• Korean Chemical Engineering Research
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• v.44 no.5
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• pp.528-534
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• 2006

The purpose of this paper is to investigate the optimal operating condition for the hydrogen production by biogas reforming using the plasmatron induced thermal plasma. The component ratio of biogas($CH_4/CO_2$) produced by anaerobic digestion reactor were 1.03, 1.28, 2.12, respectively. And the reforming experiment was performed. To improve hydrogen production and methane conversion rates, parametric screening studies were conducted, in which there are the variations of biogas flow ratio(biogas/TFR: total flow rate), vapor flow ratio($H_2O/TFR$: total flow rate) and input power. When the variations of biogas flow ratio, vapor flow ratio and input power were 0.32~0.37, 0.36~0.42, and 8 kW, respectively, the methance conversion reached its optimal operating condition, or 81.3~89.6%. Under the condition mentioned above, the wet basis concentrations of the synthetic gas were H2 27.11~40.23%, CO 14.31~18.61%. The hydrogen yield and the conversion rate of energy were 40.6~61%, 30.5~54.4%, respectively, the ratio of hydrogen to carbon monoxide($H_2/CO$) was 1.89~2.16.

• Carbon letters
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• v.14 no.1
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• pp.58-61
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• 2013

In this work, the effect of catalysts on the mechanical properties of carbon fibers-reinforced epoxy matrix composites cured by cationic latent thermal catalysts, i.e., N-benzylpyrazinium hexafluoroantimonate (BPH) was studied. Differential scanning calorimetry was executed for thermal characterization of the epoxy matrix system. Mechanical interfacial properties of the composites were studied by interlaminar shear strength (ILSS), critical stress intensity factor ($K_{IC}$), and specific fracture energy ($G_{IC}$). As a result, the conversion of neat epoxy matrix cured by BPH was higher than that of one cured by diaminodiphenyl methane (DDM). The ILSS, $K_{IC}$, $G_{IC}$, and impact strength of the composites cured by BPH were also superior to those of the composites cured by DDM. This was probably the consequence of the effect of the substituted benzene group of BPH catalyst, resulting in an increase in the cross-link density and structural stability of the composites studied.

• Journal of computational fluids engineering
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• v.16 no.1
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• pp.42-47
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• 2011

In this paper, various operating parameters of stream reforming process from methane in stream reformer and preconverter for MCFC is studied by numerical method. Commercial code is used to simulated the porous catalyst with user subroutine to model three dominant chemical reactions which are Stream Reforming(SR), Water-Gas Shift(WGS), and Direct Stram Reforming(DSR). The hydrogen production is tested with different wall temperature and different reactor shapes. The calculated results of the concentration of hydrogen in stream reformer are very well consistent with experimental results. This numerical study gives the design reactor wall temperature condition and size of reactor to satisfy the required fuel conversion.

• Microbiology and Biotechnology Letters
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• v.8 no.2
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• pp.135-142
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• 1980

The process of biological treatment of organic wastewater is principally associated with those of self-purification in the natural water environment. The treatment system has e intensive function of stabilizing wastewater more effectively than in natural water, which is like natural water concentrated in a small space. Biological treatment of wastewater involves activated sludge and various modified process, trickling filter, rotating disk, oxidation ditch, etc. for aerobic decomposition and anaerobic processes such as anaerobic decomposition and methane fermentation. The basic characteristic of these processes is the use of mixed culture for the conversion of pollutants. This review forcuses on the various kinds of microorganisms related to each treatment processes. Kinetic analysis of the activated sludge process is discussed in order to understand the basis of control and maintenance of the biological treatment process.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.93-96
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• 2007

Catalytic activities of color and conductive carbon blacks in ethane decomposition for $CO_2-free$ hydrogen production were investigated. The ethane decomposition was carried out in a conventional fixed bed reactor under atmospheric pressure at 973-1173 K for 2 hours. When the decomposition in the presence of carbon black was compared with the non-catalytic thermal decomposition, the former exhibited significantly higher ethane conversion, higher C(s) selectivity and lower ethylene selectivity with small increase of the methane selectivity, which resulted in higher hydrogen yield. This indicates that carbon black is catalytically effective for dehydrogenation of ethane as well as subsequent decomposition of ethylene. All the carbon blacks exhibited stable catalytic activity with time. In durability tests, fluffy N-330 and BP2000 maintained their activities for 36 hours.

