scholarly journals Catalysts for Methane Steam Reforming Reaction: Evaluation of CeO2 Addition to Alumina-Based Washcoat Slurry Formulation

2020 ◽  
Vol 6 (3) ◽  
pp. 52 ◽  
Author(s):  
Vincenzo Palma ◽  
Eugenio Meloni ◽  
Simona Renda ◽  
Marco Martino
Keyword(s):  
Steam Reforming ◽  
Methane Conversion ◽  
Formation Rate ◽  
Coke Formation ◽  
Methane Steam Reforming ◽  
Mechanical Resistance ◽  
Carbon Formation ◽  
Structured Catalyst ◽  
Methane Steam ◽  
Adherence Test

The effect of the addition of CeO2 to alumina-based washcoat slurry formulation on the methane steam reforming (MSR) reaction was investigated. Five Al2O3-CeO2-based washcoat slurries, differing from each other in the Al2O3/CeO2 ratio (nominal ratio equal to ∞, 0.042, 0.087, 0.250, 0.667) were prepared, dried and calcined; the resulting powders were loaded with nickel as an active metal and the obtained catalysts were tested in MSR reaction. Five cylindrical silicon carbide (SiC) monoliths were washcoated with the prepared slurries and their mechanical resistance was evaluated through the ultrasound adherence test. The activity tests results highlighted the best performance in terms of methane conversion and hydrogen selectivity of the powder catalyst, with the Al2O3/CeO2 percentage nominal ratio equal to 0.042. A structured catalyst was finally prepared by loading a SiC monolith with the most active catalytic formulation and tested in MSR reaction. The performance of the structured catalyst was evaluated in terms of methane conversion and its stability was verified in a time-on-stream test, which allowed for the evaluation of the carbon formation rate; furthermore, its activity was characterized by the estimation of the kinetic parameters. The results highlighted the beneficial effect of ceria addition on the catalytic activity; moreover, compared with data of the literature, the calculated carbon formation rate demonstrated a good resistance of the catalyst to coke formation.

Ni/x%Nb2O5/Al2O3 Catalysts Prepared via Coprecipitation-Wet Impregnation Method for Methane Steam Reforming

2020 ◽  
Vol 9 (1) ◽  
pp. 80-89
Author(s):  
Juliana F. Gonçalves ◽  
Mariana M.V.M. Souza
Keyword(s):  
Steam Reforming ◽  
Methane Conversion ◽  
Coke Formation ◽  
Methane Steam Reforming ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
X Ray ◽  
Methane Steam ◽  
Temperature Programmed ◽  
Wet Impregnation Method

Background: Hydrogen has been considered the energy source of the future and one of the processes for its production is the methane steam reforming. The catalyst used industrially is Ni/Al2O3 and the addition of promoter oxides can be an alternative to improve the performance of this catalyst, which suffers from coke formation and sintering. Objective: Evaluate the role of niobia on catalytic activity and stability. Methods: Ni/x%Nb2O5/Al2O3 (x = 5, 10 and 20) catalysts were synthesized via coprecipitation-wet impregnation method and characterized by X-ray fluorescence (XRF), N2 adsorption-desorption, X-ray diffraction (XRD), temperature- programmed reduction (TPR), temperature-programmed desorption of ammonia (TPD-NH3), etc. Finally, the catalysts were tested for methane steam reforming reaction. Results: All niobia-doped catalysts presented similar values of methane conversion and when comparing with Ni-Al, the addition of niobia slightly improved the methane conversion. In the stability test at 800oC, all doped and non-doped catalysts did not deactivate during the 24 h of reaction. Conclusion: The addition of 10 and 20 wt.% of niobia had a significant promoter effect over Ni/Al2O3 catalyst in terms of activity and stability at 800 oC and the sample with 20 wt.% of niobia presented lower coke formation.

