• Journal of Biomedical Engineering Research
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• v.38 no.5
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• pp.242-247
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• 2017

This study presents a bio-chemical energy harvesting system which can generate electric power from bioorganic substance contained in vermicompost. It produced electricity by inoculating microbial fuel cell(MFC) with earthworm-composted food waste. The generated electricity was converted into usable voltage level for mobile electronics through power conditioning circuits. The implemented prototype showed $200{\mu}W$ of maximum output electric power, which successfully supplied a beacon device which continuously transmitted data to nearby smartphone without a battery. The proposed system can help develop portable or bio-mimetic energy supply for sustainable use with further improvement.

• New & Renewable Energy
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• v.6 no.2
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• pp.27-32
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• 2010

Low Calorific Gas Turbine (LCGT) has been developed as a next generation power system using landfill gas (LFG) and biogas made from various organic wastes, food Waste, waste water and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for the optimum applications of LCGT. Main troubles of Low Calorific Gas Turbine system was derived from the impurities such as hydro sulfide, siloxane, water contained in biogas. Even if the quality of the bio fuel is not better than natural gas, LCGT may take low quality gas fuel and environmental friendly power system. The mechanical characterisitics of LCGT system is a high energy efficiency (>70%), wide range of output power (30 kW - 30 MW class) and very clean emission from power system (low NOx). A green house has been designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. LCGT is expected to contribute achieving the target of Renewable Portfolio Standards (RPS).

• Elastomers and Composites
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• v.46 no.4
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• pp.318-323
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• 2011

To recycle the waste tire rubber powder, rubber powder composite for waterproof sheet was prepared, and analyzed the effect of the kind of resin and the amount of crosslinking agent on the mechanical property of the composites. The elongation-at-break of the PE composite increased more than 3 times as EPDM was added into rubber composites. As the content of the crosslinking agent increased, the tensile strength of composite increased as well. When recycled polypropylene was used, the increase in composite's tensile strength was more than 3 times. Therefore to use the recycled PP in composite is more effective rather than PP in term mechanical properties.

• Composites Research
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• v.28 no.3
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• pp.118-123
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• 2015

In the current study explain about the bio-based composites made by groundnut shell as reinforcement with polyester resin matrix. Groundnut shell is an abundantly available natural waste byproduct and poly ester resin is widely used to fabricate of composites for good balance of mechanical properties because it is relatively low price and ease of handling. Evaluate the mechanical properties of manufactured groundnut shell/polyester composites by varying the amounts (wt %) of groundnut shell. Particulate shell reinforced polyester composites incorporating varying amounts of groundnut shell (5, 10, 15 and 20%) were characterized for their tensile strength, flexural strength, and impact strength. The mechanical properties improved with increasing particle loading up to 15% and decreased thereafter. Increasing in strength with increased particle shell loading was attributed to increase in surface area which enhanced load transfer between the polyester matrix and ground shall particulates. Scanning electron microscopic studies have been carried out to study the morphology of the composite. Thermal studies and water absorption properties of the composites also studied in this paper.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.3
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• pp.187-193
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• 2004

In this study, Anaerobic sewage sludge in a batch reactor operation at $35^\circ{C}$ was used as the seed to investigate the effect of pretreatments of waste activated sludge and to evaluate its hydrogen production potential by anaerobic fermentation. Various pretreatments including physical, chemical and biological means were conducted to utilize for substrate. As a result, SCODcr of alkali and mechanical treatment was 15 and 12 times enhanced, compared with a supernatant of activated sludge. And SCODcr was 2 time increase after re-treatment with biological hydrolysis. Those were shown that sequential hybridized treatment of sludge by chemical & biological methods to conform hydrogen production potential in bath experiments. When buffer solution was added to the activated sludge, hydrogen production potential increased as compare with no addition. Combination of alkali and mechanical treatment was higher in hydrogen production potential than other treatments.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.112-117
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• 2007

This study aims to develop an alternative energy like oil made from marine organic waste by marine products waste, spent fishing nets. There are already many commercial examples and case studies based on the petroleum industry-refuse plastic or refuse tire, however, it is rare that a research developing alternative energy from food waste and organic waste. Therefore, this study investigated the oil made from thermal decomposition under the high temperature and high pressure condition, and examined the possibility for commercial use by testing its own characteristics. A bio-oil from thermal decomposition at $250^{\circ}C$ and 40 atm was hard to remove impurities because of its high viscosity, showed lower caloric value than heavy oil, and generated various gases which were not appropriate for the use of fuel. It is noticeable that thermal decomposition was occurred at $250{\pm}5^{\circ}C$ using steam pressure, which much lower compared to the existing method of thermal decomposition, more than $500^{\circ}C$. Since the high viscosity of bio-oil, it is necessary a further study to use as liquid fuel.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2011.10a
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• pp.167-177
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• 2011

