• Title/Summary/Keyword: packed bed reactor

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Characteristics of Packed-bed Plasma Reactor with Dielectric Barrier Discharge for Treating (에틸렌 처리를 위한 충진층 유전체배리어방전 플라즈마 반응기의 특성)

  • Sudhakaran, M.S.P.;Jo, Jin Oh;Trinh, Quang Hung;Mok, Young Sun
    • Applied Chemistry for Engineering
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    • v.26 no.4
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    • pp.495-504
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    • 2015
  • This work investigated the characteristics of a packed-bed plasma reactor system and the performances of the plasma reactors connected in series or in parallel for the decomposition of ethylene. Before the discharge ignition, the effective capacitance of the ${\gamma}$-alumina packed-bed plasma reactor was larger than that of the reactor without any packing, but after the ignition the effective capacitance was similar to each other, regardless of the packing. The energy of electrons created by plasma depends mainly on the electric field intensity, and was not significantly affected by the gas composition in the range of 0~20% (v/v) oxygen (nitrogen : 80~100% (v/v)). Among the various reactive species generated by plasma, ground-state atomic oxygen and ozone are understood to be primarily involved in oxidation reactions, and as the electric field intensity increases, the amount of ground-state atomic oxygen relatively decreases while that of nitrogen atom increases. Even though there are many parameters affecting the performance of the plasma reactor such as a voltage, discharge power, gas flow rate and residence time, all parameters can be integrated into a single parameter, namely, specific input energy (SIE). It was experimentally confirmed that the performances of the plasma reactors connected in series or in parallel could be treated as a function of SIE alone, which simplifies the scale-up design procedure. Besides, the ethylene decomposition results can be predicted by the calculation using the rate constant expressed as a function of SIE.

A Study on the Biogas Production and VSS Concentration in Organic Wastewater Treatment Using a Downflow Anaerobic Packed Bed Reactor with HRT Change (하향유식 혐기성 고정상 생물반응기에서 유기성 폐수의 HRT변화에 따른 Biogas 생성 및 VSS 농도에 관한 연구)

  • 김정회;강동수;장인용
    • Journal of Environmental Health Sciences
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    • v.19 no.3
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    • pp.17-21
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    • 1993
  • Characteristics of a downflow anaerobic packed bed reactor with raschig ring ceramics as a packing were measured and discussed for the basic evaluation of the process. A synthesized glucose substrate wastewater were used as a feed and process characteristics such as pH, biogas production, composition of produced gas, COD removal and VSS were measured with the hydraulic retention time (HRT) changing from 0.25 to 2 days. As a result, this type of reactor was applicable in continuous operation within the given HRT range and the transient period approaching the steady state was about 20 days. The content of methane in produced gas increase with HRT was always high above 50% enough to use as energy source. The COD removal efficiency increased gradually as HRT increased. The axial profile of VSS concentration in the reactor usually showed the maximum at the lower region and the minimum at the middle. The VSS concentration at the upper region and the exit appeared similarly. However, at 0.25 day of HRT, the VSS concentration of effluent became higher than that of the upper region. Therefore the optimum HRT of this reactor occurred about 0.5 day, at which the production of methane began to be just stabilized and loss of VSS and COD removal were resonable.

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Continuous Production of Transglucosylated Steviosides Using Immobilized Cyclodextrin Glucanotransferase (고정화 Cyclodextrin Glucanotransferase에 의한 당전이 스테비오사이드의 연속생산)

  • In, Man-Jin;Chae, Hee-Jeong;Kim, Min-Hong
    • Korean Journal of Food Science and Technology
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    • v.29 no.5
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    • pp.969-973
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    • 1997
  • In order to produce transglucosylated steviosides continuously, some types of bioreactors were investigated with cyclodextrin glucanotransferase immobilized on a high porous anion exchange resin, Diaion HPA75. Among the bioreactors, the packed-bed reactor (PBR) showed the highest specific productivity. The effect of linear velocity in a PBR on the stevioside conversion was not significant in the range of $10{\sim}60\;cm/hr$ at the same space velocity of $1.2\;hr^(-1)$. When the space velocity of bioreactor was varied from 0.2 to $1.1\;hr^{-1}$, the optimal velocity of substrate solution was determined as $0.7\;hr^(-1)$. The stevioside conversion of more than 70% was maintained during 20 days in the continuous operation, if about 20% of immobilized enzyme was replaced in the top of reactor after two weeks operation as the one of the control methods in bioreactor. The specific production, which refers to as the amount of commercially valuable transglucosylated steviosides produced by a unit amount of immobilized cyclodextrin glucanotransferase, was found to be ca. 150g product/g immobilized enzyme.

