• 펄프종이기술
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• 제46권1호
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• pp.18-28
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• 2014

Renewable Portfolio Standards(RPS) is a regulation that requires a renewable energy generated from eco-friendly energy sources such as biomass, wind, solar, and geothermal. The RPS mechanism generally is an obligatory policy that places on electricity supply companies to produce a designated fraction of their electricity from renewable energies. The domestic companies to supply electricity largely rely on wood pellets in order to implement the RPS in spite of undesirable situation of lack of wood resources in Korea. This means that the electricity supply companies in Korea must explore new biomass as an alternative to wood. Palm kernel shell (PKS) and empty fruit bunch (EFB) as oil palm wastes can be used as raw materials used for making pellets after their thermochemical treatment like torrefaction. Torrefaction is a pretreatment process which serves to improve the properties including heating value and energy densification of these oil palm wastes through a mild pyrolysis at temperature typically ranging between 200 and $300^{\circ}C$ in the absence of oxygen under atmospheric pressure. Torrefaction of oil palms wastes at above $200^{\circ}C$ contributed to the increase of fixed carbon with the decrease of volatile matters, leading to the improvement of their calorific values over 20.9 MJ/kg (=5,000 kcal/kg) up to 25.1 MJ/kg (=6,000 kcal/kg). In particular, EFB sensitively responded to torrefaction because of its physical properties like fiber bundles, compared to PKS and hardwood chips. In conclusion, torrefaction treatment of PKS and EFB can greatly contribute to the implement of RPS of the electricity supply companies in Korea through the increased co-firing biomass with coal.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2012년도 제45회 KOSCO SYMPOSIUM 초록집
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• pp.201-204
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• 2012

Combustion characteristics of boiler fuels made of bio-oil and light-oil were experimentally investigated. Bio-oil was obtained by fast pyrolysis of woody biomass. Emulsion fuel made by mixing bio-oil (up to 30wt%) with light-oil and surfactant was completely burnt, resulting in the formation of combusted gas containing CO concentration less than 10ppm. Simple mixtures of bio-oil and light-oil with separate delivery lines also gave nice combustion characteristics.

• Carbon letters
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• 제25권
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• pp.89-94
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• 2018

In this study, we tried to prepare an isotropic spinnable pitch which can be useful to prepare the general purpose carbon fiber through the co-carbonization of biomass tar with ethylene bottom oil under two different preparation methods (atmospheric distillation, pressurized distillation). The results showed that the ethylene bottom oil added co-carbonization was very effective to decrease of the oxygen contents for obtaining a stable spinnable pitch. The pressurized distillation was more effective to reduce the oxygen functional groups of pitches than atmospheric distillation. The obtained spinnable pitch by the pressurized distillation showed higher pitch yield of 42% and lower oxygen content of 9.12% than the spinnable pitch by the atmospheric distillation. The carbon fiber derived from the pressurized distillation spinnable pitch by carbonization at $800^{\circ}C$ for 5 min showed that the higher tensile strength of carbon fiber was increased up to 800 MPa.

• Environmental Engineering Research
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• 제21권2호
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• pp.180-187
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• 2016

In the present work, bael shell (aegle marmelos) is used as the feedstock for pyrolysis, using a fixed bed reactor to investigate the characteristics of the pyrolysis oil. The product yields, e.g., liquid, char and gases are produced from the biomass at different temperatures with the particle size of 0.5-1.0 mm, at the heating rate of $150^{\circ}C/min$. The maximum liquid yield, i.e., 36.23 wt.%, was found at $5500^{\circ}C$. Some physical properties of the pyrolysis oil such as calorific value, viscosity, density, pH, flash point and fire point are evaluated. The calorific value of the bael shell pyrolysis oil was 20.4 MJ/kg, which is slightly higher than the biomass, i.e., 18.24 MJ/kg. The H/C and O/C ratios of the bio-oil were found as 2.3 and 0.56 respectively, which are quite higher than some other bio-oils. Gas Chromatography and Mass Spectroscopy (GC-MS) and Fourier Transform Infra-red (FTIR) analyses showed that the pyrolysis oil of bael shell is mostly composed by phenolic and acidic compounds. The results of the properties of the bael shell pyrolysis oil reveal the potential of the oil as an alternate fuel with the essential upgradation of some properties.

