• 유체기계공업학회:학술대회논문집
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• 1998.12a
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• pp.209-214
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• 1998

A thermodynamic simulation method is developed for the process design and the performance evaluation of the gas turbine in IGCC power plant. The present study adopts four clean coal gases derived from four different coal gasification and gas clean-up processes as IGCC gas turbine fuel, and considers the integration design condition of the gas turbine with ASU(Air Separation Unit). In addition, the present simulation method includes compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. The present prediction results show that the efficiency and the net power of the IGCC gas turbines are seperior to those of the natural gas fired one but they are decreased with the air extraction from gas turbine to ASU. The operation point of the IGCC gas turbine compressor is shifted to the higher pressure ratio condition far from the design point by reducing the air extraction ratio. The exhaust gas of the IGCC gas turbine has more abundant wast heat for the heat recovery steam generator than that of the natural gas fired gas turbine.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.452-459
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• 2010

This study is aimed to investigate changes of combustion characteristics and heat efficiency when syngas from gasification process using low-rank fuel such as waste and/or biomass is applied partially to an industrial boiler. An experimental study on syngas co-combustion was performed in a 0.7 MW (1 ton steam/hr) water tube boiler using heavy oil as a main fuel. Three kinds of syngas were used as an alternative fuel: mixture gas of pure carbon monoxide and hydrogen, syngas of low calorific value generated from an air-blown gasification process, and syngas of high calorific value produced from an oxygen-blown gasification process. Effects of co-combustion ratio (0~20%) for each syngas on flue gas composition were investigated through syngas injection through the nozzles installed in the side wall of the boiler and measuring $O_2$, $CO_2$, CO and NOx concentrations in the flue gas. When syngas co-combustion was applied, injected syngas was observed to be burned completely and NOx concentration was decreased because nitrogen-containing-heavy oil was partially replaced by the syngas. However, heat efficiency of the boiler was observed to be decreased due to inert compounds in the syngas and the more significant decrease was found when syngas of lower calorific value was used. However, the decrease of the efficiency was under 10% of the heat replacement by syngas.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.95-95
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• 2010

An apparatus for generating flames and more particularly the microwave plasma burner for generating high-temperature large-volume plasma flame was presented. The plasma burner was composed of micvrowave transmission lines, a field applicator, discharge tube, coal and gas supply systems, and a reactor. The plasma burner is operated by injecting coal powders into a 2.45 GHz microwave plasma torch and by mixing the resultant gaseous hydrogen and carbon compounds with plasma-forming gas. We in this work used air, oxygen, steam, and their mixtures as a discharge gas or oxidant gas. The microwave plasma torch can instantaneously vaporize and decompose the hydrogen and carbon containing fuels. It was observed that the flame volume of the burner was more than 50 times that of the torch plasma. The preliminary experiments were carried out by measuring the temperature profiles of flames along the radial and axial directions. We also investigated the characteristics for coal combustion and gasification by analyzing the byproducts from the exit of reactor. As expected, various byproducts such as hydrogen, carbon monoxide, carbon dioxide, hydrogen sulfide, etc. were detected. It is expected that such burner cab be applied to coal gasification, hydrocarbon reforming, industrial boiler of power plants, etc.

• Journal of Energy Engineering
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• v.10 no.3
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• pp.188-194
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• 2001

The process simulations are made on the IGCC power plant using heavy residue oil from refinery process. In order to model combined power block of IGCC, the present study employs the gas turbine of MS7001FA model integrated with ASU (Air Separation Unit), and considers the air extraction from gas turbine and the combustor dilution by returned nitrogen from ASU. The exhaust gas energy of gas turbine is recovered through the bottoming cycle with triple pressure HRSG (Heat Recovery Steam Generator). Clean syngas fuel of the gas turbine is assumed to be produced through Shell gasification of Visbreaker residue oil and Sulfinol-SCOT-Claus gas cleanup processes. The process optimization results show that the best efficiency of IGCC plant is achieved at 20% air extraction condition in the case without nitrogen dilution of gas turbine combustor find at the 40% with nitrogen dilution. Nitrogen dilution of combustor has very favorable and remarkable effect in reducing NOx emission level, while shifting the operation point of gas turbine to near surge point.

• Journal of Energy Engineering
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• v.5 no.1
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• pp.8-18
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• 1996

As a part of comprehensive IGCC process simulation, the thermal performance analysis was performed for coal gas firing combined power plant. The combined cycle analyzed consisted of il Texaco gasifier and a low temperature gas cleanup system for the gasification block and a GE 7FA gas turbine, a HRSG and steam turbine for the power block. A steady state simulator called ASPEN(Advanced System for Process Engineering) code was used to simulate IGCC processes. Composed IGCC configuration included air integration between ASU and gas turbine and steam integration between gasifier, gas clean up and steam turbine. The results showed 20% increase in terms of gas turbine power output(MWe) comparing with natural gas case based on same heat input. The results were compared with other study results which Bechtel Canada Inc. performed for Nova Scotia power plant in 1991 and the consistency was identified within two studies. As a result, the analysing method used in this study is verified as a sound tool for commercial IGCC process evaluation.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.306-309
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• 2005

One of the most critical issues in sol id oxide fuel cell (SOFC)running on hydrocarbon fuels is the risk of carbon formation from the fuel gas. The simple method to reduce the risk of carbon formation from the reactions is to add steam to the fuel stream, leading to the carbon gasification react ion. However, the addition of steam to fuel is not appropriate for the auxiliary power unit (APU) and potable power generation (PPG) systems due to an increase of complexity and bulkiness. In this regard, many researchers have focused on so-called 'direct methane' operation of SOFC, which works with dry methane without coking. However, coking can be suppressed only by the operation with a high current density, which may be a drawback especially for the APU and PPG systems. The single chamber fuel cell (SC-SOFC) is a novel simplification of the conventional SOFC into which a premixed fuel/air mixture is introduced. It relies on the selectivity of the anode and cathode catalysts to generate a chemical potential gradient across the cell. Moreover it allows compact and seal-free stack design. In this study, we fabricated honeycomb type mixed-gas fuel cell (MGFC) which has advantages of stacking to the axial direction and increasing volume power density. Honeycomb-structured SOFC with four channels was prepared by dry pressing method. Two alternative channels were coated with electrolyte and cathode slurry in order to make cathodic reaction sites. We will discuss that the anode supported honeycomb type cell running on mixed gas condition.