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A Study on the Heat Storage System for Chemical Heat Pump Using Inorganic Hydrates (III) -Numerical Analysis of Heat Transfer in Ca(OH)2 Dehydration Packed Bed- (화학열펌프에 있어서의 무기수화물계 축열시스템에 관한 연구(III) -Ca(OH)2 탈수반응층의 전열해석-)

  • Park, Young-Hae;Lee, Young-Sei;Kim, Jong-Shlk
    • Applied Chemistry for Engineering
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    • v.7 no.6
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    • pp.1181-1191
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    • 1996
  • To develope chemical heat pump, which is operated by heat of high temperature using available energy sources such as solar heat and many kinds of waste thermal energy we have studied theoretically the enhancement effects of inserted fins on the rate of heat transfer and reaction in cylinderical $Ca(OH)_2$ packed bed reactor. The results obtained by numerical analysis about profiles of temperature, completion time of reaction and exothermic heat amount released from the reactor read as the inserted copper fins in reator reduce the completion time of dehydration reaction in packed bed by half, and the rate of thermochemical reaction depends on the temperature and concentration, and it is also governed by the boundary conditions and the rate of heat transfer in the particle packed bed.

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Recycled packed-bed reactor for efficient denitrification (재순환 충전탑식 반응기를 이용한 효율적 탈질)

  • 김성홍;송승훈;박재연;유영제
    • KSBB Journal
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    • v.19 no.2
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    • pp.154-158
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    • 2004
  • Recycled packed-bed reactor emploring immobilized microorganism was suggested in this paper for efficient denitrification. In the batch reactor, the effects of initial oxidation-reduction potential and nitrate concentration on denitrification were investigated. As the initial oxidation-reduction potential was decresed to -70 mV from +40 mV, the removal rate of nitrate was increased to 3.33 from 1.25 m9 NO$_3$$\^$-/-N/min under the experimental conditions. As the initial nitrate-N concentraion was increased to 200 mg/l, the removal rate of nitrate was proportional to the concentration of nitrate. When the concentration of nitrate-N was 400 mg/min, nitrite was detected, and when the initial nitrate-N concentration was reached at 1,000 mg/l, it took longer time for the complete nitrate removal. In order to decrease the initial oxidation-reduction potential and the nitrate-N concentration in the feed stream, the effluent was recycled to the influent stream in the packed-bed reactor. In the case of recycling, the initial oxidation-reduction potential was decreased to 30 mV from 150 mV, and the initial nitrate concentration could be decreased to 85 from 120 mg NO$_3$$\^$-/-N/l. As the result of recycling, the removal rate of nitrate was increased to 91.7% from 49.2%.

Analysis of an Immobilized β-Galactosidase Reactor with Competitive Product Inhibition Kinetics (경쟁적 저해를 갖는 고정화 β-galactosidase 반응기의 해석)

  • Kang, Byung Chul
    • Journal of Life Science
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    • v.23 no.12
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    • pp.1471-1476
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    • 2013
  • The present study deals with the immobilization of Kluyveromyces lactis ${\beta}$-galactosidase on a weak ionic exchange resin (Duolite A568) as polymer support. ${\beta}$-Galactosidase was immobilized using the adsorption method. A kinetic study of the immobilized enzyme was performed in a packed-bed reactor. The adsorption of the enzyme followed a typical Freundlich adsorption isotherm. The adsorption parameters of k and n were 14.6 and 1.74, respectively. The initial rates method was used to characterize the kinetic parameters of the free and immobilized enzymes. The Michaelis-Menten constant ($K_m$) for the immobilized enzyme (120 mM) was higher than it was for the free enzyme (79 mM). The effect of competitive inhibition kinetics was studied by changing the concentration of galactose in a recycling packed-bed reactor. The kinetic model with competitive inhibition by galactose was best fitted to the experimental results with $V_m$, $K_m$, and $K_I$ values of 46.3 $mmolmin^{-1}mg^{-1}$, 120 mM, and 24.4 mM, respectively. In a continuous packed-bed reactor, increasing the flow rate of the lactose solution decreased the conversion efficiency of lactose at different input lactose concentrations. Continuous operation of 11 days was conducted to investigate the stability of a long-term operation. The retained activity of the immobilized enzymes was 63% and the half-life of the immobilized enzyme was found to be 15 days.

Effect of Sludge Pellets on $NO_x$ REmoval in $BaTiO_3$-sludge Packed-bed Reactor ($BaTiO_3$-슬러지 Packed-bed형 반응기에서 $NO_x$제거에 미치는 슬러지의 영향)

