• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.3
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• pp.143-150
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• 2009

Fuel oil mostly used for a ship is made from crude oil by refining process. In order to produce plenty of high-quality fuel oil, the Fluid catalytic cracking(FCC) method is widely adopted to many refinery factories during the decomposition process from high molecule into lower molecule. The major constituents in spent FCC catalysts are Si, Al, Fe, Ti, alkali metals and some others. The spent catalyst is also composed small amounts of rare metals such as Ce, Nd, Ni and V. The big problem in FCC oil is mixing the catalyst in the oil. This reason is unstable separation of FCC catalyst in separator. Such a FCC catalyst will become a reason of heavy wear down in moving parts of engine. The impurity in oil is ash and deposit compound, such as Al, Si, Ni, Fe and V, which will accelerate the wear down on fuel pump, fuel injection valve cylinder liner and piston ring. It is important to find a basic reason of an engine trouble for preventing similar troubles anymore. Insurance compensation will be different according to the reason of an engine trouble which might be natural abrasion or other external causes. In this study, types and reasons of engine troubles related to fuel oil will be covered.

• Journal of Soil and Groundwater Environment
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• v.10 no.4
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• pp.45-53
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• 2005

The objective of this study is to evaluate the effects of changes in soil temperature on biodegradation rate of diesel compounds from a field pilot test using hot air injection process. Total remediation time was estimated from in-situ biodegradation rate and temperature for optimum biodegradation. All tests were conducted by measuring in-situ respiration rates every about 10 days on highly contaminated area where an accidental diesel release occurred. The applied remediation methods were hot air injection/extraction process to volatilize and extract diesel compounds followed by a bioremediation process to degrade residual diesels in soils. Oxygen consumption rate varied from 2.2 to 46.3%/day in the range of 26 to $60^{\circ}C$, and maximum $O_2$ consumption rate was observed at $32.0^{\circ}C$. Zero-order biodegradation rate estimated on the basis of oxygen consumption rates varied from 6.5 to 21.3 mg/kg-day, and the maximum biodegradation rate was observed at $32^{\circ}C$ as well. In other temperature range, the values were in the decreasing trend. The first-order kinetic constants (k) estimated from in-situ respiration rates measured periodically were 0.0027, 0.0013, and $0.0006d^{-1}$ at 32.8, 41.1, and $52.7^{\circ}C$, respectively. The estimated remediation time was from 2 to 9 years, provided that final TPH concentration in soils was set to 870 mg/kg.

• Journal of Appropriate Technology
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• v.5 no.2
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• pp.91-96
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• 2019

Microalgae do not require much land and make a higher efficient oil production. However, it costs still much higher than other biodiesel resources, such as crops. Sugars charge 80% of culture media when microalgae are massively cultured in the fermenter. This study aims to develop a cost-efficient process for sugar production from Chinese cabbage byproducts. Pre-treatment with 0.25% H₂SO₄ was most effective when chopped cabbage was incubated 50℃/130 rpm for 24 hours. To hydrolyze cabbage cellulose, we used cellulases secreted from Trichoderma. harzianum. T. harzianum was cultured at 28℃/pH 7/130 rpm for five days. Optimal enzymatic activity of cellulase was obtained by incubating at 0.24 FPU/ml/45℃/pH 5/130 rpm for three days. In comparison to other agricultural waste, such as rice straw, green tea leaves, and palm residue, Chinese cabbage produced the highest sugar yield. We found the optimal conditions to produce sugar from Chinese cabbage byproducts as a carbon source to culture biodiesel-producing microalgae. The efficient process developed in this study helps microalgae as a sustainable alternative energy source by cost-down.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.298-301
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• 2003

