• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.112.2-112.2
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• 2011

미곡종합처리장에서 발생되는 농업부산물인 왕겨는 대부분 퇴비의 재료로 활용되고 있으며, 수익성이 없는 것으로 알려져 있다. 근래에 화석자원의 고갈이 진행되면서, 왕겨, 볏짚을 포함한 농업부산물은 화석연료와 달리 재생이 가능하고 지속 가능한 자원으로 각광을 받고 있다. 바이오매스를 이용하는 신재생에너지 기술로는 생물학적, 열화학적, 물리적 변환 기술 등이 있다. 그중 열화학적 변환 기술은 반응시간이 짧고, 단위부피당 처리량이 높으며 공정상의 폐기물이 적은 장점을 지니고 있어 왕겨의 에너지 활용에 효율적인 기술로 알려져 있다. 왕겨의 열분해 가스화는 CO, $H_2$, $CO_2$, 및 $CH_4$ 가스가 주성분인 합성가스로 전환되는 것을 말하며, 생산된 합성가스는 가스엔진의 발전 연료로 사용될 수 있다. 본 연구에서는 농업부산물인 왕겨를 이용한 열분해 가스화기에서 발생된 합성가스를 정제한 후, 20kW급 가스엔진을 적용하여 합성가스 에너지 활용특성에 관하여 고찰하였다. 그 결과 왕겨의 열분해/가스화반응에 의해 발생된 합성가스를 가스엔진으로 안정적으로 공급하였으며,16kw의 전력이 생산되는 것으로 나타났다.

• Advances in Energy Research
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• v.4 no.3
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• pp.223-237
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• 2016

The excess use of conventional sources of energy by the industries and power sector result in acute shortage of energy produced by fossil fuel. To overcome this energy crisis, biomass feedstock is used to produce syngas or producer gas. For cleaning the dust particle present in the producer gas cyclone separators are largely used. In this paper we investigate the performance parameters of cyclone separator mainly efficiency and pressure drop for different feedstock. Cyclone performance has been evaluated based on experimentation and empirical approach using Leith and Licht model. The same has also been calculated by using turbulent RSM in Ansys Fluent for Wood and Coconut shell feedstock. Experimental results show that using feed stock with 10 % Calcium oxide (CaO) by weight, the efficiency of cyclone got reduced from 71.87% to 70.75% for wood feed stock, whereas in case of coconut shell, the cyclone efficiency got reduced from 78% to 73.44%. It is also seen that Leith and Licht model and Reynolds stress model (RMS) predicts very close to the particle collection efficiency evaluated by using experimental data.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.58.2-58.2
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• 2012

Heavy hydrocarbon reforming is a core technology for "Dirty energy smart". Heavy hydrocarbons are components of fossil fuels, biomass, coke oven gas and etc. Heavy hydrocarbon reforming converts the fuels into $H_2$-rich syngas. And then $H_2$-rich syngas is used for the production of electricity, synthetic fuels and petrochemicals. Energy can be used efficiently and obtained from various sources by using $H_2$-rich syngas from heavy hydrocarbon reforming. Especially, the key point of "Dirty energy smart" is using "dirty fuel" which is wasted in an inefficient way. New energy conversion laboratory of KAIST has been researched diesel reforming for solid oxide fuel cell (SOFC) as a part of "Dirty energy smart". Diesel is heavy hydrocarbon fuels which has higher carbon number than natural gas, kerosene and gasoline. Diesel reforming has difficulties due to the evaporation of fuels and coke formation. Nevertheless, diesel reforming technology is directly applied to "Dirty fuel" because diesel has the similar chemical properties with "Dirty fuel". On the other hand, SOFC has advantages on high efficiency and wasted heat recovery. Nippon oil Co. of Japan recently commercializes 700We class SOFC system using city gas. Considering the market situation, the development of diesel reformer has a great ripple effect. SOFC system can be applied to auxiliary power unit and distributed power generation. In addition, "Dirty energy smart" can be realized by applying diesel reforming technology to "Dirty fuel". As well as material developments, multidirectional approaches are required to reform heavy hydrocarbon fuels and use $H_2$-rich gas in SOFC. Gd doped ceria (CGO, $Ce_{1-x}Gd_xO_{2-y}$) has been researched for not only electrolyte materials but also catalysts supports. In addition, catalysts infiltrated electrode over porous $La_{0.8}Sr_{0.2}Ga_{0.8}Mg_{0.2}O_3-{\delta}$ and catalyst deposition at three phase boundary are being investigated to improve the performance of SOFC. On the other hand, nozzle for diesel atomization and post-reforming for light-hydrocarbons removal are examples of solving material problems in multidirectional approaches. Likewise, multidirectional approaches are necessary to realize "Dirty energy smart" like reforming "Dirty fuel" for SOFC.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.5
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• pp.559-571
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• 2012

