• Journal of Advanced Marine Engineering and Technology
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• v.40 no.9
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• pp.762-767
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• 2016

High thermal efficiency and the ability to use various types of fuel are a few of the many advantages of diesel engines. However, a major disadvantage is that their exhaust emissions are more harmful to humans and the environment than that of conventional engine. Consequently, the provisions of the international emissions standards for diesel engine equipped passenger cars, commercial vehicles, and ships have become more stringent. These standards include the EU Euro 6, the IMO MEPC Tier 3, and the US EPA Tier 4. Ryu et al. published a study that applied fuel additives to two-stroke diesel engines. In this study, a four-stroke diesel engine using diesel oil for a generator is utilized as the test subject, and an experiment is performed to verify whether fuel additive can be used to improve performance and exhaust emissions. In addition, this experimental study presents research results for the application of fuel additives in both two-stroke and four-stroke diesel engines. The experimental results were compared and analyzed by placing an oil-soluble calcium-based organometallic compound in diesel oil. The results confirmed that the addition of fuel additive improved the performance (fuel consumption rate, exhaust gas temperature) and exhaust emissions (NOx, CO) of the diesel engine.

• Journal of ILASS-Korea
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• v.29 no.2
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• pp.68-74
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• 2024

As awareness of environmental pollution problems increases worldwide, interest in air pollutants is increasing. In particular, NOx and PM, which are major pollutants in diesel vehicles, are contributing significantly to emissions. As a result, its importance is increasing. In this study, based on research results applied to large diesel vehicles, the problem of natural regeneration caused by low exhaust gas temperature during low speed and low load operation is solved by applying a complex regeneration DPF that is not affected by temperature conditions to small diesel vehicles. The feasibility of application to small diesel vehicles was reviewed by measuring the emission reduction efficiency. As a result of the engine test, the power reduction rate and fuel consumption rate before and after device installation under full load conditions were 2.9% decrease and 3.5% increase, respectively, satisfying the standard for a 5% reduction, and as a result of the regeneration equilibrium temperature (BPT) test, the regeneration temperature was 310℃. appeared at the level. The reduction efficiency test results for the actual vehicle durability test equipment showed 97.3% PM, 51.0% CO, and 31.1% HC, while the city commuter vehicle had PM 97.5%, CO 61.7%, HC 40.0%, and the school bus vehicle had PM 96.8%, CO 44.4%, HC 34.3%, and low-speed logistics vehicles showed a reduction efficiency of 98.2% for PM, 36.0% for CO, and 45.7% for HC. Based on the results of this study, in the future, it is necessary to secure DPF technology suitable for all vehicle types through actual vehicle application research on temperature condition-insensitive composite regenerative DPF for medium-sized vehicles.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2563-2566
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• 2011

Government has presented a guideline for the calculation of carbon emission with infrastructures in 2011, which aims to manage the GHG(greenhouse gas) emission of construction sector. Generally, the main emission sources of construction works are divided into the fuel consumption of equipments and the use of materials. This study investigated the characteristics of GHG emission with the use of equipments under the construction of railroad track. Track types are classified into ballasted track and concrete track. As a result, the specific GHG emission on the construction of ballasted track at the A line was 39.53 ton $CO_{2e}/km$ and concrete track was 25.54 ton $CO_{2e}/km$. Ballasted track showed higher specific GHG emission than concrete track because of the additional construction works by the use of gravels. In future, it is necessary to study the comparison of GHG emissions with construction methods including the use of materials. Based on these results, the low carbon construction of railroad will be established continuously.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.29-41
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• 2020

Biodiesel is a clean energy resource that can replace diesel as fuel, which can be used without any structural changes to the engine. Vegetable oil accounts for 95 percent of the raw materials used to produce biodiesel. Thus, many problems can arise, such as rising prices of food resources and an imbalance between supply and demand. Most of the previous studies using waste cooking oil used waste cooking oil from a single material. However, the waste cooking oil that is actually collected is a mixture of various types of waste cooking oil. Therefore, in this study, biodiesel produced with mixed waste cooking oil was supplied to an agricultural single-cylinder diesel engine to assess its potential as an alternative fuel. Based on the results, the brake specific fuel consumption (BSFC) increased compared to diesel, and the axis power decreased to between 70 and 99% compared to the diesel. For emissions, NO_x and CO₂ were increased, but CO and HC were decreased by up to 1 to 7% and 16 to 48%, respectively, compared to diesel. The emission characteristics of the mixed waste cooking oil biodiesel used in this study were shown to be similar to those of conventional vegetable biodiesel, confirming its potential as a fuel for mixed waste cooking oil biodiesel.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.77-83
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• 2023

Energy consumption is increased by rapid industrialization. As a result, climate change is accelerating due to the increase in CO₂ concentration in the atmosphere. Therefore, a shift in the energy paradigm is required. Hydrogen is in the spotlight as a part of that. Currently 95% of hydrogen is fossil fuel-based reforming hydrogen which is accompanied by CO₂ emissions. This is called gray hydrogen, if the CO₂ is captured and emission of CO₂ is reduced, it can be converted into blue hydrogen. There are 3 technologies to capture CO₂: absorption, adsorption and membrane technology. In order to select CO₂ capture technology, the analysis of the exhaust gas should be carried out. The concentration of CO₂ in the flue gas from the hydrogen production process is higher than 20%if water is removed as well as the emission scale is classified as small and medium. So, the application of the membrane technology is more advantageous than the absorption. In addition, if LNG cold energy can be used for low temperature CO₂ capture system, the CO₂/N₂ selectivity of the membrane is higher than room temperature CO₂ capture and enabling an efficient CO₂ capture process. In this study, we will analyze the flue gas from hydrogen production process and discuss suitable CO₂ capture technology for it.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.2
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• pp.207-218
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• 2017

