Modified Simulation of Methane Steam Reforming in Pd-Membrane/Packed-Bed Type Reactor.

1999 ◽  
Vol 32 (6) ◽  
pp. 760-769 ◽  
Author(s):  
Jun-Hun Kim ◽  
Byung-Seok Choi ◽  
Jongheop Yi
Keyword(s):  
Steam Reforming ◽  
Packed Bed ◽  
Methane Steam Reforming ◽  
Type Reactor ◽  
Pd Membrane ◽  
Methane Steam

scholarly journals A High-Fidelity CFD Model of Methane Steam Reforming in a Packed Bed Reactor

2009 ◽  
Vol 42 (Supplement.) ◽  
pp. s73-s78 ◽  
Author(s):  
Mayu Kuroki ◽  
Shinichi Ookawara ◽  
Kohei Ogawa
Keyword(s):  
Steam Reforming ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Methane Steam Reforming ◽  
High Fidelity ◽  
Cfd Model ◽  
Methane Steam

scholarly journals Sensitivity analysis and optimization of a membrane reactor for hydrogen production through methane steam reforming

2020 ◽  
Vol 5 (6) ◽  
Author(s):  
Igor Nardi Caxiano ◽  
Lizandro De Sousa Santos ◽  
Diego Martinez Prata
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Methane Conversion ◽  
Membrane Reactor ◽  
Packed Bed ◽  
Operating Conditions ◽  
Methane Steam Reforming ◽  
Maximum Efficiency ◽  
Promising Alternative ◽  
Methane Steam

Hydrogen is one of most studied sources for clean power generation in the near future. Nowadays, hydrogen is mainly produced through methane steam reforming in packed bed reactors, with a promising alternative to this technology being the implementation of hydrogen-selective membrane reactors. This work compares the isothermal mathematical models of both designs by assessing the effects of multiple design variables on methane conversion, while also providing recommended operating conditions for maximum efficiency of the membrane reactor over the packed bed technology. Additionally, an optimization study is carried by dividing the reactor length in isothermal segments to achieve higher efficiency. Results showed that the membrane technology considerably increases hydrogen production, with temperature being the most influential variable on methane conversion. While the temperature profile optimization provided similar conversions compared to the isothermal models, the membrane reactor’s efficiency was increased, further justifying its implementation.

Ultra-Low Amounts of Palladium (0.005-0.05 Wt% Pd) Supported on Titania: Remarkable Low-Temperature Activity for NO Reduction with CO and Structure-Function Property Relationships in Methane Oxidation

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Libor Kovarik ◽  
Nicholas R. Jaegers ◽  
János Szanyi ◽  
Yong Wang
Keyword(s):  
Nitric Oxide ◽  
Carbon Monoxide ◽  
Methane Oxidation ◽  
Steam Reforming ◽  
Methane Steam Reforming ◽  
Oxide Reduction ◽  
Water Steam ◽  
Methane Steam ◽  
Anatase Titania ◽  
Nitric Oxide Reduction

<p>Atomically dispersed Pd +2 cations with ultra-dilute loading of palladium (0.005-0.05 wt%) were anchored on anatase titania and characterized with FTIR, microscopy and catalytic tests. CO infrared adsorption produces a sharp, narrow mono-carbonyl Pd(II)-CO band at ~2,130 cm<sup>-1</sup> indicating formation of highly uniform and stable Pd+2 ions on anatase titania. The 0.05 wt% Pd/TiO<sub>2</sub> sample was evaluated for methane combustion under dry and wet (industrially relevant) conditions in the presence and absence of carbon monoxide. Notably, we find the isolated palladium atoms respond dynamically upon oxygen concentration modulation (switching-on and switching off). When oxygen is removed from the wet methane stream, palladium ions are reduced to metallic state by methane and catalyze methane steam reforming instead of complete methane oxidation. Re-admission of oxygen restores Pd<sup>+2</sup> cations and switches off methane steam reforming activity. Moreover, 0.05 wt% Pd/TiO<sub>2</sub> is a competent CO oxidation catalyst in the presence of water steam with 90% CO conversion and TOF ~ 4,000 hr<sup>-1</sup> at 260 ⁰C. </p><p>More importantly, we find that diluting 0.05 wt% Pd/titania sample with titania to ultra-low 0.005 wt% palladium loading produces a remarkably active material for nitric oxide reduction with carbon monoxide under industrially relevant conditions with >90% conversion of nitric oxide at 180 ⁰C (~460 ppm NO and 150 L/g*hr flow rate in the presence of >2% water steam) and TOF ~6,000 hr<sup>-1</sup>. Pd thus outperforms state-of-the-art rhodium containing catalysts with (15-20 times higher rhodium loading; rhodium is ~ 3 times more expensive than palladium). Furthermore, palladium catalysts are more selective towards nitrogen and produce significantly less ammonia relative to the more traditional rhodium catalysts due to lower Pd amount nd lower water-gas-shift activity. Our study is the first example of utilizing ultra-low (0.05 wt% and less) noble metal (Pd) amounts to produce heterogeneous catalysts with extraordinary activity for nitric oxide reduction. This opens up a pathway to study other Pd, Pt and Rh containing materials with ultra-low loadings of expensive noble metals dispersed on titania or titania-coated oxides for industrially relevant nitric oxide abatement.</p>

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