Methane steam reforming for hydrogen production using low water-ratios without carbon formation over ceria coated Ni catalysts

2008 ◽  
Vol 345 (2) ◽  
pp. 119-127 ◽  
Author(s):  
Jiahui Xu ◽  
Connie M.Y. Yeung ◽  
Jun Ni ◽  
Frederic Meunier ◽  
Nadia Acerbi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Carbon Formation ◽  
Ni Catalysts ◽  
Methane Steam

Methane Steam Reforming Over NiO/CexZryO2-Sil-1 Catalyst Prepared by In-Situ Self-Assembly

2019 ◽  
Vol 19 (11) ◽  
pp. 7416-7420
Author(s):  
Ning Wei ◽  
Jia Zhang ◽  
Hexiang Zhong ◽  
Liwei Pan ◽  
Zeyu Wang ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Steam Reforming ◽  
Self Assembly ◽  
Methane Conversion ◽  
High Surface ◽  
Synthesis Method ◽  
Methane Steam Reforming ◽  
Molar Ratio ◽  
Methane Steam

NiO/CexZryO2-Sil-1 catalysts were prepared using an In-Situ self-assembly approach by coupling silicalite-1 and CexZryO2. This one-step synthesis method utilized the high surface area and hydrothermal stability of silicalite-1 and the good oxidation-reduction ability of the CexZryO2, and hence offered high synthesis efficiency. The catalyst structure was examined by N2-physisorption, temperature-programmed reduction, transmission electron microscopy, and X-ray diffraction. All the results showed that silicalite-1 was well-encapsulated by NiO/Ce0.5Zr0.5O2. Furthermore, the effect of the Ce/Zr molar ratio on the performance of the catalysts was investigated in detail. The catalysts were subjected to methane steam reforming at high temperatures to evaluate their catalytic performance. The result showed that the NiO/Ce0.5Zr0.5O2-Sil-1 catalyst exhibited the best performance and its methane conversion efficiency reached up to 99.5%. Even after 16 h of continuous stability test, this catalyst could retain a methane conversion efficiency of 97.8%.

An Analysis of Heat Transfer Processes in an Internal Indirect Reforming Type Solid Oxide Fuel Cell

2010 ◽  
Author(s):  
Grzegorz Brus ◽  
Zygmunt Kolenda ◽  
Shinji Kimijima ◽  
Janusz S. Szmyd
Keyword(s):  
Steam Reforming ◽  
Solid Oxide ◽  
Methane Steam Reforming ◽  
Oxide Fuel ◽  
Carbon Formation ◽  
Internal Reforming ◽  
Thermal Boundary Conditions ◽  
Methane Steam ◽  
Fuel Flow ◽  
Metal Support

This paper presents experimental and numerical studies on the fuel reforming process on an Ni/YSZ catalyst. Nickel is widely known as a catalyst material for Solid Oxide Fuel Cells. Because of its prices and catalytic properties, Ni is used in both electrodes and internal reforming reactors. However, using Ni as a catalyst carries some disadvantages. Carbon formation is a major problem during a methane/steam reforming reaction based on Ni catalysis. Carbon formation occurs between nickel and metal-support, creating fibers which damage the catalytic property of the reactor. To prevent carbon deposition, the steam-to-carbon ratio is kept between 3 and 5 throughout the entire process. To optimize the reforming reactors, detailed data about the entire reforming process is required. In the present paper kinetics of methane/steam reforming on the Ni/YSZ catalyst was experimentally investigated. Measurements including different thermal boundary conditions, the fuel flow rate and the steam-to-methane ratios were performed. The reforming rate equation derived from experimental data was used in the numerical model to predict synthetic gas composition at the outlet of the reformer.

Effect of ceria loading on the carbon formation during low temperature methane steam reforming over a Ni/CeO2/ZrO2 catalyst

2008 ◽  
Vol 95 (2) ◽  
pp. 213-220 ◽  
Author(s):  
Anton Purnomo ◽  
Susan Gallardo ◽  
Leonila Abella ◽  
Chris Salim ◽  
Hirofumi Hinode
Keyword(s):  
Low Temperature ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Carbon Formation ◽  
Methane Steam ◽  
Zro2 Catalyst

Transport Mechanism of Methane Steam Reforming on Fixed Bed Catalyst Heated by High Temperature Helium for Hydrogen Production: A CFD Investigation

2017 ◽  
Author(s):  
Feng Wang ◽  
Jing Zhou ◽  
Qiang Wen
Keyword(s):  
High Temperature ◽  
Hydrogen Production ◽  
Production Rate ◽  
Steam Reforming ◽  
Methane Conversion ◽  
Methane Steam Reforming ◽  
Inlet Temperature ◽  
Hydrogen Production Rate ◽  
Inlet Velocity ◽  
Methane Steam

