• 한국수소및신에너지학회논문집
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• 제15권4호
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• pp.283-290
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• 2004

The single-step process for conversion of syngas to DME give higher conversion than the syngas-to-methanol process. This arises because of a synergy among the three simultaneous reaction, methanol synthesis, methanol dehydration and water gas shift reaction, in the process. we would find the optimal condition of the process which these advantages. The optimal condition of DME synthesis reaction over a commercial $Cu/Zn/Al_2O_3$ catalyst and Hybrid catalyst in a fixed bed reactor. The syngas-to-dimethyl ether conversion was examined on various reaction condition (Temperature 473~553K, $H_2/CO$ ratio 1~3, Pressure 30'50atm, GHSV 1000~4000).

• 한국환경보건학회지
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• 제27권3호
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• pp.11-20
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• 2001

An anaerobic sludge-aerobic fixed-bed biofilm(packed with ceramic support carrier of 1 inch size) reactor system was built up to treat textile wastewater. The efficiency of reactor system was examined by determining the effects of textile wastewater ratio(from 25% to 100% at HRT 24 h). The influent range of SCOD concentration and color were 1,036~1,357 mg/L, and 1,487~1,853 degree, respectively. When textile wastewater ratio was 100% and hydraulic retention time was 24 hours, SCOD removal efficiency by the anaerobic stage were 39.2% 100% and hydraulic retention time was 24 hours, SCOD removal efficiency by the anaerobic stage were 39.2% and the removal efficiency of the whole system were 75.8%. Color removal efficiency by the anaerobic stage were 45.4%(soluble color), and the removal efficiency of the whole system were 70.2%. In the A/A reactor system, the aerobic stage played an important role in removing both color and COD as well as anaerobic stage.

• 청정기술
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• 제19권2호
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• pp.165-172
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• 2013

본 연구에서는 고정층 반응기(높이 15 cm, 내경 0.5 cm)에서 K-계열 건식 흡수제($K_2CO_3/Al_2O_3$, 한국전력공사 전력연구원)를 이용하여 반응압력 변화에 따른 염화수소 흡수 실험을 수행하였다. 반응온도는 가스화 직후, 필터를 거쳐서 주입되는 것을 가정하여 $400^{\circ}C$로 설정하였으며, 반응기체 농도는 750 ppm HCl ($N_2$ balance)으로 설정하였다. 반응압력은 1, 5, 10, 15, 20 bar로 증가시켰다. 압력이 증가할수록 K-계열 흡수제의 흡수 성능이 증가하였다. 흡수제를 구성하고 있는 주요 물질인 $K_2CO_3$가 HCl 가스와 반응하여 KCl 결정을 형성하였으며, 강한 결합에너지로 인하여 흡수제의 재생이 실질적으로 불가능하였다. 이에 대한 광학적, 물리적, 화학적 특성을 SEM, EDX, BET, TGA, XRD를 이용하여 분석하였다. $400^{\circ}C$, 20 bar 조건(가스화 이후 탈할로겐 공정의 온도 및 압력조건)에서 $K_2CO_3$ 흡수제는 Ca 계열 및 Mg 계열의 흡수제에 비해 높은 HCl 흡수능 및 HCl/$N_2$ 분리 거동을 보였다.

• 한국수소및신에너지학회논문집
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• 제25권4호
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• pp.355-363
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• 2014

Thermal shock or overheating of WGS catalyst for SEWGS system during hydrogen pre-treatment can cause reactivity decay of the catalyst. To select appropriate pre-treatment condition, temperature profiles of catalyst bed (or outside fluidized particle bed of bed insert) during pre-treatment were measured and then CO conversions of those catalysts during WGS reaction were also measured and compared. Drastic overheating of catalyst took place when we reduce catalyst at fixed bed condition and these catalysts showed low CO conversion during WGS reaction. On the contrary, there was no overheating of catalyst at fluidized bed condition not only physical mixing case but also bed insert case. Spring type bed insert showed acceptable CO conversion even at low WGS content. Consequently, feasibility of high CO conversion without decay of reactivity of catalyst and holding the WGS catalyst inside the SEWGS reactor as tablet shape were confirmed using spring type bed insert.

