Methylal, an important raw material and a solvent, is produced by
acetalization of aqueous
formaldehyde with methanol. This acetalization reaction was
carried out in a closed system in
the presence of a cation-exchange resin Indion 130 as catalyst and was
found to be equilibrium
limited. In order to increase the conversion for this reaction,
reactive distillation was carried.
Batch reactive distillation was performed in the presence of the
cation-exchange resin Indion
130 as catalyst. Continuous reactive distillation was performed in
a reactive distillation column
(RDC) using three different types of catalyst packing. The first
type of catalyst packing was
coarse size macroporous cation-exchange resin Indion 130, which was
directly packed along with
Raschig rings. The second type of catalyst packing was Indion 130
tied in cloth bags. The third
type of catalyst packing used was a silica-supported organic catalyst.
Up to 99% conversion of
formaldehyde was achieved by reactive distillation. Vapor−liquid
equilibrium data for the
quaternary system formaldehyde−methanol−methylal−water were
experimentally obtained and
correlated by the UNIFAC method. On the basis of the experimental
results of the single-feed
continuous reactive distillation column, preliminary modeling has been
performed for the
calculations of the minimum reflux ratio and the number of reactive
equilibrium stages in the
column used for synthesis.