Preparation of high concentration methacetal equipment

    The acetal equipment can be used for aerosols, detergents, etc., and has wide uses. In addition, POM is also a high performance polymer material, and its production process requires high concentration of methal. Methal is formed by condensation of methanol and formaldehyde in the presence of acid catalysts. At present, a solid acid catalyst, such as cation exchange resin, is usually done in a reactive distillation column. However, as methal and methanol and water all produce azeotropic substances which are very close to the boiling point (azeotrope and methanol azeotrope 41.85 C, methyl acetal 91.8%, methal and water azeotrope 42.05 C, containing methyl acetal 98.6%), the content of methylal acetal separated from the reactive distillation column is less than 92%, which is methal and methanol containing a small amount of water. The azeotrope of the azeotrope. In order to obtain high concentration of acetal (usually considered as >99.8%), the crude formaldehyde needs to be refined. In the early stage, the addition of alkali to the purification of methal was complicated and the energy consumption was very high. Because of the different extractant used in extractive distillation, the extraction process is different, and the cost of energy consumption is also very different. The methal fraction was collected at 42.5 C, and the distillates of the acetal equipment after purification were repeated again, and the high purity methal of methal obtained with high purity was complex and needed many distillation and high energy consumption.