Loop reactor staged with structured fibrous catalytic layers for liquid-phase hydrogenations

Abstract

A novel concept of a recycle loop reactor is developed with structured filamentous catalysts integrated as trays in a staged bubble column. The reactor can be operated in batch or continuous mode. Woven fabrics of activated carbon fibres (ACF) were used as support for the Pd catalyst.The loop reactor was tested in the 2-butyne-1,4-diol hydrogenation showing selectivity up to 97% towards 2-butene-1,4-diol at conversions up to 80%. The reactor behaviour was described quantitatively assuming an ideally mixed reactor and Langmuir-Hinshelwood kinetics with weak hydrogen adsorption.Catalyst reuse was demonstrated in multiple runs over a period of 6 months with more than 375 h on stream.

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

“…The catalyst arranged structure (Fig. 34) makes it a promising material for continuous applications (34), e.g., it can be used as catalytic stages in bubble column reactors (180). In a batch process it can be fixed on a stirrer between metal gauzes; catalyst recycling in this case does not require filtration as for the powdered catalyst.…”

Monodispersed Pd-nanoparticles on carbon fiber fabrics as structured catalyst for selective hydrogenation

“…Pd/ACF catalysts showed high activity and selectivity in 2-butyne-1,4-diol selective hydrogenation both in the stirred tank reactor (Joannet et al, 2002) and a loop reactor with an integrated bubble column staged by the catalyst layers (Kiwi-Minsker et al, 2004). However, conventional catalyst preparation by ion-exchange does not result in the formation of monodispersed Pd nanoparticles.…”

Solvent-Free Selective Hydrogenation of 2-Butyne-1,4-diol over Structured Palladium Catalyst

“…17,20 This procedure was not efficient for the solvent-free system. In this case, oxidation-reduction of the catalyst was necessary to get stable activities.…”

“…[19][20][21] When adsorption of water on the active sites is neglected, the transformation rate of butynediol can be expressed as follows:…”

“…17,20 (ii) With increasing pH, the rate constant k 1 drops from k 1,pH7 ) 30 kmol/kg Pd ‚h to k 1,pH11 ) 14.6 kmol/kg Pd ‚ h.…”