• Title, Summary, Keyword: Methanation

Search Result 47, Processing Time 0.036 seconds

CO and CO2 methanation over Ni catalysts supported on alumina with different crystalline phases

  • Le, Thien An;Kim, Tae Wook;Lee, Sae Ha;Park, Eun Duck
    • The Korean Journal of Chemical Engineering
    • /
    • v.34 no.12
    • /
    • pp.3085-3091
    • /
    • 2017
  • The effect of alumina crystalline phases on CO and $CO_2$ methanation was investigated using alumina-supported Ni catalysts. Various crystalline phases, such as ${\alpha}-Al_2O_3$, ${\theta}-Al_2O_3$, ${\delta}-Al_2O_3$, ${\eta}-Al_2O_3$, ${\gamma}-Al_2O_3$, and ${\kappa}-Al_2O_3$, were utilized to prepare alumina-supported Ni catalysts via wet impregnation. $N_2$ physisorption, $H_2$ chemisorption, temperature-programmed reduction with $H_2$, $CO_2$ chemisorption, temperature-programmed desorption of $CO_2$, and X-ray diffraction were employed to characterize the catalysts. The Ni/${\theta}-Al_2O_3$ catalyst showed the highest activity during both CO and $CO_2$ methanation at low temperatures. CO methanation catalytic activity appeared to be related to the number of Ni surface-active sites, as determined by $H_2$-chemisorption. During $CO_2$ methanation, Ni dispersion and the $CO_2$ adsorption site were found to influence catalytic activity. Selective CO methanation in the presence of excess $CO_2$ was performed over Ni/${\gamma}-Al_2O_3$ and Ni/${\delta}-Al_2O_3$; these substrates proved more active for CO methanation than for $CO_2$ methanation.

The Influence of a Second Metal on the Ni/SiC Catalyst for the Methanation of Syngas

  • Song, Lanlan;Yu, Yue;Wang, Xiaoxiao;Jin, Guoqiang;Wang, Yingyong;Guo, XiangYun
    • Korean Chemical Engineering Research
    • /
    • v.52 no.5
    • /
    • pp.678-687
    • /
    • 2014
  • The catalytic performance of silicon carbide supported nickel catalysts modified with or without second metal (Co, Cu and Zn) for the methanation of CO has been investigated in a fixed-bed reactor using a feed consisting of 25% CO and 75% $H_2$ without any diluent gas. It has been found that the introduction of Co species can clearly improve the catalytic activity of Ni/SiC catalyst, whereas the addition of Cu or Zn can result in a significant decrease in the catalytic activity. The characterizations by means of XRD, TEM, XPS, CO-TPD and $H_2$-TPR indicate that the addition of Co could decrease the particle size of active metal, increase active sites on the surface of methanation catalyst, improve the chemisorption of CO and enhance the reducibility of methanation catalysts. Additionally, the special interaction between Co species and Ni species is likely favorable for the dissociation of adsorbed CO on the surface of catalyst, and this may also contribute to the high activity of 5Co-Ni/SiC catalyst for CO methanation reaction. For 5Cu-Ni/SiC catalyst and 5Zn-Ni/SiC catalyst, Cu and Zn species could cover partial nickel particles and decrease the chemisorption amount of CO. These could be responsible for the low methanation activity. In addition, a 150h stability test under 2 MPa and $300^{\circ}C$ showed that 5Co-Ni/SiC catalyst was very stable for CO methanation reaction.

Manufacturing Optimization of Ni Based Disk Type Catalyst for CO2 Methanation (CO2 메탄화 반응을 위한 Ni 기반 Disk Type 촉매의 제조 최적화에 관한 연구)

  • Lee, Jae-Joung;Moon, Dea-Hyun;Chang, Soon-Wong
    • Journal of Environmental Science International
    • /
    • v.28 no.1
    • /
    • pp.65-73
    • /
    • 2019
  • The catalytic activity of Ni-0.2%YSZ (Yttria-Stabilized Zirconia) with different promoters was evaluated for $CO_2$ methanation. The catalysts were weighed for mixing and they were dried at $110^{\circ}C$ for molding into disks. The concentration of $CO_2$ and $CH_4$ for conducting of $CO_2$ methanation were analyzed by gas chromatography and the physical characteristics of the disk-type catalyst formed were analyzed by X-ray diffraction, scanning electron microscope and energy dispersive x-ray spectrometer. The addition of $CeO_2$ as a promoter for Ni-0.2%YSZ (denoted as Ni-5%Ce-0.2%YSZ) resulted in the highest $CO_2$ methanation. It also showed catalytic activity at a low temperature($200^{\circ}C$). Following this, $ZrO_2$, $SiO_2$, $Al_2O_3$ and $TiO_2$ were added to Ni-5%Ce-0.2%YSZ to compare the $CO_2$ methanation, and the highest efficiency was found for. Ni-1%Ti-5%Ce-0.2%YSZ Then, the concentration of Ti was increased to 10% and the catalytic activity was estimated using seven different types of commercial $TiO_2$. In conclusion, ST-01 $TiO_2$ showed the highest efficiency for $CO_2$ methanation.

