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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean society for New and Renewable Energy
Journal Basic Information
Journal DOI :
The Korean Society for New and Renewable Energy
Editor in Chief :
Volume & Issues
Volume 7, Issue 4 - Dec 2011
Volume 7, Issue 3 - Sep 2011
Volume 7, Issue 2 - Jun 2011
Volume 7, Issue 1 - Mar 2011
Selecting the target year
Ethanol Production From Seaweeds by Acid-Hydolysis and Fermentation
Na, Choon-Ki ; Song, Myoung-Ki ; Son, Chang-In ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 6~16
DOI : 10.7849/ksnre.2011.7.3.006
In order to study the utilization of seaweeds as an alternative renewable feedstock for bioethanol production, their properties of hydrolysis and fermentation were investigated. The seaweeds were well hydrolyzed with diluted sulfuric acid. The weight loss of seaweeds reached 75-90%, but only 12-51% of them was converted into reducing sugars after the acid-hydrolysis at
for 4-6h. The yield of reducing sugars increased with increasing the hydrolysis time up to 4h and then decreased thereafter. In contrast, the ethanol yield from the hydrolysates increased with hydrolysis time except for green seaweeds maximizing at 4h. Optimal fermentation time by Saccharomyces cerevisiae (ATCC 24858) varied with seaweeds; 48h for green seaweeds, 96h for brown and red seaweeds. The ethanol yield from the hydrolysate reached 138
37mg/g-dry for green seaweeds, 258
29mg/g-dry for brown seaweeds, and 343
53mg/g-dry for red seaweeds, which correspond to approximately 1.5-4.0 times more than the theoretical yield from total reducing sugars in the hydrolysates. The results obtained indicate clearly that the non-reducing sugars or oligosaccharides dissolved in the hydrolysate played an important role in producing bioethanol. Considering the productivity and production cost of each seaweed, brown seaweeds such as Laminaria japonica and Undaria pinnatifida seem to be a promissing feedstock for bioethanol production.
Study on Potential Feasibility of Biomethane as a Transport Fuel in Korea
Kim, Jae-Kon ; Lee, Don-Min ; Park, Chun-Kyu ; Yim, Eui-Soon ; Jung, Choong-Sub ; Kim, Ki-Dong ; Oh, Young-Sam ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 17~28
DOI : 10.7849/ksnre.2011.7.3.017
Biogas production and utilization are an emerging alternative energy technology. Biogas is produced from the biological breakdown of organic matter through anaerobic digestion. Biogas can be utilized for various energy sectors such as space heating, electricity generation and vehicle fuel. Especially, to be utilized as vehicle fuel, raw biogas needs to be upgraded that is mainly the removal of carbon dioxide to increase the methane content up to more than 95 ~ 97 vol% in some cases, similar to the composition of fossil-based natural gas. Usage of Biogas as a fuel of vehicles have an effect of reducing
emission compared to fossil fuels. Biomethane which is produced by upgrading of biogas is regarded as a good alternative energy and usage of clean energy is encouraged to deal with air pollution and waste management as well as production of clean energy. Recently, biogas projects for vehicle fuel are newly being launched and Korea government have also announced a plan for investment to develop biogas as a transport fuel. In this study, it is aimed to examine the potential feasibility of biomethane as a transport fuel. As a results, the status of biomethane, quality standard, quality characteristics, and upgrading technology of biogas were investigated to evaluate of biogas as a vehicle fuel of transportation.
Internal Flow Analysis of a Fuel Pressurized Blower for Fuel Cell System
Choi, Ka-Ram ; Jang, Choon-Man ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 29~35
DOI : 10.7849/ksnre.2011.7.3.029
This paper describes an internal flow characteristics of a fuel pressurized blower, used for 1kW domestic fuel cell system. To analyze the flow field inside the diaphragm cavity, compressible unsteady numerical simulation is introduced. SST model with scalable wall function is employed to estimate the eddy viscosity. Moving mesh system is applied to the numerical analysis for describing the volume change of a diaphragm cavity in time. Throughout numerical simulation with the modeling of the inlet and outlet valves in a diaphragm cavity, unsteady nature of an internal flow is successfully analyzed. Force variations on the lower plate of a diaphragm cavity are evaluated in time. It is found that the driving force at the suction stage of a diaphragm cavity is more necessary than that at the discharging stage.
Methods to Predict Demand for Workforce in New & Renewable Energy Industry
Lee, You-Ah ; Heo, Eunn-Yeong ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 36~45
DOI : 10.7849/ksnre.2011.7.3.036
Prediction of demand for workforce in new and renewable energy is precondition for sustainable growth of an industry. The purpose of this research is to review prediction methods and case studies of workforce in new and renewable energy industry. This research compares the three methods in the focused on possibility of applying in renewable energy industry; survey, input-output and labor function estimation methods. Also, three cases are reviewed in the focused on applied method; Korea, America and Australia. As a result, the survey method was wildly used in the new and renewable industry. Also the improvement rates of work force are difference depending on the methodology. This result can be applied to set up the policy of human resource development of renewable energy.