Performance of methane steam reforming reactor heated by helium for hydrogen production has been studied by numerical method. Results show with the increasing of reactant gas inlet velocity, temperature in the reactor drops, leading to the decreasing of methane conversion and hydrogen production rate. Methane conversion, hydrogen production and hydrogen production rate rise with the increasing of reactant gas inlet temperature, while the increasing degree of system thermal efficiency reduces. Besides, with helium inlet velocity rising, temperature in the reactor increases and reaction in the reactor becomes more sufficient. Therefore, methane conversion and hydrogen production also increase when helium inlet temperature of rises, but its influence is weaker compared to that of helium inlet velocity. In the process of methane steam reforming heated by high temperature gas cooled reactor (HTGR) for hydrogen production, lower reactant gas inlet velocity, suitable inlet temperature, higher inlet velocity and higher HTGR outlet temperature of helium are preferable.

Kinetic Effects of Non-Equilibrium Plasma-Assisted Methane Steam Reforming on Heat Recovery in Chemically Recuperated Gas Turbine

2013 ◽  
Author(s):  
Qian Liu ◽  
Hongtao Zheng ◽  
Fumin Pan ◽  
Gang Pan ◽  
Ren Yang
Keyword(s):  
Kinetic Model ◽  
Reaction Temperature ◽  
Steam Reforming ◽  
Methane Conversion ◽  
Heat Recovery ◽  
Methane Steam Reforming ◽  
Equilibrium Plasma ◽  
Methane Steam ◽  
Kinetic Effects ◽  
Non Equilibrium

Plasma is proposed as a prospective tool for chemical heat recovery process without restriction from reaction temperature. The author designed DBD catalytic reactors and carried out extensive experiments to investigate methane conversion and products yield and analyze the effect laws of steam to methane ratio, resident time and reaction temperature on methane steam reforming (MSR). Based on extensive experimental studies of steam reforming, a detailed reaction mechanism for the plasma-assisted MSR was developed and evaluated by comparison of experimentally derived and numerically predicted conversion and products yield. The comparisons showed the kinetic model well predicted methane conversion and products yield in different operating conditions. By employing the kinetic model and path flux analysis module the kinetic effects of low temperature non-equilibrium plasma assisted CH4 steam reforming on the methane conversion was studied without catalyst. The results showed that CH3 recombination was the limiting reaction for CO production; meantime O was the critical species for CO production. By adding Ni catalyst can reduce methyl recombination and promote hydroxyl into oxygen, which is beneficial to heat recovery. The proposed research ensures the effect laws and characters of MSR by plasma, and contribute to improve the objective products concentration and furthermore the energy efficiency.

Multi Objective Optimization of a Methane Steam Reforming Reaction in a Membrane Reactor: Considering the Potential Catalyst Deactivation due to the Hydrogen Removal

2017 ◽  
Vol 16 (2) ◽  
Author(s):  
Marjan Alavi ◽  
Reza Eslamloueyan ◽  
Mohammad Reza Rahimpour
Keyword(s):  
Steam Reforming ◽  
Membrane Reactor ◽  
Pareto Front ◽  
Catalyst Deactivation ◽  
Coke Formation ◽  
Optimal Solution ◽  
Methane Steam Reforming ◽  
Nsga Ii ◽  
Hydrogen Recovery ◽  
Methane Steam

AbstractSteam reforming of methane (SRM) is an important stage of hydrogen production. Using a membrane reactor (MR) to separate the produced H2positively affects CH4conversion by shifting the equilibrium. This H2removal increases the risk of coke formation in the process. In this study, the influence of different parameters such as Damkohler’s number (Da) and permeation number (θ) on CH4conversion and H2recovery are investigated. In order to find the optimum condition for this MR in which CH4conversion, H2Recovery are maximized and the risk of coke formation is minimized, the elitist non-dominated sorting genetic algorithm (NSGA-II) is employed to achieve the Pareto front in a three objective space. The single optimal solution is selected from Pareto front by TOPSIS decision making method. In the optimized condition methane conversion and hydrogen recovery are improved about 19.8% an 6.8%, respectively. Also, the risk of coke formation in the MR is reduced.

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