• 한국응용과학기술학회지
• /
• 제31권3호
• /
• pp.453-465
• /
• 2014

본 논문에서는 바이오매스로부터 급속열분해를 통해 난방용, 발전용 및 수송용 연료로 사용하기 위해 바이오오일을 생산하는 기술개발 현황을 나타내었다. 바이오매스를 작은 규모의 액체연료로 전환하기 위해 가장 효율적인 방법 중 하나는 급속열분해이다. 급속열분해를 통한 바이오오일은 $450^{\circ}C{\sim}600^{\circ}C$ 온도에서 바이오매스가 신속히 열분해 되어 증기 급냉를 위해 외부 산소가 없는 조건에서 생산된다. 이 바이오오일은 최초 건조 바이오매스 기준 최대 75 무게%까지 생산할 수 있지만, 일반적으로 60-75 무게% 수준이 적합하다. 본 연구에서는 바이오매스의 원료특성, 바이오오일 생산원리, 바이오오일의 특성 및 활용분야에 대한 최근의 개발현황을 살펴보았다.

• 생태와환경
• /
• 제36권4호통권105호
• /
• pp.420-426
• /
• 2003

지난 3년간(2000-2002), 식물플랑크톤 생체량의 역동적인 변화와 높은 투명도가 봄의 중순 기간 동안 낙동강 하류 부분에서 반복적으로 관찰되었다. 윤충류들은(Brachionus, Keratella, Polyarthra), 봄의 중순과 늦봄 기간 동안에 급격히 증가하였다. 늦봄 기간 동안 수체의 잔류시간의 중가 (약 20일 정도)와 수온의 상승시기에, $10^{\circ}C$로 부터 $20^{\circ}C$ 이상, 지각류의 증가를 나타내었다. 봄의 중순 높은 식물플랑크톤 생체량 시기 이후, 짧은 기간(약 1-2주)동안 낮은 식물플랑크톤 생체량과 높은 세키 투명도가 본 조사지점에서 나타났다. 봄 기간 동안 동물플랑크톤의 섭식률은 매우 높으며, 이러한 동물플랑크톤의 높은 섭식 활성도는 식물플랑크톤 동태를 조절하는 것으로 사료된다. 본 연구 결과는 강의 수체가 다소 정체되어 있는 봄 기간 동안 식물플랑크톤 생체량의 조절은 동물플랑크톤의 섭식에 의해 조절될 수 있음을 시사한다.

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 1979년도 춘계학술대회
• /
• pp.115.2-115
• /
• 1979

By employing a two-stage continuous culture system, some of important physiological parameters involved in cellulase bicsynthesis have been evalua-ted with an ultimate objective of detigning an op-timally controlled tellulase process. Volumetric and specific cellulase productivities obtained were 90 IU/liter/hr and 8IU/g biomass/hr respectively. The maximum specific enzyme productivity observed was 14.8 IU/g hiomass/hr. The optimal dilution rate in the second stage which corresponded to the maximum enzyme productivity was 0.026-0.028 hr$^{-1}$ , and the specific growth rate in the second stage ihat suported maximum specific enzyme productivity was equal to orslightly less than zero. The maintenance coefficients deter-mined for oxygen and for carbon source are M$_{o}$=0.85mmmole/g biomass/hr and M$_{c}$=0.14 mmole hexose/g bio mass/hr respectively. The yield constants determined are; Y(x/o) =32.3g biomass/mole oxygen, Y (x/c) =1.1g bio-mass/g carbon or 0.44g biomass/g hexose, Y(x/n) = 19.6g biomass/g nitrogen for the enzyme produc-tion stage and 12.5g biomass/g nitrogen for the cell growth stage.e.e.

• 설비공학논문집
• /
• 제16권6호
• /
• pp.514-521
• /
• 2004

Waste heat recovery system was studied numerically and experimentally. Heat exchanger system was designed specially to obtain the optimum heat exchanging performance. Brushwood biomass was used for the present experimental study. Two biomass heat recovery systems were designed and developed. Polyethylene helical pipe line of 0.03 m (inner diameter) was installed to recover the heat of biomass dump. The fermentation process of biomass dump was maintained for 12 weeks. The inner average temperature of biomass was about 51$^{\circ}C$ for both hot exchanger systems. The current heat recovery system could recover up to 6 ㎉/kg of energy.

• 한국연소학회:학술대회논문집
• /
• 한국연소학회 2012년도 제44회 KOSCO SYMPOSIUM 초록집
• /
• pp.223-226
• /
• 2012

Biomass to Liquid (BTL) is an attractive option for using biomass as an renewable energy. A syngas supplying system has been designed for BTL system, based on the Fischer-Tropsche (FT) process, and long-term operation test was conducted. The syngas supplying system is composed of a fluidized bed gasifier, gas cleaning and compression system, and methanol absorption system. Stable operation of more than hundred hours was achieved with several champaigns. In addition, a pilot scale biomass gasifier has been developed for 1 bbl/day BTL system and its performance was evaluated. Some preliminary results and current status of the development of BTL system will be presented.

