I. Iliuta et Mc. Iliuta, COMPARISON OF 2-PHASE UPFLOW AND DOWNFLOW FIXED-BED REACTORS PERFORMANCE - CATALYTIC SO2 OXIDATION, Chemical engineering & technology, 20(7), 1997, pp. 455-461
A time- and space-dependent model based on the piston-dispersion-excha
nge model for liquid flow was developed to analyze the performance of
two-phase upflow and downflow fixed bed reactors and was applied to th
e catalytic SO2 oxidation. The hydrodynamic parameters were determined
from residence time distribution measurements, using an imperfect pul
se method for time-domain analysis of nonideal pulse tracer response.
A transient diffusion model of the tracer in the porous particle coupl
ed with the PDE model was used to interpret the obtained RTD curves. G
as-liquid mass transfer parameters were determined by a stationary met
hod based on the least square fit of the calculated concentration prof
iles in gas phase to the experimental values, It is shown that two-pha
se downflow fixed bed reactor performs better at low liquid flow rates
, while two-phase upflow performs better at high liquid flow rates.