PREPARATION OF AQUEOUS FORMALDEHYDE

摘要

Formaldehyde manufacture by oxidative-dehydrogenation of methanol over a silver or copper catalyst. Aqueous formaldehyde solution is obtained from the reaction and is stripped of a mixture of methanol, formaldehyde and water by a low energy process at relatively low temperature and low reflux in a still comprising at least about 1.5 theoretical plates, the stripping conditions being selected to allow substantial reduction of the methanol content of the aqueous formaldehyde solution and recycle of the methanol to the reactor.