• Clean Technology
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• v.20 no.3
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• pp.298-305
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• 2014

Ash included in coal can cause environmental pollution and it can decrease efficiency of mass and heat transfer by getting scorched and stick in the facilities operated at high temperature. To solve this problem, a feasibility study on pulverized coal fired power plant and integrated gasification combined cycle (IGCC) using the AFC (Ash-Free Coal) as well as the development to remove the ash from the coal was conducted. In this research, optimization of operating condition was proposed by using sensitivity analysis of ASPEN $Plus^{(R)}$ to apply the coal containing under the 200 ppm ash for integrated gasification combined cycle. Particularly, the coal gasification process was classified as three parts : pyrolysis process, volatile matter combustion process and char gasification process. The dimension and operating condition of 1.5 ton/day class non-slagging gasifier are reflected in the coal gasification process model.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.39-41
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• 2012

The influence of coal blending methods such as out-furnace (external or pre-mixed) blending and in-furnace (initially non-mixed) blending with different excess oxygen (highest, medium, and lowest stoichiometric conditions) on unburned carbon and NOx emissions of blend combustion in an entrained flow reactor (EFR) has been analyzed, using experimental and numerical approaches for binary coals used by Korean power plants. The results confirm that under the medium condition, contrasting processes such as reactive and un-reactive effects occur with SBRs in the out-furnace blending method. The in-furnace blending method results in an improvement in the efficiency of unburned carbon fractions and a further reduction in the NOx emission. Under the highest condition, the unburned carbon fraction in both the out-furnace and the in-furnace blending methods corresponds with the tendency under the medium condition with contrasting processes of lower magnitude, whereas the NOx emission in the highest condition increases slightly. Under the lowest conditions, the unburned carbon fraction in the out-furnace blending method gradually decreases as SBR decreases, without a competition effect. The reduction of NOx emission under the lowest conditions is more effective than those under other conditions for the two blending methods because of a homogeneous and heterogeneous NOx reduction mechanism.

• Particle and aerosol research
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• v.4 no.2
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• pp.51-67
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• 2008

In this study, we devoted to kinetic measurement of the catalytic oxidation of iron-containing flame soot particles and better understanding the role of catalytic particles on carbon oxidation in particular at low temperature, targeting on autothermal regeneration of diesel particulate filter by diesel exhaust gas. Carbon-based Fe-containing particles generated by spraying ferrocene-doped diesel fuel in an oxy-hydrogen flame are tested and compared with a commercial carbon black powder for thermogravimetric analysis (TGA), secondary ion mass spectrometry (SIMS), Fourier-transform infrared spectroscopy (FTIR), Induced coupled plasma-Atomic emission spectroscopy (ICP-AES), and High-resolution transmission electron microscopy (HR-TEM). As a result, we found that a small amount of the ferrocene addition led to significant reductions in a on-set temperature and an activation energy of the carbon oxidation as well. An oxygenated surface complex forming at the particle surface could be thought as active species that would be readily consumed in particular at low temperature.

• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.150-162
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• 2020

The proprietary post-combustion CO₂ solvent (KoSol) developed by the Korea Electric Power Research Institute (KEPRI) was applied at the Shanghai Shidongkou CO₂ Capture Pilot Plant (China Huaneng CERI, capacity: 120,000 ton CO₂/yr) of the China Huaneng Group (CHNG) for performance evaluation. The key results of the pilot test and data on the South Korean/Chinese electric power market were used to calculate the predicted cost of CO₂ avoided upon deployment of CO₂ capture technology in commercial-scale coal-fired power plants. Sensitivity analysis was performed for the key factors. It is estimated that, in the case of South Korea, the calculated cost of CO₂ avoided for an 960 MW ultra-supercritical (USC) coal-fired power plant is approximately 35~44 USD/tCO₂ (excluding CO₂ transportation and storage costs). Conversely, applying the same technology to a 1,000 MW USC coal-fired power plant in Shanghai, China, results in a slightly lower cost (32~42 USD/tCO₂). This study confirms the importance of international cooperation that takes into consideration the geographical locations and the performance of CO₂ capture technology for the involved countries in the process of advancing the economic efficiency of large-scale CCS technology aimed to reduce greenhouse gases

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.265-266
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• 2014