Dimethyl ether (DME) is a new clean fuel as an environmentally-benign energy resource. DME can be manufactured from various energy sources including natural gas, coal, and biomass. In addition to its environmentally friendly properties, DME has similar characteristics to those of LPG. The aim of this article is to represent the development of new DME process with KOGAS's own technologies. KOGAS has investigated and developed new innovative DME synthesis process from synthesis gas in gaseous phase fixed bed reactor. DME has been traditionally produced by the dehydration of methanol which is produced from syngas, a product of natural gas reforming. This traditional process is thus called the two-step method of preparing DME. However, DME can also be manufactured directly from syngas (single-step). The single-step method needs only one reactor for the synthesis of DME, instead of two for the two-step process. It can also alleviate the thermodynamic limitations associated with the synthesis of methanol, by converting the produced methanol into DME, thereby potentially enhancing the overall conversion of syngas into DME. KOGAS had launched the 10 ton/day DME demonstration plant project in 2004 at Incheon KOGAS LNG terminal. In the mid of 2008, KOGAS had finished the construction of this plant and has successively finished the demonstration plant operation. And since 2008, we have established the basic design of commercial plant which can produce 3,000 ton/day DME.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.107-107
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas have played an important role of synthesizing the valuable chemical compound, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuels and chemical production. Current thermal processing techniques such as fast pyrolysis, slow pyrolysis, and gasification tend to generate products with a large slate of compounds. Lignocellulose feedstocks such as forest residues are promising for the production of bio-oil and synthesis gas. Pyrolysis and gasification was investigated using thermogravimetric analyzer (TGA) and bubbling fluidized bed gasification reactor to utilize forest woody biomass. Most of the materials decomposed between $320^{\circ}C$ and $380^{\circ}C$ at heating rates of $5{\sim}20^{\circ}C/min$ in thermogravimetric analysis. Bubbling fluidized bed reactor were use to study gasification characteristics, and the effects of reaction temperature, residence time and feedstocks on gas yields and selectivities were investigated. With increasing temperature from $750^{\circ}C$ to $850^{\circ}C$, the yield of char decreased, whereas the yield of gas increased. The gaseous products consisted of mostly CO, CO2, H2 and a small fraction of C1-C4 hydrocarbons.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.76-82
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• 2012

Biomass and coal are great potential energy sources for gasification process. These solids can be gasified to produce syngas and bio-oil which can be upgraded further to transportation fuel. Two biomass and three coals have been gasified with steam in a thermobalance reactor under atmospheric pressure in order to evaluate their kinetic rate information The effects of gasification temperature ($600{\sim}850^{\circ}C$) and partial pressure of steam (30~90 kPa) on the gasification rate have been investigated. The three different types of gas-solids reaction models have been applied to the experimental data to compare their predictions of reaction behavior. The modified volumetric reaction model predicts the conversion data well, thus that model was used to evaluate kinetic parameters in this study. The gasification reactivity of five solids has been compared. The obtained activation energy of coal and biomass gasification were well in the reasonable range. The expression of apparent reaction rates for steam gasification of five solids have been proposed as basic information for the design of coal gasification processes.

