• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.1815-1820
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• 2008

Self-catalytic behavior of combustion-synthesized carbon nanotubes (CNTs) is evaluated using a double-faced wall stagnation flow burner with a CNT-deposited stainless steel plate wall. CNT formation is observed using field-emission scanning and transmission electron microscopies and Raman spectroscopy. A self-catalytic behavior of multi-walled CNTs (MWCNTs) shows the enhanced ratio of channel diameter to tube wall thickness and the enhanced intensity ratio of G-band to D-band in Raman spectroscopy, implying that the quality of metal-catalytic, flame-synthesized MWCNTs can be much improved via a CNT self-catalytic flame-synthesis process. Thus, using a DWSF burner through the self-catalytic process has potential in mass production of CNTs having much improved quality.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.42-45
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• 2006

A new and reusable energy source is water-treatment sludges. There is a significant need for understanding the characteristics of sludge combustion related to improving efficiency and ensuring the safety of this new energy source. Because sludges are composed of solids and gas mixture, the combustion of the mixture may become quite complex. Not only decomposition of conventional organic elements but also dust explosion may be important during the process of converting sludges into a new and safe form of energy. Sludge combustion mainly involves hydrogen, methane, hydro carbons, carbon, and organic particles. Dust explosion during the gasification stage may depend on the surrounding temperature and the composition of gases. The uncertainty in the explosive behavior of energetic source is noted in this work. We study the explosion characteristics of sludge combustion while the reusability of sewage sludges as a new form of energy is also investigated.

• 한국대기환경학회지
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• 제16권2호
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• pp.191-198
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• 2000

For a characterization of the pretreated waste automotive catalyst the following analysis techniques were applied : EA(Elemental Analysis) BET(Brunaure-Emmett-Teller) and ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry). The combustion activity of waste automotive catalyst was investigated for methanol acetaldehyde and toluene as model VOCs in a fixed bed reactor. carbon deposit amount was decreased with increasing catalyst showed a good catalytic activity for VOCs combustion at 40$0^{\circ}C$. Catalytic activity for methanol acetaldehyde and toluence combustion was very excellent and decreased with mileage. The catalytic activity of a waste automotive catalyst for methanol combustion increased after acid treatment. The acid effect of catalytic activity was summarized as follows: HNO3>HCI>H2SO4>CH3COOH. The waste automotive catalyst regenerated by the pretreatment method might have a excellent catalytic activity for VOCs combustion.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.774-779
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• 2012

MILD(Moderate and Intense Low Oxygen Dilution) 연소는 연소 가스의 재순환을 이용하여 고온 형성을 최대한 억제하고 질소산화물의 발생을 저감하는 동시에 연소로의 내부 온도 균일화를 통한 열 이용 효율을 향상시킬 수 있는 연소기술이다. 본 연구에서는 원추형 연소로에서 연료 유량은 고정하고 공기 유량으로 당량비(${\Phi}$)를 조절하고 배기가스를 측정하여 MILD 연소특성을 도출하였다.

• 한국연소학회지
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• 제16권1호
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• pp.22-29
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• 2011

This paper focuses on the combustion characteristics of blended coals with bituminous and sub-bituminous coals under air and oxy-fuel combustion conditions. The effects of oxygen concentration and blending ratio on the combustion characteristics were experimentally investigated using a thermogravimetric analyser (TGA). Characteristic temperatures including ignition, burnout temperature and activation energy were determined from TG and DTG combustion profiles. As oxygen concentration increased and the presence of sub-bituminous coal, characteristic temperatures and activation energy decreased. The ignitability, reactivity and kinetics have all been greatly improved under oxy-fuel combustion conditions. Based on this, co-firing with bituminous and sub-bituminous coals under oxy-fuel combustion conditions may be suggested as an alternative method to the fuel flexibility and cost-effective power production with carbon capture and sequestration.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.571-580
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• 2016

In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

• 수산해양기술연구
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• 제57권3호
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• pp.256-263
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• 2021

In this study, blending oils of diesel oil and butanol were used as fuel oil for diesel engine to measure combustion pressure, fuel consumption, air ratio and exhaust gas emission due to various operating conditions such as engine revolution and torque. Using these data, the results of analyzing the engine performance, combustion characteristics and exhaust emission characteristics such as NOx (nitrogen oxides), CO₂ (carbon dioxide), CO (carbon monoxide) and soot were as follows. The fuel conversion efficiency at each load was highest when driven in the engine revolution determined by a fixed pitch propeller law. Except 30% butanol blending oil, fuel conversion efficiency of the other fuel oils increased as the load increased. Compared to diesel oil, using 10% and 20% butanol blending oil as fuel oil was advantageous in terms of thermal efficiency, but it did not have a significant impact on the reduction of exhaust gas emissions. On the other hand, future research is needed on the results of the 20% butanol blending oil showing lower or similar levels of smoke concentration and carbon monoxide emission rate other than those types of diesel oil.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.99-102
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• 2015

To operate coal fired power plant efficiently is considered unburned carbon as important factor. But, unburned carbon contents change does not have an impact on Boiler performance simultaneously. we evaluated that unburned carbon contents change had an little influence on unburned carbon loss change for performance side at a real power plant.

• 한국폐기물자원순환학회지
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• 제35권7호
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• pp.600-605
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• 2018

In this study, the combustion characteristics were investigated based on the biodrying solid recovered fuel (SRF) in a 5 Ton/day scale combustion boiler. The composition of the combustion gas containing the biodrying SRF was analyzed, the particulate matter, and its HCl content was determined with the air pollutant process test method. Mass balance, carbon balance, and combustion efficiency were calculated according to the equivalence ratio (ER) method; the energy recovery efficiency of the combustion boiler was also analyzed. The overall combustion efficiency of the biodrying SRF was 97.3 % and the energy recovery efficiency was 80.2%.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.299-303
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• 2006

From the analysis of fly ash, which contains unburned carbon, collected from the coal-fired Yong Hung power station, most particles are turned out to be hollow cenosphere and agglomerated soot particles. The sooting potential from six coals used in the plant were investigated with CPD model. The results show that the higher potential presented to Peabody, Arthur, Shenhua coals rather than other coals. It is necessary to measure the coal flow rates at each coal feeding pipe for four burner levels since they affect the extent of mixing of soot with oxidant, in turn, the oxidation rate of soot particles. The unbalance in coal flow rate was found in several coal pipes. We successfully reduced unburned carbon in ash by increasing the excess air and changing the SOFA yaw angle.