• Journal of ILASS-Korea
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• 제19권2호
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• pp.55-63
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• 2014

Pyrolysis oil (PO), also known as Bio crude oil (BCO), has the potential to displace significant amounts of fuels that are currently derived from petroleum sources. PO has been regarded as an alternative fuel for petroleum fuels to be used in diesel engine. However, the use of PO in a diesel engine requires modifications due to low energy density, high water contents, low acidity, and high viscosity of the PO. One of the easiest way to adopt PO to diesel engine without modifications is emulsification of PO with the fuels that has higher cetane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel. Thus, to stabilize a homogeneous phase of diesel-PO blends, a proper surfactant should be used. In this study, a DI diesel engine operated with diesel and diesel-PO emulsions was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine fuelled by diesel-PO emulsions were examined. Results showed that stable engine operation was possible with the emulsions and engine output power was comparable to diesel operation.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제39권3호
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• pp.237-243
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• 2015

In this study, the effects of the mixing ratio of emulsified fuel on the droplet evaporation and spray behavior characteristics were analyzed. A surfactant comprising span 80 and tween 80 mixed at a 9:1 ratio was used for the emulsified fuel. The fuel and surfactant were mixed at a ratio of 3:1 for the emulsified fuel. In addition, considering the mixing ratio of the surfactant, the mixing ratio of $H_2O_2$ in the emulsified fuel was set as EF (emulsified fuel)0, EF2, EF12, EF22, EF32, and EF42. To observe the evaporation characteristics, droplets of the emulsified fuel were dropped on a heating plate and observed using scattered light and a Schlieren system. In addition, to analyze the effect of the $H_2O_2$ mixing ratio, the behavior characteristics of the evaporative free spray were investigated in the mixing ratio range of EF0 to EF22 using a constant volume chamber with heaters. Consequentially, it was found that in the case of EF22, the free spray development of the emulsified fuel was faster than that of EF0 (diesel only) because of the promotion of the evaporation due to the phase change in the peroxide contained in the emulsion fuel.

• Journal of ILASS-Korea
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• 제8권2호
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• pp.38-45
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• 2003

This study was carried on the combustion characteristics of a pure light oil and emulsified fuels at high-pressure injection in a spray combustion installation, The volume fractions of water in an emulsion were varied up to 30% and the injection pressures were 7.5, 100, 200, and $300kg_f/cm^2$. The concentrations of NOx and the average temperatures of flame were measured. And Images of OH radical using ICCD camera and instantaneous schlieren photography of flames were photographed. It was found that the temperature distribution of axial distance in the emulsified fuels was increased in the upstream and decreased in the down stream. The temperature distribution of radial distance was high at the peripheral regions of the spray in the upstream and at the central regions of spray in the downstream, The intensity of OH radical was denser at the water content 10% than at the pure light oil over the injection pressure $200kg_f/cm^2$.

• Transactions of the Korean Society of Automotive Engineers
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• 제20권5호
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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 Society of Mechanical Engineers B
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• 제26권12호
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• pp.1756-1762
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• 2002

To effectively meet current regulations on the exhaust emissions of diesel engine required to control the deterioration of air pollution in the whole world, this study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in IDI diesel engine. A method fur supplying water through the air intake system to reduce the exhaust emissions has been considered with other methods such as water introduction in the form of water-in-fuel emulsion or water injection directly into the combustion chamber, but it has not been studied about the effects of water on the combustion concepts and the characteristics of exhaust emissions in detail until now. In this study, the formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased by increasing water amount.

• Journal of Aerospace System Engineering
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• 제13권5호
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• pp.39-48
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• 2019

The turbulent flow in the rotor-stator mixer is based on shear characteristics generated by the interaction of the stator with the rotor rotating at high speed. In this study, the flow characteristics analysis of the unsteady state generated by the interaction of the rotor and the stator in the prototype model of the emulsion-fuel related mixer development was performed with the MRF and SMM by applying the ANSYS FLUENT $k-{\varepsilon}$ (RKE) turbulence model. The behavior and shear characteristics of the flow particles generated at the interface between the designed rotor and stator, and trends such as velocity distribution and turbulence eddy dissipation, were predicted and verified using the CFD analysis.

