• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.288-294
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• 2013

Recently, sustainable production of biofuel using algal biomass is being pursued because of its enormous potential. First and foremost, securing superior strains to develop an efficient production system for algal biodiesel through screening or genetic improvement of microalgae is necessary. The genus of Botryococcus is regarded as one of the superior microalgae for biodiesel production due to its ability to accumulate high amounts of lipids and hydrocarbons. However, its low growth rate is a bottleneck for large-scale production and commercialization. The purpose of this study is to obtain indigenous Botryococcus strains which possess high lipid content and biomass productivity. The Botryococcus sp. was isolated from the Seobu Reservoir in Jeju Island and identified as Botryococcus sudeticus J2 by comparative analysis of 18s rRNA gene and ITS regions. The biomass productivity and lipid content of B. sudeticus J2 were 0.116 g $L^{-1}day^{-1}$ and 40.1% of dry wt., respectively. This was higher than the value of B. braunii UTEX 572, which is widely regarded as a superior strain among Botryococcus species. The relatively high growth rate of B. sudeticus J2 was achieved under a light intensity of 240 ${\mu}mol$ photons $m^{-2}s^{-1}$ with ambient air spargingwhen compared to 120 ${\mu}mol$ photons $m^{-2}s^{-1}$ with 2% $CO_2$ supply. In summary, it is likely that the isolated B. sudeticus J2 can be used for the mass cultivation and biodiesel production.

• Applied Chemistry for Engineering
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• v.27 no.2
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• pp.171-178
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• 2016

Extensive efforts from all over the world have been made to solve energy problems, such as high oil prices, global warning due to the depletion of oil. Among them, biofuel has been drawing attention as a clean energy, which can replace fossil fuels. However, conventional biofuels were often converted from eatable biomass such as sugar cane, corn and soy which should be replaced with uneatable biomass. In this study, a techno-economical evaluation of the gasification of biomass waste with mixed alcohol synthesis process was performed. Considering available domestic biomass wastes, a 2000 ton/day conversion plant were assumed to produce 533000 L/day ethanol. Also, financial data from previous studies were evaluated and used and economical sensitivities with various operation conditions were established. Economic analysis were conducted by the payback period and internal rate of return (IRR) and net present value (NPV). Sensitivity analyses of raw material costs, initial investment, the major process cost, ethanol price changes and operating costs were all performed.

• The monthly packaging world
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• s.217
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• pp.45-56
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• 2011

바이오 플라스틱은 탄소저감, 인체 무해성, 플라스틱의 대체재로서 주목을 받고 있으나 아직 해결할 과제가 남아 있는 실정이다. 그 중에서 시급한 것은 (1) 가격 경쟁력 확보, (2) 내열성, 가공성, 내충격성 등 물성 개선, (3) 가공기술 개발, 응용분야 확대, (4) 분해기간 조절에 따른 유통기간이 1년 이상인 제품에 적용성 등 보완 연구, (5) 표준화, 규격기준 제정 작업 등이 필요하다. 특히 고추장, 된장, 김치, 젓갈, 치즈, 발효유 등 발효식품 포장재의 경우 제품 중에 미생물이 살아 있는 경우가 있고, 유통기한이 길기 때문에 분해기간을 장기화할 필요가 있다. 또한 유통중 및 보관 중 이산화탄소 등 가스 발생 우려가 있는 농산물, 수산물, 식품류 등은 포장재에 숨쉬는 기능 등 유사 생체막 기능 부여가 필요한 실정이다. 현재 바이오 폴리머 생산기술이 계속 발전하고 있고, 또한 가격 경쟁력도 강화되고 있어 급속한 시장 확대도 개대할 수 있는 수준이다. 석유계 플라스틱의 생산단가는 kg당 1.5~2달러 수준인 반면, 생분해 플라스틱인 PLA, 지방족폴리에스터, TPS, PHB 등은 kb당 4~5 달러 수준이다. 또한 이를 보완한 바이오매스 플라스틱은 약 2달러 수준을 유지하고 있다.

• Clean Technology
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• v.23 no.4
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• pp.435-440
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• 2017

Fast pyrolysis of third generation biomass, including micro- and macroalgae for biofuel production has recently been studied and compared experimentally to first- and second-generation biomass. Compared to microalgae, however, process design and simulation study of macroalgae for scale-up has been rare in literature. In this study, we designed and simulated an industrial scale process for producing diesel range biofuel from brown algae based on bench scale experimental data of fast pyrolysis using a commercial process simulator. During process design, special attention was paid to the process design to accommodate the differences in composition of brown algae compared to terrestrial biomass. The entire process of converting 380,000 tonnes of dry brown algae per year into diesel range biofuel was economically evaluated and the minimum (diesel) selling price was also estimated through techno-economic analysis.

• Journal of the KSME
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• v.50 no.9
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• pp.39-42
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• 2010

바이오가스는 세계적으로 풍부한 바이오매스 자원에서 발생하고 지구온난화 문제에 대응할 수 있는 탄소중립 청정에너지원이다. 이 글에서는 유럽의 바이오가스 생산 및 시작동향 중에서도 EU 생산량의 35%를 차지하는 독일의 현황에 대해 살펴보고자 한다.

