Three-dimensional Simulation and Experimental Investigation of a Novel Biomass Fast Pyrolysis Reactor

A novel autothermal reactor, named internally interconnected fluidized beds (IIFB), was developed for biomass fast pyrolysis to produce liquid fuels and chemicals. The IIFB reactor includes a pyrolysis bed and a combustion bed to conduct biomass pyrolysis and char burning, respectively. In this study, numerical simulation and experimental studies on volume fraction of particles, solid circulation rate and pressure distribution of the IIFB are reported. The stable flow photographed from the simulations coincides with that in the experiments at the same operating conditions. At the same height, the velocity of gas is twice as larger as the velocity of solid, which is favorable for catalytic reactions. The particles move up unsteadily in the draft tube, and yet they fall down with an almost constant velocity 0.07 m/s in the dipleg. The pressure in the fluidization region is higher than that in the spouted region at H=10 mm and it shows an opposite pressure distribution. It is also observed that the experimental value of pressure is in well agreement with that obtained from simulations on the bottom, and yet it shows very different characteristics on the two outlets. Simulation results show that solid circulation rate at different cross-sections converged to 110 kg/h which is in well agreement with experimental data of 104.5 kg/h.