• Transactions of the Korean Society of Automotive Engineers
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• 제22권5호
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• pp.116-125
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• 2014

Pyrolysis oil (PO), derived from biomass through fast pyrolysis process have the potential to displace significant amounts of petroleum fuels. The PO derived from wood has been regarded as an alternative fuel to be used in diesel engines. However, the use of PO in a diesel engine is very limited due to its poor properties like low energy density, low cetane number, high acidity and high viscosity of PO. Therefore, one of the easiest way to adopt PO to diesel engine without modifications is blended with other fuels that have high centane number. However, PO that has high amount of polar chemicals is immiscible with non polar hydrocarbons of diesel or biodiesel. Thus, to stabilize a homogeneous phase of diesel/biodiesel-PO blends, a proper surfactant should be used. Nevertheless, PO which was produced from different biomass type have varied characteristics and this complicates the selection of a suitable additive for a specific PO-diesel emulsion. In this regard, a more simple approach such as the use of a co-solvent like ethanol or butanol to induce a more stable phase of the PO-diesel mixture could be a promising alternative. In this study, a diesel engine operated with diesel/biodiesel-PO-butanol blends was experimentally investigated. Performance and gaseous & particle emission characteristics of a diesel engine were examined under the engine loads of IMEP 0.2 ~ 0.8MPa.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• 제9권1호
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• pp.1-11
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• 2011

Tetraethoxysilane(TEOS) as a silica precursor and hydrochloric acid as an acid catalyst have been used in a surfactant-template synthesis of micrometer-sized mesoporous silica microspheres based on the macroemulsion technique. Increase in the concentration of tetraethoxysilane of the reaction mixture has a serious destructive effect on the particle shape and pore structure. As the acid concentration increases, relatively small microspheres are formed without destroying their spherical morphology of the particles as well as the pore structures. However, due to the attractive interaction between particles in an acidic condition, strong silica agglomerates are formed, and therefore are subject to a post-ultrasonic treatment to separate into an individual single particle.

• Journal of the Korean Recycled Construction Resources Institute
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• 제6권3호
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• pp.199-206
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• 2018

Due to the advantages of less raw materials and fossil fuel consumption, lower carbon footprint, and the capability of pavement performance improvement, the recycling technology of asphalt is developed and applied for road rehabilitation and construction in the western countries over the past two decades. Cold recycled asphalt mixtures are bituminous materials normally made by mixing recycled aggregate from wasted asphalt with an asphalt emulsion and water at room temperature. This paper aims at investigating the properties of cold recycled asphalt mixture with alkali-activated filler according to wasted asphalt aggregate content. As a result, as the content of wasted asphalt aggregate increased, the marshall stability of cold recycled asphalt mixture decreased and void ratio increased. Also, grading curves for cold recycled asphalt mixture as specified in GR criteria were satisfied in all aggregate mixing conditions regardless of the wasted asphalt aggregate content.

• Resources Recycling
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• 제13권4호
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• pp.32-38
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• 2004

Recently, Orimulsion (a bitumen-in emulsion) has received increasing attention as an alternative fuel. Orimulsion combusion produces an ash rich in V, Ni and Mg which are processed to recover metals. As a basic study to recover V from Orimulsion ash, physico-chemcial properties and leaching behaviours were investigated. Orimulsion ash was fine size grains ($d_{50}$ 5.9 $\mu\textrm{m}$) with 16% V, 4 % Ni and 9% S. Vanadium was easily leached in water because Orimulsion ash was mainly constituted of metal sulfates. However, the increase of leaching temperature decreased the extraction percentage of vanadium because of hydrolysis of V(V) to vanadium pentoxide. The addition of sulfuric acid could increase the leaching percentage vanadium. In case of alkaline leaching for selective recovery of vanadium, the oxidzing agent such as $H_2$$O_2$ is required to improve the leaching per-centage