• Clean Technology
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• v.26 no.4
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• pp.239-250
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• 2020

Biomass is an abundant renewable energy resource that can replace fossil fuels for the reduction of greenhouse gas (GHG). Indonesia has a large number of cheap biomass feedstocks, such as reforestation (waste wood) and palm residues (empty fruit bunch or EFB). In general, raw biomass contains more than 20% moisture and lacks calorific value, energy density, grindability, and combustion efficiency. Those properties are not acceptable fuel attributes as the conditions currently stand. Recently, torrefaction facilities, especially in European countries, have been built to upgrade raw biomass to solid fuel with high quality. In Korea, there is no significant market for torrefied solid fuel (co-firing) made of biomass residues, and only the wood pellet market presently thrives (~ 2 million ton yr-1). However, increasing demand for an upgraded solid fuel exists. In Indonesia, torrefied woody residues as co-firing fuel are economically feasible under the governmental promotion of renewable energy such as in feed-in-tariff (FIT). EFB, one of the chief palm residues, could replace coal in cement kiln when the emission trading system (ETS) and clean development mechanism (CDM) system are implemented. However, technical issues such as slagging (alkali metal) and corrosion (chlorine) should be addressed to utilize torrefied EFB at a pulverized coal boiler.

• Journal of the Korean Wood Science and Technology
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• v.48 no.2
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• pp.181-195
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• 2020

Characteristics of carbonized biomass obtained from a Wood charcoal briquette manufacturing process using an open hearth kiln are analyzed in this research, and differences in the characteristics based on the results of a mechanical screening process and the position within the kiln. One type of biomass and five types of carbonized biomass were collected from a Wood charcoal briquette manufacturer. After screening and grinding processes were performed on samples of 1 type of biomass and 5 types of carbonized biomass extracted from a Wood charcoal briquettes manufacturer to classify by particle size, fixed carbon, ash, volatile matters, elemental composition, and high heating value (HHV) were measured. Experimental results showed that the carbonized biomass collected from the middle layer had the highest HHV, 20.4 MJ/kg, and therefore had the highest fuel quality. In terms of particle size, the carbonized biomass below 100 mesh had the lowest ash content and the highest HHV, carbon content, and fixed carbon content. Correlation analyses showed that ash content had negative correlations with HHV, volatile matters, fixed carbon, and carbon content, which suggested that ash content affected negatively on fuel quality.

• Clean Technology
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• v.29 no.3
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• pp.200-216
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• 2023

Ginkgo leaves are considered waste biomass and can cause problems due to the strong insecticidal actions of ginkgolide A, B, C, and J and bilobalide. However, Ginkgo leaf biomass has high organic matter content that can be converted into fuels and chemicals if suitable technologies can be developed. In this study, the effect of pyrolysis temperature, minimum fluidized velocity, and Ginkgo leaf size on product yields and product properties were systematically analyzed. Fast pyrolysis was conducted in a bubbling fluidized bed reactor at 400 to 550℃ using silica sand as a bed material. The yield of pyrolysis liquids ranged from 33.66 to 40.01 wt%. The CO₂ and CO contents were relatively high compared to light hydrocarbon gases because of decarboxylation and decarbonylation during pyrolysis. The CO content increased with the pyrolysis temperature while the CO₂ content decreased. When the experiment was conducted at 450℃ with a 3.0×U_mf fluidized velocity and a 0.43 to 0.71 mm particle size, the yield was 40.01 wt% and there was a heating value of 30.17 MJ/kg, respectively. The production of various phenol compounds and benzene derivatives in the bio-oil, which contains the high value products, was identified using GC-MS. This study demonstrated that fast pyrolysis is very robust and can be used for converting Ginkgo leaves into fuels and thus has the potential of becoming a method for waste recycling.

• Journal of the Korean Wood Science and Technology
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• v.40 no.3
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• pp.147-155
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• 2012

Switchgrass was selected as a promising biomass resource for bioethanol production through popping pretreatment, enzymatic saccharification and fermentation using commercial cellulase and xylanase, and fermenting yeast. The reducing sugar yields of popping pretreated switchgrass after enzymatic saccharification were above 95% and the glucose in thesaccharificaiton solution to ethanol conversion rate after fermentation with $Saccharomyces$ $cerevisiae$ was reached to 89.6%. Chemical compositions after popping pretreatment developed in our laboratory were 40.8% glucose and 20.3% xylose, with much of glucose remaining and only xylose decreased to 4.75%. This means that the hemicelluloses area broke off during popping pretreatment. FE-SEMexamination of substrate particles after popping pretreatment was showed fiber separation, and tearing and presence of numerous micro pores. These changes help explain, enhanced enzymatic penetration resulting in improved hydrolysis of switchgrass particles after popping pretreatment.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.76-82
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• 2012

Biomass and coal are great potential energy sources for gasification process. These solids can be gasified to produce syngas and bio-oil which can be upgraded further to transportation fuel. Two biomass and three coals have been gasified with steam in a thermobalance reactor under atmospheric pressure in order to evaluate their kinetic rate information The effects of gasification temperature ($600{\sim}850^{\circ}C$) and partial pressure of steam (30~90 kPa) on the gasification rate have been investigated. The three different types of gas-solids reaction models have been applied to the experimental data to compare their predictions of reaction behavior. The modified volumetric reaction model predicts the conversion data well, thus that model was used to evaluate kinetic parameters in this study. The gasification reactivity of five solids has been compared. The obtained activation energy of coal and biomass gasification were well in the reasonable range. The expression of apparent reaction rates for steam gasification of five solids have been proposed as basic information for the design of coal gasification processes.