• 대한기계학회논문집B
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• 제31권10호
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• pp.855-859
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• 2007

Hydrogen as an energy carrier in fuel cell offers perhaps the largest potential benefits of reduced emissions of pollutants and greenhouse gases. The generation of high-purity hydrogen from hydrocarbon fuels is essential for efficient operation of fuel cell. Reduction of carbon monoxide to an acceptable level of 10ppm involves high temperature and low temperature water gas shift (WGS), followed by selective oxidation of residual carbon monoxide. The WGS reactor was designed and tested in this study to produce hydrogen-rich gas with CO to less than 5000 ppm. In the water gas shift operation, gas emerges from the reformer is taken through a high temperature shift (HTS) catalyst to reduce the CO concentration to about $2{\sim}4%$ followed to about 5000 ppm via a low temperature shift (LTS) catalyst.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.75.1-75.1
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• 2011

Coal gasification is considered as one of the most prospective technologies in energy field since it can be utilized for various products such as electricity, SNG (Synthetic Natural Gas or Substitute Natural Gas) and other chemical products. Among those products from coal gasification, SNG is emerging as a very lucrative product due to the rising prices of oil and natural gas, especially in Asian countries. The process of SNG production is very similar to the conventional IGCC in that the overall process is highly dependent on the type of gasifier and coal rank. However, there are some differences between SNG production and IGCC, which is that SNG plant requires higher oxygen purity from oxygen plant and more complex gas cleanup processes including water-gas shift reaction and methanation. Water-gas shift reaction is one of the main process in SNG plant because it is a starting point for the latter gas cleanup processes. For the methanation process, syngas is required to have a composition of $H_2$/CO = 3. This study reviewed various considerations for water-gas shift process in a conceptual design on an early stage like a feasibility study for a real project. The factors that affect the design parameters of water-gas shift reaction include the coal properties, the type of gasifier, the overall thermal efficiency of the plant and so on. Water-gas shift reaction is a relatively proven technology compared to the other processes in SNG plant so that it can reduce technological variability when designing a SNG project.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
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• pp.514-517
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• 2008

Water gas shift(WGS) is an important step in fuel process for fuel cells, and improperness of commercial WGS catalysts for use in fuel cell systems has prompted numerous researches on noble metal catalysts. A selected noble metal catalyst for water gas shift reaction(WGS) was prepared with various metal loadings. The prepared catalysts were tested under two feeding conditions. At moderate residence time, carbon monoxide conversion was much higher on the noble metal catalysts as compared to commercial high-temperature shift catalyst. Effects of metal loading were examined by activity tests at short residence time. Higher metal loading effected higher reaction rate. The kinetic data was fitted to simple reaction equations and effectiveness factor was estimated. The results suggest the necessity of a structural design for the highly active noble metal catalysts.

• 자원리싸이클링
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• 제30권6호
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• pp.12-18
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• 2021

수성가스 전환 반응은 가스화로 생성된 합성 가스에 수소 생산 증가와 H₂/CO 비율 제어를 위해 수증기를 첨가하는 가스화 후속 공정이다. 본 연구에서는 RPF(Refuse plastic fuel) 가스화 시스템의 합성가스를 대상으로 수성가스 전환 반응을 연구하였다. 수성가스 전환 반응은 촉매를 이용하여 high temperature shift(HTS) 와 low temperature shift(LTS) 반응에 대하여 lab scale 관형 반응기를 이용하여 반응 온도, steam/carbon ratio, 유량의 변화가 H₂ 생성과 CO 전환율에 미치는 영향을 조사하였다. 운전 온도는 HTS 시스템이 250-400℃, LTS 시스템이 190-220℃이며 steam/carbon ratio는 1.5-3.5로 변화시켰다. 반응 모의 가스의 농도는 RPF 합성가스의 농도를 기준으로 CO, 40vol%, H₂, 25vol%, CO₂, 25vol%이다. 반응 온도와 steam/carbon ratio가 증가함에 따라 CO 전환율 및 H₂ 생성량이 증가하고, 유량이 증가하면 촉매층의 체류시간 단축으로 CO 전환율과 H₂ 생성량이 감소하였다.