• Environmental Engineering Research
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• v.24 no.2
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• pp.354-361
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• 2019

Renewable energy from biomass and biodegradable wastes can significantly supplement the global energy demand if properly harnessed. Pyrolysis is the most profound modern technique that has proved effective and efficient in the energy conversion of biomass to yield various products like bio-oil, biochar, and syngas. This study focuses on optimization of slow pyrolysis of banana peels waste to yield banana peels vinegar, tar and biochar as bio-infrastructure products. Response surface methodology using central composite design was used to determine the optimum conditions for the banana wastes using a batch reactor pyrolysis system. Three factors namely heating temperature ($350-550^{\circ}C$), sample mass (200-800 g) and residence time (45-90 min) were varied with a total of 20 individual experiments. The optimal conditions for wood vinegar yield (48.01%) were $362.6^{\circ}C$, 989.9 g and 104.2 min for peels and biochar yield (30.10%) were $585.9^{\circ}C$, 989.9 g and 104.2 min. The slow pyrolysis showed significant energy conversion efficiencies of about 90% at p-value ${\leq}0.05$. These research findings are of primary importance to Uganda considering the abundant banana wastes amounting to 17.5 million tonnes generated annually, thus using them as pyrolysis feedstock can boost the country's energy status.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.391-395
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• 2009

For the conversion of domestic waste-wood into energy, a fixed bed gasifier ($0.9 m{\times}2.4 m$) having the capacity of 2 ton/day was designed and constructed. The dual knife valve was used to feed waste-wood of which size was 3~5 cm and a rotary stoker system was installed in the bottom of gasifier. The pilot gasification system consisted of feeding system, fixed bed gasifier, gravity fine particle collector, heat exchanger for syngas cooling, ID fan, and cooling tower. The operation temperatures of gasifier were $700{\sim}1000^{\circ}C$ and the concentrations of syngas were CO: 25~40 vol%, $H_2$: 7~12 vol%, $CH_4$: 2~4 vol%, $CO_2$: 12~24 vol%. The calorific value of syngas was $1100{\sim}1500kcal/Nm^3$ and was enough to be applied in the industrial combustor. Also the gas engine was operated by using syngas from biomass gasifier and produced 1~4 kW of power.

• Transactions of the Korean hydrogen and new energy society
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• v.25 no.5
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• pp.459-467
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• 2014

The catalytic steam reforming of toluene, a major component of biomass tar, was studied using several catalysts at various temperatures $400-800^{\circ}C$, kind of metal, and metal loading content. Ru and K promoted Ni-base catalyst were prepared, and used for steam reforming of toluene with steam/toluene molar ratio of 25. Concentration of toluene in reactant flow is $30g/Nm^3$ that is usual content of tar from biomass gasifier. The result from experiments showed that $H_2$ content in product gas and toluene conversion increased with temperature. Where in high temperature range, CO and $CO_2$ content in product gas were affected mainly by Boudouard reaction. Ni/Ru-K(3wt%)/$Al_2O_3$ catalyst showed best performance on steam reforming of toluene than used catalysts in this study at whole temperature. Catalysts have been characterized by XRD, TG. XRD analysis displayed that Ni particle size on Ni/Ru-K (3wt%)/$Al_2O_3$ catalyst was 29.4nm. Activation energy of Ni/Ru-K (3wt%)/$Al_2O_3$ catalyst was calculated 36.8kJ/mol by Arrhenius plot.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.58-65
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• 2017

Fluidized bed gasification is technically and economically proven technology, which shows the high possibility of realization and commercialization. However, in Korea, development of FBG to the commercial scale for power generation and industry is mainly blocked by the fact that there is no experience of design, troubleshooting and operation of even pilot scale fluidized bed gasifier. In this study, a $3MW_{th}$ circulating fluidized bed(CFB) was newly developed for biomass gasification. The fluidized bed was mainly composed of circulating and bubbling fluidized reactors integrating in-situ tar removal step in the system. For cleaning of the tar and acid gas in the product gas, the sequential gas cleaning process comprised of a ceramic filter, rapid quencher and wet scrubber was adopted. Effect of equivalence ratio was investigated to find the optimal operating conditions for the $3MW_{th}$ integrated system of fluidized bed gasification.