• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.29-32
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• 2014

The practical route for disposal of sewage sludge becomes energy recovery by combustion after its ocean dumping is banned in 2012 in Korea. Due to the high moisture content, however, sewage sludge is required to be dried before transport and combustion. In this study, pyrolysis and combustion characteristics of dried sewage sludge was investigated in a small-scale fixed bed reactor in order to provide fundamental data for energy recovery of the fuel. As the first step of combustion, the primary products of pyrolysis were analyzed in a fixed bed reactor for the condensable volatiles (tar), non-condensable gases, and char. For the combustion characteristics, another fixed bed reactor was constructed to monitor the weight and temperature of the fuel particles during ignition and combustion under different air flow rates. The test results were used to derive the ignition and burning rates.

• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 고분자리싸이클링 심포지엄
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• pp.3-12
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• 2006

The main feature of these total technologies is that we can constitute the optimum treatment scheme fitting to the property of wastes, amount of wastes and energy requirement. For high moisture content wastes or biomass resources, high pressure steam process (MMCS) for crush, dry and deodorize wastes to produce high quality fertilizer of fuel is most appropriate. For dry or semi-dry solid wastes, the STAR-MEET system can be applied to produce low-BTU gases for power generation using duel fueled diesel engines of Stirling engines, and the REPRES and HyPR-MEET systems can be applied to produce hydrogen rich medium-BTU gas. For waste plastics and oils, liquefaction technology is best fit to produce light oil or kerosene equivalent fuel oils. These total technologies are completely different from the existent waste treatment technologies based on land-filling or incineration, and are expected to disseminate all over the world in the near future.

• 한국추진공학회지
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• 제23권5호
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• pp.53-59
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• 2019

고체연료는 추진제 연소 시 산화제와 반응하여 추진제 성능을 증가시키는 역할을 한다. 대표적인 고체연료는 Al, RDX, HMX 등이 있다. 이들 물질은 연소 시 수분과 만나 흰색 연기를 발생시키고, 일산화탄소, 이산화탄소, 메탄가스 등의 환경유해 물질을 다량 발생시킨다. 이러한 문제를 해결하기 위해 본 연구에서는 고체 연료로 사용 가능한 고질소 에너지 물질인 hydrazinium 5-aminotetrazolate(HAT)를 제조하였다. 분광분석(NMR)을 통해 HAT의 구조를 분석하였으며, DSC를 이용하여 열특성 분석을 하였다. 또한, EXPLO5 프로그램을 이용하여 비추력, 가스발생량 등을 계산하였다.

• 한국농림기상학회:학술대회논문집
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• 한국농림기상학회 2019년도 하계 학술발표초록집
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• pp.122-123
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• 2019

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.244.1-244.1
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• 2010

Bio energy development by using Low Calorific Gas Turbine(LCGT) has been developed for New & Renewable energy source for next generation power system, low fuel and operating cost method by using the renewable energy source in landfill gas (LFG), Food Waste, water waste and Livestock biogas. Low calorific fuel purification by pretreatment system and carbon dioxide fixation by green house system are very important design target for evaluate optimum applications for bio energy. Main problems and accidents of Low Calorific Gas Turbine system was derived from bio fuel condition such as hydro sulfide concentration, siloxane level, moisture concentration and so on. Even if the quality of the bio fuel is not better than natural gas, LCGT system has the various fuel range and environmental friendly power system. The mechanical characterisitics of LCGT system is a high total efficiency (>70%), wide range of output power (30kW - 30MW class) and very clean emmission from power system (low NOx). Also, we can use co-generation system. A green house designed for four different carbon dioxide concentration from ambient air to 2000 ppm by utilizing the exhaust gas and hot water from LCGT system. We look forward to contribute the policy for Renewable Portfolio Standards(RPS) by using LCGT power system.

• 신재생에너지
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• 제7권2호
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• pp.10-17
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• 2011

Korea is the 11th largest energy consumption country and 96% of its total energy consumption depends on imports from overseas. Therefore it is a very important task to secure renewable energy sources which can reduce both the carbon-dioxide emission and dependency on overseas energy imports. Among the various renewable energy sources, organic wastes are important sources. In Korea, 113 million toe of methane is generated from organic wastes annually, but only 3.7% is effectively used for energy conversion. Thus, it is very important to make better use of organic wastes, especially for power generation. The goals of this project are to develope the fuel supplying system of Bio Gasturbine (GT) for 5MW-class co-generation system. The fuel supplying system mainly consists of $H_2S$ removal system, Bio Gas compression system, Siloxane removal system and moisture separating systems. The fuel requirement of 5MW-class GT is at around 60% of $CH_4$, $H_2S$ (<30 ppm), Siloxane(<10 mg/$nm^3$) and supply pressure (> 25 bar) from biogas compressor. Main mechnical charateristics of Bio Gasturbine system have the specific performance; 1) high speed turbine speed (12,840 rpm) 2) very clean emmission NOx (<50 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for food waste biogas pretreatment system for 5MW-class biogas turbine. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of bioenergy, this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• Journal of Biosystems Engineering
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• 제23권3호
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• pp.229-244
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• 1998

