수산물 위판장 폐기물의 처리용 소화조의 Start-up에 있어서 반응조 형상 및 슬러지층 유동화가 미치는 영향

정병곤,김병효 7개 국립대학교 환경연구논문집 공동발행 위원회 2005 공업기술연구 Vol.5 No.-

Effect of organic loading rate on digester performance is evaluated under the conditions of same surface are/reactor volume ratio and different reactor diameter. At the low loading rate of 0.4kg COD/㎥·d, high rate of organic removal could be obtained regardless of reactor diameter. It can be estimated that reactor configuration can not affect reactor performance at the low lpading rate. However, different performance depending on reactor diameter is observed at the organic loading rate of 6kg COD/㎥·d. That is, volatile acid accumulation and low COD removal efficiency is observed in reacor having 6.4cm diameter, while volatile acid is not accumulated at all and high COD removal efficiency is observed in reactor having 3cm diameter. Such a differenfe of reactor performance depending on reactor diameter can be explained that sludge bed can be fluidized by evolved gas bubble in narrow reactor, while sludge bed can not be fluidized by evolved gas bubble only in wide reactor. At a high organic loading rate of 20kg COD/㎥·d, It can be judged that there is no relation between reactor configuration and reactor performance because all reactors showed very low COD removal efficiencies regardless of reactor diameter. Sludge bed fluidization is one of the most imjprotant factors in achieving efficient start-up of anaerobic digester. Narrow and tall type reactor is favorable condition for making sludge bed fluidization at a constant surface area/reactor volume ratio.Thus, it can be judged that reactor configuration and sludge bed fluidization have great influence to reactor performance.

반응조 형태 및 슬러지층 유동화 특성에 따른 Upflow Anaerobic Sludge Blanket (UASB) 반응조의 운전효율

정병곤,Jeong Byung-Gon 한국환경보건학회 2006 한국환경보건학회지 Vol.32 No.2

Effect of organic loading rate on UASB performance was evaluated under the renditions of some surface area/reactor volume ratio and different reactor diameter. At the low leading rate of 0.4 kg $COD/m^3{\cdot}d$, reactor performance was not affected by reactor diameter. At the organic loading rate of 6 kg $COD/m^3{\cdot}d$, however, volatile acid accumulation and low COD removal efficiency is observed in reactor having 6.4 cm diameter, while volatile acid is not accumulated at all and high COD removal efficiency is observed in reactor having 3 cm diameter. Such a difference of reactor performance depending on reactor diameter can be explained that sludge bed can be fluidized by evolved gas bubble in narrow reactor, while sludge bed ran not be fluidized by evolved gas bubble only in wide reactor. At a high organic loading rate of 20 kg $COD/m^3{\cdot}d$, it can be judged that there is no relation between reactor configuration and reactor performance because all reactors showed very low COD removal efficiencies regardless of reactor diameter. Narrow and tall type reactor is favorable condition for making sludge bed fluidization at a constant surface area/reactor volume ratio. Thus, it can be judged that reactor configuration and sludge bed fluidization have great influence to reactor performance.

Optimization fluidization characteristics conditions of nickel oxide for hydrogen reduction by fluidized bed reactor

이재랑,Naim Hasolli,전성민,이강산,김광득,김용하,이관영,박영옥 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.11

We evaluated the optimal conditions for fluidization of nickel oxide (NiO) and its reduction into highpurity Ni during hydrogen reduction in a laboratory-scale fluidized bed reactor. A comparative study was performed through structural shape analysis using scanning electron microscopy (SEM); variance in pressure drop, minimum fluidization velocity, terminal velocity, reduction rate, and mass loss were assessed at temperatures ranging from 400 to 600oC and at 20, 40, and 60min in reaction time. We estimated the sample weight with most active fluidization to be 200g based on the bed diameter of the fluidized bed reactor and height of the stocked material. The optimal conditions for NiO hydrogen reduction were found to be height of sample H to the internal fluidized bed reactor diameter D was H/D=1, reaction temperature of 550oC, reaction time of 60min, superficial gas velocity of 0.011m/s, and pressure drop of 77Pa during fluidization. We determined the best operating conditions for the NiO hydrogen reduction process based on these findings.

