• Journal of Energy Engineering
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• v.24 no.3
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• pp.40-47
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• 2015

Integrated gasification combined cycle (IGCC) power plants not only emit less greenhouse gases and air pollutants than conventional coal-fired power plants, but also use low-price, low-quality, and internationally easily procurable coal. Thus we can benefit from safeguarding energy security through building the IGCC power plant. This paper attempts to value the benefits of energy security enhanced by IGCC power plant. To this end, we report here the results from a contingent valuation survey of randomly selected 600 households. A combination of a double-bounded model and a spike model is applied for the purpose of increasing statistical efficiency and dealing with zero(0) willingness to pay data, respectively. The results show that the respondents are additionally willing to pay 6.05 won for 1kWh of electricity generated from IGCC power plant. In other words, the benefits from safeguarding energy security through building the IGCC power plant are 6.05 won per kWh. Given that the expected amount of generation from the Taean IGCC power plant that is scheduled to be built in late 2015 is 2.27 TWh per year, the benefits are estimated to be 13.74 billion won per year.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.77-86
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• 1997

In this study, numerical computations were performed to scrutinize the effect of the size of coal particles on reactive flow fields and concentration distribution of product gases for five cases with four different particle sizes (40 $\mu\textrm{m}$, 60 $\mu\textrm{m}$, 100 $\mu\textrm{m}$, 120 $\mu\textrm{m}$, 140 $\mu\textrm{m}$) in an axisymmetric cylindrical coal gasifier in which Alaska Usibelli subbituminous coals were gasified. Predictions showed that coal particle size affected the concentration distribution of product gases. When coals of 100 $\mu\textrm{m}$ were gasified, the maximum average concentrations of major products, H$_2$and CO, were predicted at the exit of the gasifier. The average mole fractions of CO and H, were shown to be 0.62, and 0.16 (dry basis, inert free), respectively. The cold gas efficiency of 83% was also predicted for the same particle size of 100 $\mu\textrm{m}$.

• Journal of Hydrogen and New Energy
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• v.22 no.1
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• pp.118-127
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• 2011

An IGCC was evaluated as one of the next generation technologies that would be able to substitute for coal-fired power plants. According to "The 4th Basic Plan of Long-term Electricity Supply & Demand" which is developed by the Electricity Business Acts, the first IGCC will be operated at 2015. Like other new and renewable energy such as solar PV, Fuel cell, The IGCC is considered as non-competitive generation technology because it is not maturity technology. Before the commercial operation of an IGCC in our electricity market, its economic feasibility under the Korean electricity market, which is cost-based trading system, is studied to find out institutional support system. The results of feasibility summarized that under the current electricity trading system, if the IGCC is considered like a conventional plant such as nuclear or coal-fired power plants, it will not be expected that its investment will be recouped within life-time. The reason is that the availability of an IGCC will plummet since 2016 when several nuclear and coal-fired power plants will be constructed additionally. To ensure the reasonable return on investment (NPV>0 IRR>Discount rate), the availability of IGCC should be higher than 77%. To do so, the current electricity trading system is amended that the IGCC generator must be considered as renewable generators to set up Price Setting Schedule and it should be considered as pick load generators, not Genco's coal fired-generators, in the Settlement Payment.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.566-574
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• 2011

Coal gasifier is a key component for achieving high efficiency in integrated gasification combined cycle and indirect coal liquefaction. Although there have been several successful coal gasifiers that were commercially proven, many different design configurations are still possible for a simple and reliable gasifier operation. Four different gasifier design concepts of dry-feeding were compared in terms of residence time, exit syngas temperature and syngas composition. First, cold-flow simulation was applied to pre-select the configuration concepts, and the hot-flow simulation including chemical reactions was performed to compare the concepts at more actual gasifier operating conditions. There are many limitations in applying CFD method in gasifier design, particularly in estimating slag behavior and slag-tap design. However, the CFD analysis proved to be useful in comparing the widely different gasifier design concepts as a pre-selection tool.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.58-67
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• 1997

In this study numerical computations were performed to predict reacting flow fields of gasification processes of pulverized subbituminous coal in a cylindrical coal gasifier. To check the size effects of particles on flow fields in the gasifier, simulations were performed for five cases with four sizes of particles such as 40 $\mu\textrm{m}$, 60 $\mu\textrm{m}$, 80 $\mu\textrm{m}$ and 100 $\mu\textrm{m}$. Each case has a unique size of particles with one more case that has evenly mixed four sizes of particles. Predictions showed that the gasification which uses coals of the mixed sizes reveals more preferable gas velocity and temperature distributions than that uses coals of a unique size. Predicted gas temperature at the exit of the gasifier ranged 1,400 to 1580$^{\circ}C$, 1,480 to 1,700$^{\circ}C$, 1,600 to 1740$^{\circ}C$, 1630 to 1790$^{\circ}C$ and 1500 to 1680$^{\circ}C$ for particle sizes of 40 $\mu\textrm{m}$, 60 $\mu\textrm{m}$, 80 $\mu\textrm{m}$, 100 $\mu\textrm{m}$ and the evenly mixed four sizes, respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.132.2-132.2
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• 2010

