• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.273-275
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• 2014

An ammonia fuel system is developed and applied to both a spark ignition engine and a compression ignition engine to use ammonia as primary fuel in this study. Ammonia is injected separately into the intake manifold in liquid phase while gasoline or diesel is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline or diesel, the spark or diesel injection timing is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output with large amount of ammonia. The final goal of the study is to implement a methodology to ignite ammonia-air mixture and have complete combustion without any use of the conventional fuels.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.11-18
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• 2023

This study explained the need for ammonia fuel and the value chain as a hydrogen carrier. The basic concept of ammonia combustion characteristics and the development of flame stability and low NOx combustion technology were introduced. In addition, through the trend of ammonia combustion technology, the characteristics of ammonia combustion technology in the power generation and industrial sectors were examined, and the author's opinions were included. Through this paper, the author intends to give some overview of basic knowledge about ammonia fuel and its future development direction and meaning.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.6
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• pp.155-165
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• 2013

The effect of gaseous ammonia direct injection on the engine performance and exhaust emissions in gasoline-ammonia dual fueled spark-ignition engine was investigated in this study. Results show that based on the gasoline contribution engine power increases as the ammonia injection timing and duration is advanced and increased, respectively. However, as the initial amount of gasoline is increased the maximum power output contribution from ammonia is reduced. For gasoline-ammonia, the appropriate injection timing is found to range from 320 BTDC at low loads to 370 BTDC at high loads and the peak pressures are slightly lower than that for gasoline due to the slow flame speed of ammonia, resulting in the reduction of combustion efficiency. The brake specific energy consumption (BSEC) for gasoline-ammonia has little difference compared to the BSEC for gasoline only. Ammonia direct injection causes slight reduction of $CO_2$ and CO for all presented loads but significantly increases HC due to the low combustion efficiency of ammonia. Also, ammonia direct injection results in both increased ammonia and NOx in the exhaust due to formation of fuel NOx and ammonia slip.

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.1-7
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• 2015

An ammonia fuel system is developed and applied to a 1 liter gasoline engine to use ammonia as primary fuel. Ammonia is injected separately into the intake manifold in liquid phase while gasoline is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline, the spark ignition is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output to lead high increase in THC emission with large amount of ammonia, that is, higher than 0.7 ammonia-gasoline fuel ratios.

• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.1-10
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• 2023

Due to the development of the industrial revolution, regulations on exhaust emissions have been continuously strengthened to reduce the rapidly increasing greenhouse gas emissions. The use of environmentally friendly fuels is essential to meet these regulations. Hydrogen has been attracting attention as a future environmentally friendly fuel, but due to its material properties, it faces significant challenges in handling and storage. As an alternative, ammonia has been proposed. Ammonia can be easily liquefied at room temperature compared to hydrogen and has a high energy density. In order to examine the applicability of ammonia as an engine fuel, experiments were conducted to investigate the effects of changes in combustion control parameters in a direct injection ammonia combustion engine. The experiments were conducted by varying two variables: spark timing and excessive air ratio. Observations were made on combustion stability and the trends of exhaust emissions such as nitrogen oxides and unburned ammonia under the conditions of an engine speed of 1,500 rpm and medium to high loads (brake torque of 200 Nm). By optimizing the combustion control parameters, conditions for stable combustion even when using ammonia as the sole fuel were identified, and plans are underway to apply strategies for future expansion of the operating range.

• Corrosion Science and Technology
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• v.21 no.6
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• pp.514-524
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• 2022

Carbon emissions from fuel consumption have been pointed by scientists as the cause of global warming. In particular, fossil fuels are known to emit more carbon when burned than other types of fuels. In this regard, International Maritime Organization has announced a regulation plan to reduce carbon dioxide emissions. Therefore, recently, Liquefied Natural Gas propulsion ships are responding to such carbon reduction regulation. However, from a long-term perspective, it is necessary to use carbon-free fuels such as hydrogen and ammonia. Nitrogen oxides might be generated during ammonia combustion. There is a possibility that incompletely burned ammonia is discharged. Therefore, rather than being used as a direct fuel, Ammonia is only used to reduce NO_X such as urea solution in diesel vehicle Selective Catalyst Reduction. Currently, LPG vehicle fuel feed system studies have evaluated the durability of combustion injectors and fuel tanks in ammonia environment. However, few studies have been conducted to apply ammonia as a ship fuel. Therefore, this study aims to evaluate corrosion damage that might occur when ammonia is used as a propulsion fuel on ships.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.55-62
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• 2006

