• Journal of Microbiology and Biotechnology
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• 제17권2호
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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.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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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.

• 한국수소및신에너지학회논문집
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• 제23권4호
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• pp.337-345
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• 2012

To check effects of operating variables on reaction characteristics of WGS catalyst for SEWGS process, water gas shift reaction tests were carried out in a pressurized fluidized bed reactor using commercial WGS catalyst and sand(as a substitute for $CO_2$ absorbent) as bed materials. Simulated syngas(mixed with $N_2$) was used as a reactant gas. Operating temperature was $210^{\circ}C$ and operating pressure was 20 bar. WGS catalyst content, steam/CO ratio, gas velocity, and syngas concentration were considered as experimental variables. CO conversion increased as the catalyst content and steam/CO ratio increased. CO conversion at fluidized bed condition was higher than that of fixed bed condition. However, CO conversion were maintained almost same value within the fluidized bed condition. CO conversion decreased as the syngas concentration increased. The optimum operation condition was confirmed and long time water gas shift reaction test up to 24 hours at the optimum operating conditions was carried out.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.55-58
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• 2007

To check the feasibility of SMART (Steam Methane Advanced Reforming Technology)system, an experimental investigation was conducted. A fluidized bed reactor of diameter 0.052 m was operated cyclically up to the $10^{th}$ cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone (domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) system. However, the hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased.

• 한국수소및신에너지학회논문집
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• 제22권4호
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• pp.465-473
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• 2011

To find the optimum mixing ratio of WGS catalyst with $CO_2$ absorbent for SEWGS process, water gas shift reaction tests were carried out in a fluidized bed reactor using commercial WGS catalyst and sand (as a substitute for $CO_2$ absorbent). WGS catalyst content, gas velocity, and steam/CO ratio were considered as experimental variables. CO conversion increased as the catalyst content increased during water gas shift reaction. Variations of the CO conversion with the catalyst content were small at low gas velocity. However, those variations increased at higher gas velocity. Within experimental range of this study, the optimum operating condition(steam/CO ratio=3, gas velocity = 0.03 m/s, catalyst content=10 wt.%) to get high CO conversion and $CO_2$ capture efficiency was confirmed. Moreover, long time water gas shift reaction tests up to 20 hours were carried out for two cases (catalyst content = 10 and 20 wt.%) and we could conclude that the WGS reactivity at those conditions was maintained up to 20 hours.

• 한국수소및신에너지학회논문집
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• 제23권2호
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• pp.173-182
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• 2012

Effects of temperature, pressure, and gas residence time on methane combustion characteristics of mass produced oxygen carrier particle (OCN706-1100) were investigated in a pressurized fluidized bed reactor using methane and air as reactants for reduction and oxidation, respectively. The oxygen carrier showed high fuel conversion, high $CO_2$ selectivity, and low CO concentration at reduction condition and very low NO emission at oxidation condition. Moreover OCN706-1100 particle showed good regeneration ability during successive reduction-oxidation cyclic tests up to the 10th cycle. Fuel conversion and $CO_2$ selectivity decreased and CO emission increased as temperature increased. These results can be explained by trend of calculated equilibrium CO concentration. However, $CO_2$ selectivity increased as pressure increased and fuel conversion increased as gas residence time increased.

• 한국수소및신에너지학회논문집
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• 제23권1호
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• pp.83-92
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• 2012

Syngas combustion characteristics of mass produced oxygen carrier particle (OCN706-1100) were investigated in a pressurized fluidized bed reactor using simulated syngas and air as reactants for reduction and oxidation, respectively. The oxygen carrier showed high fuel conversion, high $CO_2$ selectivity, and low CO concentration at reduction conditions and no NO emission at oxidation conditions. Moreover, OCN706-1100 particle showed good regeneration ability during successive reduction-oxidation cyclic tests up to the 10th cycle. Fuel conversion and $CO_2$ selectivity decreased and CO emission increased as temperature increased. These results can be explained by trend of calculated equilibrium CO concentration with temperature. However, fuel conversion and $CO_2$ selectivity increased and CO emission decreased as pressure and gas residence time increased.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.791-793
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• 2009

Hydrogen has been recognized of the energy source for the future, in terms of the most environmentally acceptable energy source. A pressurized fluidized bed reactor made of carbon steel with 0.076 m I.D. and 1.0 m in height was employed for the thermocatalytic decomposition of methane to produce amount of $CO_2$ - free hydrogen with validity from a commercial point of view. The fluidized bed was proposed for withdrawing of product carbons from the reactor continuously. The methane decomposition rate with the carbon black N330 catalyst was rapidly reached a quasi-steady state and remained for several hour. The methane thermocatalytic decomposition reaction was carried out at the temperature range of 850 - 950 $^{\circ}C$, methane gas velocity of 2.0 $U_{mf}$ and the operating pressure of 1.0 -3.0 bar. Effect of operating parameters such as reaction temperature, pressure on the reaction rates was investigated and predicted the effect of a change in conditions on a chemical equilibrium thermodynamically, according to Le Chatelier's principle.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.581-588
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• 2016

To compare reduction reactivity of oxygen carrier particles, $CH_4$ combustion characteristics were measured and investigated in a bubbling fluidized bed reactor with increasing $CH_4$ concentration from 10 to 100 %. Among five oxygen carriers (OC-1, OC-2, SDN70, C14, C28), OC-1, OC-2, SDN70 particles were selected as better oxygen carriers from the viewpoints of fuel conversion and $CO_2$ selectivity. However, some oxygen carriers showed lower fuel conversion and $CO_2$ selectivity even though they have high oxygen transfer capacity. Therefore, we could conclude that not only TGA tests to measure the oxygen transfer capacity but also fluidized bed tests to analyze exhaust gas concentration should be performed to select better oxygen carrier without misunderstanding of carriers reactivity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.388-391
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• 2006

A fluidized bed reactor made of quartz with 0.055m I.D. and 1.0m in height was employed for the thermocatalytic decomposition of propane to produce $CO_2-free$ hydrogen. The fluidized bed was proposed for the continuous withdraw of product carbons from the reactor The propane decomposition rate used carbon black DCC-N330, Hi-900L as a catalyst. The propane decomposition reaction was carried out at the temperature range of $600-800^{\circ}C$, propane gas velocity of $1.0U_{mf}$ and the operating pressure of 1.0 atm. Effect of operating parameters such as reaction temperature on the reaction rates was investigated. Resulting production in our experiment were not only hydrogen but also several by products such as methane, ethylene, ethane, and propylene.