• Title/Summary/Keyword: 재생연료

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Characteristics of the Gasification from Mixed Fuels of Charcoal and Undried Woodchip (미건조 우드칩과 숯 혼합에 따른 가스화 특성 분석)

  • Wang, Long;Kang, Ku;Lee, Tae Ho;Choi, Sun Hwa;Hong, Seong Gu
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.5
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    • pp.81-88
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    • 2015
  • 바이오매스는 유망한 신재생 에너지이다. 바이오매스는 액체 및 기체 연료로 전 환 할 수 있고, 다양한 공정을 통해 열 및 전력을 생산시키는데 사용된다. 바이오매스 가스화 공정은 바이오매스를 일산화탄소, 이산화탄소, 수소 및 메탄으로 이루어진 합성 가스로 전환시키는 기술이다. 바이오매스를 이용한 합성 가스 생산 및 활용은 세계적으로 늘어나는 에너지 필요성을 충족시킬 수 있는 대체에너지이다. 현재, 바이오매스 가스화의 주요 원료는 목질계 우드 칩을 주로 사용하고 있지만, 일반적으로 우드칩의 경우 수분을 다량 함유하고 있기 때문에 가스화 공정을 위해서는 별도의 건조처리를 필요로 한다. 우드칩의 건조에는 많은 에너지가 소요되고, 다량의 우드칩 건조에는 시간과 기상 및 공간적인 환경에 영향을 받는다. 본 연구에서는 미건조 우드칩의 가스화 공정을 위하여 미건조 우드칩에 숯을 각각 10, 30, 50 % 비율로 혼합하여 실험을 수행하였고, 실험결과 생산된 합성가스의 CO 농도 는 숯의 비율에 따라 14.9 ~ 25.6 % 증가되는 경향을 나타내었지만, 반대로 $CO_2$$CH_4$ 농도는 감소하였다. 이에 따라 합성가스 생산을 위한 미건조 우드칩과 숯의 최적혼합비율은 약 30 %로 판단되며, 발열량은 $1285.7kcal/Nm^3$, Gas yield는 $2.3Nm^3/kg$ 로 나타났다. 이에 적절한 숯의 혼합사용은 미건조 우드칩의 직접적인 가스화에 도움이 될 것으로 사료되며, 바이오매스 건조 공정에 필요한 에너지를 절약할 수 있을 것으로 판단된다.

Production of Biopolyols, Bioisocyanates and Biopolyurethanes from Renewable Biomass (바이오매스 자원을 활용한 바이오폴리올, 바이오이소시아네이트 및 바이오폴리우레탄 제조)

  • Jo, Yoon Ju;Choi, Sung Hee;Lee, Eun Yeol
    • Applied Chemistry for Engineering
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    • v.24 no.6
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    • pp.579-586
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    • 2013
  • The shortage of fossil fuel and problem of greenhouse gas exhaustion drive the production of biopolymer in a environment-friendly manner. Polyurethane is a polymer formed by reacting an isocyanate (-NCO) with a polyol (-OH) to form urethane link (-NHCOO-). Polyurethane is one of the most widely used polymers in automobile, construction and chemical industries. Two monomers for the polymerization of polyurethane, polyols and isocyanates, can be produced from renewable biomass such as plant oil, cellulose, lignin and etc. Biopolyol production from plant oil has already been implemented in commercial-scale production. In this paper, recent progresses on bio-based approaches on the production of biopolyols, bio-isocyanates and bio-substituent or isocyanate from bio-feedstock are reviewed alongside polymerization and characterization of biopolyurethane for industrial applications.

Performance Prediction of Liquid Rocket Thrust Chambers with Nonuniform Propellant Mixing (추진제의 비균일 혼합분포를 고려한 액체로켓 추력실의 성능 예측기법 개발)

  • 김성구;최환석;한영민;이광진
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.9
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    • pp.82-88
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    • 2006
  • In order to effectively reduce thermal loads on regenerative cooled walls, fuel cooling injectors and film cooling devices have often been employed. The present study has established a numerical methodology for prediction of performance and near-wall temperature distribution taking into account the nonuniform mixing due to these additional cooling devices. A correction procedure for main propulsive parameters has also been proposed based on comparison between prediction and experimental data. Under the computational framework of this study, the predicted results were in good agreement with hot-firing test data for a 30 tonf-class full-scale combustor at the design and off-design conditions. As a consequence, the present numerical method is expected to be useful for design and evaluation of regenerative cooled liquid rocket thrust chambers.