This study was performed to determine proper fan and heater management schemes for natural air drying of rough rice in round steel bin with stirring device under Korean weather conditions. A computer simulation model was developed to predict moisture content changes, energy requirements, and drymatter losses during drying of rough rice by natural air. Drying test was conducted to validate the simulation model using round steel bin of holding capacity of 300ton at Rice Processing Complex in Jincheon. The bin was filled with rough rice every day and mixing by stirring device. Moisture contents, ambient air temperatures, relative humidities, static pressures in plenum chamber in the bin, airflow rates, and electrical and fuel energy were measured. Relative errors of moisture content changes predicted by the simulation model were below 5ft, and relative errors of final moisture content, final grain weight, required energy ranged from 0.9% to 6%. These not levels indicated that the simulation model can satisfactorily predict the performance factors of natural air drying system such as drying rates and energr consumptions comparing error level of 10% to 15% in other drying simulation models generally used in dryer desists. Twelve different fan and heater management schemes were evaluated using the computer simulation model based on three hourly weather data from Suweon for the period of 1952-1994. The best management schemes were selected comparing the drymatter losses, required drying times, required energy consumptions. Operating fan without heating only when ambient relative humidity was below 85% or 90% appeared to be the most effective method of In operation in favorable drying weather. Under adverse drying climates or to reduce required drying time, operating fan continuously, and heating air with $1.5^{\circ}C$ temperature rise only when ambient relative humidity was over 85% appeared to be the most suitable method.

• 한국도로학회논문집
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• 제18권4호
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• pp.29-35
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• 2016

PURPOSES : The new waste management policy of South Korea encourages the recycling of waste materials. One material being recycled currently is tire-derived fuel (TDF) ash. TDF is composed of shredded scrap tires and is used as fuel in power plants and industrials plants, resulting in TDF ash, which has a chemical composition similar to that of the fly ash produced from coal. The purpose of this study was to evaluate the properties of an asphalt concrete mix that used TDF ash as the mineral filler. METHODS : The properties of the asphalt concrete were evaluated for different mineral filler types and contents using various measurement techniques. The fundamental physical properties of the asphalt concrete specimens such as their gradation and antistripping characteristics were measured in accordance with the KS F 3501 standard. The Marshall stability test was performed to measure the maximum load that could be supported by the specimens. The wheel tracking test was used to evaluate the rutting resistance. To investigate the moisture susceptibility of the specimens, dynamic immersion and tensile strength ratio (TSR) measurements were performed. RESULTS : The test results showed that the asphalt concrete containing TDF ash satisfied all the criteria listed in the Guide for Production and Construction of Asphalt Mixtures (Ministry of Land, Infrastructure and Transport, South Korea). In addition, TDF ash exhibited better performance than that of portland cement. The Marshall stability of the asphalt concrete with TDF ash was higher than 7500 N. Further, its dynamic stability was also higher than that listed in the guide. The results of the dynamic water immersion and the TSR showed that TDF ash shows better moisture resistance than does portland cement. CONCLUSIONS : TDF ash can be effectively recycled by being used as a mineral filler in asphalt, as it exhibits desirable physical properties. The optimal TDF ash content in asphalt concrete based on this study was determined to be 5%. In future works, the research team will compare the characteristics of asphalt concrete as function of the mineral filler types.

• The Korean Journal of Ecology
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• 제18권3호
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• pp.333-340
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• 1995

This study aims to examine how the amount of sample and changes in combustible temperature of living branches and leaves treated with high temperature are associated with combustible time of two coniferous trees, Pinus rigida (R) and Larix leptolepis (L), which are the main victims of forest fire. During the first thirty minutes at $80^{\circ}C$, moisture content of R was higher than that of L by 12%, but after four hours, the moisture content was both lowered by 4~5% and turned to highly combustible leaves. With living leaves, the maximal combustible temperature, regardless of heating temperature, turned out to be higher than normal temperature by $67~140^{\circ}C$, and that with living branches, it was higher by $113~207^{\circ}C$. Also, with living leaves (R, L), the duration time of combustion was as follows: 605, 906 seconds at $400^{\circ}C$ and 76, 227 seconds at $600^{\circ}C$, respectively. Concerning the relation between the amount of burnt fuel and maximal temperature, the more the former was, the higher the latter. The total amounts of combustion heat of living branches and living leaves were 1, 121 Cal (20.8%) and 1, 137 Cal (21.4%), respectively. The total amount of combustion heat increased in proportion to the amount of consumed fuel: 100 g of living leaves and branches gave rise to 128 Cal, whereas 300 g did 556 Cal, that was more than three times.

• Journal of Ecology and Environment
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• 제33권4호
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• pp.343-349
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• 2010

In Korea, man-caused forest fires are known originate primarily in coniferous forests. We have hypothesized that the vulnerability of Pinus densiflora forests is principally a consequence of the ignition characteristics of the species. To assess this hypothesis, we conducted two combustion experiments using fallen leaves with a reference species, Quercus variabilis. In the first experiments, in which a cigarette was employed as a primary heat source for the initiation of a forest fire, the Pinus leaves caught fire significantly faster (1'1" at Pinus, 1'31" at Quercus, P < 0.001), and ignition proceeded normally. Quercus leaves, on the other hand, caught fire but did not ignite successfully. In the second set of experiments utilizing different moisture contents and fuel loads, the maximum flame temperature of the Pinus leaves was significantly higher ($421^{\circ}C$ at Pinus, $361^{\circ}C$ at Quercus, P < 0.001) and the combustion persisted for longer than in the Quercus leaves (8'8" at Pinus, 3'38" at Quercus, P < 0.001). The moisture contents of the leaves appeared to be a more important factor in the maximum temperature achieved, whereas the most important factor in burning time was the amount of fuel. Overall, these results support the assumption that Pinus leaves can be ignited even by low-heat sources such as cigarettes. Additionally, once ignited, Pinus leaves burn at a relatively high flame temperature and burn for a prolonged period, thus raising the possibility of frequent fire occurrences and spread into crown fires in forests of P. densiflora.