유동상 담체를 이용한 Loop Reactor에서 유기물 및 질소, 인 제거

선용호(Yong-Ho Seon) 한국생물공학회 2009 KSBB Journal Vol.24 No.4

본 연구에서는 혐기조 및 무산소조, 호기조로 구성된 상향류식 고정상 담체 반응장치와 호기조로 고정상 담체 대신에 유동상 담체를 사용한 Loop Reactor로 이루어진 장치에서 생활하수를 이용하여 성능실험을 수행한 후 HRT에 따른 유기물 및 T-N, T-P 등 오염물질의 제거 특성을 비교 분석하였다. 두 반응기 모두 평균 BOD 제거율과 SS 제거율은 HRT가 증가함에 따라 증가하다가 HRT 16 h 이상에서는 일정한 수치를 나타내고 있으며 HRT 16 h에서 고정상 담체 반응기와 Loop Reactor의 평균 BOD 제거율은 각각 86.6%, 90.9%이었으며 평균 SS 제거율은 각각 78.0%, 88.2%로 Loop Reactor의 경우가 각각 4.3%, 10.2% 의 더 높은 BOD와 SS 제거율을 나타내었다. 또한 평균 CODCr 제거율 및 평균 CODMn 제거율은 BOD와 SS 제거율과 마찬가지로 HRT가 증가함에 따라 증가하다가 HRT 16 h에서 일정한 수치를 나타내고 있으며 고정상 담체 반응기와 Loop Reactor의 평균 CODCr 거율은 각각 63.5%, 75.2%이었으며 평균 CODMn 제거율은 각각 60.7%, 73.6%로 Loop Reactor의 경우가 11.7%, 12.9% 더 높은 제거율을 나타내었다. 반면에 평균 T-N 제거율 및 T-P 제거율은 두 반응기 모두 HRT가 증가함에 따라 제거율은 계속 증가하는 양상을 보여주고 있으며 HRT 16 h에서 Loop Reactor의 경우 평균 T-N 제거율 및 평균 T-P 제거율은 각각 33.6%, 54.5%로 고정상 담체 반응기보다 14.1%, 10.8%의 더 높은 제거율을 나타내었다. 이상의 결과에서 Loop Reactor가 성능이 훨씬 더 우수하였으며 최적 HRT는 16 h임을 알 수 있었다. This study was accomplished using Anaerobic/Anoxic/Oxic upflow packed-bed column reactors with fixed media and Loop Reactor with fluidized media instead of Oxic reactor. The objectives of this study was to investigate the characteristics of organics, nitrogen and phosphorus removal from sewage with the HRT. The average removal efficiencies of BOD5 and SS increase as increasing the hydraulic retention time (HRT) until 16 h of the HRT, and they were constant over 16 h of the HRT. The removal efficiency of BOD5 in case of packed-bed reactor and Loop Reactor was about 86.6% and 90.9% respectively at 16 h of the HRT. The removal efficiency of SS in packed-bed reactor and Loop Reactor was about 78.0% and 88.2% respectively at 16 h of the HRT. The average removal efficiencies of CODCr and CODMn showed similar trends as hose of BOD5 and SS. At the HRT of 16 h, the removal efficiency of CODCr in case of packed-bed reactor and Loop Reactor was 63.5%, 75.2% and that of CODMn was 60.7%, 73.6% respectively. The average removal efficiencies of T-N and T-P increase as increasing the HRT. The removal efficiencies of T-N and T-P in Loop Reactor were 33.6% and 54.5% respectively at 16 h of the HRT and T-N and T-P were better removed in Loop Reactor. From this result, it was found that the performance of Loop Reactor was much higher than the performance of packed-bed reactor and the optimum HRT was 16 h.

Thermal-fluid characteristics on near wall of gas-solid fluidized bed reactor

Moon, Hokyu,Choi, Seungyeong,Park, Yong-Ki,Cho, Hyung Hee Pergamon Press 2017 International journal of heat and mass transfer Vol. No.

<P><B>Abstract</B></P> <P>Gas-solid circulating fluidized beds (CFBs) are for carbon capture process because of their remarkable heat and mass transfer characteristics in the target reactor. Bed-to-wall heat transfer is an important issue in designing a reactor to satisfy the required conditions. Bed-to-wall heat transfer is characterized by near-wall particle behavior. Thus, in this study, local bed-to-wall heat transfer and near-wall particle dynamic characteristics were measured in a lab-scale CFB riser. The clustered particle behavior near the wall was investigated primarily using a non-intrusive method, particle-imaging velocimetry (PIV), within the CFB riser. To determine the effects of bed instability on the clustered particle behavior at the wall, bed instability was controlled. Bed instability was estimated by the degree of pressure fluctuation in the riser, and the fluctuation effect was compared, depending on the fluidization regime. Ultimately, the clustered particle behavior on the adjacent wall was compared depending on the pressure fluctuations using the PIV system. We estimated the clustered particle behavior on the adjacent wall of the CFB riser considering fluidization instability. Detailed analysis of the relationship between the bed-to-wall heat transfer and the particle behavior was conducted.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Heat transfer is measured to design heat-exchangeable CO<SUB>2</SUB> capture reactor. </LI> <LI> Near-wall thermal-fluid characteristics is distinguished by operating conditions. </LI> <LI> Bed-to-wall heat transfer is enhanced with increasing particle clustering. </LI> </UL> </P>

