• Advances in environmental research
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• 제2권1호
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• pp.19-33
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• 2013

Microalgae are receiving an increasing attention because of their potential use as $CO_2$ capture method and/or as feedstock for biofuels production. On the other hand the current microalgae-based technology is still not widespread since it is characterized by technical and economic constraints that hinder its full scale-up. In such contest the growth kinetics of Nannochloris eucaryotum (a relatively unknown marine strain) in batch and semi-batch photobioreactors is quantitatively investigated with the aim of obtaining the corresponding kinetic parameters suitable for process engineering and its optimization. In particular the maximum growth rate was evaluated to be 1.99 $10^{-3}\;h^{-1}$. Half saturation concentrations for nitrates ($K_N$) and phosphates uptake ($K_P$) were evaluated as 5.4 $10^{-4}\;g_N\;L^{-1}$ and 2.5 $10^{-5}\;g_P\;L^{-1}$, respectively. Yield factors for nitrogen ($Y_N$) and phosphorus ($Y_P$) resulted to be 5.9 $10^{-2}\;g_N\;g^{-1}$ biomass and 6.0 $10^{-3}\;g_P\;g^{-1}{_{biomass}}$, respectively. The possibility of using 100% (v/v) $CO_2$ gas as carbon source is also evaluated for the first time in the literature as far as N. eucaryotum is concerned. The strain showed a good adaptability to high concentrations of dissolved $CO_2$ as well as to low pH. The lipid content under 100% $CO_2$ is about 16.16 %wt $wt^{-1}$ and the fatty acid methyl esters composition of the extracted oil is in compliance with the European regulation for quality biodiesel.

• 한국응용과학기술학회지
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• 제35권2호
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• pp.540-559
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• 2018

액상 바이오연료를 생산할 수 있는 하수슬러지는 자국의 에너지 안보와 지속가능한 생산이 가능하고 경제적인 원료로 여겨지고 있다. 열화학적 기술은 하수슬러지를 에너지화, 연료화할 수 있는 가장 효과적인 방법이다. 일반적으로 하수슬러지는 수분 함량이 80% 이상으로 높은 금속 함량과 14 ~ 20 MJ/kg의 발열량을 갖고 있다. 본 논문에서는 하수슬러지를 활용한 액상 바이오연료를 생산하는 열분해 반응, 전이에스테르화 반응, 초임계 반응 기술에 대해 살펴보고자 한다. 또한, 하수슬러지 유래 액상 바이오연료의 연료적 특성과 액상 바이오연료와 관련한 국내 법에 대해 검토하였다.

• 대한기계학회논문집B
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• 제35권11호
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• pp.1163-1168
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• 2011

압축착화 방식의 디젤엔진은 스파크점화 방식의 가솔린 엔진에 비하여 열효율이 높아 연비가 향상되고 그 결과 $CO_2$ 저감효과도 높다. 또한 디젤엔진은 점화계통 장치의 불필요 등 기존 엔진의 개조비용이 적어 세탄가가 높은 바이오연료의 적용엔진으로서 적합한 장점이 있다. 따라서 본 연구에서는 식물성 자트로파유, 대두유 2종의 바이오연료와 경유연료의 분무특성을 비교 분석하였다. 실험변수로서는 분사압력과 자트로파 연료의 경우는 혼합비율(BD3, BD5, BD20)을 달리하였다. 분사압력은 500bar, 1000bar, 1500bar 및 1600bar로 설정하고 분사기간은 500ms로 동일하게 하였다. 본 연구의 결과로서, 사용한 바이오디젤 연료의 종류 및 분사압력 변화에 대한 분무거동특성(분무각)의 변화는 뚜렷하지 않으나, 고압분사의 경우가 분무각이 약간 감소하는 결과를 얻을 수 있었다.

• Carbon letters
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• 제17권1호
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• pp.1-10
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• 2016

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.277-280
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• 2014

Global energy demand has continued to rise due to population increase and economic development. National governments and international bodies try to seek the ways to reduce the demand growth. Energy Technology Perspectives (ETP) have provided the current status of energy system, technology developments and external events that have changed ETP scenario since 2006. The status and prospects for key energy technologies of transport sector are presented. Technology portfolio for the transport sector should be needed to meet very low CO2 targets. The portfolio includes improved fuel economy of current internal combustion engine vehicles, advanced technologies such as electric and fuel-cell vehicles, advanced biofuels and demand-side management.

