• Journal of the Korean Applied Science and Technology
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• v.33 no.2
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• pp.374-384
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• 2016

Concern about air pollution is gradually rising up in domestic and foreign, automotive and fuel researchers are trying to reduce vehicle exhaust emissions, through a lot of approaches, which consist of new engine design and innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research is proceeding by two main issues : exhaust emissions and PM particle emissions of gasoline vehicle. Exhaust emissions, non-regulated emissions and PM (particulate matter) particles of automotive are causing many problems which ambient pollution and harmful effects on the human body. The main particulate fraction of automotive exhaust emissions consists of small particles. Because of their small size, inhaled particles can easily penetrate deep into the lungs. The rough surfaces of these particles make it easier for them to combine with other toxins in the environment. Thus, the hazards of particle inhalation are increased. Based on the oxygenated fuel additive types (MTBE, Bio-ETBE, Bio-ethanol, Bio-butanol), this paper discussed the influence of oxygen contents on gasoline vehicle exhaust emissions, non-regulated emissions and nano-particle emissions. Also, this paper assessed exhaust emission characteristics at 2 type test modes. The test modes were FTP-75 and HWFET. All measurement items be verified less than the value of regulated emissions. It could be known difference increase and decrease by each measurement item depending on increase the oxygen contents.

• Journal of Energy Engineering
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• v.25 no.4
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• pp.214-225
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• 2016

Gasification is one of the important contribution to resource recycling by conversion of biomass to a variety of energy sources such as alcohol, SNG etc., and to global warming prevention by reduction of green house gases such as $CO_2$. The aim of this study is to draw the optimal operation condition of dual fluidized-bed gasifier with biomass fuel, to verify SNG production efficiency and to establish the basis for the domestic commercialization of dual fluidized bed gasification. As a result, dual fluidized-bed gasifier has the optimal conditions at $826^{\circ}C$ with steam input 1,334 g/hr, air input 5.56 L/min. The carbon conversion is 81% and SNG production efficiency was $CH_4$ 92%.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.1
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• pp.57-65
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• 2017

In a column experiment with low rank coal, rice straw was additionally supplied to induce methane gas generation by microorganisms in the state of supplying microorganisms and nutrients, and long-term biogas production characteristics were observed. When the weight ratio of the rice straw to coal was 0.04 or less, there was no significant gas generation. At 0.08, the biogas was generated for about 90 days. However, the methane gas generation was only 5% compared with the vial test result at optimum condition. Therefore, in order to produce biogas in the coal deposit in situ, a reactor that operates at COD concentration of 2000 mg/L or more at a ratio of 1:3 or more of rice straw to coal should be installed on the ground or under the ground. Liquid from the column filled with coal and rice straw and a liquid from vial containing rice straw were analyzed by microbial community analysis using pyrosequencing method, and compared the dominant microbial species among the two samples. In terms of the uniformity and diversity of the bacteria, the coal-filled column showed various species distribution, which has shown to be a disadvantageous microbial distribution to methane production.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.70-76
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• 2001

Proper design and improvement of the biofiltration process depend upon quantitative understanding of the kinetic behavior in the biofilter. This study was conducted to evaluate kinetics of biofiltration of gasoline vapor. Filling material of the biofilter was compost. Gas inlet concentration ranged from about $300mg/m^3$ to $7,000mg/m^3$. Gas velocities were 6m/hr and 15m/hr, respectively. At 6m/hr gas velocity, about 60% of gasoline TPH below $3,000mg/m^3$ was removed in the lower quarter part of the biofilter. First order kinetics described well the degradation rate of gasoline TPH with high correlation. First order kinetic removal constant at the gas velocity of 6m/hr was higher than that of 15m/hr from about $300mg/m^3$ to $7,000mg/m^3$. When the inlet concentration was over $3,000mg/m^3$, first order kinetic removal constant at the gas velocity of 6m/hr was over twice that at 15m/hr. In order to obtain over 80% of removal efficiency, gasoline vapor should be injected into the biofilter at concentration below about $2,000mg/m^3$, 100cm filling height and the gas velocity of 6m/hr.

