• Clean Technology
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• v.29 no.1
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• pp.53-58
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• 2023

This study shows the summary of the economic performance of excess electricity conversion to hydrogen as well as methane and returned conversion to electricity using a fuel cell. The methane production process has been examined in a previous study. Here, this study focuses on the conversion of methane to electricity. As a part of this study, capital expenditure (CAPEX) is estimated under various sized plants (0.3, 3, 9, and 30 MW). The study shows a method for economic optimization of electricity generation using a fuel cell. The CAPEX and operating expenditure (OPEX) as well as the feed cost are used to calculate the discounted cash flow. Then the levelized cost of returned electricity (LCORE) is estimated from the discounted cash flow. This study found the LCORE value was ¢10.2/kWh electricity when a 9 MW electricity generating fuel cell was used. A methane production plant size of 1,500 Nm³/hr, a methane production cost of $11.47/mcf, a storage cost of $1/mcf, and a fuel cell efficiency of 54% were used as a baseline. A sensitivity analysis was performed by varying the storage cost, fuel cell efficiency, and excess electricity cost by ±20%, and fuel cell efficiency was found as the most dominating parameter in terms of the LCORE sensitivity. Therefore, for the best cost-performance, fuel cell manufacturing and efficiency need to be carefully evaluated. This study provides a general guideline for cost performance comparison with LCORE.

• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.325-330
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• 2015

Performance of solid oxide fuel cells (SOFCs), in comparison with that under hydrogen fuel, were investigated under direct internal reforming conditions. Anode supported cells were fabricated with an Ni+YSZ anode, YSZ electrolyte, and LSM+YSZ cathode for the present work. Measurements of I-V curves and impedance were conducted with S/C (steam to carbon) ratio of ~ 2 at $800^{\circ}C$. The outlet gas was analyzed using gas chromatography under open circuit condition; the methane conversion rate was calculated and found to be ~ 90% in the case of low flow rate of methane and steam. Power density values were comparable for both cases (hydrogen fuel and internal steam reforming of methane), and in the latter case the cell performance was improved, with a decrease in the flow rate of methane with steam, because of the higher conversion rate. The present work indicates that the short-term performance of SOFCs with conventional Ni+YSZ anodes, in comparison with that under hydrogen fuel, is acceptable under internal reforming condition with the optimized fuel flow rate and S/C ratio.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.3-4
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• 2007

Many electrochemical power devices such as solid state batteries and solid oxide fuel cell have been studied and developed for solving energy and environmental problems. Fuel cell is a modular, high efficient and environmentally energy conversion device, it has become a promising option to replace the conventional fossil fuel based electric power plants. This paper offers some new perspectives on fuel cell development and commercialization which come from the broad consideration of the commercialization efforts of the entire fuel cell industry.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.519-530
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• 2009

Reducing the emission of carbon dioxide, which is the main contributor to the green house effect, is becoming a global hot issue. Great attention has been thus given to utilization of carbon dioxide rather than just capturing and isolating it because it could convert carbon dioxide to high-value chemicals. In this paper, recent research trends are investigated on the catalytic conversion of carbon dioxide to syngas in the context of $CH_4$, dry-reforming, trireforming, and the electro-catalytic conversion of carbon dioxide through SOFC(Solid Oxide Fuel Cell) system. Research trends for utilizing syngas to high-value-added useful products, mainly fuel such as DME(Dimethyl Ether) are also discussed.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.367-376
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• 2013

This study investigated mixing scenarios of the low and high conversion ratios (CRs) of fast reactors (FRs). The fuel cycle was modeled so as to minimize the spent fuel (SF) or transuranics (TRU) inventories. The scenarios were modeled for a single low CR of 0.61 and a high CR of 1.0. The study also investigated the mixing scenario of low-high CR and/or high-low CR. The SF and TRU inventories, associated with different scenarios, were compared to those of the light water reactor (LWR) once-through (OT) case. Also, the important isotope concentration and long-term heat (LTH) load were calculated and compared to those of the OT cycle. As a result, it is known that the deployment of FRs of low CR burns more TRU and results in a reduction of the out-of-pile TRU inventory and LTH with low deployment capacity. This study shows that the mixing strategy of FRs of low and high CR can reduce the SF and TRU inventories with lower deployment capacity as compared with a single deployment of FRs of high CR.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.5
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• pp.550-556
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• 2022