• Korean Journal of Chemical Engineering
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• 제35권11호
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• pp.2157-2163
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• 2018

Catalytic reactors have been essential for chemical engineering process, and different designs of reactors in multi-scales have been previously studied. Computational fluid dynamics (CFD) utilized in reactor designs have been gaining interest due to its cost-effective advantage in designing the actual reactors before its construction. In this work, butadiene synthesis via oxidative dehydrogenation (ODH) of n-butene using tubular reactor was used as a case study in the CFD model. The effects of coolant and reactor diameter were investigated in assessing the reactor performance. Based on the results of the CFD model, the conversion and selectivity were 86.5% and 59.5% respectively in a fixed bed reactor under adiabatic condition. When coolants were used in a tubular reactor, reactor temperature profiles showed that solar salt had lower temperature gradients inside the reactor than the cooling water. Furthermore, higher conversion (90.9%) and selectivity (90.5%) were observed for solar salt as compared to the cooling water (88.4% for conversion and 86.3% for selectivity). Meanwhile, reducing the reactor diameter resulted in smaller temperature gradients with higher conversion and selectivity.

• 한국지하수토양환경학회지:지하수토양환경
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• 제9권3호
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• pp.49-55
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• 2004

염화에틸렌 화합물에 오염된 토양으로부터 고농도 (150mg/L)의 PCE를 cis-DCE까지 탈염소화하는 혼합미생물 농화 배양계 LYF-1을 구축하였다. LYF-1은 효모추출물, 펩톤, 포름산, 아세트산, 락트산, 피루브산, 시트르산, 석신산, 글루코오스, 수크로오스, 에탄올 등을 전자공여체로 이용하여 PCE를 탈염소화할 수 있었다. 한편, PCE를 대신할 수 있는 전자 수용체에 의한 PCE 탈염소화에 미치는 영향을 살펴본 결과, NO$_3$$^{-}$와 NO$_2$$^{-}$는 PCE의 탈염소화반응을 완전히 저해하였으나, S$_2$O$_3$$^{-2}$ , SO$_3$$^{-2}$ 및 SO$_4$$^{-2}$ 는 PCE의 탈염소화반응에 그다지 큰 영향을 미치지 않았다. LYF-1 혼합미생물을 혐기성 고정생물막 반응기내의 세라믹 메디아에 부착하고, PCE의 유입부하율 변화에 따른 처리 효율을 조사한 결과, PCE의 부하율 0.13-0.78 $\mu$moles/L/hr의 범위 내에서 99% 이상의 PCE 탈염소화 효율을 보였으며, PCE 탈염소화 반응의 최종산물은 cis-DCE이었다.

• 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.

• Korean Chemical Engineering Research
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• 제49권2호
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• pp.129-136
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• 2011

SMB 공정은 주로 4개의 구역으로 나뉘어지는 다수의 크로마토그래피 컬럼으로 구성된다. 이러한 특성은 회분식 크로마토그래피 공정보다 우수한 이성분계 물질의 연속적인 분리를 구현한다. SMB는 회분식 크로마토그래피에 비해 연속성 및 높은 생산성과 순도로 목적물질을 분리해 낼 수 있는 장점을 갖는다. 경제적이며 효율적인 공정의 운용을 위해 반응과 회수를 결합시키는 연구가 보고되고 있으며, 이와 같은 연구 중 SMBR은 연속분리공정인 SMB와 반응기가 결합된 공정이다. 다양한 반응을 적용한 SMBR에 대해 많은 연구가 진행되고 있으며, 촉매반응, 효소반응, 이온 교환 수지를 통한 화학반응이 주를 이루고 있다. 초기의 SMBR은 촉매를 사용한 고정층의 형태이며, 유동성 효소를 사용하는 SMBR, 고정화 효소를 사용하는 SMBR, 반응구역과 흡착구역이 분리되어 있는 SMBR순으로 발전하였다. 공정 설계에 있어서 필수적인 모델링 및 최적화를 위하여 대류현상만을 고려한 간단한 기법이 있지만, 실제 물질거동을 설명하기 위해서는 축 방향 분산이나 물질전달 저항을 고려한 복잡한 해석을 필요로 한다. SMBR같이 반응과 분리가 결합된 공정의 경우 설비의 간소화를 통한 시설비용의 축소뿐 아니라 가역반응평형의 극복을 통해 물질의 순도와 수율을 향상시킬 수 있는 장점이 있다.

