• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.63-68
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• 2007

An experimental study was carried out to investigate gasification process of wood sawdust in the 1-dimensional downdraft fixed bed gasifier. The preheated air which was used oxidizer and steam were used as a gasifying agent. The downdraft fixed bed gasifier obtains more amount of hydrogen and methane by increasing residence time of supplied air. 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. We get the sample gas at the end of gasifier and it was eonugh time to finishing the chemical reaction. Finally, the amount of hydrogen and methane were increased widely as increasing the oxidizer temperature and adding steam.

• 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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• 2010.11a
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• pp.129.2-129.2
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• 2010

As a part of the government renewable energy policy, KOWEPO is constructing 300MW IGCC plant in Taean. IGCC plant consists of gasification block, air separation unit and power block, which performance test is separately conducted. Overall performance test for IGCC plant is peformed to comply with ASME PTC 46. Major factors affected on the overall efficiency for IGCC plant are external conditions, each block performance(gasification, ASU, power block), water/steam integration and air integration. Performance parameters of IGCC plant are cold gas efficiency, oxygen consumption, sensible heat recovery of syngas cooler for gasification block and purity of oxygen, flow amount of oxygen and nitrogen, power consumption for air separation unit and steam/water integration among the each block. The gas turbine capacity applied to the IGCC plant is 20 percent higher than NGCC gas turbine due to the low caloric heating value of syngas, therefor it is possible to utilize air integration between gas turbine and air separation unit to improve overall efficiency of the IGCC plant and there is a little impact on the ambient condition. It is very important to optimize the air integration design with consideration to the optimized integration ratio and the reliable operation. Optimized steam/water integration between power block and gasification block can improve overall efficiency of IGCC plant where the optimized heat recovery from gasification block should be considered. Finally, It is possibile to achieve the target efficiency above 42 percent(HHV, Net) for 300MW Taean IGCC plant by optimized design and integration.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.5
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• pp.1-8
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• 2022

Hydrogen can be produced by gasification of biomass and other combustible fuels. Depending on oxydant agents, syngas or producer gas compositions become quite different. Since biomass has limited amount of hydrogen including moisture in it, the hydrogen concentration in the syngas is about 15% when air is supplied for oxidant agent. Experiments were conducted to investigate the channges in hydrogen concentrations in syngas with different oxidant agent conditions, fuel conditions, and external heat supply. Allothermal reaction resulted in higher concentrations of hydrogen with the supply of steam over air, reaching over 60%. Hydrogen is produced by water-gas and water-gas shift reactions. These reactions are endothermic and require enough heat. Autothermal reaction occurred in the downdraft gasifier used in the experiment did not provide enough heat in the reactions for hydrogen production. Steam seems a more desirable oxidant agent in producing the syngas with higher concentrations of hydrogen from biomass gasifications since nitrogen is included in syngas when air is used.

• 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.

• Korean Chemical Engineering Research
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• v.53 no.6
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• pp.783-791
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• 2015

A fluidized-bed reactor with an inside diameter of 0.1 m and a height of 1.2 m was used to study the effect of steam and catalyst additions to air-blown biomass gasification on the production of producer gas. The equipment consisted of a fluidized bed reactor, a fuel supply system, a cyclone, a condenser, two receivers, steam generator and gas analyzer. Silica sand with a mean particle diameter of $380{\mu}m$ was used as a bed material and calcined dolomite ($356{\mu}m$), which is effective in tar reduction and producer gas purification, was used as the catalyst. Both of Korea wood pellet (KWP) and a pellet form of EFB (empty fruit bunch) which is the byproduct of Southeast Asia palm oil extraction were examined as biomass feeds. In all the experiments, the feeding rates were 50 g/min for EFB and 38 g/min for KWP, respectively at the reaction temperature of $800^{\circ}C$ and an ER (equivalence ratio) of 0.25. The mixing ratio (0~100 wt%) of catalyst was applied to the bed material. Air or an air-steam mixture was used as the injection gas. The SBR (steam to biomass ratio) was 0.3. The composition, tar content, and lower heating value of the generated producer gas were measured. The addition of calcined dolomite decreased tar content in the producer gas with maximum reduction of 67.3 wt%. The addition of calcined dolomite in the air gasification reduced lower heating value of the producer gas. However The addition of calcined dolomite in the air-steam gasification slightly increased its lower heating value.

• Journal of Energy Engineering
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• v.16 no.1 s.49
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• pp.32-39
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• 2007

Coal pyrolysis processes vary with the origin and rank of coal. It is difficult to generalize the characteristics of coal pyrolysis reaction because the process consists of numerous reactions including pyrolysis, gasification, and combustion. To find out the optimum process condition it is necessary to determine the condition fur each coal from the smatter scale experiment. In this study pressurized ($2kg_{f}/cm^{2}$) fluidized bed, low temperature ($735{\sim}831^{\circ}C$) gasification using Kideco coal was performed. The reaction condition and product gas composition were determined from the variables including steam flow rate, coal feed rate and air flow rate. Optimum reaction condition was determined from the concentrations of $H_{2}$, and CO in the product gas. The ratio of air/coal was 4.45 and that of steam/coal was 0.21 respectively. The concentrations of CO and $H_{2}$ decreased with the increase of $CO_{2}$. It is important to control the feed rates of coal and steam because the reaction temperature rapidly increased when the combustion reaction dominates over the gasification reaction. The concentrations of CO and $H_{2}$ were 18%, 17% respectively from the continuous operating condition.

• 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%.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.1237-1242
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• 2008

A study on waste heat utilization of melted slags at pyorlysis, gasification and melting system was performed. Researchers studied heat balance of substances that flow and flow out to the system which is consisted of melting furnace, combustion chamber, and waste heat boiler, then they calculated melting slags' quantity of heat by the first law of thermodynamics. If they use water cursh pit outflow which is gotten by quenching of melting slag as a energy for heating and cooling system, steam of waste heat boiler would be delivered to a steam turbine, making energy, then they will get 67,671,000 won of profit a year. It will take 3 years to repossess the cost that they invested for building it. And, if we predict durability of trash burner is 20 years, we will get approximately 1,150,407,000 won of profits in 17 years without the period when we repossess the building costs.

• Journal of Energy Engineering
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• v.6 no.1
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• pp.104-113
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• 1997

This study aims to develop an analysis model using a commercial process simulator-ASPEN PLUS for an IGCC (Integrated Gasification Combined Cycle) system consisting a dry coal feeding, oxygen-blown entrained gasification process by Shell, a low temperature gas clean up process, a General Electric MS7001FA gas turbine, a three pressure, natural recirculation heat recovery steam generator, a regenerative, condensing steam turbine and a cryogenic air separation unit. The comparison between those results of this study and reference one done by other engineer at design conditions shows consistency which means the soundness of this model. The greater moisture contents in Illinois#6 coal causes decreasing gasifier temperature and the greater ash and sulfur content hurt system efficiency due to increased heat loss. As the results of sensitivity analysis using developed model for the parameters of gasifier operating pressure, steam/coal ratio and oxygen/coal ratio, the gasifier temperature increases while combustible gases (CO＋H2) decreases throughout the pressure going up. In the steam/coal ratio analysis, when the feeding steam increases the maximum combustible gas generation point moves to lower oxygen/coal ratio feeding condition. Finally, for the oxygen/coal ratio analysis, it shows oxygen/coal ratio 0.77 as a optimum operating condition at steam/coal feeding ratio 0.2.