• Transactions of the KSME C: Technology and Education
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• v.3 no.4
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• pp.285-290
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• 2015

Oxy gasification was performed for the production of high quality syngas from the waste. $CO_2$ was used as reactant with $O_2$ for $CO_2$ gasification and greenhouse gas reduction. Therefore, gasification was performed at high temperature of $1000-1400^{\circ}C$. RPF was gasified in the thermobalance and 0.5 ton/day pilot plant gasifier. Weight variation with temperature and CO production by Boudouard reaction were studied for $CO_2$ gasification of RPF in thermobalance reactor. Syngas of high $H_2$ concentration was produced from oxy gasification in 0.5 ton/day pilot system, which showed appropriate $H_2$/CO ratio for the production of transport fuel and chemical products.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.4
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• pp.347-355
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• 2019

As a solution to the growing concern on the global warming, researches are being actively carried out to apply carbon dioxide capture and storage technology to power generation systems. In this study, the integrated gasification combined cycle (IGCC) adopting oxy-combustion carbon capture was modeled and the effect of replacing the conventional air separation unit (ASU) with the ion transport membrane (ITM) on the net system efficiency was analyzed. The ITM-based system was predicted to consume less net auxiliary power owing to an additional nitrogen expander. Even with a regular pressure ratio which is 21, the ITM-based system would provide a higher net efficiency than the optimized ASU-based system which should be designed with a very high pressure ratio around 90. The optimal net efficiency of the ITM-based system is more than 3% higher than that of the ASU-based system. The influence of the operating pressure and temperature of the ITM on system efficiency was predicted to be marginal.

• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.71-73
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• 2012

With numerical simulations, this study investigated the combustion and heat transfer of three different coals under air- and oxy-fuel combustion in a 100 MWe boiler. The boiler is retrofitted to an opposed-firing type while maintain the original furnace shape of downshot firing. The boiler achieved good combustion in both combustion modes for three coals tested. However, the contribution of gasification reactions by $CO_2$ and $H_2O$ significantly increased due to the lack of gaseous mixing. This was different from a typical front-wall firing boiler, which showed larger contribution of char oxidation during air-coal combustion. The wall heat flux was lower in oxy-coal mode at a $O_2$ level of 27%, which has to be considered in further development of the process.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.417-423
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• 2007

Oxy-gasification or oxygen-blown gasification, enables a clean and efficient use of coal and opens a promising way to CO2 capture. The coal gasification process of a slurry feed type, entrained-flow coal gasifier was numerically predicted in this paper. The purposes of this study are to develop an evaluation technique for design and performance optimization of coal gasifiers using a numerical simulation technique, and to confirm the validity of the model. By dividing the complicated coal gasification process into several simplified stages such as slurry evaporation, coal devolatilization, mixture fraction model and two-phase reactions coupled with turbulent flow and two-phase heat transfer, a comprehensive numerical model was constructed to simulate the coal gasification process. The influence of turbulence on the gas properties was taken into account by the PDF (Probability Density Function) model. A numerical simulation with the coal gasification model is performed on the Conoco-Philips type gasifier for IGCC plant. Gas temperature distribution and product gas composition are also presented. Numerical computations were performed to assess the effect of variation in oxygen to coal ratio and steam to coal ratio on reactive flow field. The concentration of major products, CO and H2 were calculated with varying oxygen to coal ratio (0.2-1.5) and steam to coal ratio(0.3-0.7). To verify the validity of predictions, predicted values of CO and H2 concentrations at the exit of the gasifier were compared with previous work of the same geometry and operating points. Predictions showed that the CO and H2 concentration increased gradually to its maximum value with increasing oxygen-coal and hydrogen-coal ratio and decreased. When the oxygen-coal ratio was between 0.8 and 1.2, and the steam-coal ratio was between 0.4 and 0.5, high values of CO and H2 were obtained. This study also deals with the comparison of CFD (Computational Flow Dynamics) and STATNJAN results which consider the objective gasifier as chemical equilibrium to know the effect of flow on objective gasifier compared to equilibrium. This study makes objective gasifier divided into a few ranges to study the evolution of the gasification locally. By this method, we can find that there are characteristics in the each scope divided.