• 에너지공학
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• 제25권4호
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• pp.214-225
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• 2016

목재 바이오매스를 이용한 가스화 공정은 고열량의 합성가스를 통해 알콜류, SNG 등 다양한 에너지 자원으로 변환시킴으로써 자원의 재순환에 기여할 수 있으며, $CO_2$ 등의 온실가스를 감소시킴으로써 지구온난화 방지에 기여할 수 있다. 본 연구에서는 이중유동층 가스화기에 목재 바이오매스를 투입하여 가스화기의 최적운전 조건을 도출하고, SNG 생산효율을 검증함으로써 이중유동층 가스화기에 대한 국내 상용화 기반을 마련하고자 하였다. 목재 바이오매스에 대한 가스화기의 최적 운전조건 도출 결과, 운전온도 $826^{\circ}C$에서 Steam 투입량 1,334g/hr, Air 투입량 5.56L/min일 때 탄소전환율이 81%로 확인되었으며, SNG 생산을 위한 $CH_4$가스 농도를 확인한 결과, 92%로 나타났다.

• 한국농공학회논문집
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• 제58권3호
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• pp.39-46
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• 2016

This study investigated the potential use and the effectiveness of biomass ashes for the stabilization of heavy metals in soil through a series of experiments. The ashes used for the experiments were obtained from the gasification of biomass including miscanthus and woodchips. The amounts of nickel and chromium released from the soil and ash mixture were analyzed. Chemical analysis showed that the ash contained unburned carbon as well as silica and alkali metals. Miscanthus ashes have C (83.400 %) > Si (9.040 %) > K (3.180 %) > Ca (1.800 %), and woodchip ashes have C (93.800 %) > Ca (2.220 %) > Fe (1.370 %) > K (1.200 %). KSLT and TCLP test results implied that the heavy metal concentrations were below the environmental standards and would not impose the risks. The results also showed that Ni releases were more limited as more ashes were mixed with the soil due to the increases in exchangeable, carbonate, and oxide nikels. Both miscanthus and woodchip ahses were effective in stabilizing nickel and chromium through mixing with the soil. It could be seen that ashes produced from biomass gasification can be used to stabilize the heavy metals in soils.

• 한국농공학회논문집
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• 제57권1호
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• pp.79-87
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• 2015

A thermochemical equilibrium model was constructed for predicting composition of synthesis gas in biomass gasification. The model included estimation of equilibrium constants using Gibbs free energy. After constructing the model, the results were compared with the experimental values and predictions from a previous model. Gas compositions were reasonably well agreed with them and showed effects of operational and fuel condition. When the reaction temperature increased, the lower heating values decreased due to the decrease in CH4 concentrations. The methane concentrations were lower than those observed in experimental results. The model was used to predict the gas composition and heating values for the cases of mixed fuel of charcoal and un-dry woodchips. Although downdraft gasifiers require fuels less than 15% of moisture contents, the model results indicated that the mixed fuel with charcoal and woodchips which had over 25% of moisture contents could be used in the downdraft gasifiers. It might be explained by increase in energy density resulting from mixing charcoal. The results imply that the efforts and costs for drying biomass fuels could be reduced by mixing charcoal or fuels with higher calorific values.

• 한국농공학회논문집
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• 제50권4호
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• pp.51-58
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• 2008

Unit costs for energy production in bioenergy facilities are dependent upon both fixed cost for facility construction and operational costs including biomass feedstock supply. With the increase of capacity, unit fixed cost could be decreased while supply cost tends to increase due to the longer transportation distance. It is desirable to take into account biomass availability in planning bioenergy facilities. A cumulative curve relationship was proposed to relate biomass availability and cumulative products of biomass amount and transportation distance. Optimum size of gasification facilities was affected by collection cost, biomass cumulative relationship. Based on biomass availability of Icheon-City, optimum sizes were about $400kW_{th}$ for gas production, and about $200kW_{el}$ for power generation. Unit cost of bioenergy production could be substantially reduced by reducing collection cost through supplying biomass from diverse sources including land development areas where significant amount of waste wood is generated. When planning bioenergy facilities, however, biomass availability and spatial distribution are key factors in determining the size of capacity.

