• Journal of Biosystems Engineering
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• v.30 no.6 s.113
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• pp.354-359
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• 2005

This is a fundamental study to develop a bio-gas utilization technology using livestock manure. Especially, this study was carried out to develop an engine using bio-gas. A bio-gas engine was designed and manufactured by modification of a diesel engine of 3 cylinders powering 13.31 kW/2800 rpm, changing the fuel supplying system fit for bio-gas. The result showed that, when the Air/Fuel ratio was controlled with fixed spark timing, the power of biogas-fueled engine is about $10.6{\~}14.6\%$ lower then that of LNG-fueled engine because of low volumetric efficiency. The engine output and torque was $11.85{\~}13.3$ kW, $39.5{\~}40.8\;N{\cdot}m$, respectively at the engine speed of 2600 rpm. Bio-gas consumption rate was 260.20 g/kW/hr, 315.20 g/kW/hr in engine speed or 1000 rpm, 2800 rpm, respectively.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.3
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• pp.249-254
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• 2013

The integrated gasification combined cycle (IGCC) system is well known for its high efficiency compared with other coal fueled power generation system. The aim of this study is to confirm the feasibility of using bio gas in coal feeding system and syngas recirculation system. The effects of using bio gas in the gasifier on the syngas composition were investigated through simulations using the Aspen Plus process simulator. It was found that these changes had an influence on the syngas composition of the final stream and bio gas can be used in a gasifier system.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.74-82
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• 2014

The government is planning to expand the bio-gas supply as a method for mitigating greenhouse gas emissions to deal with climate change. By means of a policy instrument, the government is considering an introduction of the Renewable Fuel Standard (RFS) whose targets include bio-gas. This paper attempts to look into the economic effects of expanding the bio-gas supply by applying an input-output (I-O) analysis using a 2011 I-O table. The bio-gas supply sector consists of liquefied petroleum gas supply sector and city gas supply sector, based on the tenets of introducing the RFS. The production-inducing effect, value-added creation effect, and employment-inducing effect of the bio-gas sector are analyzed. The supply shortage effect and the price pervasive effect are also investigated. The results show that the production or investment of 1.0 won in the bio-gas supply sector induces the production of 1.0539 won and the value-added of 0.1998 won in the national economy. Moreover, the production or investment of 1.0 billion won, supply shortage of 1.0 won, and a price increase of 10.0% in the bio-gas supply sector touch off the employment of 0.5279 person, 1.6229 won, and an increase in overall price level by 0.0183%, respectively.

• Journal of the Korean Applied Science and Technology
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• v.22 no.1
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• pp.21-27
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• 2005

This study was conducted to evaluate the biofiltration treatment characteristic for benzene vapor gas. Compost and calcium silicate porous material were used as biofilter fillers. Gas velocity and empty bed retention time were 15 m/hr and 4 min, respectively. Benzene gas removal efficiency of P-Bio (calcium silicate porous material with inoculation) was the highest and maintained in over 98%. After shock input of benzene gas, the removal efficiency of P-Bio biofilter was recovered within 2 days, while 5 days were taken in CP-Bio (compost + calcium silicate porous material mixture with inoculation) and CP (compost + calcium silicate porous material mixture without inoculation) biofilters. The removal efficiency of P-Bio biofilter was near 100% in the loading rate of <$85g/m^3$(filling material)/hr, It was shown that the maximum elimination capacities of P-Bio, CP-Bio, and CP biofilters were 95, 69, and $66\;g/m^3$(filling material)/hr, respectively. Microbial number of P-Bio, which the number was the lowest at start-up, was 3 orders increased on operational day 48. $CO_2$ was generated greatly in order of P-Bio, CP-Bio, and CP biofilters.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.1
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• pp.51-57
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• 2013

A demand for bio-diesel oil increases as one of solution for exhaustion of fossil fuel and reduction of $CO_2$ emission, and research on bio-diesel is being carried out. Bio-diesel oil is mainly esterified from vegetable oil with methanol in order to use for fuel on diesel engine and has demerit that costs are increased as compared with directly using like non-esterified one. Bio-diesel oil within 3% mixed with gas oil is used at present, proportion of bio-diesel oil will be increase by 5% in future. We judged that wasted soybean oil non-esterified could be used on diesel engine with an electronic fuel injection according to previous researches with a mechanical fuel injection. A performance test using only gas oil, gas oil with esterified bio-diesel oil 5% and wasted soybean oil non-esterified 5% on diesel engine with the electronic fuel injection were carried out. It is noticed that gas oil with wasted soybean oil non-esterified 5% has more similar characteristics to gas oil than gas oil with esterified bio-diesel oil 5%.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.414-422
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• 2006