Effect of Cerium loading on Stability of Ni-bimetallic/ZrO2 Mixed Oxide Catalysts for CO Methanation to Produce Natural Gas

  • Bhavani, Annabathini Geetha;Youn, Hyunki
    • Korean Chemical Engineering Research
    • /
    • v.56 no.2
    • /
    • pp.269-274
    • /
    • 2018
  • All the $Ni-Co-Ce-ZrO_2$ mixed oxides are prepared by co-precipitations methods. Methanation of CO and $H_2$ reaction is screened tested over different fractions of cerium (2, 4, 7 and 12 wt.%) over $Ni-Co/ZrO_2$ bimetallic catalysts are investigated. The mixed oxides are characterized by XRD, CO-Chemisorption, TGA and screened methanation of CO and $H_2$ at $360^{\circ}C$ for 3000 min on stream at typical ratio $CO:H_2=1:1$. In $Ni-Co/CeZrO_2$ series 2 wt.% Ce loading catalyst shows most promising catalyst for $CH_4$ selectivity than $CO_2$, which directs more stability with less coke formation. The high activity is attributed to the better bimetallic synergy and the well-developed crystalline phases of NiO, $ZrO_2$ and $Ce-ZrO_2$. Other bimetallic mixed oxides NCoZ, $NCoC^{4-12}Z$ has faster deactivation with low methanation activity. Finally, 2 wt.% Ce loading catalyst was found to be optimal coke resistant catalyst.

Computer Simulation of Methanation Reactor with Monolith Catalyst (전산 모델링을 통한 모노리스 촉매형 메탄화 반응기의 성능 특성 연구)

  • Chi, Junhwa;Kim, Sungchul;Hong, Jinpyo
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.25 no.4
    • /
    • pp.425-435
    • /
    • 2014
  • Simulation studies on catalytic methanation reaction in externally cooled tubular reactor filled with monolithic catalysts were carried out using a general purpose modelling tool $gPROMS^{(R)}$. We investigated the effects of operating parameters such as gas space velocity, temperature and pressure of feeding gas on temperature distribution inside the reactor, overall CO conversion, and chemical composition of product gas. In general, performance of methanation reaction is favored under low temperature and high pressure for a wide range of their values. However, methane production becomes negligible at temperatures below 573K when the reactor temperature is not high enough to ignite methanation reaction. Capacity enhancement of the reactor by increasing gas space velocity and/or gas inlet pressure resulted no significant reduction in reactor performance and heat transfer property of catalyst.

Mathematical Model and Numerical Analysis for Packed Bed Methanation Reactors (충전층 메탄화 반응기의 수학적 모델 및 전산 수치해석)

  • CHI, JUNHWA
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.26 no.3
    • /
    • pp.260-270
    • /
    • 2015
  • One-dimensional packed bed reactor model accounting for interfacial and intra-particle gradients was developed and based on it numerical analyses were performed to investigate the dynamic behavior of a commercial scale methanation reactor. Methanation reaction was almost complete near the reactor inlet and gases with equilibrated composition were discharged from the reactor. Both the intra-particle temperature gradient and differential surface temperature rise were found to be severe near the reactor inlet. To reduce the possible degradation or fracture of catalyst particles and prevent local overheating on the catalyst, addition of inert material can be an effective way.

Hydrothermal Pressure Effect over Preparation of MoS2: Catalyst Characterization and Direct Methanation (수열 압력 제조 조건이 MoS2 촉매 특성과 직접 메탄화 반응에 미치는 영향)

  • PARK, JEONGHWAN;KIM, SEONGSOO;KIM, JINGUL
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.29 no.2
    • /
    • pp.170-180
    • /
    • 2018
  • After $MoS_2$ catalyst was prepared at 1, 30, and 70 atm, the hydrothermal pressure effect over preparation of $MoS_2$ was investigated in terms of catalyst characterization and direct methanation. Multifaceted characterization techniques such as XRD, BET, SEM, TPR, EDS, and XPS were used to analyze and investigate the effect of high pressure over the preparation of surface and bulk $MoS_2$ catalyst. Result from XRD, SEM, and BET demonstrated that $MoS_2$ was more dispersed as preparation pressure was increased, which resulted finer $MoS_2$ crystal size and higher surface area. EDS result confirmed that bulk composition was $MoS_2$ and XPS result showed that S/Mo mole ratio of surface was about 1.3. TPR showed that $MoS_2$ prepared at 30 atm possessed higher active surface sites than $MoS_2$ prepared at 1 atm and these sites could contribute to higher CO yield during methanation. Direct methanation was used to evaluate the CO conversion of the both catalysts prepared at 1 atm and 30 atm and reaction condition was at feed mole ratio of $H_2/CO=1$, GHSV=4800, 30 atm, temperature($^{\circ}C$) of 300, 350, 400, and 450. $MoS_2$ prepared at 30 atm showed more stable and higher CO conversion than $MoS_2$ prepared at 1 atm. Faster deactivation was occurred over $MoS_2$ prepared at 1 atm, which indicated that preparation pressure of $MoS_2$ catalyst was the dominant factor to improve the yield of direct methanation.

