Fremgangsmåde til fremstilling af vandige formaldehydopløsninger

摘要

Continuous preparation of an aqueous formaldehyde solution, having a formaldehyde-content of 25-56 wt.%, relative to the weight of the aqueous formaldehyde solution, comprises: (a) preparing formaldehyde from methanol by oxidation and obtaining as an aqueous formaldehyde solution; (b) measuring the formaldehyde-content of the aqueous formaldehyde solution by online-analysis; (c) comparing the measured formaldehyde-content with a predetermined set value; and (d) optionally adjusting the desired formaldehyde-content of the aqueous formaldehyde solution by the addition of water.