• 한국환경보건학회지
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• 제44권1호
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• pp.63-75
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• 2018

Objectives: The aim of this research is to explore the total heavy metals from a coal-fired power plant burning bituminous coal with wood pellets due to the implementation of the Renewable Portfolio Standard policy (RPS, 10% of electricity from renewable energy resources by 2023). Methods: The research was carried out by collecting archival data and using the USEPA's AP-42 & EMEP/EEA compilation of emission factors for use in calculating emissions. The Monte Carlo method was also applied for carrying out the calculations of measurement uncertainty. Results: In this paper, the results are listed as follows. Sb was measured at 110 kg (2015) and calculated as 165 kg (2019) and 201 kg (2023). Cr was measured at 1,597 kg (2015) and calculated as 1,687 kg (2019) and 1,728 kg (2023). Cu was measured at 2,888 kg (2015) and calculated as 3,133 kg (2019) and 3,264 kg (2023). Pb was measured at 2,580 kg (2015) and calculated as 2,831 kg (2019) and 2,969 kg (2023). Mn was measured at 3,011 kg (2015) and calculated as 15,034 kg (2019) and 23,014 kg (2023). Hg was measured at 510 kg (2015) and calculated as 513 kg (2019) and 537 kg (2023). Ni was measured at 1,720 kg (2015) and calculated as 1,895 kg (2019) and 1,991 kg (2023). Zn was measured at 7,054 kg (2015) and calculated as 9,938 kg (2019) and 11,778 kg (2023). Se was measured at 7,988 kg (2015) and calculated as 7,663 kg (2019) and 7,351 kg (2023). Conclusion: This shows that most heavy metals would increase steadily from 2015 to 2023. However, Se would decrease by 7.9%. This analysis was conducted with EMEP/EEA's emission factors due to the limited emission factors in South Korea. Co-firewood pellets in coal-fired power plants cause the emission of heavy metals. For this reason, emission factors at air pollution control facilities would be presented and the replacement of wood pellets would be needed.

• Korean Chemical Engineering Research
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• 제62권1호
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• pp.80-86
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• 2024

본 연구는 고체 바이오연료 생산용 원료로서 유채대의 상용화 가능성을 평가하기 위하여 수행하였다. 대형 플라스틱통에 넣은 유채대를 1% 농도의 초산 수용액에 침지하여 단리된 환원당의 함량을 분석한 결과, glucose의 함량이 가장 높았으며, 다음으로 xylose, galactose, arabinose, mannose 순으로 조사되었다. 파일럿 규모의 평다이 펠릿성형기를 이용하여 무침지 및 침지 유채대로 연료용 펠릿으로 제조하였다. 펠릿의 겉보기밀도와 발열량은 침지처리 및 목분의 혼합과 함께 증가하였으며, 이 측정치는 International Organization for Standardization(ISO)의 비목재펠릿 A 등급 기준을 크게 상회하였다. 회분 함량도 침지처리와 함께 감소하여 ISO의 A등급 기준을 만족하였다. 펠릿 내구성의 경우, 유채대의 침지처리로 증가하였으며, 펠릿 제조에 목분의 첨가와 함께 향상되었다. 그러나 그 측정치는 ISO의 B등급 기준(≧96.0%)에 미치지 못하였다. 따라서 초산 수용액 침지 유채대로 생산할 비목재 펠릿의 상용화를 위하여 내구성 향상을 위한 바인더의 사용이 필요하다는 결론을 얻었다.

• 한국산학기술학회논문지
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• 제19권2호
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• pp.660-667
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• 2018

본 연구에서는 천안시 병천 하수종말처리장의 '열건조물'로 고형연료를 제조하기 위하여 유중건조 공정의 최적 조건을 선정하는 연구를 수행하였다. 연구결과물의 특성을 평가하기 위하여 $130^{\circ}C$, $160^{\circ}C$, $190^{\circ}C$의 온도조건에서 '유증발량 측정실험' 및 '열건조물의 유중건조 실험'을 수행하였으며, 칼로리미터와 TGA 장비를 이용하여 고형연료의 성능을 측정하였다. 또한 휴대용 복합악취측정기를 이용하여 유중건조 중 복합악취, 암모니아, 황화수소 및 총 휘발성 유기화합물의 발생농도를 측정하고, EDS 장비를 이용하여 성분분석 연구를 수행하였다. 대량생산을 고려하여 기름과 열건조물의 무게비를 임의의 비율인 4:1로 고정하였고, $130^{\circ}C$에서는 일부 내부수의 순간적인 건조 이후 기름과 열건조물의 물리적인 혼합만이 진행된다고 판단된다. 환경 친화적인 측면을 고려하였을 때, $160^{\circ}C$와 $190^{\circ}C$의 건조효율에 큰 차이가 없으므로 $160^{\circ}C$의 건조온도에서 5분 이내로 처리하는 것을 최적 조건으로 선정하였다. 본 연구에서 재조한 고형연료의 신뢰성을 확보하기 위해 화력발전소 현장연료와의 성능비교 연구를 진행한 결과 발열량 4,449kcal/kg, 함수율 2%, 회분함량 34%로 현재 사용 중인 현장연료보다 대체로 우수한 성능을 나타내었으므로 기존의 목재펠릿 뿐만 아니라 석탄에너지 또한 충분히 대체할 수 있을 것이라 판단된다.