• Journal of Microbiology and Biotechnology
• /
• 제16권8호
• /
• pp.1210-1215
• /
• 2006

The properties related to the temperature and oxygen stability of the cytoplasmic hydrogenases from the fermentative strict anaerobic bacterium, Clostridium butyricum NCIB 9576 (Cl. butyricum), and purple sulfur phototrophic bacterium, Thiocapsa roseopersicina NCIB 8347 (T. roseopersicina), were compared. The optimum temperatures for the growth of Cl. butyricum and T. roseopersicina were 37$^{\circ}C$ and 25$^{\circ}C$, respectively, whereas those for the H$_2$ evolution of the cytoplasmic hydrogenases prepared from Cl. butyricum (C-H$_2$ase) and T. roseopersicina (T-H$_2$ase) were 45$^{\circ}C$ and 65$^{\circ}C$, respectively. The T-H$_2$ase was more thermostable than the C-H$_2$ase and retained its full activity for 5 h at 50$^{\circ}C$ under anaerobic conditions and 90% of its activity at 60$^{\circ}C$, whereas the C-H$_2$ase lost its activity drastically at 50$^{\circ}C$. The optimum pHs for H$_2$ oxidation of the C-H$_2$ase and T-H$_2$ase were 9.0 and 7.5, respectively. Both enzymes showed a maximum H$_2$ evolution activity at pH 7.0. Under aerobic conditions, 80% of the T-H$_2$ase activity was retained for 10 h at 30$^{\circ}C$, and 50% of the activity remained after 6 days under the same experimental conditions. However, the C-H$_2$ase was labile to oxygen and lost its activity immediately on exposure to air. Therefore, these properties of the T-H$_2$ase are expected to be advantageous for application in in vitro biological H$_2$ production systems.

• 한국토양비료학회지
• /
• 제42권6호
• /
• pp.500-512
• /
• 2009

유기물원을 항온 배양했을 때 온도가 토양미생물체량과 효소활성 및 PLFA함량에 미치는 영향을 토양 특성별로 평가하고자 입상과 분상 혼합유기질비료, 돈분퇴비, 음식물퇴비를 화산회토양과 비화산회토양 30g에 2g을 잘 혼합 후 10, 20, $30^{\circ}C$에서 항온배양을 하면서 pH, 토양질소, 유기물 함량, Microbial biomass C와 N, 토양효소활성, 인지질지방산 함량을 분석하였다. 돈분과 음식물퇴비는 토양종류와 온도에 상관없이 토양 pH의 변화가 크지 않았으나 입상유기질비료는 온도가 높을수록 낮아졌으며, 비화산회토양에서 변화폭이 컸다. 미생물체량 C는 화산회토양의 경우 배양 온도가 높고 유기질비료를 처리할 때 높아지는 경향이었지만 토양종류에 상관없이 점차 감소하였다. 미생물체량 N은 비화산회토양에서 유기질비료, 화산회토양에서는 돈분과 음식물퇴비를 처리할 때 높게 나타났다. 인지질 지방산함량은 항온배양 75일후 비화 산회토양이 화산회토양보다 높았고, 270일후 화산회토양에서 높게 나타났으나 점차 낮아지는 경향이었다. Urease활성은 150일에 비화산회토양의 입상유기질비료처리에서 $10^{\circ}C$(75.0)>$20^{\circ}C$(16.3)>$30^{\circ}C$($4.6ug\;NH{_4-}N\;g^{-1}\;2h^{-1}$)순으로 $10^{\circ}C$에서 가장 높게 나타났으며 온도가 높고, 시간이 경과할수록 낮아졌으며 화산회토양의 Urease활성은 $10^{\circ}C$에서 높게 나타났다. ${\beta}-glucosidase$ 활성은 비화산회토양이 화산회토양보다 높았고 시간이 경과할수록 낮아졌다. 토양미생물체량 C와 미생물활성지표간의 상관계수는 비화산회토양에서 PLFA ($r^2=0.91$), 화산회토양에서 ${\beta}-glucosidase$ ($r^2=0.83$)가 높았으며, 미생물활성지표는 토양종류와 온도에 따라 상대적으로 민감도가 다르게 나타났다.

