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

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. (C) 2004 Elsevier Ltd. All rights reserved.