2019 EJRNL PP GIORGIO BESAGNI 1.pdf)u
Terbatas Suharsiyah
» ITB
Terbatas Suharsiyah
» ITB
It is generally admitted that experimental data obtained in “laboratory-scale” bubble columns are
representative of “industrial-scale” reactors if the well-known three “Wilkinson et al. scale-up criteria” are
satisfied: (a) the diameter of the bubble column is larger than 0.15 m, (b) the sparger openings are larger
than 1e2 mm and (c) the aspect ratio is larger than 5. The aim of this communication is to contribute to
the existing discussion. To this end, this communication collects relevant experimental investigation and
include new experimental data: in particular, we have experimentally studied the combined effect of the
aspect ratio (within the range of 1e15) and the sparger design (considering both “coarse” and “fine”
spargers) on the gas holdup in a large-diameter and large-scale gas-liquid bubble column. The bubble
column has been operated both in the batch mode and in the counter-current mode. Filtered air has been
used as the gaseous phase in all the experiments, while the liquid phase has included deionized water
and different aqueous solutions of organic (i.e., ethanol) and inorganic (i.e., sodium chloride, NaCl) active
agents. It is found that the “Wilkinson et al. scale-up criteria” are valid for the air-water case in the batch
mode for “very-coarse” spargers. Conversely, they are no more valid when considering different liquid
velocity, and/or aqueous solutions of active agents, and other sparger openings