Patents and Papers Trends of Solar-Photovoltaic(PV) Technology using LDA Algorithm (LDA알고리즘을 활용한 태양광 에너지 기술 특허 및 논문 동향 연구)

  • Lee, Jong-Ho;Lee, In-Soo;Jung, Kyeong-Soo;Chae, Byeong-Hoon;Lee, Joo-Yeoun
    • Journal of Digital Convergence
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    • v.15 no.9
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    • pp.231-239
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    • 2017
  • Solar energy is attracting attention as an alternative to fossil fuels. However, there was a lack of discussion on the overall research direction and future direction of research in technology development. In order to develop more effective technology, we analyzed and discussed the technology trend of solar energy using patent data and thesis data. As an analysis method, topics were selected by using topic modeling and text mining, the increase of included keywords was analyzed, and the direction of development of solar technology was analyzed. Research on solar power generation technology is expected to proceed steadily, and it is analyzed that intensive research will be done especially on high efficiency and high performance technology. Future studies could be conducted by adding overseas patent data and various paper data.

Energy Consumption of Biodiesel Production Process by Supercritical and Immobilized Lipase Method (초임계와 Lipase 고정화에 의한 바이오디젤 생산 공정의 에너지소비량)

  • Min, Eung-Jae;Lee, Euy-Soo
    • Korean Chemical Engineering Research
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    • v.50 no.2
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    • pp.257-263
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    • 2012
  • Biodiesel is a renewable energy which is nontoxic and acting as a replacement for conventional diesel which derived from fossil fuel. Classified biodiesel producing way such as acid, base, supercritical and enzyme methods, this study focused on eco-friendly production of biodiesel using supercritical and immobilized enzyme process. Assuming a plant with a production rate of 10,000 tons a year, a PRO II simulator program was used to simulate the product conversion rate and total energy consumption. The product conversion in supercritical process and immobilized enzyme was found to be 91.17% (including 0.9% glycerol) and 93.18% (including 1.0% glycerol) respectively. The result shows that the efficiency of immobilized enzyme process is higher compared to supercritical process but having lower end product purity. From the energy consumption point of view, supercritical process consume about 8.9 MW while immobilized enzyme process consume much lower energy which is 3.9 MW. Consequently, this study certifies that energy consumption of supercritical process is 2.3 times higher than immobilized enzyme process.

Comparative Study of NIR-based Prediction Methods for Biomass Weight Loss Profiles

  • Cho, Hyun-Woo;Liu, J. Jay
    • Clean Technology
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    • v.18 no.1
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    • pp.31-37
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    • 2012
  • Biomass has become a major feedstock for bioenergy and other bio-based products because of its renewability and environmental benefits. Various researches have been done in the prediction of crucial characteristics of biomass, including the active utilization of spectroscopy data. Near infrared (NIR) spectroscopy has been widely used because of its attractive features: it's non-destructive and cost-effective producing fast and reliable analysis results. This work developed the multivariate statistical scheme for predicting weight loss profiles based on the utilization of NIR spectra data measured for six lignocellulosic biomass types. Wavelet analysis was used as a compression tool to suppress irrelevant noise and to select features or wavelengths that better explain NIR data. The developed scheme was demonstrated using real NIR data sets, in which different prediction models were evaluated in terms of prediction performance. In addition, the benefits of using right pretreatment of NIR spectra were also given. In our case, it turned out that compression of high-dimensional NIR spectra by wavelet and then PLS modeling yielded more reliable prediction results without handling full set of noisy data. This work showed that the developed scheme can be easily applied for rapid analysis of biomass.

