CAUSTIC TREATMENT OF FORMALDEHYDE RECYCLE COLUMN FEED

摘要

An improved method for removing formaldehyde from a crude butynediol product stream comprising the step of providing a crude butynediol stream containing butynediol and formaldehyde. A pH control agent is then mixed with the crude butynediol stream to form a treated product stream, wherein the pH of the treated product stream is raised to a level that limits the reaction of butynediol and formaldehyde to form acetal complex and decrease the solubility of trace metals. The treated product stream then flows into the inlet of a continuous distillation column. Finally, a concentrated formaldehyde stream from the overhead stream of the distillation column and a concentrated butynediol stream from the distillation bottoms stream that is essentially free of formaldehyde and acetal complex are both recovered.