Improving fuel consumption, particularly that of commercial vehicles, has become a global concern. The reduction in logistics cost has been a key issue in efforts to improve fuel economy and efficiency of transportation equipment. Typical technologies for reducing reduce fuel usage include air resistance reduction technologies, tire rolling resistance technologies, and idle technologies among others. Air resistance technology is a highly effective method that can be easily applied in a short period. As with air resistance technology, several devices involving side skirt, boat tail and gap fairing have been developed based on an analytical 3-D modeling technique for reducing air resistance attributed to the vehicle configuration. The devices were on a 45 feet tractor-trailer and the emission test was done using PEMS equipment. Fuel economy was evaluated by introducing several devices to reduce outer air resistance. The test was conducted by changing the experimental method of SAE J1321 Joint TMC/SAE Fuel Consumption Test Procedure - Type II test. As a result, air resistance decreased by at least 15 % and fuel economy improved by at least 13 %. This study sought to reduce greenhouse gas and improve fuel economy by applying several devices to a test vehicle to lower air resistance.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.730-731
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• 2015

This study aims at giving the framework to estimate the environmental load at planning and schematic phase. With increasing awareness of environmental issues, the effort to reduce the environmental impacts caused by human activity has been increasingly enlarged. So far most of researches estimating CO₂ emissions have analyzed energy consumption based on BOQ (Bills of Quantity) acquired after detailed design. There is also lack of reliability in the estimated environmental impact using the basic unit of a facility at the planning stage, because it uses a limited specific section of historical data. Thus, this study is targeted at developing framework to assess reliable environmental loads based on information available at project early phases by making case-bases from historical design information on PSC Beam Bridge. Historical database is built on the basis of the LCA (Life Cycle Assessment) and in order to set input information for estimating model, the literature about information in an early project phase are reviewed. Using the information available in the planning and schematic design stage, the Framework is presented to estimate the environmental load in an early stage in the project. Developing an environmental load estimation model in accordance with the Framework presented in this study, it is expected that the environmental load in the initial project phase can be estimated more quickly and accurately.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.269-280
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• 2011

Today, global warming is one of main problems all over the world. The cause of the global warming is carbon dioxide outbreak by the rapidly increasing energy use. Therefore, it is necessary to save energy in each industrious field. It was investigated that the half of total energy consumption over the world was used for construction and building. Therefore, the saving of the building energy plays a significant role in decreasing total energy consumption. With the considerable increase in building energy consumption, a green building rating system and certification are required to reduce building energy consumption and $CO_2$ emissions. Of various elements reducing building energy, the thermal conductivity of materials affects the energy consumption as a basic element, which is directly related with reducing energy consumption. In particular, as the thermal conductivity of finishing materials is an important factor to decide heating energy efficiency of floor heating system, the investigation and development are necessary.

• Journal of the Korean Wood Science and Technology
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• v.44 no.3
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• pp.449-456
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• 2016

This study was aimed to quantify the amount of carbon dioxide emissions and to suggest suitable plans which consider the carbon emission reduction in the manufacturing process of the domestic structural glued laminated timber. Field investigation on two glued laminated timber manufacturers was conducted to find out material flow input values such as raw materials, transportation, manufacturing process, and energy consumption during manufacturing process. Based on the collected data and the relevant literatures about life cycle inventory (LCI), the amount of carbon dioxide emission per unit volume was quantified. Results show that the carbon dioxide emissions for sawing, drying and laminating process are 31.0, 109.0, 94.2 kg $CO_2eq./m^3$, respectively. These results show 13% lesser amount of total carbon dioxide emissions compared with the imported glued laminated timber in Korea. Furthermore, it was decreased about 37% when the fossil fuel would be replaced with biomass fuel in drying process. Findings from this study is effectively used as the basic data on the life cycle assessment of wooden building.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.6
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• pp.620-625
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• 2015

In an effort to reduce the onset of global warming, the International Maritime Organization Marine Environment Protection Committee (IMO MEPC) proposed the reduction in ship speeds as a way of lowering the proportion of carbon dioxide ($CO_2$) in the Green House Gas emissions from ships. To minimize fuel costs, shipping companies have already been performing slow steaming for their own fleets. Specifically, the slow steaming approach has been adopted for most ocean-going container lines. In addition, because of the increased marine fuel cost that is required to enable increased capacity, there is an urgent need for more advanced fuel-saving technologies. Therefore, in this present study, we propose a fuel-cost reduction method that can improve the performance of diesel engines. We introduce a predetermined amount (0.025% of the amount of fuel used) of fuel additive (oil-soluble calcium-based organometallic compound). For improved experimental accuracy, as the test subjects, we utilize a large two-stroke diesel engine installed in land plants. The loads of the test engine were classified as low, medium, and high (50, 75, and 100%, respectively). We compare the engine performance parameters (power output, fuel consumption rate, p-max, and exhaust temperature) before and after the addition of fuel additives. Our experimental results, confirmed that we can realize fuel-cost savings of at least 2% by adding the fuel additive in low load conditions (50%). Likewise, the maximum combustion pressure was found to have increased. On the other hand, we observed that there was a reduction in the exhaust temperature.