A Study on Operational Concept of Solar Powered HALE UAV Using Directed-Energy
Ahn, Hyo-Jung ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 59~66
DOI : 10.7849/ksnre.2011.7.3.059
Recently, an UAV using green energy for propulsion has been developed due to exhaustion of fossil fuel. This aircraft runs on electric motors rather than internal combustion engines, with electricity coming from fuel cells, solar cells, ultracapacitors, and/or batteries. Especially solar cells are installed in HALE UAV and flight tests are performed in the stratosphere. Although the solar powered UAV has the advantage of zero emission, its energy conversion efficiency is low and operation time is limited. Therefore, the solar powered UAV has been designed to operate with the secondary battery obtaining flexibility of energy management. In this study, we suggest the new operational concept of the solar powered UAV using directed-energy rayed from the surface of earth to UAV. An UAV is able to secure additional power through attaching solar cell to the lower surface of elevator. As a result, the additional energy supplied by directed-energy can improve the energy management and operational flexibility of the solar powered UAV.
Experimental Study of the Landfill Gas Fuelled Micro Gas Turbine Exhaust Gas Analysis
Park, Jung-Keuk ; Hur, Kwang-Beom ; Rhim, Sang-Gyu ; Oh, Il-Hong ; Lee, In-Hwa ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 67~73
DOI : 10.7849/ksnre.2011.7.3.067
MGT fuelled by landfill gas was tested to asses feasibility of its exhaust gas application for
enrichment. The exhaust gas was analyzed during start-up and normal operation with different MGT load conditions. Due to the changes of air/fuel ratio and combustion mode,
, CO and NOx concentration were varied within wide ranges during the MGT start-up. Especially, NOx emissioin level was increased up to 20.01 ppmv. Different tendencies of
, CO and NOx concentrations were observed with MGT output changes.
and CO concentrations were shown to be decreased and NOx and
concentrations were shown to have opposite trends. NOx emission level (0.8~1.88 ppmv) was very low compared to other types of combustion based power generation equipment. Unburned hydrocarbon emission level was substantially decreased with MGT load increase. Especially,
concentration was below the detection limit(0.2 ppmv) around the nominal load condition. The exhaust gas from landfill gas fuelled MGT system was shown to be feasible for
fertilization. Concentrations of major components were within or below the maximum allowable ranges.
Examination on the Maximum-Cp Control of Wind Turbine by Sliding Mode Control
Shin, Yun-Ho ; Moon, Seok-Jun ; Nam, Yong-Yun ; Kim, Chang-Hyun ; Ryu, Ji-June ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 74~82
DOI : 10.7849/ksnre.2011.7.3.074
Because concern on the problem of the limited energy is growing and the wind energy is considered as one of the biggest solutions, the researches on the wind energy and turbine are accomplished vigorously. The simulation tools on the non-linear characteristics of wind turbine system are various and it could describe the non-linear characteristics well but, the tool and methodology to apply non-linear control theory rarely exist. In this paper, the application procedure of sliding mode control theory to 2-DOF non-linear wind turbine system is suggested and the application results of it are also shown as compared with a torque loop control theory.
A Study on the Site Selection for Wind Power Using GIS
Jeon, Sang-Hee ; An, Seung-Man ; Choi, Young-Jean ; Sung, Hyo-Hyun ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 83~91
DOI : 10.7849/ksnre.2011.7.3.083
The purpose of this study is to select appropriate location factors for wind power plant, provide detailed classification criteria, and find out appropriate sites for installing wind power plant in Gangwondo. In this study, the following 11 factors were extracted for site selection of wind power plant : wind resource, topography (valley angle, distance to the ridge), forest density, land use, preservation area, national park, Baekdu-Daegan, noise, shade, Transmission Line, and approaching roads. Each factor had relatively different level of importance so that AHP (Analytic Hierarchy Process) technique was used to calculated the weighted value per factor. For overlay analysis, classification criteria were prepared for each factor and each factor was classified into 3 grades : very appropriate, intermediate, poor. According to overlay analysis, the areas which received the highest grade (grade 5) was only in 0.16% of the total area of Gangwondo and had a tendency to exist along the mountain ridge over 600-meter elevation. Through analyzing the yearly average of wind power density, it was proved that the wind power density of areas with grade 4 or 5 had abundant wind resource over
Design of Horizontal Axis Tidal Current Power Turbine with Wake Analysis
Jo, Chul-Hee ; Kim, Do-Youb ; Lee, Kang-Hee ; Rho, Yu-Ho ; Kim, Kook-Hyun ;
Journal of the Korean society for New and Renewable Energy, volume 7, issue 3, 2011, Pages 92~100
DOI : 10.7849/ksnre.2011.7.3.092
With the increased demand of clean energy and global warming measures, the renewable energy development has been increased recently. The TCP (Tidal Current Power) is one of the ocean renewable energy sources. Having the high tidal energy source in Korea, there are many potential TCP sites with strong current speed. The rotor, which initially converts the energy, is a very important component because it affects the efficiency of the entire system. The rotor performance is determined by various design parameters including number of blades, shape, sectional size, diameters and etc. However, the interactions between devices also contribute significantly to the energy production. The rotor performance considering the interaction needs to be investigated to predict the exact power in the farm. This paper introduces the optimum design of TCP turbine and the performance of devices considering the interference between rotors.