생물학적 토양오염 복원기술은 산소와 영양염류를 오염토양에 공급하여 호기성 미생물의 대사작용을 자극함으로써 유류를 생분해 하는 방법으로 널리 사용되고 있다. 유류에 오염된 토양은 혐기성 상태인 경우가 대부분이기 때문에, 호기성 미생물을 이용하기 위해서는 충분한 산소를 공급하여야 하므로 운전비가 많이 드는 단점이 있다. 최근에는 혐기성 미생물을 이용하여 유류오염 토양을 정화하는 방법이 보고되고 있다. 혐기성 생분해 방법은 다소 분해 속도는 느리지만 산소를 공급하지 않기 때문에 경제적인 유류오염토양 복원 방법으로 주목받고 있다. 본 연구에서는 디젤을 사용하여 인위적으로 10000 mg/kg.TPH soil의 농도로 오염시킨 토양 50g을 100$m\ell$ 용적의 vial에 주입하고 하수처리장의 혐기성 소화조 슬러지를 15$m\ell$, 30$m\ell$을 주입하여 배양하였으며 TPH의 분해량과 CH$_4$ 및 $CO_2$ 발생량을 측정하였다. vial의 기상을 $N_2$가스로 치환함으로써 혐기성 상태가 되도록 하였으며, 35$^{\circ}C$에서 90일간 배양하였다. 그 결과, 슬러지를 주입하지 않은 대조군의 경우에는 TPH의 분해가 거의 없었지만, 슬러지를 주입한 경우에는 TPH(Total Petroleum Hydrocarbon)농도가 55% 제거된 것으로 나타났다. TPH의 분해는 CH$_4$ 및 $CO_2$ 발생량과 밀접한 상관관계를 보였다. 본 연구의 결과로부터 하수처리장의 혐기성 소화조 슬러지를 이용한 유류오염 토양의 복원 가능성을 확인할 수 있었다.양에서 유동 가능성이 있는 중금속만을 추출하였다. 분석실험은 토양의 Cd2+ 와 Pb2+를 대상으로 행하여졌으며, 여러 토양에서 추출 분석한 결과를 EDTA분석결과와 비교하였다. 실험결과, 중금속은 매우 신속하게 고분자 자성체와 결합하였고, 그 후 자성체를 외부 자장으로 모은 후 산으로 용해시키고, 결합된 중금속은 Graphite furnace AAS로 분석함으로써 빠르고 효율적으로 분석실험을 수행할 수 있음을 알 수 있었다. 한편, 실험에서 나타난 수치들을 비교 검토한 결과 토양 분석시 sandy soil에서는 자성체를 이용한 분석이 EDTA에 의한 방법보다 더 높은 추출도를 보인 반면, silt 함량이 많은 토양의 경우에서 EDTA분석에서 더 높은 중금속 추출도를 보였다.s 중에서 490nm와 555nm의 복합밴드를 포함하는 OC2 알고리즘(ocean color chlorophyll 2 algorithm)을 사용하는 것이 OC2 series 및 OC4 알고리즘보다 좋은 추정 값을 도출할 수 있을 것으로 기대된다.환경에서는 5일에서 7월에 주로 이 충체의 유충이 발육되고 전파되는 것으로 추측되었다.러 가지 방법들을 적극 적용하여 금후 검토해볼 필요가 있을 것이다.잡은 전혀 삭과가 형성되지 않았다. 이 결과는 종간 교잡종을 자방친으로 하고 그 자방친의 화분친을 사용할 때만 교잡이 이루어지고 있음을 나타내고 있다. 따라서 여교잡을 통한 종간잡종 품종육성 활용방안을 금후 적극 확대 검토해야 할 것이다하였다.함을 보이고 있다.X> , ZnCl$_{3}$$^{-}$같은 이온과 MgCl$^{+}$, MgCl$_{2}$같은 이온종을 형성하기 때문인것 같다. 한편 어떠한 용리액에서

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.3
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• pp.380-388
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• 2017

Wood pyrolysis oil(WPO) has been regarded as an alternative fuel for diesel engines. However, WPO is not feasible for use directly in diesel engines due to its poor fuel quality such as low energy density, high acidity, high viscosity and low cetane number. The most widely used approach to improve WPO fuel quality is to blend WPO with other hydrocarbon fuels that have a higher cetane number. However, WPO and fossil fuels are not usually blended because of their different polarity. Also, clogging and polymerization problems in the fuel supply system can occur when the engine is operated with WPO. Polymerization can be prevented by diluting WPO with other alcohol fuels. However, WPO-alcohol blended fuel does not produce self-ignition. Therefore, additional cetane enhancement to the blended fuel is required to enhance auto-ignitability. In this study, WPO was blended with n-butanol and two cetane enhancements(PEG 400 and 2-EHN) for application to a diesel generator. Experimental results showed that the WPO-butanol blended fuel achieved a very stable engine operation under maximum WPO content of 20 wt%.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.5
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• pp.102-112
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• 2012