• 한국식품영양과학회지
• /
• 제21권3호
• /
• pp.263-269
• /
• 1992

무청즙액을 식물녹엽단백질의 생산과 효모의 균체생산을 위한 두가지 목적으로 이용하는 연구를 하였다. 무청즙액을 80-10$0^{\circ}C$로 가열하거나 pH를 조정하여 침전시켰을 때 침전물의 양은 모두 무청즙액 1리터당 10.0-16.5g(평균 13.5g)이었고 이 침전물의 조단백질 함량은 25-30%이었다. 단백질을 침전시켜 제거한 여액은 전당의 함량이 1.0%정도 되게 희석하여 효모 Candida utilis를 배양하였을 때 무청 여액원액 1리터당 최고 19.59의 효모균체를 생산할 수 있었다. 따라서 무청즙액 1리터로부터 생산할 수 있는 고단백질자원은 33g이었다.

• 임산에너지
• /
• 24권2호
• /
• pp.10-15
• /
• 2005

본 연구는 기후변화협약에 대응하기 위해 우리나라의 산지전용에 따른 탄소배출량을 측정할 목적으로 수행되었다. 산지전용자료는 2000년부터 2004년까지 최근 5년간 산림기본통계자료에서 추출하였으며, 임목바이오매스 탄소배출량은 임상별 바이오매스 확장계수와 탄소전환계수를 이용하였다. 최근 5년동안 산지전용면적은 연평균 약 7.2천ha가 타용도로 전용되었으며, 임목축적은 연평균 약 212천$m^3$이 벌채되었다. 최근 5년간 산지전용에 따른 임목바이오매스 총탄소배출량은 연평균 105천tC 배출한 것으로 나타났으며, 임상별 임목바이오매스 탄소배출량은 침엽수림이 54천tC, 활엽수림이 51천tC 배출한 것으로 나타났다. 최근 5년간 산지전용에 따른 ha 당 탄소배출량은 연평균 약 14.4tC/ha으로 나타났으며, 임상별로는 침엽수림이 약 13.3tC/ha, 활엽수림이 18.5tC/ha로 나타났다. 따라서 활엽수림이 단위면적당 탄소를 더 많이 배출하는 것으로 나타났다.

• 펄프종이기술
• /
• 제48권2호
• /
• pp.34-45
• /
• 2016

Global warming and climate change have been caused by combustion of fossil fuels. The greenhouse gases contributed to the rise of temperature between $0.6^{\circ}C$ and $0.9^{\circ}C$ over the past century. Presently, fossil fuels account for about 88% of the commercial energy sources used. In developing countries, fossil fuels are a very attractive energy source because they are available and relatively inexpensive. The environmental problems with fossil fuels have been aggravating stress from already existing factors including acid deposition, urban air pollution, and climate change. In order to control greenhouse gas emissions, particularly CO2, fossil fuels must be replaced by eco-friendly fuels such as biomass. The use of renewable energy sources is becoming increasingly necessary. The biomass resources are the most common form of renewable energy. The conversion of biomass into energy can be achieved in a number of ways. The most common form of converted biomass is pellet fuels as biofuels made from compressed organic matter or biomass. Pellets from lignocellulosic biomass has compared to conventional fuels with a relatively low bulk and energy density and a low degree of homogeneity. Thermal pretreatment technology like torrefaction is applied to improve fuel efficiency of lignocellulosic biomass, i.e., less moisture and oxygen in the product, preferrable grinding properties, storage properties, etc.. During torrefacton, lignocelluosic biomass such as palm kernell shell (PKS) and empty fruit bunch (EFB) was roasted under an oxygen-depleted enviroment at temperature between 200 and $300^{\circ}C$. Low degree of thermal treatment led to the removal of moisture and low molecular volatile matters with low O/C and H/C elemental ratios. The mechanical characteristics of torrefied biomass have also been altered to a brittle and partly hydrophobic materials. Unfortunately, it was much harder to form pellets from torrefied PKS and EFB due to thermal degradation of lignin as a natural binder during torrefaction compared to non-torrefied ones. For easy pelletization of biomass with torrefaction, pellets from PKS and EFB were manufactured before torrefaction, and thereafter they were torrefied at different temperature. Even after torrefaction of pellets from PKS and EFB, their appearance was well preserved with better fuel efficiency than non-torrefied ones. The physical properties of the torrefied pellets largely depended on the torrefaction condition such as reaction time and reaction temperature. Temperature over $250^{\circ}C$ during torrefaction gave a significant impact on the fuel properties of the pellets. In particular, torrefied EFB pellets displayed much faster development of the fuel properties than did torrefied PKS pellets. During torrefaction, extensive carbonization with the increase of fixed carbons, the behavior of thermal degradation of torrefied biomass became significantly different according to the increase of torrefaction temperature. In conclusion, pelletization of PKS and EFB before torrefaction made it much easier to proceed with torrefaction of pellets from PKS and EFB, leading to excellent eco-friendly fuels.