Due to global economic growth, there is an increasing need for energy. Fossil fuels will continue to dominate the world energy supplies in the 21st century and coal will play a significant role. Since coal is one of the most important fossil fuels in the world, coal gasification technology appears to be an inevitable choice for power and chemicals production and has a leading place in Clean Coal Technology (CCT). The most eminent environmental advantage of coal gasification lies in its inherent reaction features that produce negligible sulfur and nitrogen oxides, as well as other pollutants in a reducing atmosphere. The gasifier was operated for a throughput of 1.0 ton & 10.0ton coal per day at pressures of 1~20Bar. Gasification was conducted in a temperature range of $1,100{\sim}1,450^{\circ}C$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.405-413
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• 2013

The char oxidation characteristics of high ash coal were experimentally investigated at several temperatures (from 900 to $1300^{\circ}C$) for 4 types of coals (Gunvor, Glencore, Noble, and ECM) under atmospheric pressure in a drop tube furnace (DTF). The char reaction rate was calculated from the exhaust gas concentrations (CO and $CO_2$) using FT-IR, and the particle temperature was measured using the two-color method. In addition, the activation energy and pre-exponential factor for high ash coal char were calculated based on the Arrhenius equation. The results show that as the ash content increases, the particle temperature and area reactivity decreases. This is because in high ash coal, the large heat capacity of the ash, ash vaporization, and relatively low fixed carbon content of ash suppress combustibility during char oxidation. As a result, the higher ash content of coal leads to high activation energy.

• Clean Technology
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• v.24 no.1
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• pp.21-26
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• 2018

The coal is a useful industrial resource for a long time. However, coal waste is generated by the mining process. Coal wastes are the main cause of pollution in the surrounding environment, and the amount of coal waste is set at hundreds of millions of tons. Significant amounts of these components in the coal waste are $SiO_2$ and $Al_2O_3$, which is also the main source of zeolites useful in various industries. This study is that the synthesis-zeolite was prepared from coal waste and properties and adsorption performance of synthesis-zeolite were compared with commercial zeolite. The synthesis-zeolite is showed similar properties to the commercial zeolite and also showed excellent adsorption performance against atmospheric pollution induced gases ($CO_2$, Toluene, $SO_2$, etc).

• Journal of Energy Engineering
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• v.23 no.2
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• pp.42-48
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• 2014

Soot and tar which were derived from combustion or pyrolysis processes in Puverized Coal(PC) furnace or boiler have been significantly dealing in a radiative heat transfer and an additional source of NOx. Furthermore, the increasing for the use of a coal with low caloric value gives rise to a lot of tar-soot yield and LOI in a recycled ash for using cement materials. So, the ash with higher tar-soot yield and LOI can not recycle due to decreased strength of concrete. In this study, tar-soot yields and flame structures were investigated using the LFR for a blending combustion with bituminous coal and sub-bituminous coal. Also, The investigation were conducted as each single coals and blending ratio. The coals are used in a doestic power plant. In the experimental results, sub-bituminous coal with high volatile contents shows longer soot cloud length than bituminous coal, but overall flame length was shorter than bituminous coal. Tar-soot yields of sub-bituminous coal is lower than those of bituminous coal. Combustion characteristics are different between single coal and blended coal. Therefore, finding an optimal coal blending ratio according to coal rank effects on tar-soot yields.

• Advances in Energy Research
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• v.8 no.4
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• pp.265-273
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• 2022

In this study, a product gas yield and carbon conversion were measured during the coal pyrolysis. The pyrolysis process occurred under two different atmospheres such as subcritical (45 bar, 10℃) and supercritical CO₂ condition (80 bar, 35℃). Under the same pressure (80 bar), the atmosphere temperature increased from 35℃ to 45℃ to further examine temperature effect on the pyrolysis at supercritical CO₂ condition. For all three cases, a power input supplied to heating wire placed below coal bed was controlled to make coal bed temperature constant. The phase change of CO₂ atmosphere and subsequent pyrolysis behaviors of coal bed were observed using high-resolution camcorder. The pressure and temperature in the reactor were controlled by a CO₂ pump and heater. Then, the coal bed was heated by wire heater to proceed the pyrolysis under supercritical CO₂ condition.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2898-2903
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• 2008

The coal considerably is the energy resource which is important with the new remarking energy resource. The coal conversion has two processes which are coal devolatilization and char oxidation. Coal devolatilization is important because it describes up to 70% weight loss and has been shown that nitrogen contribute 60 to 80% of the total NOx produced. The chemical percolation devolatilization(CPD) model is used here to describe coal devolatilization. The model was developed to describe coal devolatilization behavior of rapidly heated coal based on characteristics of the chemical structure of the parent coal. This paper describes CPD model in detail and makes an analysis of Shenhua coal(bituminous) which is used calculated 13-C NMR(carbon-nuclear magnetic resonance).