Methanation with Variation of Temperature and Space Velocity on Ni Catalysts (니켈촉매를 이용한 온도 및 공간속도 변화에 따른 메탄화 반응 특성)

  • Kim, Sy-Hyun;Yoo, Young-Don;Ryu, Jae-Hong;Byun, Chang-Dae;Lim, Hyo-Jun;Kim, Hyung-Taek
    • New & Renewable Energy
    • /
    • v.6 no.4
    • /
    • pp.30-40
    • /
    • 2010
  • Syngas from gasification of coal can be converted to SNG(Synthesis Natural Gas) through gas cleaning, water gas shift, $CO_2$ removal, and methanation. One of the key technologies involved in the production of SNG is the methanation process. In the methanation process, carbon oxide is converted into methane by reaction with hydrogen. Major factors of methanation are hydrogen-carbon oxide ratio, reaction temperature and space velocity. In order to understand the catalytic behavior, temperature programmed surface reaction (TPSR) experiments and reaction in a fixed bed reactor of carbon monoxide have been performed using two commercial catalyst with different Ni contents (Catalyst A, B). In case of catalyst A, CO conversion was over 99% at the temperature range of $350{\sim}420^{\circ}C$ and CO conversions and $CH_4$ selectivity were lower at the space condition over 3000 1/h. In case of catalyst B, CO conversion was 100% at the temperature over $370^{\circ}C$ and CO conversions and $CH_4$ selectivity were lower at the space condition over 4700 1/h. Also, conditions to satisfy $CH_4$ productivity over 500 ml/h.g-cat were over 2000 1/h of space velocity in case of catalyst A and over 2300 1/h of space velocity in case of catalyst B.

Preparation and Characterization of Ni-Co Bimetallic Catalyst for Methanation (메탄화 반응을 위한 Ni-Co 이원 금속 촉매의 제조와 특성 분석)

  • Yia, Jong-Heop;Kanga, Mi-Yeong;Kim, Woo-Young;Cho, Won-Jun
    • Journal of the Korean Institute of Gas
    • /
    • v.13 no.5
    • /
    • pp.33-38
    • /
    • 2009
  • Synthetic natural gas was producd by the reaction of carbon monoxide and hydrogen via methanation. Ni-Co bimetallic catalyst supported on $Al_2O_3$ for methanation was prepared using deposition-precipitation method. For the comparison, Ni, Co monometallic catalyst was prepared using the same method. The prepared catalysts were characterized by TEM, XRD and TPR and applied to methanation reaction. The catalysts prepared using deposition-precipitation method showed the high metal dispersion. The activity of Ni-Co bimetallic catalyst was higher than that of Ni, Co monometallic catalyst. TPR measurements indicated that Ni-Co bimetallic catalyst had more active hydrogen species than Ni, Co monometallic catalyst due to the synergetic effect in the presence of Ni and Co.

  • PDF

Enhanced CO methanation over Ni-based catalyst using a support with 3D-mesopores

  • Cao, Hong-Xia;Zhang, Jun;Ren, Xiang-Kun;Guo, Cheng-Long
    • The Korean Journal of Chemical Engineering
    • /
    • v.34 no.9
    • /
    • pp.2374-2382
    • /
    • 2017
  • Ni-based catalysts supported on a support with 3D-mesopores, including Ni/KIT-6(EG), Ni/KIT-6(PS) and Ni/KIT-6(DS), were prepared by adding ethylene glycol, direct synthesis and post synthesis methods, respectively, and their catalytic properties were investigated for CO methanation as one of the core technologies of synthetic natural gas production in a continuous flow fixed-bed reactor. The catalysts were characterized by $N_2$ adsorption-desorption, X-ray diffraction (XRD), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), hydrogen temperature-programmed reduction ($H_2-TPR$), hydrogen temperature-programmed desorption ($H_2-TPD$) and thermal gravimetric analysis (TGA), respectively. The results showed that Ni/KIT-6(EG) exhibited the best catalytic performance with CO conversion of almost 100% and $CH_4$ yield of 75% at $450^{\circ}C$, atmospheric pressure and 60,000 mL/g/h due to the higher dispersion of Ni species, stronger reducibility of NiO and formation of smaller Ni nanoparticles fixed into 3D-mesopores, indicating that adding ethylene glycol was effective to improve catalytic performance of Ni-based catalyst for CO methanation. Moreover, compared with $Ni/Al_2O_3$(EG) prepared using $Al_2O_3$ as a support, Ni/KIT-6(EG) showed better catalytic performance owing to the higher specific surface area, stronger reducibility of NiO and confinement effect of 3D-mesopores promoting to produce more active sites. After 60h lifetime test of Ni/KIT-6(EG) at $500^{\circ}C$, atmospheric pressure and 60,000 mL/g/h, 3D-mesopores were still maintained and no obvious agglomeration of Ni nanoparticles was observed, meaning that Ni species were still well dispersed into 3D-mesopores. As a consequence, Ni/KIT-6(EG) exhibited superior catalytic performance and stability, which makes it a promising candidate for CO methanation.