• Journal of the Korean Society of Combustion
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• v.13 no.2
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• pp.23-32
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• 2008

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in partial oxidation condition. Gasification characteristics are investigated with results from thermogravimetric analyzer and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction is delayed by the moisture content. However, RDF samples those are easy to break-up don't show the effect of moisture content. The result of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasification of the solid fuel. A simulation to predict the syn-gas composition was conducted by the Aspen Plus process simulator. The cold gas efficiency of the experiment was compared with results from the simulation.

• Resources Recycling
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• v.15 no.1 s.69
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• pp.58-65
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• 2006

A new technology for refused derive fuel(RDF) utilization in circulating fluidized bed is under development. The RDF is tested in a bench scale circulating fluidized bed(CFB) combustor and its burning characteristics were investigated and collected as design parameters. The combustions were controllable and the HCl emission which is most important toxic emission were below 150 ppm at the exit of the combustor. The differences between conventional coal homing circulating fluidized bed boiler and the exclusive RDF boiler were studied and commercial scale co-generation CFB for RDF was designed.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.81-85
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• 2007

A fluidized bed reactor is made with quartz. The size of FBR is 0.055 m I.D. and 1.0 m in height. The FBR was employed for the thermocatalytic decomposition of propane to produce hydrogen without $CO_{2}$. The fluidized bed was proposed for the continuous withdraw of product carbons from the reactor. Carbon black DCC-N330 is used to decompose the propane gas. The propane decomposition reaction over carbon black catalyst in a fluidized bed reactor was carried out the temperature range of 600 ${\sim}$ 800 $^{\circ}C$, propane gas velocity of 1.0 ${\sim}$ 4.0$U_{mf}$($1U_{mf}$ = 0.61cm/s) and the catalyst loading of 100 ${\sim}$ 200g. Production of $H_{2}$ such as other reaction temperature, gas velocity, catalytic loading on the reaction rates was investigated. The carbon depositied on the catalyst surface was observed by FE-SEM. The particle size of the carbon black was observed by Particle size analyzer. Resulting production in the experiment was not only hydrogen but also several by-products such as methane, ethylene, ethane, and propylene.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.161-167
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• 2007

Gasification characteristics in the fluidized bed reactor are essential for the design of a gasification furnace to optimize the operation condition. Moisture content of the solid fuel is one of the important factors to influence directly the gasification characteristics. So it is necessary to investigate the effect of moisture content of solid fuel in gasification process. Gasification characteristics are investigated with results from thermogravimetric analyser and lab-scale fluidized bed reactor for wood and RDF samples along with changing moisture contents. Additionally lab-scale fluidized bed reactor was run continuously and gas concentrations at the exit were measured. It is observed that the rate of reaction in partial oxidation condition is in between the results from the combustion environment and from the inert condition. Moisture content in a particle slows down the heating rate of a particle. So, reaction time is delayed by the moisture content. However, RDF samples that are easy to break-up doesn't show the effect of moisture content. The results of continuous operation condition shows that proper moisture content promotes gasification because steam from the particles helps gasifcation of the sold fuel.

• Proceedings of the Korean Institute of Resources Recycling Conference
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• 2005.10a
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• pp.124-134
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• 2005

A new technology for refused derive fuel(RDF) utilization in circulating fluidized bed is under development. The RDF is tested in a bench scale circulating fluidized bed(CFB) combustor and it's burning characteristics were investigated and collected as design parameters. The combustions were controllable and the HCl emission which is most important toxic emission were below 150ppm out of combustor. The differences between conventional coal burning circulating fluidized bed boiler and the exclusive RDF boiler were studied and commercial scale co-generation RDF CFB's were designed.

• Journal of Power System Engineering
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• v.16 no.4
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• pp.24-29
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• 2012

The numerical analysis by using CFX 11.0 commercial code was done for prediction of fluid flow and thermal field in the vertical heat exchanger. The present experimental studies were also conducted to investigate the effects of circulating solid particles on the fluid flow and temperatures in the fluidized bed vertical shell and tube type heat exchanger with counterflow, at which the solid particles of glasses (3 $mm{\Phi}$) were used in the fluidized bed with a smooth tube. The effect of circulation on the distance(L) of tube inlet and baffle plate was also examined. The present experimental and numerical results showed that the particles in the distance (Ds) of 15 mm showed a more efficient circulation without stacked the space and the LMTD(Log Mean Temperature Difference) in the fluidized bed type was much lower than that in the typical type shell and tube heat exchanger.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.2
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• pp.57-62
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• 2017

The heat transfer performance of a multi-heat-source fluidized bed heat exchanger was analyzed. The fluidized bed heat exchanger examined in this study can simultaneously recover the waste heat from gas, water vapor, and hot water. The effects of waste water flow rate, gas flow rate, and cooling water flow rate were examined to find their experimental correlations with the heat transfer coefficient. A computer program using the correlations was developed in this study to predict the thermal performance of the fluidized bed heat exchanger. The calculated heat transfer rates of gas, water vapor, waste water, and cooling water were compared with the measured values. It was found that the error of the calculated values was less than 12%.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.320-324
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• 2007

The removal of hydrogen sulfide ($H_2S$) from aqueous media was investigated using Thiobacillus novellas cells immobilized on a $SiO_2$ carrier (biosand). The optimal growth conditions for the bacterial strain were $30^{\circ}C$ and initial pH of 7.0. The main product of hydrogen sulfide oxidation by T. novellus was identified as the sulfate ion. A removal efficiency of 98% was maintained in the three-phase fluidized-bed reactor, whereas the efficiency was reduced to 90% for the two-phase fluidized-bed reactor and 68% for the two-phase reactor without cells. The maximum gas removal capacity for the system was 254 g $H_2S/m^3/h$ when the inlet $H_2S$ loading was $300g/m^3/h(1,500ppm)$. Stable operation of the immobilized reactor was possible for 20 days with the inlet $H_2S$ concentration held to 1,100 ppm. The fluidized bed bioreactor appeared to be an effective means for controlling hydrogen sulfide emissions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.209-213
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• 2016

The characteristics of fluidization in a centrifugal fluidized bed with a 184 mm inner diameter, 50 mm width of the gas distributor was observed by photographs and experimental works using Cu-ZSM-5 zeolite catalysts with a mean diameter of $26{\mu}m$ and $32{\mu}m$ as bed materials at a rotor at 400rpm and 600rpm. Under these experimental ranges, the experimental results clearly showed the effects of the number of rotation of the rotor on the behavior of bubbles in the centrifugal fluidized bed. As the number of rotations of the rotor increased, the gas velocity at which bubbles begin to be formed also increased but the diameter of the bubbles decreased. In addition, the size of the bubbles in the centrifugal fluidized bed were relatively smaller than those in the conventional bubbling fluidized bed.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.71-77
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• 2005

Combustion of RDF and wastewater sludge was performed in a 0.1MWth bench scale circulating fluidized bed combustor(CFBC), Combustion characteristics of the RDF and sludge mixture demonstrated stable combustion conditions. Component analysis, Combustion characteristics was measured before and after the test, and applications for commercial 1MWe CFBC boiler were prepared. The release of hazardous components such as $SO_2$ and HCl was relatively low values of 50 and 150ppm, respectively.