英语翻译
to directly affect the reaction extent,which takes place at the
liquid-solid interface.Indirectly,a larger gas flow rate has two
effects:(i) it can increase the mass transfer rate between gas
and liquid (i.e.,higher conversion),and (ii) it reduces the
volumetric fraction of liquid,causing larger liquid velocities,
then lower liquid/solid contact time (i.e.,a smaller conversion).
The first effect is negligible,unless the liquid flow rate is large,
requiring a comparatively large transfer rate from the gas.Soon
after the minimum gas flow rate,the second effect prevails all
the time.We conclude that larger gas flow rates almost always
cause a lower conversion.
H2 always increases the H2O2 degradation.Overall,both paths
can decompose up to 20% of the H2O2 available,at the low
0.5% mol concentration,with a minimum >1% at the highest
flow rates.These values provide an upper bound for the
synthesis,given that H2O2 is gradually produced along the bed.
Hydrogenation accounts for approximately 1/3 of the total
degradation,suggesting that synthesis can be viable,if its rate
can be sufficiently higher than the significant degradation
processes.