| Popis: |
When speciality chemicals are manufactured within the pharmaceutical industry, they are often produced in stirred batch/semi-batch reactors. A ‘methodology’ was explored, to help with the development of continuous fixed-bed catalytic reactors for this sector. This was tested on two different types of model reactions: (a) In the first, the viability of producing tertiary amines via ‘borrowing hydrogen’ was explored, and the reaction of morpholine and benzyl alcohol was studied, on Ru and Pt catalysts. This provided an opportunity for an early involvement in small-scale batch testing of catalysts, and then experiments were performed with the catalyst supported on granules in a packed bed (i.d. = 7 mm, length = 300 mm). Although it was shown that continuous processing is viable, and that high conversions (e.g. 73 to 98%, at 150 ºC) could be achieved, unfortunately further work was necessary to identify a more robust catalyst system, before moving on to pilot-scale trials. (b) In the second, the partial oxidation of benzyl alcohol to benzaldehyde was studied, using a Pt catalyst on a carbon support. This proved to be successful, and the reaction was finally demonstrated at pilot-scale. Carbon monoliths were used as catalyst supports (monolith o.d. = 19 mm; length = 50 mm long; square 0.7 mm x 0.7 mm channels; catalyst loading 2.5 and 2.7 wt% Pt). With a liquid flow of 1 L h-1 and a reactant concentration of ~1 mol L-1, operating at 110 ºC, conversion ranged from 80 to 90% and selectivity from 65 to 99%. The catalyst system was tested for 160 h of operation, and retained its performance. While testing the 2nd reaction, a pilot-scale reactor was also developed, which could be used for a variety of novel reactions. The design was flexible and it was easy to insert and remove the catalytic monoliths. |
