摘要:
In the recovery and purification of acrylonitrile or methacrylonitrile obtained by the ammoxidation reaction of propylene or isobutylene, the bottoms stream associated with the column for extractively distilling acrylonitrile or methacrylonitrile is both reduced in size and increased in polymer concentration by removing a vapor stream containing water from the lower fourth of said column, thus reducing the amount of solids-containing waste streams to be treated.
摘要:
The present invention relates to a new and improved process for the removal of urea entrained in air streams by passing the particulate-laden air through a mist eliminator or a demister, the surface of which is continuously contacted with multiple water sprays to wash the water soluble contaminants from the surface of the demister.
摘要:
Urea is destroyed in aqueous waste streams containing various anions and cations plus urea by contacting the stream with a cation exchange resin, then reacting the resulting stream with nitric oxide, nitrous acid or a nitrite salt to convert the urea to nitrogen, carbon dioxide and water and treating the resulting stream with an anion exchange resin. A pure aqueous stream is obtained which does not adversely affect the environment and which may be recycled to a plant as fresh water resulting in large monetary savings in fresh water cost.
摘要:
The present invention relates to a process for removing cyanides from a crude acetonitrile stream. Caustic and formaldehyde are added to an aqueous acetonitrile stream that contains cyanide. The formaldehyde "kills" the cyanides and provides a waste stream that can be conveniently disposed of.