• 한국수소및신에너지학회논문집
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• 제30권6호
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• pp.567-577
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• 2019

Due to the depletion of fossil fuels and environmental pollution, demand for alternative energy is gradually increasing. Among the various methods, a method to convert biomass into alternative fuel has been proposed. The bio-fuel obtained from biomass through pyrolysis process is called pyrolysis oil (PO) or bio-oil. Because PO is difficult to use directly in conventional engines due to its poor fuel properties, various methods have been proposed to upgrade pyrolysis-oil. The simplest approach is to mix it with conventional fossil fuels. However, due to their different polarity of PO and fossil fuel, direct mixing is impossible. To resolve this problem, emulsification of two fuels with a proper surfactant was proposed, but it costs additional time and cost. Alternatively, the use of alcohol fuels as an organic solvent significantly improve the fuel properties such as fuel stability, calorific value and viscosity. In this study, blends of diesel, n-butanol, and coffee ground pyrolysis oil (CGPO) which is one of the promising PO, was applied to diesel generator. Combustion and emissions characteristics of blended fuels were investigated under the entire load range. Experimental results show that ignition delay is similar to that of diesel at high load. Although, hydrocarbon and carbon monoxide emissions are comparable to diesel, significant reduction of nitrogen oxides and particulate matter emissions were observed.

• Journal of Microbiology and Biotechnology
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• 제33권9호
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• pp.1238-1249
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• 2023

In this study, we sought to investigate the production and optimization of biosurfactants by soil fungi isolated from petroleum oil-contaminated soil in Saudi Arabia. Forty-four fungal isolates were isolated from ten petroleum oil-contaminated soil samples. All isolates were identified using the internal transcribed spacer (ITS) region, and biosurfactant screening showed that thirty-nine of the isolates were positive. Aspergillus niger SA1 was the highest biosurfactant producer, demonstrating surface tension, drop collapsing, oil displacement, and an emulsification index (E₂₄) of 35.8 mN/m, 0.55 cm, 6.7 cm, and 70%, respectively. This isolate was therefore selected for biosurfactant optimization using the Fit Group model. The biosurfactant yield was increased 1.22 times higher than in the nonoptimized medium (8.02 g/l) under conditions of pH 6, temperature 35℃, waste frying oil (5.5 g), agitation rate of 200 rpm, and an incubation period of 7 days. Model significance and fitness analysis had an RMSE score of 0.852 and a p-value of 0.0016. The biosurfactant activities were surface tension (35.8 mN/m), drop collapsing (0.7 cm), oil displacement (4.5 cm), and E₂₄ (65.0%). The time course of biosurfactant production was a growth-associated phase. The main outputs of the mathematical model for biomass yield were Yx/s (1.18), and µ_max (0.0306) for biosurfactant yield was Y_p/s (1.87) and Y_p/x (2.51); for waste frying oil consumption the So was 55 g/l, and Ke was 2.56. To verify the model's accuracy, percentage errors between biomass and biosurfactant yields were determined by experimental work and calculated using model equations. The average error of biomass yield was 2.68%, and the average error percentage of biosurfactant yield was 3.39%.

• 펄프종이기술
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• 제47권1호
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• pp.24-34
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• 2015

Domestic companies supplying electricity must increase obligatory duty to use renewable energy annually. If not met with obligatory allotment, the electricity-supply companies must pay RPS (Renewable Portfolio Standards) penalty. Although the power plants using a pulverizing coal firing boiler could co-fire up to around 3 per cent with wood pellets mixed in with coal feedstock without any major equipment revamps, they recorded only about 60 per cent fulfillment of RPS. Consequently, USD 46 million of RPS penalty was imposed on the six power supplying subsidiaries of GENCOs in 2014. One of the solutions to reduce the RPS penalty is that the power supply companies adopt the co-firing of torrefied lignocellulosic biomass in coal plants, which may contribute to the use of over 30 per cent of torrefied biomass mixed with bituminous coals. Extra binder was required to form pellets using torrefied biomass such as wood chips, PKS (Palm Kernel Shell) and EFB (Empty Fruit Bunch). Instead of corn starch, 30, 50 and 70 per cent of Larix saw dusts were respectively added to the torrefied feedstocks such as Pinus densiflora chips, PKS and EFB. The addition of saw dusts led to the decrease of the calorific values of the pellets but the forming ability of the pelletizer was exceedingly improved. Another advantage from the addition of saw dusts stemmed from the reduction of ash contents of the pellets. Finally, it was confirmed that torrefied oil palm biomass such as PKS and EFB could be valuable feedstocks in making pellets through improved binding ability.

