• Journal of Forest and Environmental Science
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• 제34권4호
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• pp.352-358
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• 2018

This research paper investigates available options for implementing clean development mechanism (CDM) project in Sarawak state, Malaysia. To investigate economic feasibility, data was collected using survey and field research methods. Also, economic analysis was estimated using net present value (NPV), internal rate of return (IRR) and payback period (PBP) during the 30 years CDM: afforestation and reforestation periods. The result of economic analysis indicated that, the payback period was estimated at 9 years with 18 percent of internal rate of return (IRR). This study also highlighted that CDM biomass supply project have a lot of challenges due to the reduction and exclusion of bio-Solid Recovered Fuel (SRF), supply and demand scenario, and impact of restriction of illegal logging in Malaysia. This study results demonstrate the methodology and guideline for future CDM investment and projects.

• Journal of Plant Biotechnology
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• 제34권2호
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• pp.103-109
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• 2007

The increasing industrialization of the world has led to precipitous rise for the demand of petroleum-based fuels. The world is presently confronted with the twin crises of fossil fuel depletion and environmental pollution. The search for alternative fuels, which promise a harmonious correlation with sustainable development, energy conservation, efficiency and environmental preservation, has become highly pronounced in the present. Bioenergy is playing an increasingly important role as an alternative and renewable source of energy. Use of Bioenergy has several potential environmental advantages. The most important perhaps is reduction in life cycle greenhouse gases emissions relatives petroleum fuels, since bioenergy is derived from plants which convert Carbon dioxide ($CO_{2}$) into Carbohydrates in their growth. Bioenergy includes solid biomass, biomas and liquid bio-fuels which are fuels derived from crop plants, and include biomass that's directly burned. The two most important bio liquid fuels today are bioethanol from fermenting grain, grass, straw or wood, and biodiesel from plant seed oil.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.719-725
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• 2004

Mesquite or Vilayati babul (Prosopis juliflora) is a drought resistant, evergreen, spiny tree with drooping branches and a deep laterally spreading root system. It grows in semi-arid and arid tracts of tropical and sub-tropical regions of the world and is spreading because the leaves are unpalatable and animals do not digest its seed. The mesquite has become a major nuisance; cutting or pruning its branches to form a canopy would provide shade for travelers, aid harvesting of pods, as well as make available wood for fuel. An average plant starts fruiting by 3-4 years of age and yields annually 10-50 kg pods/ tree, which can be collected from May-June and September-October. Availability of pods worldwide is estimated to be about 2-4 million metric tonnes. Ripe pods are highly palatable; on dry matter basis they contain 12% crude protein, 15% free sugar, a moderate level of digestible crude protein (7% DCP) with a high level of energy (75% TDN). The pods contain low tannin levels below those toxic to animals. Seeds contain 31-37% protein; pods should be finely ground before feeding to facilitate utilization of the seeds. Mesquite pods could replace costlier feed ingredients such as grain and bran contributing 10-50% of the diet. Phosphorus supplements need to be added when mesquite pod, exceeds 20% of animals' diet.

• 대한화학회지
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• 제6권1호
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• pp.47-53
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• 1962

The "reactivity" of coal is one of the important characteristics of a coal used as a process raw material as well as a fuel. In this study, the reactivity was measured in terms of the magnitude of the reaction rate constant in the reduction of carbon dioxide with coal. A reactivity-testing apparatus was designed and constructed, and its performance characteristics were investigated by using Korean anthracite and hard-wood charcoal. Experiments were carried out at temperatures ranging from 750 to 1100$^{\circ}C$ with pulverized Korean anthracite whose sizes range from 1 to 10mm in diameter. Results showed that the reaction rate constant was not appreciably affected by the particle size investigated, and the reactivities of the anthracite and the charcoal were found to be a function of reaction temperature alone. It was also found that a straight line was produced when the logarithm of the rate constant is plotted against the reciprocal of the absolute temperature. The reactivities of the charcoal were found to be 2 to 10 times higher than those of the anthracite at a temperature ranging from 750 to 1100$^{\circ}C$, and 90% of carbon dioxide was reduced to carbon monoxide by the anthracite at a temperature above 1050$^{\circ}C$.

