• 한국연소학회:학술대회논문집
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• 2012.11a
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• pp.175-176
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• 2012

As a carbon neutral fuel, biomass can be converted into various types of high-valued products such as synthetic natural gas (SNG), Hydrogen, Fischer - Tropsch (FT) diesel. and valuable chemicals. In order to make above mentioned products, gasificaion process is essential as energy utilization platform of solid biomass. In this study, state of the art and prospect for biomass gasification technologies are presented.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.247-250
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• 2008

Biomass gasification is a promising technology for producing a fuel gas which is useful for power generation systems. In biomass gasification processes, tar formation often causes some problems such as pipeline plugging. Thus, proper tar treatment is necessary. So far, nickel (Ni)-based catalysts have been intensively studied for the catalytic tar removal. However, the deactivation of Ni-based catalysts takes place because of coke deposition and sintering of Ni metal particles. To overcome these problems, we have been using ruthenium (Ru)-based catalyst for tar removal. It is reported by Okada et al., that a Ru/$Al_2O_3$ catalyst is very effective for preventing the carbon deposition during the steam reforming of hydrocarbons. Also, this catalyst is more active than the Ni-based catalyst at a low steam to carbon ratio (S/C). Benzene was used for the tar model compound because it is the main constituent of biomass tar and also because it represents a stable aromatic structure apparent in tar formed in biomass gasification processes. The steam reforming process transforms hydrocarbons into gaseous mixtures constituted of carbon dioxide ($CO_2$), carbon monoxide (CO), methane ($CH_4$) and hydrogen ($H_2$).

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3429-3434
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• 2007

An experimental study was carried out to investigate gasification process of wood sawdust in the I-dimensional downdraft fixed bed gasifier. The preheated air was used oxidizer and steam were used as a gasifying agent. The operating parameters, the supplied air temperature and steam were used. The oxidizer temperature was varied from 500K to 620K and vapor was added. The gasification process was monitored by measuring temperature at three position near the biomass using R-type thermocouples and the syngas composition was analyzed by gas chromatograph. The change of hydrogen and carbon monoxide, carbon dioxide, methane was observed. Overall, the volume fraction of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.606-609
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• 2007

An experimental study was carried out to investigate the heat value change by various conditions of wood sawdust gasification in the 1-dimensional downdraft flow fixed bed gasifier. The preheated air and steam were used as a gasifying agent. The components of syngas were influenced increasing residence time of supplied agent. The operating parameters, the supplied agent temperature and steam addition were used. The oxidizer temperature was varied from 500K to 620K. The gasification process was monitored by measuring temperature at three points near the biomass using R-type thermocouples and the syngas composition was analyzed by gas chromatograph. We get the sample gas at the end of gasifier. Finally, the amount of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.4
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• pp.59-63
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• 2013

In biomass gasification, efficiency of energy quantification is a difficult part without finishing the process. In this article, a radial basis function neural network (RBFN) is proposed to predict biomass efficiency before gasification. RBFN will be compared with a principal component regression (PCR) and a multilayer perceptron neural network (MLPN). Due to the high dimensionality of data, principal component transform is first used in PCR and afterwards, ordinary regression is applied to selected principal components for modeling. Multilayer perceptron neural network (MLPN) is also used without any preprocessing. For this research, 3 wood samples and 3 other feedstock are used and they are near infrared (NIR) spectrum data with high-dimensionality. Ash and char are used as response variables. The comparison results of two responses will be shown.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.355-356
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• 2014

Catalytic steam reforming of tar produced from biomass gasification was conducted using several Ni-based catalysts. K and Mn were used as a promoter over $Ni/Ru/Al_2O_3$ catalyst. The pellet and monolith type catalysts were prepared and applied to lab and bench-scale biomass gasification system. The $Ni/Ru-K/Al_2O_3$ catalyst shown higher performance than $Ni/Ru-Mn/Al_2O_3$ catalyst at low temperature range.

• 한국연소학회:학술대회논문집
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• 2012.04a
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• pp.231-233
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• 2012

Circulating Fluidized Bed (CFB) is a technically and economically proven technology for boiler systems and large CFB coal boilers are making inroads into the domestic power boiler market. For biomass gasification, it is also considered as a very promising technology for commercial. Due to the lack of experiences of a large scale CFB gasifier, however, any large scale CFB gasifiers are hard to in Korea in spite of fast-growing demand of domestic market. In this study, a 3 $MW_{th}$ CFB gasifier was developed for biomass gasification. The CFB gasifier consists of interconnected fast and bubbling fluidized bed reactors including unique features for in-situ tar removal. Various numerical and experimental approaches will be presented such as basic modeling works, investigation of hydrodynamics with a cold model, computational particle fluid dynamics and experiments in the 3 MWth gasifier.

• Journal of the Korean Society of Combustion
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• v.16 no.1
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• pp.8-14
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• 2011

Biomass gasification is a promising technology in terms of clean energy and flexible options for end use such as heat, steam, electricity, gaseous or liquid fuels. In a gasification process, reduction of tar is very important because it can cause any mechanical problems and small tar implies high energy efficiency. However, generation and conversion mechanisms of tar have not been fully understood due to its complex nature. In this study, characteristics of tar generated from different gasification stages were investigated. Korean pine woodchip was used as feedstock and tar was sampled in a separate way during devolatilization and char gasification stage, investigated. As a result. more various kinds of hydro carbon compounds were identified in the devolatilization stage than char gasification stage because primary tar compounds are released mostly from pyrolysis of cellulose and hemicellulose. When the reaction temperature increased up to $900^{\circ}C$, tar composition becomes simplified into about 10 aromatic compounds mostly with 1-4 rings without substitution up to phenanthrene. The sampled tar in the char gasification stage mostly contains 5-7 simple aromatic compounds.

• 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.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.6
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• pp.587-594
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• 2010

Hydrogen is an alternative fuel for the future energy which can reduce pollutants and greenhouse gases. Synthesis gas has played an important role of synthesizing the valuable chemical compounds, for example methanol, DME and GTL chemicals. Renewable biomass feedstocks can be potentially used for fuel and chemicals. 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 was used 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, $CO_2$, $H_2$ and a small fraction of $C_1-C_4$ hydrocarbons.