• Journal of the Korean Applied Science and Technology
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• v.34 no.4
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• pp.874-882
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• 2017

As the interest on the air-pollution is gradually rising up at home and abroad, automotiv e and fuel researchers have been working on the exhaust emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward three main issues : evaporative, performance, air pollution. In addition, researcher studied the environment problems of the bio-ethanol, bio-butanol, bio-ETBE (Ethyl Tertiary Butyl Ether), MTBE (Methyl Tert iary Butyl Ether) fuel contained in the fuel as octane number improver. The researchers have many dat a about the health effects of ingestion of octane number improver. However, the data support the con clusion that octane number improver is a potential human carcinogen at high doses. Based on the bio-fuel and octane number improver types (bio-ethanol, bio-butanol, bio-ETBE, MTBE), this paper dis cussed the influence of gasoline fuel properties on the evaporative emission characteristics. Also, this p aper assessed the acceleration and power performance of gasoline vehicle for the bio-fuel property. As a result of the experiment, it was found that all the test fuels meet the domestic exhaust gas standards, and as a result of measurement of the vapor pressure of the test fuels, the bio - ethanol : 15 kPa and the biobutanol : 1.6 kPa. thus when manufacturing E3 fuel, Increasing the biobutanol content reduces evaporation gas and vapor pressure. In addition, Similar accelerating and powering performance was shown for the type of biofuel and when bio-butanol and bio-ethanol were compared accelerated perf ormance was improved by about 3.9% and vehicle power by 0.8%.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.179.2-179.2
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• 2011

바이오매스 가스화 프로세스 개발에 있어서 가장 기본적인 해결과제는 고발열량의 합성가스 제조, 냉가스 효율의 향상, 타르 발생량 저감 및 제거이다. 가스화 효율 향상에 대한 연구는 국내외 적으로 많이 이루어지고 있으나, 타르 발생량 저감에 대한 연구는 많이 이루어져 있지 않다. 타르는 분자량이 큰 방향적 탄화수소로 응축되면 점성이 높아 배관폐쇄, 정제설비의 압력손실 증가로 인해 운전정지 및 가스화율 저하의 원인이 된다. 가스화로에서 타르 발생량을 저감시키는 방법 중에는 Ni계 촉매를 이용하는 방법이 있으나, 카본 누적에 의한 활성저하, 알칼리금속에 의한 응집 등의 문제가 발생할 수 있다. 한편 철산화물은 합성가스 중의 C2-C3계의 타르를 분해하는데 효과가 알려져 있다. 따라서 본 연구에서는 적벽돌, 염색슬러지 회재 등에는 철산화물이 다량 함유되어 있는 것에 착안하여 폐기물중의 폐금속을 이용한 바이오매스 가스화에 대한 연구를 수행하였다. 점토광물계 폐기물인 적벽돌 파쇄물($SiO_2$ 67.2%, $Al_2O_3$ 19.7%, $Fe_2O_3$ 8.7%, $K_2O$ 2.0%, $TiO_2$ 1.2%, MgO 0.7%)을 전처리 한 후 유동매체로하여 우드펠렛을 가스화한 결과, 가스 생성량이 증가하고, 타르 및 탄화수소류가 감소하는 경향을 나타내었다. 특히 타르는 후단의 타르 트랩에서 타르가 거의 검출이 되지 않았다. 전처리를 하지 않은 적벽돌 파쇄물은 반응시간이 경과한 후에 가스화율이 증가함에 따라 철화합이 가스화로내에서 환원되어 타르를 분해하는데에는 어느 정도의 반응시간이 필요한 것을 확인하였다.