• 대한환경공학회지
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• 제36권4호
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• pp.231-236
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• 2014

톱밥은 목재부산물로 생산되는 바이오매스 자원으로 액화할 경우 가솔린에 함유된 고옥탄가 물질과 유사한 화학구조를 가지고 있기 때문에 액체 연료물질로서 사용할 수 있는 가능성이 높다. 본 연구에서는 톱밥의 열화학적 전환방법으로 아세톤-용매분해반응을 실시하여 반응온도, 반응시간, 용매의 종류가 미치는 영향과 분해 생성물 등과 같은 분해특성을 조사하였다. 아세톤-용매분해반응에 의해 톱밥으로부터 생성된 액상 생성물은 다양한 케톤, 페놀 및 퓨란 화합물이었다. 액상생성물의 연소열량은 7,824 cal/g이었으며, $350^{\circ}C$, 40분에서 액상생성물의 에너지 수율과 질량수율은 각각 60.8%, 386.4 g-oil/100 g-sawdust를 얻었다. 아세톤을 사용한 톱밥의 용매 열분해 반응시 생성된 주요물질은 4-methyl-3-pentene-2-one, 1,3,5-trimethylbezene, 2,6-dimethyl-2,5-heptadiene-4-one, 3-methyl-2-cyclopenten-1-one 등과 같은 케톤화합물로서 고옥탄가의 액체 연료로 사용 가능한 물질인 것으로 판단되었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.482-493
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• 2005

Biomass is originally photosynthesized from inorgainic compounds such as $CO_2$, minerals, water and solar energy. Recent studies have shown that anaerobic bacteria have the ability to convert recalcitrant biomass such as cellullosic or chitinoic materials to useful compounds. The biomass containing agricultural waste, unutilized wood and other garbage is expected to utilize as feed, food and fuel by microbial degradation and other metabolic functions. In this study we isolated several anaerobic, cellulolytic and chitinolytic bacteria from rumen fluid, compost and soil to study their related enzymes and genes. The anaerobic and cellulolytic bacteria, Clostridium thermocellum, Clostridium stercorarium, and Clostridium josui, were isolated from compost and the chitinolytic Clostridium paraputrificum from beach soil and Ruminococcus albus was isolated from cow rumen. After isolation, novel cellulase and xylanase genes from these anaerobes were cloned and expressed in Escherichia coli. The properties of the cloned enzymes showed that some of them were the components of the enzyme (cellulase) complex, i.e., cellulosome, which is known to form complexes by binding cohesin domains on the cellulase integrating protein (Cip: or core protein) and dockerin domains on the enzymes. Several dockerin and cohesin polypeptides were independently produced by E. coli and their binding properties were specified with BIAcore by measuring surface plasmon resonance. Three pairs of cohesin-dockerin with differing binding specificities were selected. Two of their genes encoding their respective cohesin polypeptides were combined to one gene and expressed in E. coli as a chimeric core protein, on which two dockerin-dehydrogenase chimeras, the dockerin-formaldehyde dehydrogenase and the dockerin-NADH dehydrogenase are planning to bind for catalyzing $CO_2$ reduction to formic acid by feeding NADH. This reaction may represent a novel strategy for the reduction of the green house gases. Enzymes from the anaerobes were also expressed in tobacco and rice plants. The activity of a xylanase from C. stercorarium was detected in leaves, stems, and rice grain under the control of CaMV35S promoter. The digestibility of transgenic rice leaves in goat rumen was slightly accelerated. C. paraputrificum was found to solubilize shrimp shells and chitin to generate hydrogen gas. Hydrogen productivity (1.7 mol $H_2/mol$ glucos) of the organism was improved up to 1.8 times by additional expression of the own hydrogenase gene in C. paraputrficum using a modified vector of Clostridiu, perfringens. The hydrygen producing microflora from soil, garbage and dried pelletted garbage, known as refuse derived fuel(RDF), were also found to be effective in converting biomass waste to hydrogen gas.

