Liquid-Phase Hydrogenation of Cinnamaldehyde over a Ru−Sn Sol−Gel Catalyst. 1. Evaluation of Mass Transfer via a Combined Experimental/Theoretical Approach

2004 ◽  
Vol 43 (9) ◽  
pp. 2030-2038 ◽  
Author(s):  
Jan Hájek ◽  
Dmitry Yu. Murzin
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Theoretical Approach ◽  
Sol Gel ◽  
Liquid Phase Hydrogenation

Granulated Carbon Nanotubes as the Catalyst Support for Pt for the Hydrogenation of Nitrobenzene

2010 ◽  
Vol 63 (1) ◽  
pp. 131 ◽  
Author(s):  
Shao Jin ◽  
Weizhong Qian ◽  
Yi Liu ◽  
Fei Wei ◽  
Dezeng Wang ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Mass Transfer ◽  
Catalytic Activity ◽  
Activated Carbon ◽  
Liquid Phase ◽  
Transfer Rate ◽  
High Selectivity ◽  
Mass Transfer Rate ◽  
Catalyst Support ◽  
Liquid Phase Hydrogenation

Granulated Pt/carbon nanotubes (CNTs) were found to have a much better catalytic activity in the liquid phase hydrogenation of nitrobenzene than Pt/activated carbon (AC). The granulated CNTs had much larger pores than the AC particles, which gave a faster mass transfer rate of H2 that helped produce aniline with high selectivity.

Mass-Transfer Limitation in Mesopores of Ni–MgO Catalyst in Liquid-Phase Hydrogenation

2000 ◽  
Vol 191 (2) ◽  
pp. 261-270 ◽  
Author(s):  
Satoshi Sato ◽  
Ryoji Takahashi ◽  
Toshiaki Sodesawa ◽  
Fumio Nozaki ◽  
Xing-Zhou Jin ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Liquid Phase ◽  
Mass Transfer Limitation ◽  
Liquid Phase Hydrogenation

scholarly journals Mass Transfer in Hierarchical Silica Monoliths Loaded With Pt in the Continuous-Flow Liquid-Phase Hydrogenation of p-Nitrophenol

2021 ◽  
Vol 3 ◽  
Author(s):  
Haseeb Ullah Khan Jatoi ◽  
Michael Goepel ◽  
David Poppitz ◽  
Richard Kohns ◽  
Dirk Enke ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Flow Rate ◽  
Continuous Flow ◽  
Flow Reactor ◽  
Sol Gel ◽  
Catalyst Support ◽  
Test Reaction ◽  
Silica Monoliths ◽  
Monolithic Catalysts ◽  
Liquid Phase Hydrogenation

Sol-gel-based silica monoliths with hierarchical mesopores/macropores are promising catalyst support and flow reactors. Here, we report the successful preparation of cylindrically shaped Pt-loaded silica monoliths (length: 2 cm, diameter: 0.5 cm) with a variable mean macropore width of 1, 6, 10, or 27 μm at a fixed mean mesopore width of 17 nm. The Pt-loaded monolithic catalysts were housed in a robust cladding made of borosilicate glass for use as a flow reactor. The monolithic reactors exhibit a permeability as high as 2 μm2 with a pressure drop below 9 bars over a flow rate range of 2–20 cm3 min−1 (solvent: water). The aqueous-phase hydrogenation of p-nitrophenol to p-aminophenol with NaBH4 as a reducing agent was used as a test reaction to study the influence of mass transfer on catalytic activity in continuous flow. No influence of flow rate on conversion at a fixed contact time of 2.6 s was observed for monolithic catalysts with mean macropore widths of 1, 10, or 27 µm. As opposed to earlier studies conducted at much lower flow velocities, this strongly indicates the absence of external mass-transfer limitations or stagnant layer formation in the macropores of the monolithic catalysts.

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

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