• 한국수소및신에너지학회논문집
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• 제34권4호
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• pp.327-333
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• 2023

The water gas shift reaction was carried out using the commercial catalyst pellet and the simulated gases expected to occur from waste plastic gasification. In the water gas shift reaction, the high temperature shift reaction and the low temperature shift reaction were continuously performed with CO:H₂O ratio of 1:2, 1:2.5, and 1:3, and the CO conversion and H₂ increase rate were evaluated. The H₂ increase rate increased in order to CO:H₂O ratio of 1:3 > CO:H₂O ratio of 1:2.5 > CO:H₂O ratio of 1:2. The CO conversion showed a high value of more than 97% at each CO:H₂O ratio. The water gas shift reaction at a CO:H₂O ratio of 1:3 showed the highest H2 increase rate and CO conversion.

• 신재생에너지
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• 제5권2호
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• pp.9-14
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• 2009

Automobile Shredder Residue (ASR) is very appropriate in a gasification melting system. Gasification melting system, because of high reaction temperature over than $1,350^{\circ}C$, can reduce harmful materials. To use the gasification processes for hydrogen production, the high concentration of CO in syngas must be converted into hydrogen gas by using water gas shift reaction. In this study, the characteristics of shift reaction of the high temperature catalyst (KATALCO 71-5M) and the low temperature catalyst (KATALCO 83-3X) in the fixed - bed reactor has been determined by using simulation gas which is equal with the syngas composition of gasification melting process. The carbon monoxide composition has been decreased as the WGS reaction temperature has increased. And the occurrence quantity of the hydrogen and the carbon dioxide increased. When using the high temperature catalyst, the carbon monoxide conversion ratio ($1-CO_{out}/CO_{in}$) rose up to 95.8 from 55.6. Compared with average conversion ratio from the identical synthesis gas composition, the low temperature catalyst was better than the high temperature catalyst.

• 한국수소및신에너지학회논문집
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• 제27권5호
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• pp.494-502
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• 2016

A 1-dimensional heterogeneous reactor model with the gas-solid interfacial phase gradients was developed for the simulation of the packed bed reactor where the exothermic reversible water gas shift reaction for the natural gas steam reformed gas was proceeding in adiabatic mode. Experimental results obtained over the WGS catalyst, C18-HA, were best simulated when the frequency factor of the reaction rate constant was adjusted to a half the value reported over another WGS catalyst, EX-2248, having the same kinds of active components as the C18-HA. For the reactor of the inside diameter 158.4 mm and the bed length 650 mm, the optimum feeding temperature of the reformed gas was simulated to be $194^{\circ}C$, giving the lowest CO content in the product gas by 1.68 mol% on the basis of dried gas. For reactors more extended in the bed length, the possible lowest CO content in the product gas with the optimum feeding temperature of the reformed gas were suggested.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.156.2-156.2
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• 2011

본 연구에서는 일단 수성가스전이반응 (Single stage water gas shift reaction)을 위해 높은 활성을 가진 백금 담지 촉매를 함침법 (Incipient wetness impregnation method)으로 제조하여 높은 공간 속도 (Gas hourly space velocity) $45,515h^{-1}$에서 담체에 따른 촉매 활성을 평가하였다. 담체는 $CeO_2$, $ZrO_2$, MgO, MgO-$Al_2O_3$ (MgO = 30 wt%) 그리고 $Al_2O_3$를 사용하였으며 백금의 담지량은 1 wt%로 고정하였다. BET, XRD, TPR, CO-chemisorption 분석을 통하여 담체의 구조적 특성이 촉매 활성에 미치는 영향에 대하여 조사하였다.

• 멤브레인
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• 제20권3호
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• pp.228-234
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• 2010

본 연구에서는 Water Gas Shift (WGS) 반응이 일어나는 분리막 반응기 (MR) 대상공정에 대해서 동적모사 (dynamic simulation)를 실시하고 시간과 위치에 따른 온도 및 수소 농도 변화 등을 살펴보았다. 모사 결과에 의하면 도입부에서 반경방향으로의 수소 농도, 수소 분압 및 온도차가 가장 컸으며 출구에서 가장 작았다. 또한, 수소분압의 차이가 가장 큰 도입부에서 수소의 flux가 가장 크게 나타나며 출구에서 일산화탄소의 전환률은 0.65였다.

• 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.