| 摘要 |
A continuous process is described for the production of an acid-free alkyl maleate stream from a feed stream containing a major amount of said dialkyl maleate and a minor amount of at least one acidic material selected from a monoalkyl maleate, maleic acid, fumaric acid, a monoalkyl fumarate, maleic anhydride, and a mixture of two or more thereof, which process comprises intimately contacting the feed stream in a washing zone with an aqueous alkaline wash liquor which has a density of at least about 1.15 and which comprises a base selected from an alkali metal hydroxide, an alkali metal carbonate, an alkali metal bicarbonate, and a mixture thereof, dissolved in an aqueous solution of the di-(alkali metal) salt of maleic acid, and recovering from the washing zone an acid-free dialkyl maleate stream. |
