This paper relates to a multi-orifice distributor for a gas-fluidised bed, using many upwardfacing nozzles, equally spaced in a horizontal plate. Each orifice contained a removable helical coil, which made the gas swirl as it entered the bed. For a single orifice in such a distributor, ultra-fast magnetic resonance imaging (MRI) and pressure measurements were applied to study: (i) the formation of jets and bubbles, and (ii) the orifice pressure drop. Results from MRI show that the swirling flow induced by the helix significantly improves the fluidisation quality compared to a plain nozzle without spiral. The helix gives rise to secondary flow which increases pressure drop across the nozzle, the measured values of which are predicted satisfactorily by using a friction factor correlation for helical coils.

This paper explores the feasibility of controlling the selectivity of a partial oxidation reaction by simultaneous modulation of local oxygen concentration and coolant temperature along the length of a reactor. The microstructured membrane reactor (MMR) concept consists of an oxygenpermeable membrane for distributing the oxygen feed with the coolant channel divided into zones of different temperatures. The reactor concept was explored in simulation of the selective oxidation

Oxidation of n-pentane with molecular oxygen to sec-pentanols was performed in the presence of a free radical initiator (di-tert-butyl peroxide) and a boron compound (sec-butyl metaborate), with in situ adsorption of water on molecular sieve 3A. Kinetics of the reaction was studied in a laboratory-scale batch reactor over a broad range of conditions (130-150°C, 20-30 bar, 5-10 vol% O 2) in order to establish the optimum parameters for maximising the selectivity and yield of sec-pentanols. Results show that the initiator markedly improves the rate of oxidation, and hence yield, compared to thermal oxidation without an initiator, while the boron species enhances the selectivity to sec-pentanols. Under the conditions investigated, maximum secpentanol selectivity is 56% with an alcohol-to-ketone ratio of 3.6:1 for the borate-assisted oxidation compared to 33% and 1.1:1, respectively, for the oxidation without borate. This work demonstrates the feasibility of oxyfunctionalization of n-pentane with industrially relevant selectivity and yield.

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