In this study, the flow uniformity was analyzed by performing numerical analysis on the 1 kWe internal manifold type solid oxide fuel cell stack according to the channel height of the separator. Also, it was examined by varying the fuel utilization rate and oxygen utilization rate. From the calculation results, we found that as the channel height of the separator decreased, the pressure drop increased exponentially. In addition, it was found that as the channel height of the separator decreased, the gas flow resistance inside the unit cell increased, and the flow resistance increased the pressure drop, thereby improving the flow uniformity inside the stack. Finally, the calculation results showed that as the fuel and oxygen utilization increased, the flow uniformity also improved.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.159.1-159.1
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• 2011

Partial oxidation reformer was fabricated and operated using commercial transportation fuels. Fuel injector and heating coil were used for fuel atomization and startup, respectively. The reformer was designed to produce syngas for $150{\sim}200W_e$ class solid oxide fuel cell. The reformer was operated in the $O_2$/C range between 0.6 and 0.8 while the capacity was fixed at $150W_e$. The temperature range in catalyst bed was between $500^{\circ}C$ and $900^{\circ}C$. Only 83% fuel was converted to $H_2$, CO, $CO_2$ and $CH_4$ at the operating conditions. The lowest temperature increase to $700^{\circ}C$ when the reformer was operated at $200W_e$, Although the temperature profiles was improved, fuel conversion was 88%. On the other hand, fuel was completely converted when micro-reactor operated at the same condition. This difference maybe due to aromatic compounds formation at homogeneous region. In addition, a significant amount of coke deposition was observed at vent line. Homogeneous reaction depends on the degree of mixing. For this purpose, two fluid nozzle and Ultra sonic injector were compared to investigate the effect of atomization. Sauter mean diameter(SMD) of Ultra sonic injector was lower than two-fluid nozzle at test condition. However, conversion efficiency and fuel conversion were not improved by using two-fluid nozzle. these results imply that the temperature of homogeneous reaction region should be controlled to prevent coke formation.

• Journal of the Korean Electrochemical Society
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• v.10 no.2
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• pp.104-109
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• 2007

Single fuel cell was fabricated with a MEA (membrane electrode assembly) that had a $4cm^2$ active area and with silicon bipolar plates those were introduced to miniaturize the fuel cell by replacing heavy weight graphite plates. Optimum humidification condition for the single cell was selected based on performance results obtained varying humidifier temperature at a fixed feed rate of hydrogen and oxygen. Furthermore, to study the effect of humidification condition on the performance of a fuel cell stack, the fuel cell stack consisting of two MEAs and silicon bipolar plates was studied, then problems and characteristics of silicon-based fuel cell stack were examined.

• Journal of Energy Engineering
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• v.3 no.2
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• pp.130-150
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• 1994

Coal-water mixture(CWM) fuel has attracted much attention as a substitute fuel for oil by which high economics and short-term commercialization might be realized in comparison with other coal conversion technologies. There are many factors that affect the CWM combustibility, such as the physical properties of CWM, the performance of atomizer and burner, operating conditions, capacity and load of the boiler, etc. Particularly, atomization quality is extremely critical to achieving acceptable carbon conversion efficiency of CWM fuel and maintaining the flame stability, because the coal particles in the CWM droplets burn as agglomerates. This paper presents the R&D results about the CWM atomization characteristics, including the significance of CWM atomization the R&D results about the CWM atomization characteristics, including the significance of CWM atomization quality, the atomization and combustion mechanism, the type of CWM atomizer, size and size distribution of CWM droplets and some factors that influence the atomization performance.

• Korean Journal of Organic Agriculture
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• v.22 no.4
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• pp.531-547
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• 2014

This study analyzed the effect of Greenhouse of wood pellet fuel conversing from Diesel. Analyzed through a life cycle assessment of greenhouse gas emissions of carbon dioxide for the environmental assessment, In evaluation of the Ministry of the Environment, analyzed through the life cycle assessment of carbon dioxide emissions of the greenhouse gas and, In the case of economic evaluation, we analyzed the investment payback period to the total revenue generated by each of the calculated incentive based on the RHI and institutions reduction projects a reduction of costs associated with the reduction of fuel costs.