• 동력기계공학회지
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• 제19권2호
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• pp.90-95
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• 2015

Recently worldwide concern and research is being actively conducted on green energy which can reduce environmental pollution. A plant such as the natural rapeseed oil, soybean oil, palm, etc. is used as a bio source in home and industry. Biofuels is a sustainable fuel having economically benefits and decreasing environmental pollution problems caused due to fossil fuel, and it can be applied to the conventional diesel engine without changing the existing institutional structure. Waste vegetable oil contains a high cetane number and viscosity component, the low carbon and oxygen content. A lot of research is progressing about the conversion of waste vegetable oil as renewable clean energy. In this study, waste oil was prepared to waste cooking oil generated from the living environment, and applied to diesel engine to confirm the possibility and cost-effectiveness of biodiesel blend waste oil. As a result, brake specific fuel consumption and NOx was increased, carbon monoxide and soot was decreased.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.529-532
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• 2006

Recently the production of ethanol from lignocecllulosics has received much attention due to immense potential for conversion of renewable biometerials into biofuels and chemicals. Fomitopsis palustris causes a typycal brown-rot and is unusual in that it rapidly depolymerize the cellulose in wood without removing the surrounding lignin that normally prevents microbial attack. This study demonstrated that the brown rot basidiomycete F. palustris was able to degrade crystalline cellulose. This fungus could also produce the three major cellulases (BGL, EXG and EG) when the cells were grown on 2.0% Avicel. The fungus was able to degrade both the crystalline and amorphous forms of cellulose from woody biomasses. Moreover, we found that this fungus has the processive EG like CBH which are able to degrade the crystalline region of cellulose. To establish the cellulase system in relation with degradation of woody biomass, we performed that purification, characterization and molecular cloning of a BGL, EGs and GLA from F. palustris grown on Avicel.

• 한국농공학회논문집
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• 제52권4호
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• pp.35-44
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• 2010

Biofuel based on available biomass in rural area could contribute to increase the vitality and income of rural residents. This study estimates the potential production and environmental benefits of biofuel production from surplus rice, rice straw, cow manure, and food waste in South Korea. We could produce about 2.4 billion liters of ethanol using surplus rice and rice straw and 841 million $m^3$ of methane from cow manure and food waste. 1.7 billion liters of gasoline and 800 million liters of diesel could be replaced with these potential biofuel productions, which can annually reduce 4.9 million ton $CO_2$ eq. GHGs.

• Environmental Engineering Research
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• 제21권3호
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• pp.265-275
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• 2016

In this study, the microalga Neochloris oleoabundans was cultivated in a sustainable manner using diluted anaerobic digestate to produce biomass as a potential biofuel feedstock. Prior to microalgae cultivation, the anaerobic digestate was characterized and several pretreatment methods including hydrogen peroxide treatment, filtration, and supernatant extraction were investigated and their impact on the removal of suspended solids as well as other organic and inorganic matter was evaluated. It was found that the supernatant extraction was the most convenient pretreatment method and was used afterwards to prepare the nutrient media for microalgae cultivation. A bench-scale experiment was conducted using multiple dilutions of the supernatant and filtered anaerobic digestate in 16 mm round glass vials. The results indicated that the highest growth of the microalga N. oleoabundans was achieved with a total nitrogen concentration of 100 mg N/L in the 2.29% diluted supernatant in comparison to the filtered digestate and other dilutions.

• KSBB Journal
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• 제26권6호
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• pp.561-564
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• 2011

In this study, we carried out the development of high performance photobioreactor, which can be used to develop the biological $CO_2$ fixation technology as well as the renewable biofuels, the microalgae Botryococcus braunii. When B. Braunii was cultured in Anti-biofouling photobioreator, growth rate of it showed about 3 times higher than that of bubble column photobioreactor at the same conditions. In case of photobioreactor without bead, after 3 days culture time, biofouling occur rapidly in wall of the photobioreactor. However, with bead 5% (V/V), biofouling do not occur all experimental days.