• KEPCO Journal on Electric Power and Energy
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• 제2권4호
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• pp.595-600
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• 2016

다상 고정층 촉매반응기(Multiphase catalytic fixed-bed reactor)에서 기체 유동과 관련, 반응기 내부 구조 디자인에 따른 feed 가스의 분산성 변화를 분석하였다. 다상 촉매반응기의 경우 feed gas의 투입방법이 전체 공정의 반응효율을 크게 결정하는바 본 연구에서는 산업현장에서 활용도가 높은 환형 가스 주입부로 구성된 다상 고정층 촉매반응기를 대상으로 다양한 조건하에서 촉매 반응기 내부에서의 feed가스 분산성 변화를 분석하였다. 다상 촉매반응기의 feed gas 주입과 관련하여 다양한 방안이 제시되고 있는데 그 중 환형 가스 주입방식을 활용하는 방법은 타 기술대비 상대적으로 저렴한 투자비와 좁은 작업공간하에서 기체의 분산성을 향상 시킬수 있는 특징이 있어 실제 상업 공정에서의 활용성이 매우 높다. 본 논문에서는 특히 기-고 촉매 반응기 내부 반응기체의 분산성 향상을 위해 환형 가스 주입장치 내부에 설치된 가스 주입홀 구성방법에 따른 반응기 내부 유동을 분석하였다. 분석결과 주입홀의 위치가 가스 투입라인의 접선방향에 위치하는 것은 전체 분산성에 큰 영향을 주지 못하며 대부분 가스투입 입구와 맞은편 부분에 위치하는 경우 분산성이 향상되는 것으로 분석되었다. 결과적으로 환형 가스주입장치의 최적 설계는 feed 가스의 분산성에 큰 영향을 미치므로 초기단계에서 이러한 점을 고려한 설계 및 분석연구가 선행되어야 할 것으로 사료된다.

• 환경위생공학
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• 제13권1호
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• pp.16-25
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• 1998

Laboratory-scale experiment using anaerobic fluidized bed reactor was carried out to investigate the prehydrolysis step with caustic soda on the treatment efficiency of anaerobic sludge treatment, since the overall rate-limiting step for the complete anaerobic digestion of sludge was the hydrolysis step by extracellular bacterial enzymes of insoluble polymeric molecules. Reactors received a sludge which had not been pretreated, a 50-50 mixture of pretreated and untreated sludge, and the fully pretreated sludge. Hydraulic retention time of 10, 5, 2.5 days and 1 day were applied with an respective equivalent organic loading rate of 1.17, 2.23, 4.17, 11.24 gCOD/L/d. Reactor with the untreated sludge did not archieve adequate digestion even at the HRT of 5 days, and reactor, which received the 50-50 mixture, operated well at the HRT of 5 days, but began to show signs of unstable digestion at the HRT of 2.5 days. While, reactor, which was fed the hydrolyzed sludge, operated reasonably well at the 2.5 days, but was showing somewhat decrease in removal efficiencies. Results, therefore, have substantiated that the limiting reaction in the anaerobic treatment process is hydrolysis. The soluble COD did not significantly accumulate in the reactor as organic acid form, even when they were highly stressed. It was believed that this resistance to a build-up of organic acids and soluble COD behavior was mainly due to the maintenance of the methane bacteria in the fixed-film system which prevents washout as the organic loading increased. The anaerobic fluidized bed reactor was therefore effective for the digestion of waste activated sludge at short HRT.