• 한국수소및신에너지학회논문집
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• 제30권2호
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• pp.178-187
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• 2019

Due to the increasing demand of high rank coal, the use of low rank coal, which has economically advantage, is rising in various industries using carbonaceous solid fuels. In addition, the severe disaster of global warming caused by greenhouse gas emissions is becoming more serious. The Republic of Korea set a goal to reduce greenhouse gas emissions by supporting the use of biomass from the Paris International Climate Change Conference and the 8th Basic Plan for Electricity Supply and Demand. In line with these worldwide trends, this paper focuses on investigating the combustibility of high rank coal Carboone, low rank coal Adaro from Indonesia, Baganuur from Mongolia and, In biomass, wood pellet and herbaceous type Kenaf were simulated as kinetic reactivity model. The accuracy of the pore development model were compared with experimental result and analyzed using carbon conversion and tau with grain model, random pore model, and flexibility-enhanced random pore model. In row lank coal and biomass, FERPM is well-matched kinetic model than GM and RPM to using numerical simulations.

• 유기물자원화
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• 제23권4호
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• pp.86-94
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• 2015

반탄화 공정은 약 $250^{\circ}C$정도의 온도에서 진행되는 열화하적 반응으로, 본 반응에 의하여 바이오매스 중에 포함된 헤미세루로스가 분해되고, 휘발성 가스를 생성하여 분리되는 과정이 진행된다. 바이오매스를 반탄화하는 중요한 이유로는 반탄화에 의하여 에너지 집적도(바이오매스 단위 중량에 포함된 열량)가 증가하게 되어 수송 등에 필요한 열량이 감소하는 장점이 있는 반면, 반탄화의 결과로 생산된 반탄화물은 화재 및 분진 폭발의 위험이 높아지는 단점이 있다. 본 연구에서는 바이오매스 연료 중 목질류로서 자연 건조된 폐목재와 초본류로서는 볏짚을 대상으로 약 $200^{\circ}C{\sim}300^{\circ}C$범위의 온도에서 반탄화 실험을 실시하여 반탄화 후 결과물의 연료적 특성을 평가하였다. 특히 C/H(탄소와 수소 비) 및 C/O(탄소와 산소비)는 연료적 특성 중 생물학적 안정성 및 연소시 오염물질(특히 수트, Soot)과 관계되는 요소로서 중요하다. 실험 결과 반탄화에 의하여 C/H는 약 2배 증가하였으며, C/O는 약 3배 증가하였다. 이는 생물학적 안정성은 감소하여 자연적으로 분해(생분해)가 진행되는 어려운 상태로 변화되었으나, 연료 중 수소의 감소에 의하여 휘발성 가스의 생성은 감소할 수 있는 것을 나타낸다. 한편 탄화된 바이오매스의 TGA(Thermogravimetric Analysis)를 실시한 결과, 저온에서의 진행되는 열분해 부분이 상대적으로 감소하였으며, 이는 단순 바이오매스 연료에 비하여 석탄과 연소 특성이 유사할 수 있는 것으로 나타내었다.

• 한국건축시공학회지
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• 제23권6호
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• pp.663-671
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• 2023

본 연구에서는 목질계 바이오매스(Bio-SRF, 우드펠릿)를 연료로 사용하는 발전소 3곳에서 배출된 4종의 목질계 플라이애시(FA)의 재활용성을 실험적으로 검토하였다. FA의 물리 분석(입형, 입도분포, 분말도, 밀도)과 화학 분석(화학조성, 중금속 함량)을 수행하였고, KS L 5405에 준하여 혼입률 5~20%의 모르타르 시험체를 제작하고 플로우와 압축강도를 측정하였다. 4종의 FA는 입경 약 20~30㎛, 밀도 약 2.3~2.5g/cm³, 분말도 2,600~4,900cm²/g, SiO₂, Al₂O₃, Fe₂O₃, CaO 성분이 약 50~90%를 차지하고 있으며, 염소와 SiO₂ 함량을 배제하고 KS L 5405의 FA 2, 3형과 유사한 특성을 보였다. 모르타르 혼입 평가 결과, 펠릿 연소 FA는 5~20% 혼입 범위에서 모르타르 압축강도는 34~47MPa로 측정되었다. 목질계 연료 100%를 연소한 FA는 혼화재 대체재로서 재활용성이 높다고 평가된다.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.294-301
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• 2017