기후변화협약 등으로 인하여 기존 화력발전기술보다 효율이 높고 온실가스 발생을 줄일 수 있는 고효율 청정석탄 이용기술에 대한 사회적 요구가 높아짐에 따라 석탄 가스화와 관련된 기술 개발이 확대되고 있다. 석탄을 가스화하면 CO와 $H_2$가 주성분으로 구성된 합성가스를 얻을 수 있는데, 이를 청정가스연료로 사용하기 위해서는 합성가스에 포함된 분진의 제거가 필수적이다. 대부분의 석탄가스화 공정에서는 캔들형 필터를 사용한 여과식 집진시스템을 적용하여 합성가스에 포함된 분진을 제거하고 있다. 본 연구에서도 Pilot급 석탄 가스화기에서 제조된 합성가스에 포함된 분진 제거를 위하여 고온/고압 집진시스템을 구축하였으며, 다양한 운전조건과 필터 종류에 따른 집진시스템의 운전특성 파악을 수행하였다. 연구결과 석탄 합성가스를 안정적으로 정제 하기위한 집진시스템의 중요한 운전 기준과 방법을 도출할 수 있었으며, 이렇게 도출된 운전 기준과 방법은 용량이 증대된 집진시스템의 연속운전을 진행하여 향후 실증할 예정이다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.5
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• pp.1639-1648
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• 1996

Protection of gas turbine blade from its erosion and abrasion at high temperature and pressure is the first goal to cleanup the hot gas upstream for IGCC and PFBC. Ceramic filters represent an attractive technology for particle removal at high temperature and high pressure condition. They have demonstrated being a good system for improvement of thermal efficiency and reduction of effluent pollutants in advanced coal-based power systems such as IGCC and PFBC. Ceramic filter elements currently being developed were evaluated in the previous paper. In this paper, we measured the ash size and distribution on cleaning of ceramic candle filter. The results are as follows : in this experimental range, ceramic candle filter was shown to be fully adequate for the removal process of dust under high temperature and pressure. Also filtration efficiency of ceramic candle filter was higher than 98% compared with the regulation limit of particle size in gas turbine inlet.

• Journal of Electrochemical Science and Technology
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• v.7 no.2
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• pp.91-96
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• 2016

Oxidation behaviours of ash free coal (AFC), carbon, and H₂ fuels were investigated with a coin type molten carbonate fuel cell. Because AFC has no electrical conductivity, its oxidation occurs via gasification to H₂ and CO. An interesting behaviour of mass transfer resistance reduction at higher current density was observed. Since the anode reaction has the positive reaction order of H₂, CO₂ and H₂O, the lack of CO₂ and H₂O from AFC results in a significant mass transfer resistance. However, the anode products of CO₂ and H₂O at higher current densities raise their partial pressure and mitigate the resistance. The addition of CO₂ to AFC reduced the resistance sufficiently, thus the resistance reduction at higher current densities did not appear. Electrochemical impedance results also indicate that the addition of CO₂ reduces mass transfer resistance. Carbon and H₂ fuels without CO₂ and H₂O also show similar behaviour to AFC: mass transfer resistance is diminished by raising current density and adding CO₂.

• Applied Chemistry for Engineering
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• v.27 no.1
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• pp.56-61
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• 2016

In this study, the effect of natural minerals on the reaction kinetics for lignite-$CO_2$ gasification was investigated. After physical mixing of lignite from Meng Tai area with 5 wt% of each natural mineral catalysts among Dolomite, Silica sand, Olivine and Kaolin, $CO_2$ gasification was performed using TGA at each 800, $850^{\circ}C$ and $900^{\circ}C$. The experimental data was analyzed with volumetric reaction model (VRM), shrinking core model (SCM) and modified volumetric reaction model (MVRM). MVRM was the most suitable among three models. As increasing the reaction temperature, the reaction rate constant became higher. With natural mineral catalysts, the reaction rate constant was higher and activation energy was lower than that of without catalysts. The lowest activation energy, 114.90 kJ/mol was obtained with silica sand. The highest reaction rate constant at $850^{\circ}C$ and $900^{\circ}C$ and lower reaction rate constant at $800^{\circ}C$ were obtained with Kaolin. Conclusively, the better catalytic performance could be observed with Kaolin than that of using other catalysts when the reaction temperature increased.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.132.1-132.1
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• 2010

자원고갈과 지구온난화 등으로 재생에너지의 사용 및 보급이 지속적으로 증가할 것으로 예상되지만, 세계적으로 매장량이 풍부한 석탄의 사용량은 2030년 이후에도 지속적으로 증가될 전망이다. 따라서 세계 각국은 기후변화 규제에 대응하면서도 청정하게 석탄을 사용하기 위한 기술의 개발 및 보급을 활발히 진행 중이며, 국내에서도 온실가스 감축과 동시에 국가 성장 동력화를 추진하고 있다. 석탄가스화 기술은 석탄을 가스화하여 생산된 CO, $H_2$가 주성분인 합성가스를 연료로 활용하는 기술로, 이용 효율이 높고 석탄을 천연가스 수준으로 청정하게 사용할 수 있는 차세대 석탄이용 기술이다. 본 연구에서는 pilot급 석탄 가스화기에서 생산된 합성가스에 함유된 산성가스를 고온에서 건식으로 제거하는 시스템을 구축하였으며, 석탄 합성가스를 고온 건식 정제시스템에 공급하기 위한 석탄가스화기의 운전특성을 파악하였다.