• 대한가정학회지
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• 제43권1호
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• pp.145-165
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• 2005

In 1937, most Korean compatriot who lived in Yunhaeju moved to Kazakhstan and Uzbekistan in Central Asia following the deportation policy of Russia. Korean compatriot have kept their traditional life style for 140 years, without a deep relationship with Korea. This study examined the heating systems of Korean compatriot in Yunhaeju, Kazakhstan and Uzbekistan, Russia. A literature review and field research, based on Ethnography as a research method, was employed. The results of the research were as following: 1) Korean compatriot in Yunhaeju use a Pechika, which is a radiator that uses hot water, and a Gudul as the main heating systems, but the use of a Pechika was most common. A Pechika functions for cooking as well as for warming the house. The room with the Gudul was connected to the kitchen, so this space was used as a place for cooking and eating, for family members to meet. Many kinds of fuel, like gas and electricity, were used to power the heating systems. 2) Korean compatriot in Kazakhstan use radiators, with hot water as the main heating system, with ratio using Gudul used in this region being the highest of all the three areas. The most common fuels used for a Gudul were wood and coal, and gas was also used in cooking. The room with the Gudul was planned to be located beside the fireplace, without any walls. The people using a Gudul use that place for eating and meeting, as well as for family members to sleep. 3) The main heating system of Korean compatriot in Uzbekistan was a radiator using hot water, and those with pipes containing hot water buried under the floor were very common. The function is very similar to that of a Gudul, so most people using this type of radiator would sleep on the floor. Those people with a traditional Gudul not using them were mostly in Uzbekistan. The reason for this was that the family members had diminished, so it was hard work for elderly parents to manage an extra building containing a Gudul. Gas was the fuel generally used for heating and cooking in Uzbekistan. 4) Guduls were used in the Korean compatriot's houses in all three areas, even though they have changed in structure to adapt to the Russian life style. However, Guduls have still been functioning to maintain a traditional life style in Korean compatriot's houses for the gathering of family members.

• 에너지공학
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• 제26권3호
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• pp.78-89
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• 2017

미분탄화력발전소에서 사용되는 각종 발전연료의 탄화도에 따른 발열개시온도(CPT;Cross Point Temperature), 발화온도(IT; Ignition temperature) 및 발화온도 승온속도(CPS;Cross Point Slope)는 전기로 내부에 설치된 백금망에 $74{\mu}m$이하 입도의 시료를 넣고 공기분위기, $25^{\circ}C$에서 $600^{\circ}C$까지의 승온조건에서 평가하였다. 발열개시온도 및 발화온도는 탄화도에 대한 의존성이 크지 않은 반면, 발화온도 승온속도는 탄화도에 크게 의존하는 것으로 나타났다. 탄화도가 낮은 우드펠렛의 발화온도 승온속도는 $20.995^{\circ}C/min$으로 기장 높은 자연발화성을 가지며, 아역청 KIDECO탄은 $15.370^{\circ}C/min$인 반면, 가장 높은 탄화도를 가지는 석유코크스는 $20.950^{\circ}C/min$로 나타냈다. 자연발화 경향성은 석탄 표면의 산화반응에 주요한 변수로서 작용하는 휘발분 함량 및 산소관능기의 농도 뿐만 아니라 촤의 비표면적, 정압몰비열이 높을수록 증가하는 것으로 확인되었다.

• Korean Chemical Engineering Research
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• 제61권2호
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• pp.258-264
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• 2023