본 연구에서는 유중건조 공정으로 가축분뇨 슬러지 고형 연료를 제조하기 위한 최적 조건을 선정하는 연구를 수행하였다. 연구결과물(슬러지 고형 연료)의 특성 평가를 위하여 유증 증발량 측정 실험, 슬러지 유중건조 실험, 그리고 건조 슬러지 성형 실험을 수행하였으며, 칼로리미터와 PXRF 장비를 이용하여 고형 연료의 성능을 측정하였다. 또한, 현재 시중에서 일반적으로 사용되고 있는 목재 고형 연료와 본 연구에서 개발한 슬러지 고형 연료 사이의 열량 비교 연구를 수행하였다. 실험결과에 따르면 대량생산 및 환경 친화적 측면을 함께 고려하였을 때, 30g의 슬러지를 $130^{\circ}C$의 식물성 기름으로 25분간 처리하는 것이 고형연료 생산에 가장 적합한 조건으로 나타났다. 본 연구에서 제조한 슬러지 고형 연료의 열량은 5211kcal/kg이었으며, 이는 시중에서 널리 사용되고 있는 목재 고형 연료의 열량보다 큰 값이다. 마지막으로, PXRF 측정 결과 황을 제외한 중금속은 검출되지 않았다. 그러므로 추후 산업용 제조기술로의 개발 시 황 성분 제어 공정에 대한 추가적인 연구가 필요할 것으로 보인다.

• 한국환경복원기술학회지
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• 제3권3호
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• pp.81-99
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• 2000

The shelterbelts are very important to conserve and protect the sandy land, vegetation coverage, farmland, livestock and human life in the desertified land. The shelterbelts are constructed by the several row-plantings of high-adaptable species in the desertified land. The shelterbelts have various kind of type, and there are shelterbelts for conservation of farmland in dry the region, the protective shelterbelts (windbreaks for blowing-sand, artificial sanddune fixation by revegetation, and construction of farmland shelterbelts to protect farmland and pasture from wind erosion, etc.) in the semi-dry steppe, shelterbelts around the villages and oasis for sanddune fixation, shelterbelts for protection of railroads, and so on. The shelterbelts consist of main she1terbelts and minor shelterbelts. The main shelterbelts were constructed by being perpendicular to main wind direction, and the minor shelterbelts were constructed by being perpendicular to the main shelterbelts. Generally, the width of shelterbelts is 8~20m, and the number of row-planting is 4~10. The grid sizes of shelterbelts networks are $400{\times}400m$, $300{\times}500m$, $100{\times}200m$, and so on, and there are ventilation type and closing type in the type of shelterbelt. The width, number of row-planting, grid size and type of shelterbelt are selected by the local characteristics. The effects of shelterbelts are mainly the climate improvement and mitigation, such as prevention of occurrence of strong wind, cold wind and blowing-sand. And, the other effects of shelterbelts are effect of reforestation, increase of agricultural productions, establishment of greenbelts and green forests, construction of landscape-eco shelterbelts, improvement of life environment of local villages, supply of fuel wood and agricultural wood, land amelioration, effect of revegetation and restoration of desertified land, and so on. The kinds of the tree species mainly used for the construction of shelterbelts have differences between regions, but main species are Populus euphratica, Populus simonii, Populus bolleana, Populus tomentosa, Salix flavida, Salix mongolica, Tamarix chinensis, Hedysarum scoparium, and so on.

• 유기물자원화
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• 제26권3호
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• pp.55-61
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• 2018

본 연구에서는 D시 내의 바이오매스와 폐플라스틱을 적정 비율로 혼합하여 고형연료제품(SRF) 품질기준을 만족하는지 분석하기로 하였다. 수분함량의 경우 바이오매스 구성비가 약 40% 이하일 때부터 9.81% 이하로 분석되었다. 회분함량의 경우 최대 4.19%로 분석되었고, 원소분석 추정식(Steuer, Dulong) 및 발열량계에 근거한 저위발열량은 최소 4,851, 4,181 및 3,847kcal/kg로 나타났다. 원소분석 결과 황(S)과 염소(Cl)는 0.05% 이하로 측정되었고 중금속(Hg, Cd, Pb, As) 함량 또한 기준치 이하를 나타냄으로써 SRF 품질기준치를 만족하였다. 이러한 결과를 바탕으로, 현재 적절하게 활용되지 못하고 산림에 버려져 있는 임목부산물을 효율적으로 사용할 수 있을 뿐만 아니라 수분에 약한 목재의 물리적 특성을 플라스틱으로 보완할 수 있을 것으로 사료된다. 또한 플라스틱 소각 시 고온으로 인한 소각로의 수명문제도 비교적 완화시킬 수 있을 것으로 판단하였다.