The vast stores of biomass available in the worldwide have the potential to displace significant amounts of fuels that are currently derived from petroleum sources. Fast pyrolysis of biomass is one of possible paths by which we can convert biomass to higher value products. The wood pyrolysis oil (WPO), also known as the bio crude oil (BCO), have been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of BCO in a diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the BCO. One of the easiest way to adopt BCO to diesel engine without modifications is emulsification of BCO with diesel and bio diesel. In this study, a diesel engine operated with diesel, bio diesel (BD), BCO/diesel, BCO/bio diesel emulsions was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine fuelled by BCO emulsions were examined. Results showed that stable engine operation was possible with emulsions and engine output power was comparable to diesel and bio diesel operation. However, in case of BCO/diesel emulsion operation, THC & CO emissions were increased due to the increased ignition delay and poor spray atomization and NOx & Soot were decreased due to the water and oxygen in the fuel. Long term validation of adopting BCO in diesel engine is still needed because the oil is acid, with consequent problems of corrosion and clogging especially in the injection system.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.567-577
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• 2019

Due to the depletion of fossil fuels and environmental pollution, demand for alternative energy is gradually increasing. Among the various methods, a method to convert biomass into alternative fuel has been proposed. The bio-fuel obtained from biomass through pyrolysis process is called pyrolysis oil (PO) or bio-oil. Because PO is difficult to use directly in conventional engines due to its poor fuel properties, various methods have been proposed to upgrade pyrolysis-oil. The simplest approach is to mix it with conventional fossil fuels. However, due to their different polarity of PO and fossil fuel, direct mixing is impossible. To resolve this problem, emulsification of two fuels with a proper surfactant was proposed, but it costs additional time and cost. Alternatively, the use of alcohol fuels as an organic solvent significantly improve the fuel properties such as fuel stability, calorific value and viscosity. In this study, blends of diesel, n-butanol, and coffee ground pyrolysis oil (CGPO) which is one of the promising PO, was applied to diesel generator. Combustion and emissions characteristics of blended fuels were investigated under the entire load range. Experimental results show that ignition delay is similar to that of diesel at high load. Although, hydrocarbon and carbon monoxide emissions are comparable to diesel, significant reduction of nitrogen oxides and particulate matter emissions were observed.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.2
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• pp.106-114
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• 1996

Extensive experiments were conducted to investigate the emission of DI diesel engine by using DMC(dimethyl carbonate) as an oxygenated fuel additives. The results indicate that smoke reduces almost linearly with fuel oxygen contents. Reductions of HC and CO were attained noticeably, while a small increase in NOx was encountered concurrently. The effective reduction in smoke with DMC was maintained with the presence of CO2, which suggested a low NOx and smoke operation could be obtained in combination of using oxygenated fuel and EGR. Further experiment was conducted a thermal cracking set-up for mechanism studies.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.162-175
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• 1995

Exhaust emissions in diesel engine are affected by fuel properties, but the reason for this is not clear. Especially, the recent strong interest in using low-grade fuel such as used vegetable oil as alternative diesel fuel demands extensive investigation in order to clarify the exhaust emissions. The purpose of this study is to evaluate the feasibility of a used vegetable oil as an alternative fuel in a diesel engine in terms of exhaust emissions. The emission concentration of used vegetable oil such as formaldehyde and acrolein is two times than that of diesel fuel. However, since that of alcohol is ten times than that of used vegetable oil and that concentration is very low, it is not a problem for human health.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.38 no.6
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• pp.501-511
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• 2014

Bio-oil derived from biomass through fast pyrolysis process has the potential to displace a significant amount of petroleum fuels. However, the use of bio-oil in a diesel engine is very limited because of its poor properties, e.g., its low energy density, low cetane number, and high viscosity. Therefore, bio-oil should be emulsified or blended with other fuels that have high centane numbers. Because bio-oil has poor miscibility with petroleum fuels, the most suitable candidate fuels for direct mixing are alcohol fuels. In this study, bio-oil was blended with ethanol, and two types of cetane improvers were added to a blended fuel to improve the self-ignition property. The two types of cetane improvers, PEG 400 and 2-EHN, made it possible for bio-oil blended fuels to combust in a diesel engine with a maximum bio-oil content of 15 wt%. A high-compression-ratio piston is also proposed for the combustion of bio-oil in a diesel engine.