O_5$ (32 ton/yr) in JJ respectively. Therefore, P runoff has to be considered an eutrophication occurs in rural small stream when an integration of crop-livestock farm system is applied into both sites.

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

• Journal of Climate Change Research
• /
• v.4 no.2
• /
• pp.115-126
• /
• 2013

Recently Korea considers the source of biomass burning emissions reflecting national characteristic, so that includes the inventory of emission source but preceding research is rarely implemented in Korea. Therefore, a study on characteristics of greenhouse gas emissions from biomass burning is necessary and it also makes the source management effectively when the climate-atmospheric management system takes effect. In this study, using the manufactured charcoal kiln and the number of experiment was three times to get a reliable experiment result. The sampling time was decided by changing degree in charcoal kiln and charcoal manufacturing process. The results of calculation greenhouse gas emission factor from charcoal kiln were $668g\;CO_2/kg$, $20g\;CH_4/kg$, $0.01g\;N_2O/kg$. Using the emission factor developed in this study, estimate the emissions from charcoal kiln in Korea. The results of calculation were $46,040ton\;CO_2/yr$, $1,378ton\;CH_4/yr$, $0.69ton\;N_2O/yr$ and greenhouse gas emissions applying GWP are as follows. $CH_4$ emissions was $28,947ton\;CO_2eq./yr$, $N_2O$ emissions was $214ton\;CO_2eq./yr$. As a results, Gross emissions of charcoal kiln in Korea was $75,201ton\;CO_2eq./yr$, but the oak used in this study is included to the biomass so emissions of $CO_2$ are excluded. Therefore the net emissions of charcoal kiln in Korea was $29,161ton\;CO_2eq./yr$.

• Journal of Life Science
• /
• v.32 no.7
• /
• pp.578-587
• /
• 2022

Korea, as the world's 7^th largest emitter of greenhouse gases, has raised the national greenhouse gas reduction target as international regulations have been strengthened. As it is possible to utilize coastal and marine ecosystems as important nature-based solutions (NbS) for implementing climate change mitigation or adaptation plans, the blue carbon ecosystem is now receiving attention. Blue carbon refers to carbon that is deposited and stored for a long period after carbon dioxide (CO₂) is absorbed as biomass by coastal ecosystems or oceanic ecosystems through photosynthesis. Currently, there are only three blue carbon ecosystems officially recognized by the Intergovernmental Panel on Climate Change (IPCC): mangroves, salt marshes, and seagrasses. However, the results of new research on the high CO₂ sequestration and storage capacity of various new blue carbon sinks, such as seaweeds, microalgae, coral reefs, and non-vegetated tidal flats, have been continuously reported to the academic community recently. The possibility of IPCC international accreditation is gradually increasing through scientific verification related to calculations. In this review, the current status and potential value of seaweeds, seagrass fields, and non-vegetated tidal flats, which are sources of blue carbon on the east coast, are discussed. This paper confirms that seaweed resources are the most effective NbS in the East Sea of Korea. In addition, we would like to suggest the direction of research and development (R&D) and utilization so that new blue carbon sinks can obtain international IPCC certification in the near future.