• Journal of Korean Institute of Industrial Engineers
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• v.22 no.1
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• pp.155-164
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• 1996

Biomass to methane via anaerobic digestion conversion is a good supply method of substitutable energy resources. The economic viability of this technology is contingent upon managing the production facilities in a cost effective manner. The problem is to determine the batch production sequence as well as the batch residence times in the digester so as to maximize total gas production over a given planning horizon. The problem is difficult to solve since the batch sequencing decisions and the batch residence time decisions cannot be isolated. This paper developes a heuristic algorithm which is based on a dynamic programming procedure for the multiple feedstock sequencing and scheduling biogas production systems and demonstrates to yield good results.

• Journal of Energy Engineering
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• v.24 no.2
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• pp.84-90
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• 2015

Hydrogen has some remarkably high values of the key properties for transport processes, such as kinematic viscosity, thermal conductivity and diffusion coefficient. Hydrogen, as an energy medium, has some distinct benefits for its high efficiency and convenience in storage, transportation and conversion. Hydrogen has much wider limits of flammability in air than methane, propane or gasoline and the minimum ignition energy is about an order of magnitude lower than for other combustibles. Statistical thermodynamics provides the relationships that we need in order to bridge this gap between the macro and the micro. Our most important application will involve the calculation of the thermodynamic properties of the ideal gas.

• Journal of Marine Bioscience and Biotechnology
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• v.6 no.1
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• pp.8-16
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• 2014

Macroalgae has been strongly touted as an alternative biomass for biofuel production due to its higher photosynthetic efficiency, carbon fixation rate, and growth rate compared to conventional cellulosic plants. However, its unique carbohydrate composition and structure limits the utilization efficiency by conventional microorganisms, resulting in reduced growth rates and lower productivity. Nevertheless, recent studies have shown that it is possible to enable microorganisms to utilize various sugars from seaweeds and to produce some energy chemicals such as methane, ethanol, etc. This paper introduces the basic information on macroalgae and the overall conversion process from harvest to production of biofuels. Especially, we will review the successful efforts on microbial engineering through metabolic engineering and synthetic biology to utilize carbon sources from red and brown seaweed.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.117-120
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• 2013

The reactions of indole with carbonyl groups have been efficiently carried out in the presence of catalytic amounts of 1,3-dibromo-5,5-dimethylhydantoin under solvent-free conditions and corresponding bis(indolyl)-mathanes were obtained in good to excellent yields. Synthesis of di[bis(indolyl)methyl]benzene was also accomplished by this catalyst. Furthermore, chemoselective conversion of aromatic aldehydes to their corresponding bis(indolyl)methanes in the presence of aliphatic aldehydes or ketones was achieved by this method.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.3
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• pp.75-80
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• 2012

Gasification is a therm-chemical conversion process to convert various solid fuels into gaseous fuels under limited supply of oxygen in high temperature environment. Considering current availability of biomass resources in this country, the gasification is more attractive than any other technologies in that the process can accept various combustible solid fuels including plastic wastes. Mixed fuels of biomass and polyethylene pellets were used in gasification experiments in this study in order to assess their potential for synthesis gas production. The results showed that higher reaction temperatures were observed in mixed fuel compared to woodchip experiments. In addition, carbon monoxide, hydrogen, and methane concentrations were increased in the synthesis gas. Heating values of the synthesis gas were also higher than those from woodchip gasification. There are hundred thousand tons of agricultural plastic wastes generated in Korea every year. Co-gasification of biomass and agricultural plastic waste would provide affordable gaseous fuels in rural society.