A two-step fuel-rich/fuel-lean catalytic combustion seems to be one of the most effective methods to control simultaneously the NO generation and the hydrocarbon (HC) conversion from fuel-bound nitrogen. By controlling equivalent air ratio for maintaining fuel-rich and fuel-lean condition over each catalytic layer, space velocity, inlet temperature, and catalyst component, the HCand ammonia conversion efficiency higher than 95% could be achieved, with ammonia conversion to NO remaining below 5%. The experimental results wouldbe applied to the combustion of land fill gas and to gasified refuse-derived fuels as a method of minimizing NO generation.

• Clean Technology
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• v.28 no.2
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• pp.131-137
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• 2022

The semiconductor process currently emits various by-products and unused gases. Emissions containing pollutants are generally classified into categories such as organic, acid, alkali, thermal, and cabinet exhaust. They are discharged after treatment in an atmospheric prevention facility suitable for each exhaust type. The main components of organic exhaust are volatile organic compounds (VOC), which is a generic term for oxygen-containing hydrocarbons, sulfur-containing hydrocarbons, and volatile hydrocarbons, while the main components of alkali exhaust include ammonia and tetramethylammonium hydroxide. The purpose of this study was to determine the combustion characteristics and analyze the NO_X reduction rate by maintaining a direct combustion and temperature to process organic and alkaline exhaust gases simultaneously. Acetone, isopropyl alcohol (IPA), and propylene glycol methyl ether acetate (PGMEA) were used as VOCs and ammonia was used as an alkali exhaust material. Independent and VOC-ammonia mixture combustion tests were conducted for each material. The combustion tests for the VOCs confirmed that complete combustion occurred at an equivalence ratio of 1.4. In the ammonia combustion test, the NO_X concentration decreased at a lower equivalence ratio. In the co-combustion of VOC and ammonia, NO was dominant in the NO_X emission while NO₂ was detected at approximately 10 ppm. Overall, the concentration of nitrogen oxide decreased due to the activation of the oxidation reaction as the reaction temperature increased. On the other hand, the concentration of carbon dioxide increased. Flameless combustion with an electric heat source achieved successful combustion of VOC and ammonia. This technology is expected to have advantages in cost and compactness compared to existing organic and alkaline treatment systems applied separately.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.E2
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• pp.47-56
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• 2007

Among all the nitrogen species present in the atmosphere, ammonia forms a considerable portion along with the nitrogen oxides. The major sources of atmospheric ammonia are animal feedlot operations including emission from excreta of domestic animals and agricultural activities, followed by emission from synthetic fertilizers, biomass burning and to some lesser extent, fossil fuel combustion. Ammonia emission factor, expressed as the weight of ammonia per unit weight, volume, or duration of the activity emitting it, is generally used in developing emission estimates for emission inventories. The factors determining ammonia loss from soil or from manures are the temperature, pH, humidity, precipitation and the velocity of wind above it.

• Journal of the Korean Society of Combustion
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• v.4 no.1
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• pp.59-65
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• 1999

Ignition of $NH_3-O_2-Ar$ mixtures have been studied behind reflected shock waves over the temperature range of 1600-2300 K and the pressures in the range of 1.1-1.6 atm. The pressure profile and the radiation emitted behind the shock waves have been monitored to give empirical correlations between ignition delay times and the mixture concentrations with the experimental conditions. On the basis of this data, several kinetic mechanisms proposed for ammonia oxidation at high temperatures have been tested. The ignition delay times obtained from the mechanism proposed by Miller and Smook were in good agreement with our experimental results.