액체-고체 유동층반응기에서 폐수로부터 동입자의 회수

송평섭 ( Song Pyeong Seob ),김현태 ( Kim Hyeon Tae ),강용 ( Kang Yong ),김승재 ( Kim Seung Jae ),김상돈 ( Kim Sang Don ) 한국공업화학회 2003 공업화학 Vol.14 No.6

직경이 0.102 m이고 높이가 1.0 m인 액체-고체 유동층 반응기에서 전자공장의 산업폐수로부터 동을 회수하는 반응의 특성에 대해 연구하였다. 반응기에 첨가되는 고체 유동입자의 양, 액체유속, 음극판과 양극판간의 거리와 전류밀도, 그리고 반응시간이 액체-고체 유동층 반응기에서 동을 회수하는 효율에 미치는 영향을 결정하였다. 액체-고체 유동층 반응기의 성능을 일반적인 관상반응기와 비교하기 위하여 유동층 반응기에서 회수되는 동분말의 평균입도와 입도분포를 측정하여 해석하였다. 액체-고체 유동층 반응기에서 운전조건인 액체의 유속, 음극판과 양극판간의 거리 또는 반응기에 투입되는 고체 유동입자의 양이 증가함에 따라 동의 회수율은 증가하다가 최대값을 나타낸 후 감소하였다. 그러나, 음극판과 양극판간의 전류밀도가 증가함에 따라서는 동의 회수율이 증가하는 경향을 나타내었다. 본 연구의 실험범위에서 전자공장 폐수로부터 95% 이상의 동을 회수하는 최적조건은 유동입자의 투입량(W)이 1.0 wt%, 양극간의 전류밀도(I)는 3.0 A/dm², 양극간의 거리(L_(AC))는 1.5×10^(-2) m 그리고 액체의 유속(U_(L))은 1.0×10^(-3) m/s이었다. Characteristics of copper recovery from waste water of electronic industries were investigated in a liquid-solid fluidized-bed reactor whose diameter was 0.102 m and 1.0 m in height. Effects of amount of fluidized solid particles (W)_(l), liquid velocity (U_(L)), current density (I) and distance between the two electrodes (anode and cathode) (L_(AC))_(l) and reaction time (t) on the recovery of copper in the liquid-solid fluidized-bed reactor were determined. The mean size and size distribution of copper powder recovered in the reactors were measured to analyze the characteristics of performance of liquid-solid fluidized-bed reactor by comparing with a simple tubular reactor. The recovery of copper exhibited its maximum value by increasing liquid velocity, distance between the two electrodes, or amount of fluidized solid particles added into the reactor. But, the recovery increased steadily with increasing current density between the anode and the cathode electrodes. For this study, the optimum operating condition to obtain the copper recovery above 95% within 120 min was W=1.0wt%, 1 = 3.0 A/dm^(2) and U_(L) = 1.0×10^(-3) m/s.

Thermal design of heat-exchangeable reactors using a dry-sorbent CO₂ capture multi-step process

Moon, Hokyu,Yoo, Hoanju,Seo, Hwimin,Park, Yong-Ki,Cho, Hyung Hee Elsevier 2015 ENERGY Vol.84 No.-

<P><B>Abstract</B></P> <P>The present study proposes a multi-stage CO<SUB>2</SUB> capture process that incorporates heat-exchangeable fluidized-bed reactors. For continuous multi-stage heat exchange, three dry regenerable sorbents: K<SUB>2</SUB>CO<SUB>3</SUB>, MgO, and CaO, were used to create a three-stage temperature-dependent reaction chain for CO<SUB>2</SUB> capture, corresponding to low (50–150 °C), middle (350–650 °C), and high (750–900 °C) temperature stages, respectively. Heat from carbonation in the high and middle temperature stages was used for regeneration for the middle and low temperature stages. The feasibility of this process is depending on the heat-transfer performance of the heat-exchangeable fluidized bed reactors as the focus of this study. The three-stage CO<SUB>2</SUB> capture process for a 60 Nm<SUP>3</SUP>/h CO<SUB>2</SUB> flow rate required a reactor area of 0.129 and 0.130 m<SUP>2</SUP> for heat exchange between the mid-temperature carbonation and low-temperature regeneration stages and between the high-temperature carbonation and mid-temperature regeneration stages, respectively. The reactor diameter was selected to provide dense fluidization conditions for each bed with respect to the desired flow rate. The flow characteristics and energy balance of the reactors were confirmed using computational fluid dynamics and thermodynamic analysis, respectively.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CO<SUB>2</SUB> capture process is proposed using a multi-stage process. </LI> <LI> Reactor design is conducted considering heat exchangeable scheme. </LI> <LI> Reactor surface is designed by heat transfer characteristics of fluidized bed. </LI> </UL> </P>

