Abstract
The effect of solvent composition (water, 2-propanol and mixtures of the two) on the three phase, heterogeneously catalysed, two-step hydrogenation of 2-butyne-1,4-diol on Pd/alumina was investigated in a stirred reactor and for the first time, bubble sizes were measured in situ simultaneously with reaction rates. The first step forming the alkene is slow and gas-liquid mass transfer limitation is unlikely whilst the second step to alkane is much faster and may be mass transfer dominated. Overall, reaction rates displayed a complex relationship with solvent composition. The smallest bubbles where observed with 5% v/v 2-propanol in water and under gas-liquid mass transfer limited conditions (energy dissipation rates < 4 W / kg), the overall reaction closely follows the ratio of mean bubble diameter to hydrogen solubility, both of which are a function of solvent. Overall, the solvent 5% v/v 2-propanol/water gave faster reactions combined with good selectivity compared to the others and is therefore recommended.
Original language | English |
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Pages (from-to) | 5392-5396 |
Number of pages | 5 |
Journal | Chemical Engineering Science |
Volume | 62 |
Issue number | 18-20 |
DOIs | |
Publication status | Published - Sept 2007 |
Externally published | Yes |
Keywords
- Catalysis
- Mass transfer
- Multiphase reactions
- Reaction engineering
- Stirred tank reactor
ASJC Scopus subject areas
- General Chemistry
- General Chemical Engineering
- Industrial and Manufacturing Engineering