Renewable energy resources and technologies have the potential to provide long-lasting solutions of the global energy-requirements faced by the economic and environmental sectors of a nation. Therefore, waste money bills were used as renewable energy source for the production of bio-ethanol. In this study, different concentrated NaOH 0.5%. 1.0%, 2.0%, 3.0% and 0.0% (as a control) were used for 10, 20 and 30 mins at $121^{\circ}C$/15 psi in an autoclave. Saccharification and fermentation (aerobic and anaerobic) were carried out through commercial enzyme Celluclast 1.5 L, Novozymes 188 and Saccharomyces cerevisiae KCCM 11304 respectively. The results of pretreatment showed that the NaOH pre-treated substrate enhanced enzyme action and released more amount of glucose. The amount of glucose was found with the increasing concentration of NaOH and time $44996.95{\pm}6.30$, $46763.10{\pm}3.56$, $53421.32{\pm}4.72$, $63431.25{\pm}6.95$ and $56850.98{\pm}6.75\;ng/{\mu}l$ for 30 min respectively. As for bioethanol, the conversion rate of NaOH resulted $1010.08{\pm}4.71$, $1050.25{\pm}4.37$, $1109.49{\pm}4.39$, $1139.25{\pm}3.26$ and $1020.77{\pm}3.89$ ppm for aerobic; $16730.54{\pm}6.67$, $17076.45{\pm}6.25$, $17516.17{\pm}4.49$, $19782.68{\pm}6.19$ and $17973.39{\pm}7.50$ ppm for anaerobic and $18935.02{\pm}4.59$, $19895.45{\pm}5.39$, $21912.95{\pm}4.83$, $24895.21{\pm}6.72$ and $18961.21{\pm}4.90$ ppm for anaerobic condition with benzoic acid for respective condition. Thus, the results of the present work clearly revealed that with the increasing of alkali concentration might be more effective for bio-ethanol production from waste money bill, which is economic and environmental friendly.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.299-306
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• 2005

Anaerobic fermentation of food waste (FW) and waste activated sludge (WAS) for hydrogen production was performed in CSTR (Continuous Stirred tank reactor) under various HRTs and volumetric mixing ratio (V/V) of two substrates, FW and WAS. The specific hydrogen production potential of FW was higher than that of WAS. However, pH drop in the CSTR for hydrogen production from FW was higher than that from WAS. The maintenance of desired pH during fermentative hydrogen production is regarded as the most important operation parameter for the stable hydrogen production. Therefore, when the potential of hydrogen production from FW and better buffer capacity of WAS, the proper mixture of FW and WAS for fermentative hydrogen production were considered as a useful complementary substrate. The maximum yield of specific hydrogen production, 140 mL/g VSS, was found at HRT of 2 day and the volumetric mixing ratio of 20:80 (WAS : FW). The spatial distribution of hydrogen producing bacteria was observed in anaerobic fermentative reactor using fluorescent in situ hybridization (FISH) method.

• Journal of Mushroom
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• v.14 no.4
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• pp.237-243
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• 2016

Spent mushroom substrate (SMS) has generally been used for the manufacture of animal feed and production of bio fuel. Limited research has been conducted in the utilization of SMS as a co-material for composting. Therefore, the main purpose of this study was to evaluate the feasibility of composting vegetable waste mixed with various ratios of SMS (30, 40, and 50%). The results showed that the C/N ratio decreased when both sawdust (from 22.0~28.8 to 17.7~20.4) and SMS (from 18.5~19.5 to 12.7~16.8) were applied for composing, owing to increased contents of nitrogen. A maturity test conducted using mechanical (Solvita) and germination tests revealed that both sawdust (92.0~101.9%) and SMS (87.8~89.2%) satisfied a criteria of maturity standard (70%). A correlation analysis between compost maturity and its chemical properties revealed that the C/N ratio and pH were the most dominant parameters for compost maturity. Overall, SMS could be utilized as a compost material and especially, vegetable waste mixed with SMS could provide sufficient nutrients for crop growth.

• Advances in environmental research
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• v.7 no.2
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• pp.73-85
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• 2018

The anaerobically digestion and agricultural application of organic wastes was conducted using food wastes and cow dung. Twenty kilograms each of the feed stocks was added into two 30 liters-capacity batch digesters. The anaerobic digestion was carried out within a temperature range of $25-31^{\circ}C$ for a retention time of 51 days. The results showed a cumulative gas yield of 5.0 bars for food waste and no gas production for cow dung within the retention time. Bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris and Clostridium sp were isolated. Fungi isolated included Aspergillus niger, Aspergillus nidulan, Trichophyton rubrum and Epidermophyton flocossum. The non-dispersive infrared (NDIR) analysis of the biogas produced confirmed that the gas consisted of $CH_4$, $CO_2$ and $H_2$. Statistical analysis revealed there was no significant correlation between temperature and biogas produced from the organic wastes (r= 0.177, p = 0.483).The organic wastes from the biogas production process stimulated maize growth when compared to control (soil without organic waste) and indicated maximum height. The study therefore reveals that food waste as potential substrates for biogas production has a moderate bio-fertilizer potential for improving plant growth and yield when added to soil.