Acetalization of Formaldehyde with Methanol in Batch and Continuous Reactive Distillation Columns

Abstract

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.

Relative messenger RNA expression profiling of collagenases and aggrecanases in human articular chondrocytes in vivo and in vitro

“…The advantages of coupling chemical reaction and separation have been exploited since 192111 for methyl acetate production with reactive distillation (RD) process12 and have been applied in the petrochemical industry. RD technology is also being applied for (1) production of oxygenates such as methyl tert ‐butyl ether (MTBE),13, 14 ethyl tert ‐butyl ether (ETBE),15 or tertiary amyl methyl ether (TAME)16 and (2) acetalization of formaldehyde with methanol 17. However, there are constraints and difficulties in RD implementation, mainly volatility constraints.…”

Novel process for diethylacetal synthesis

“…RD technology is also being applied for (1) production of oxygenates such as methyl tert-butyl ether (MTBE), 13,14 ethyl tert-butyl ether (ETBE), 15 or tertiary amyl methyl ether (TAME) 16 and (2) acetalization of formaldehyde with methanol. 17 However, there are constraints and difficulties in RD implementation, mainly volatility constraints. It is necessary that both products have different boiling points to ensure the separation; therefore, the production of diethylacetal using RD technology is not feasible, given the close boiling points of acetal and water.…”

Challenges and Opportunities in the Production of Oxymethylene Dimethylether

“…, The latter reaction is reversible and hence, the yield is limited by chemical equilibrium , . The equilibrium can be overcome by evaporating the low boiling OME 1 during the reaction , , . Here, very good yields were achieved in a reactive distillation setup .…”