Coupled Fluidized Bed Reactor for Pyridine Synthesis

To eliminate the feeding device coking deposit in a commercial pyridine synthesis reactor, a coupled fluidized bed reactor is proposed. The coupled reactor is composed of a feeding zone (FZ), a riser reaction zone (RRZ), and a fluidized bed reaction zone (FRZ). During 15 days of continuous operation, there is no coke deposit in the feeding device. Experimental results show that the product yield reaches as high as 75%. The selectivity is around 2.5 and is higher than that in commercial reactors, which is around 2.2. A core–annulus model and a dispersion model are proposed to model different zones of this coupled reactor, and the predicted average deviation from experimental data is 12%. The prediction results show that the main reactions take place at FZ and FRZ. RRZ contributes the least conversion, because of the limit by the mass transfer between the core and the annulus.