도금폐수처리를 위한 입상활성탄 유동 메디아 적용 유동상 멤브레인 여과기술의 적용가능성 평가에 관한 연구

장수민,권대은,김정환 한국막학회 2018 멤브레인 Vol.28 No.4

실 산성 도금폐수를 입상활성탄(GAC)이 유동메디아로 첨가된 유동상 멤브레인 반응기를 이용하여 처리하였다. GAC 유동조건에서 적용 투과플럭스에 대해 시간에 따른 흡입압의 증가는 관찰되지 않았다. 폐수의 중성 pH에서 파울링 속도는 산성 조건에 비해 GAC 유동조건에서 크게 감소하였다. 해당 폐수의 용액 pH 증가는 입자크기의 증가를 가져왔고 이는 멤브레인 표면에서 상대적으로 성긴 구조의 케이크층 형성을 야기시켰다. 유동상 멤브레인 반응기에서 GAC 유동 하에 95% 이상의 COD 제거율이 관찰되었으며 총부유물질은 거의 완벽하게 제거되었다. 실 도금폐수의 pH에서, 유동상 멤브레인 반응기의 구리 및 크롬의 제거는 거의 관찰 되지 않았다. 그러나 pH를 중성으로 증가 시켰을 시 구리와 크롬의 제거율은 각각 99%와 94%까지 증가를 하였다. 적용해 준 pH에 상관 없이, 시안의 경우 95% 이상의 제거율을 달성하였다. 이는 유기물과 시안 착물 형성으로 인해 유동상 멤브레인 반응기 내 GAC의 강한 흡착으로 제거된 것으로 사료된다. An acidic, real metal-plating wastewater was treated by a fluidized bed membrane reactor introduced with granular activated carbon (GAC) as fluidized media. With GAC fluidization, there was no increase in suction pressure with time at each flux set-point applied. At neutral solution pH, much less fouling rate was observed than acidic pH under GAC fluidization. Higher solution pH resulted in the increase in particle size in metal-finishing wastewater, thus producing a less dense cake structure on membrane. More than 95% of chemical oxygen demand was observed from the fluidized bed membrane reactor under GAC fluidization. Total suspended solid concentration in membrane permeate was near zero. At the raw wastewater pH, no removal of copper and chromium by the fluidized bed membrane reactor was observed. As the pH was increased to 7.0, removal efficiency of copper and chromium was increased considerably to 99 and 94%, respectively. Regardless of solution pH tested, more than 95% of cyanide was removed possibly due to the strong adsorption of organic- cyanide complex on GAC in fluidized bed membrane reactor.

Increasing ethylene production as a high value hydrocarbon in Fischer-Tropsch (FT) reactor: A concept reactor for combining FT with oxidative coupling of methane

Sattar Ghader,Abbas Ghareghashi,Farhad Shahraki,Kiyanoosh Razzaghi,Mohammad Ali Torangi 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.5

The paper proposes a concept configuration of reactors for coupling OCM and FTS, and presents systematic simulation results. FTS section is a combination of fixed bed and membrane fluidized bed reactor, and feed of the FT reactor is supplied by OCM. The reactor configuration is compared with the consecutive reactors of OCM and one fixed bed FT reactor. Effects of CH4/O2 ratio, percent of N2 in the feed, contact time, and input temperature on the yield of ethylene and valuable hydrocarbons are studied. The results show that compared with one FTS reactor configuration, the dual FTS reactor configuration is more effective and thus gives much higher product yields. Furthermore, a main decrease is observed in the formation of CO2 and CH4.

유동층 반응기에서 합성가스 생성에 미치는 반응온도와 반응물 유속의 영향

김상범 ( Sang Bum Kim ),김영국 ( Young Kook Kim ),황재영 ( Jae Young Hwang ),김명수 ( Myung Soo Kim ),박홍수 ( Hong Soo Park ),함현식 ( Hyun Sik Hahm ) 한국유화학회 2004 한국응용과학기술학회지 Vol.21 No.3

N/A Synthesis gas is a high valued compound as a basic chemicals at various chemical processes. Synthesis gas is mainly produced commercially by a steam reforming process. However, the process is highly endothermic so that the process is very energy-consuming process. Thus, this study was carried out to produce synthesis gas by the partial oxidation of methane to decrease the energy cost. The effects of reaction temperature and flow rate of reactants on the methane conversion, product selectivity, product ratio, and carbon deposition were investigated with 13wt% Ni/MgO catalyst in a fluidized bed reactor. With the fluidized bed reactor, CH4 conversion was 91%, and H₂ and CO selectivities were both 98% at 850,C and total flow rate of 100 mL/min. These values were higher than those of fixed bed reactor. From this result, we found that with the use of the fluidized bed reactor it was possible to avoid the disadvantage of fixed bed reactor (explosion) and increase the productivity of synthesis gas.