  • 박재윤;송원섭;고희석;박상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.10
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    • pp.861-867
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    • 2001
  • In this paper, in order to investigate the catalytic effect of the sludge exhausted from waterworks on NO$_{x}$ removal, we measure NO removal characteristics with and without sludge pellets in BaTiO$_3$-sludge packed-bed reactor of plate-plate geometry. NO initial concentration is 50 ppm balanced with air and a gas flow rate is 5ι/min. Gas temperature is changed from 25 to 10$0^{\circ}C$ to investigate the role of sludge pellet on removing active oxygen species and NO$_2$. BaTiO$_3$pellets is filled for coronal discharge at upstream of reactor and sludge pellets is filled for catalytic effect at downstream of reactor. The volume percent of sludge pellets to BaTiO$_3$pellets is changed from 0% to 100% and AC voltage is supplied to the reactor for discharging simulated gases. In the results, when sludge pellets is put at the downstream of plasma reactor, NO removal rate is slightly increased. However, NO$_2$and $O_3$ as by-products during NO removal is significantly decreased from 51ppm without sludge pellets to 5 ppm with sludge pellets and from 50 ppm without sludge pellets to 0.004ppm with sludge pellets, respectively. Therefore, NO$_{x}$(NO+NO$_2$) removal rate is increased up to 93%. It is thought that sludge pellet maybe react with active oxygen species and NO$_2$ generated by corona discharge in surface of BaTiO$_3$pellets, the then NO$_2$O$_3$as by-products are considerably decreased. When we increase gas temperature from room temperature to 10$0^{\circ}C$, NO removal rate is decreased, while NO$_2$ concentration is independent on gas temperature. These result suggest that the removal mechanism of active oxygen species and NO$_2$in sludge pellet is not absorption, but chemical reaction. Therefore we expect that sludge pellets exhausted for waterworks could be used as catalyst for NO$_{x}$ removal with high removal rate and low by-product.oduct.

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Effect of Various Factors on the Operational Stability of Immobilized Cells for Acrylamide Production in a Packed Bed Reactor

  • Lee, Cheo-Young;Choi, Sang-Kyo;Chang, Ho-Nam
    • Journal of Microbiology and Biotechnology
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    • v.3 no.1
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    • pp.39-45
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    • 1993
  • The effect of concentrations of phosphate buffer and acrylonitrile, pH, and various salts on the operational stability of the immobilized cells of Brevibacterium CH2 in a packed bed reactor were investigated. The effects of salts and carriers on the swelling of the immobilized beads during hydrolysis in a columnreactor were also investigated. Immobilization of the cells in Ba-alginate was more desirable than those in polyacrylamide and Ca-alinate for the swelling of the immobilized beads and the desired quality of the acrylamide produced. High quality acrylamide was produced using the Ba-alginate beads in a recycle fed-batch reactor without using an isotonic substrate. The conversion yield was nearly 100%, including a trace amount of acrylic acid produced as a by-product.

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Study on the Method of Measurement the Heat Sink of the Endothermic Catalytic Reaction in the Flow Reactor (흐름형 반응기에서 흡열 촉매반응의 흡열량 측정 방법에 대한 연구)

  • Lee, Tae Ho;Hyeon, Dong Hun;Kim, Sung Hyun;Jeong, Byung Hun;Han, Jeong Sik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.991-994
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    • 2017
  • In hypersonic aircraft, increase of aerodynamic and engine heat lead thermal load in airframe. It could lead structural change of aircraft's component and malfunctioning. Endothermic fuels are liquid hydrocarbon fuels which are able to absorb the heat load by undergoing endothermic reactions. In this study, we investigated the method of measuring the heat sink of catalyst by using exo-tetrahydrodicyclopentadiene as a fuel in a packed bed flow reactor similar to the actual reaction conditions.

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Catalystic effect of Sludge on $NO_x$ removal in Packed bed reactor (Packed bed형 반응기에서 $NO_x$ 제거에 미치는 슬러지의 촉매효과)

  • Park, Jae-Yoon;Lee, Dong-Hoon;Koh, Hee-Suk;Jung, Jang-Gun;Bae, Myung-Whan;Kim, Jong-Dal
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1780-1782
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    • 2001
  • In this experiment, an attempt to use the sludge pellets as catalyst for NO removal from simulated gas is experimentally investigated by using $BaTiO_3$-sludge packed-bed reactor of plate-plate geometry. An experimental investigation has been conducted for NO concentration of 50[ppm] balanced with air, a gas flow rate of 5[1/min]. $BaTiO_3$ pellets are filled at upstream of reactor for corona discharge and sludge pellets are put at downstream of reactor for catalystic effect. The volume rate of sludge pellets to $BaTiO_3$ pellets is 50[%] and AC voltage to dischare the gases was supplied. In the result, when sludge pellets is seperated to $BaTiO_3$ by other reactor and AC voltage is supplied to $BaTiO_3$ and sludge pellets NO, $NO_2$ removal rate is higher. When gas temperature increase from room temperature to 100[$^{\circ}C$], NO removal is decreased while $NO_2$ concentration is independent on gas temperature. This result suggest that the removal mechanism of active oxyzen species and $NO_2$ in sludge is not absorption, but chemical reaction. Temperature of heating treatment is on sludge pellets increased, $NO_x$ removal rate is decrease. It is thought that organic compound is removed by heating treatment.

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