Before applying PVA bio-beads to practical biological treatment of nitrate-containing wastewater, their characteristics were examined. PVA bio-beads could steadily produce nitrogen gas from nitrate for 28 batches with 0.04 ml/l/h of the maximum gas production rate; however, the maximum gas production rate dropped remarkably thereafter with apparent deformation of beads. Addition of 2.2% solution containing 1% casamino acid, 1% yeast extract, 0.1% mineral solution, and 0.1% vitamin solution to the culture medium resulted in not only recovery of activity of deactivated beads, but also a higher rate of gas production. Calculation of economic benefit for the use of bio-beads in a long-run operation indicated that reactivation of bio-beads by chemicals had economical advantages over packing new bio-beads in the system. The continuously stirred bioreactor exhibited a satisfactory performance at HRT of 20.0 h. With a 9.5 mg $NO_{3}^{-}N/l/h$ nitrate removal rate, nitrate could completely be removed without nitrite accumulation. The use of PVA bio-beads in nitrate removal appears very promising.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.2
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• pp.114-121
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• 2009

There are increased in using the bio-ethanol, as the carbon neutral attracts many researchers due to a reduction in carbon dioxide spotted as the global warming gas. A gasoline engine with 100% of the bioethanol was developed and used in Brazil already, but researches of using the bio-ethanol in diesel engines are lack. In this study, combustion tests with blend fuel of the gas oil and bio ethanol by 50% maximally due to a low cetane number of bio-ethanol were accomplished as a basic study of introduction of using the bioethanol in diesel engines. The result was that smoke emission was decreased with increase in proportion of the bio-ethanol, due to the increase of a amount of pre-mixed combustion with ignition delay. Although the amount of $CO_2$ is reduced according as the bio-ethanol is used(carbon neutral), the emission of $CO_2$ with increase in the proportion of the bio-ethanol was more increased due to lower a heat value of bio-ethanol than gas oil.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.174-174
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• 2012

The nature of feed gas is essential for the active species formed in the nonthermal plasma jets, which would induce various biological phenomena. We investigated the different physiological effects of atmospheric pressure soft-plasma jets on Esherichia coli and blood cells according to the feed gas. Cell death rate, growth curve, membrane molecular changes and induced genes were examined. The relationship between cellular reactions and active species generated by discharge will be discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.239-242
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• 2008

As the distributed generation becomes more reliable and economically feasible, it is expected that a higher application of the distributed generation units would be interconnected to the existing grids. In this context, the Micro Gas Turbines (MGT) by using Bio-gas is being considered as a promising solution. In order to propose a feasible concept of those technologies such as improving environmental effect and economics, we performed a sensitivity study for a biomass fueled MGT using a simulation model. The study consists of 1) the fundamental modeling using manufacturer's technical specifications, 2) the correction with the experimental data, and 3) the prediction of off-design characteristics. The performance analysis model was developed by PEPSE-GT 72, commercial steam/gas turbine simulation technicque.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.435-443
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• 2023

Global concern over climate change, driven by greenhouse gas emissions, has prompted widespread interest in sustainable solutions. In the agricultural sector, biochar has emerged as a focal point for mitigating these emissions. This study investigated the impact of continuous biochar application on CO₂ and N₂O emissions during the spring cabbage cultivation period. Greenhouse gas emissions in the biochar treatment groups (soils treated with 1, 3, and 5 tons/ha of rice husk biochar) were compared to those in the control group without biochar. During the spring cabbage cultivation period in 2022, the total CO₂ emissions were in the range of 71.6-119.0 g/m² day, and in 2023, with continuous biochar application, they were in the range of 71.6-102.1 g/m² day. The total emissions of N₂O in 2022 and 2023 were in the range of 11.7-23.7 and 7.8-19.9 g/m² day, respectively. Overall, greenhouse gas emissions decreased after biochar treatment, confirming the positive influence of biochar on mitigating greenhouse gas release from the soil. Nevertheless, further research over an extended period exceeding five years is deemed essential to delve into the specific mechanisms behind these observed changes and to assess the long-term sustainability of biochar's impact on greenhouse gas dynamics in agricultural settings.