지속가능한 바이오에너지 이용을 위해서는 국내 바이오매스 이용 확대와 지속가능성 증대가 필수적인데, 국내 관련 체계는 아직 미비한 상황이다. 이에 바이오 연료에 대한 지속가능성 평가를 위한 앞선 체계가 마련되어 있는 EU의 RED-II 방법론을 활용하여 국내 농업 잔재물 바이오매스인 케나프(Hibiscus cannabinus L.) 줄기 펠릿을 이용한 바이오매스 발전의 전과정 온실가스 배출량을 이론적으로 산정하였다. 케나프 잔재물 펠릿의 생산경로에 대해 EU 공동연구센터(Joint Research Center)의 배출계수를 이용하여 잔재물 수집, 운송, 펠릿 연료화까지의 전과정 온실가스 배출량을 산정한 결과, 배출량은 3.0 gCO₂eq/MJ로 나타났고 이를 25% 발전효율로 연소하여 전력을 생산하는 경우 전과정 온실가스 배출량은 11.9 gCO₂eq/MJ로 산출되었다. 이는 전력배출계수로 환산하면 42.8 kgCO₂eq/MWh로, 국내 전력배출계수 443.4 kgCO₂eq/MWh와 비교하면 90.3%의 온실가스 배출량 감축을 달성할 수 있는 것으로 분석되었다. 또한 수입 목재펠릿과 비교하는 경우 최소 59.6%의 온실가스 배출 감축이 가능하여, 국내 발생 잔재물 바이오매스를 바이오에너지 생산에 이용하는 경우 기존 수입 목재펠릿에 비하여 높은 수준의 온실가스 배출 감축 달성이 가능함을 확인하였다. 이는 국내 바이오에너지의 전과정온실가스 배출량평가 체계 마련을위한 기초자료로 활용될 수있을 것으로기대된다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.43-43
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• 2014

White rot fungi have been useful source of enzymes for the degradation of environmental pollutants including polycyclic aromatic hydrocarbons (PAHs) and synthetic dyes. PAHs are widespread organic compounds present in fossil fuels and are routinely generated by incomplete fuel combustion. PAHs are some of the major toxic pollutants of water and soil environments. Synthetic dyes are major water-pollutants, which are toxic to organisms in water environments and interfere photosynthesis of water plants. Removal of PAHs and synthetic dyes has been of interests in the environmental science especially in the environmental microbiology. Mushrooms are fungal groups that function as primary degraders of wood polyphenolic lignin. The ligninolytic enzymes produced by mushroom, including manganese peroxidase, lignin peroxidase, and laccase, mediate the oxidative degradation of lignin. The catalytic power of these enzymes in the degradation of aromatic ring compounds has been sought for the degradation of various organic compounds. In this project, we have screened 60 wild mushroom strains for their degradation activity against two representative PAHs, naphthalene and anthracene, and five aromatic dyes, including alizarin red S, crystal violet, malachite green, methylene blue, rose bengal. The degradation of PAHs was measured by GC while the decolorization of dyes was measured by both UV spectrophotometer and HPLC. As results, 9 wild mushroom strains showed high activity in degradation of PAHs and textile dyes. We also describe the secretive enzyme activities, the transcription levels, and cloning of target genes. In conjunction with this, activities of degradative enzymes, including laccase, lignin peroxidase, and Mn peroxidase, were measured in the liquid medium in the presence of PAHs and dyes. Our results showed that the laccase activity was directed correlated with the degradation, indicating that the main enzyme acts on PAHs and dyes is the laccase. The laccase activity was further simulated by the addition of $Cu^{2+}$ ion. Detailed studies of the enzyme system should be sought for future applications.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2000년도 학술발표대회논문집
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• pp.91-95
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• 2000

With 106 detached houses where the aged people live alone, this study was conducted to perform a location survey of their residential environment. The result of this study is summarized as follows: While the surveyed houses' safety, sanitation and convenience appeared to be positive, with respect to the conditions of location, 73％ of the surveyed houses did not meet the requirement for comfort. The average area of each space indicated that the bedding room was 12.05$m^2$, the living room 14.71$m^2$, the kitchen 9.06$m^2$, the bathing room 4.05$m^2$, and the rest room 2.59$m^2$. Then, 93.3％ of the bedding rooms had the doorsill. Also, 97.2％ of the surveyed houses had retrievable space. The form of their living room door showed a hinged door(54.5％) and a sliding door(45.5％) which were similar with each other. The finished material was that wood accounted for 42.6％ which was highest. The cooking table form of kitchen was mainly "\ulcorner"-shaped(49.5％) and "\ulcorner"-shaped(48.5％) which were highest, and their average height appeared to be 815mm. The fuel used for kitchen was that gas accounted for 93.3％, while 95.2％ of the surveyed houses was not equipped with any gas-warning device. 75.5％ had an integrated type of bath room and toilet. In addition, the stepped difference between the bath room and other space was that 70.8％ had the difference, but they had no a satisfactory sliding-prevention device(Not for 91.6％) or heating system(Not for 92.9％).stem(Not for 92.9％).