• 한국유기농업학회지
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• 제12권4호
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• pp.359-375
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• 2004

Recently, many researches on the biomass of the agricultural and livestock wastes are being conducted in several respects. The use of biomass is of benefit to the curtailment of oil import, environmental pollution decrease, global warming mitigation and so on. And, in the agricultural sphere, making use of agricultural byproducts can contribute to the revitalization of the agricultural industry and rural community. In other words, making new products or energy by using biomass have a possibility to be developed as a new industry. The industry can create new businesses and job opportunities for rural dwellers. Also, major 3 positive effects of market formation for the agricultural wastes, increase of the idle land use and creation of the new business are expected. However, the use of biomass may be difficult to secure a proper right as a market good in the autonomic market economy. It is necessary to establish or amend related laws or systematic tools for the revitalization of the biomass use. Also, it is required for the government to bear partial costs of the facilities and others in the beginning stage.

• 한국산림과학회지
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• 제96권6호
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• pp.639-643
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• 2007

숲가꾸기 사업에 의해 산출되는 바이오매스 자원과 상업적 벌채지에서의 미이용 잔존 임목 바이오매스 등의 이용은 신고유가 시대에 바이오에너지원으로 각광받을 수 있을 것이다. 이점에 착안하여 이들 사업지에서의 바이오매스 자원량 계산 및 화석연료와의 대체 가능성에 대하여 구명해 보았다. 2005년 연간 숲가꾸기 사업지 면적은 294,115 ha이며, 이중 수집되는 물량은 $143,747m^3$, 이를 바이오매스 및 발열량으로 전환하면, 115천톤, 533, 199 Gcal이다. 그러나 숲가꾸기 후 임내에 잔존하는 가지, 잎, 초두부 등 잠재공급가능한 물량은 2,483천톤이며, 등유 환산가는 약 11,133억원에 이른다. 이는 숲가꾸기에 의해 실제 수집되는 산물의 약 20배에 달하는 화석연료 대체효과를 갖는 양이다. 그리고 용재로서 임목을 이용하기 위한 상업적 벌채지의 미 이용 잔존 바이오매스량은 475천톤, 발열량으로 전환시키면 2,206,235 Gcal이 되며, 실내등유가로 환산하면, 2,211억원으로, 이 역시 화석연료를 대체할 수 있는 에너지원이 된다. 친환경적이며 재생가능한 자원으로서 임목 바이오매스의 화석연료 대체효과에 관심을 가질 시점이다.

• 공업화학
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• 제30권6호
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• pp.712-718
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• 2019

가스화(gasification)는 바이오매스로부터 에너지를 얻을 수 있는 방법 중 하나로 열화학적 변환을 통해 수소, 일산화탄소, 메탄 등으로 조성된 가연성 가스인 'producer gas'를 생산할 수 있다. 하지만 producer gas와 함께 타르(tar)를 비롯한 ash 등의 입자상 물질이 함께 생성돼, 발전 터빈이나 연소 엔진 등에 유입되어 고장을 일으키거나 배관 등에 축적되어 막힘 현상 등을 야기하므로 제거가 필요하다. 본 연구에서는 producer gas 중 타르 및 입자 제거를 위해 오일 스크러버(oil scrubber)와 집진장치를 도입하였다. 흡수용매로써 타르를 효과적으로 제거가 가능한 대두유를 사용하였고, 스크러버의 용매 온도에 따라 제거효율이 어떻게 변화하는지 실험을 통해 관찰하였다. 집진장치에는 타르로 인한 필터 눈 막힘 현상 등의 문제를 방지하기 위해 pre-coating 기술을 도입하였다. Pre-coating에 사용할 물질로써 분말 소석회와 목탄계 활성탄(wood char)을 사용하였으며, 타르(tar)를 비롯한 입자 평균 제거 효율은 소석회를 pre-coating 물질로 사용 시 86%, 활성탄의 경우 80%로 나타났다. 스크러버와 집진장치를 동시에 사용한 경우에는 평균 제거효율이 소석회는 88%, 활성탄의 경우 83%로 나타났다.