Basic Study on Flame-Stabilization Characteristics in a Multi-Channel Combustor via a Model of a Porous-Media Combustor (다공성 연소기 모델로서의 다중 채널 연소기 내부 화염의 안정화 특성 기초 연구)

  • Park, Seung-Il;Lee, Min-Jung;Kim, Nam-Il
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.8
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    • pp.815-823
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    • 2011
  • Combustion phenomena in porous media combustors are widely used in industrial fields for the combustion of lowgrade fuels and the regeneration of combustion heat. However, studies of combustion phenomena in porous media have been limited, because these phenomena are difficult to observe, and the configurations of porous media are complex. We propose a simple model combustor: a multi-channel combustor that consists of many layers of combustion channels made of quartz plates. We conducted an experimental observation of the flames in the multi-channel combustor and obtained experimental results for the flame stabilization limits. Flames formulated in the multi-channel combustor showed variation in the spatial distribution depending on the heat transfer between neighboring channels. A simple analytical model was developed and the variation in the flammability limits of the multi-channel combustor was discussed. This study will enhance our understanding of flame behavior in a porous-media combustor.

Optimal Design of Magnetically Levitated Flywheel Energy Storage System Based on System Stability Using Rigid-Body Model (강체모델 기반 시스템 안정성을 고려한 자기부상 플라이휠 에너지 저장장치의 최적 설계)

  • Kim, Jung-Wan;Yoo, Seong-Yeol;Bae, Yong-Chae;Noh, Myoung-Gyu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.3
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    • pp.283-289
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    • 2010
  • Owing to the increasing worldwide interest in green technology and renewable energy sources, flywheel energy storage systems (FESSs) are gaining importance as a viable alternative to traditional battery systems. Since the energy storage capacity of an FESS is proportional to the principal mass-moment of inertia and the square of the running speed, a design that maximizes the principal inertia while operatingrunning at the highest possible speed is important. However, the requirements for the stability of the system may impose a constraint on the optimal design. In this paper, an optimal design of an FESS that not only maximizes the energy capacity but also satisfies the requirements for system stability and reduces the sensitivity to external disturbances is proposed. Cross feedback control in combination with a conventional proportional-derivative (PD) controller is essential to reduce the effect of gyroscopic coupling and to increase the stored energy and the specific energy density.

State of the Art in the Development of Methane/Oxygen Liquid-bipropellant Rocket Engine (메탄/산소 이원액체추진제 로켓엔진 기술개발 동향)

  • Kim, Jeong Soo;Jung, Hun;Kim, Jong Hyun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.6
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    • pp.120-130
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    • 2013
  • A study was conducted for the performance characteristics of methane taking recently the limelight in the world as a next-generation propellant, with the survey for state of the art in the development of methane/oxygen rocket engine being accompanied. Liquid methane as a rocket fuel has the favorable characteristics such as non-toxic, low cost, regenerative cooling capability, and potential for in-situ resource utilization (ISRU). The combination of liquid methane and liquid oxygen also provides the excellent performance including high specific impulse and low system mass. For these reasons, many researches have been actively carried out on the methane/oxygen engine, nevertheless, its technology readiness level is not that high enough just yet. Therefore, it is judged that it is the time to mitigate the technical gap with the space technology of advanced countries through a swift onset of the development of methane rocket engine.

A Review on R&D and Commercialization of Oil Recovery from Waste Plastics by Pyrolysis (폐합성수지(廢合成樹脂)류의 열분해(熱分解) 유화(油化) 기술(技術) 동향(動向))

  • Shin, Dae-Hyun;Nho, Nam-Sun;Kim, Sung-Soo;Kim, Kwang-Ho;Jeon, Sang-Gu
    • Resources Recycling
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    • v.19 no.1
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    • pp.3-12
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    • 2010
  • Recently, the waste energy utilization has become the main interest in energy industries, due to high oil prices, the low carbon, green growth policy and the RPS (Renewable Portfolio Standards) of our government. Therefore, energy guzzling companies such as district heating companies, textile industries are replacing energy to RDP/RPF. Especially, a lot of big companies are carrying out survey to commercialize the waste plastics pyrolysis technologies developed in Korea. In this paper, status of the pyrolysis technology of Korea were reviewed overall including basis of technology, waste plastics resources, research & development, and commercialization.