• 자원리싸이클링
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• 제18권2호
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• pp.51-55
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• 2009

초고온의 수증기를 발생하는 brown gas 화염을 이용하여 톱밥, 하수슬러지 및 PE의 가스화를 수행하였다. Steam/carbon ratio를 $1{\sim}5$로 변화시키면서 생성가스 농도, 가스화 속도, 타르 생성량 및 합성가스의 발열량에 대한 steam/carbon ratio의 영향을 고찰하였으며 반응기내 온도 분포를 살펴보았다. 생산된 합성 가스는 steam/carbon ratio의 변화에 따라 최고 70 vol%의 가연성 가스를 함유한 가스를 생산하였으며 가연성 가스 중 수소의 농도가 가장 높은 것으로 나타났다. 가연성 가스의 발열량 및 타르의 생성량은 steam/carbon ratio가 증가할수록 감소하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.256-259
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• 2008

The gasification of biomass, sawdust, was carried out in order to investigate gasification characteristics. The experiment was performed using a down-draft fixed bed gasifier to surpass tar components generation in the gasification process. In the experiments, we investigated synthetic gas composition by varying reaction temperature, steam/carbon ratio, and excess ratio (ER), respectively. Higher reaction temperature, $700^{\circ}C$ to $900^{\circ}C$, could obtain higher $H_2$ yield. However, we could not obtain any meaning data by varying S/C ratio. Using $O_2$-LNG burner in the top of the gasifier may surpass water-gas shift reaction by increasing $CO_2$ concentration from the LNG-$O_2$ combustion reaction.

• 한국농공학회논문집
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• 제53권6호
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• pp.17-22
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• 2011

Biomass gasification provides synthesis gas or syngas that can be used for internal combustion engines as fuel or chemical synthesis as feedstock. Among different types of gasifiers, downdraft gasifier can produce relatively clean syngas with lower tar contents. In this study, a downdraft gasifier was fabricated with 150 mm of hearth diameter to gasify woodchip that is commercially available in this country. After drying woodchip to about 20 %, gasification experiments were conducted measuring temperature, pressure, air and gas flow rates. The volumetric concentrations of CO, $H_2$, $CO_2$, $CH_4$ were 10.7~14.5, 16.5~21.4, 12.5~16.6, and 2.3~2.9, respectively. They were overall within the ranges of the results that the previous studies showed. However, CO concentration was relatively lower and H2 was slightly higher than those from other studies. It seemed that water gas shift reaction was occurred due to the moisture in the fuel woodchip. Additional drying process coupled with syngas cooling would be required to improve the overall efficiency and syngas quality.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.784-787
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• 2007

A process flowsheet simulation model based on ASPEN PLUS was developed to investigate the effect of co-gasification of coal and rice husk on the gasifier performance and pollutant emissions in IGCC power plant. The analyses were done for an 02-blown, pulverized gasifier using coal and rice husk as feedstock, parameter employed the blending ratio of rice husk in coal were investigated. From the simulation results, it was found that gaseous pollutant emissions were reduced substantially with the increase of the blending ratio of rice husk. An optimum range between 15% and 25% rice husk-to-coal ratio was found to be the optimum point in terms of gaseous pollutant emission per energy output for sui fur and nitrogen compounds.

• 공업화학전망
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• 제15권6호
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• pp.39-53
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• 2012

지속가능한 바이오매스 자원으로부터 열, 전력을 비롯하여 연료부터 화학원료까지 다양한 제품들을 생산하는 열화학적 전환 공정들이 높은 관심을 받고 있다. 특히 수소, 일산화탄소로 구성된 합성가스를 생산하고 이를 전력, 연료 등을 동시에 생산하는 가스화 공정에 대한 학계, 산업계, 정부의 관심이 매우 높다. 그러나 바이오매스 가스화를 통해 생산된 합성가스는 타르, 황산화물 등의 오염물질들을 함유하고 있어 후속 공정들의 이용을 위하여 정제 공정을 반드시 거쳐야 한다. 본고에서는 바이오매스 가스화 기술에 적용되는 일반적인 정제 과정에 대해서 서술하였으며 세부적으로 불순물 제거 공정, 산성가스 제거 공정, 타르 제거 공정 등의 연구 개발 동향을 살펴보았다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2014년도 제49회 KOSCO SYMPOSIUM 초록집
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• pp.267-270
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• 2014

Since contaminants of syngas obtained from the biomass gasification are removed, the syngas is clean fuel. In this study a high-efficiency energy production system is developed. The system produces electricity using a waste pressure and feeds a low-pressure steam to Dyeing industrial complex. Also, iron oxide derived from dyeing sludge is utilized as a self-catalyst to reform a tar and reduce a tar emission from gasifier. This system increases the amount of syngas and finally achieves a highly efficient gasification.