• Journal of Environmental Impact Assessment
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• v.13 no.4
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• pp.187-196
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• 2004

매립지에서 배출되는 메탄가스는 이산화탄소에 이어 두 번째로 많이 배출되는 지구온난화 가스이지만 열을 흡수하는 능력에 있어서는 이산화탄소 보다 25에서 35배 정도 더 크기 때문에 지구 온난화 현상에 대한 메탄가스의 영향은 중요하다고 할 수 있다. 매립지로부터 배출되는 메탄가스는 호기성 상태의 매립지 복토층을 통과 할 때 산화될 수 있으므로 매립지 복토층은 메탄가스의 배출을 저감시키는 바이오필터의 역할을 할 수 있다. 본 연구에서는 batch 실험을 통하여 매립지 복토층에서의 메탄산화속도에 대한 토양수분과 온도의 영향을 연구하였다. 최대 산화속도는 토양수분 15%(w/w), 배양온도 $35^{\circ}C$의 환경조건에서 $1.03{\mu}mol\;CH_4g^{-1}soil\;h^{-1}$으로 나타났다. 이러한 실험결과를 이용하여 토양수분과 온도를 함수로 하는 회귀모형을 개발하였다. 또한 전국에 4 군데 지역을 선발하여 각 지역의 토양수분과 온도 데이타를 수집하고 개발된 모형을 이용하여 각 지역에 위치하고 있는 매립장에서의 월 평균 메탄산화량을 예측하였다. 예측 결과 환경조건이 양호한 지역의 매립지 복토는 메탄의 배출량을 저감시킬 수 있는 효율적인 바이오필터의 효과를 가지지만 환경조건이 불리한 지역의 매립지 복토에서는 바이오필터의 효과가 크지 않는다고 할 수 있다.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.2
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• pp.91-100
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• 2017

The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. In accordance with the government's mid-to long-term policies on bio-gasification and energization of organic wastes, the expansion of the waste-to-energy (WTE) facilities is being remarkably promoted. However, because of the limitation of livestock manure containing low-concentration of volatile solids, there has been increased in combined bio-gasification without installing new anaerobic digestion facilities. The characteristics and common problems of each treatment processes were investigated for on-going 13 bio-gasification facilities. The seasonal precision monitoring of chemicophysics analysis on anaerobic digestor samples was conducted to provide guidelines for design and operation according to the progress of bio-gasification treatment. Consequently, major problems were investigated such as large deviation of organic materials depending on seasons, proper dehumidification of biogas and pretreatment of hydrogen sulfide.

• Korean Chemical Engineering Research
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• v.61 no.2
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• pp.258-264
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• 2023

The greenhouse gas (GHG) emission assessment of kenaf pellet, produced from locally generated kenaf residues in South Korea, has been studied based on the EU RED-II methodology for calculating GHG impact of biomass fuels. Based on the production pathway of kenaf residue pellet and emission coefficients from EU JRC report, the life cycle GHG emission of kenaf residue pellet is assessed as 3.0 gCO₂eq/MJ_pellet and the life cycle GHG emission of electricity generated from kenaf residue pellet is assessed as 11.9 gCO₂eq/MJ when electrical efficiency of final conversion is 25%. The potential GHG emission reduction of electricity produced from kenaf pellet is 90.3% compared to the domestic electricity emission factor 42.8 kgCO₂eq/MWh. Also, the electricity produced from kenaf pellet can reduce at least 59.6% of GHG emission compared to the electricity produced from imported wood pellets.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.57-66
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• 2014

The leachate recirculation anaerobic digestion system has the advantage of stable methane gas generation compared with existing one phase systems. In this study, an anaerobic digestion system fed with source separated food waste from school cafeteria was studied with different food waste/inoculum anaerobic sludge volume ratios (8:2, 3:7, 2:8). From this study, leachate recirculation anaerobic reactor with food waste/inoculum anaerobic sludge volume ratio of 2:8 that is 9 gVS/L of OLR(Organic Loading Rate) had the highest gas production. Also this anaerobic reactor showed daily decrease of H2S and NH3 contents in produced gas. Average biogas yield was 1.395 m3 Biogas/kg VS added. Other anaerobic reactors with food waste/inoculum anaerobic sludge volume ratio of 8:2 and 3:7 stopped methane gas production.