摘要 |
<p>An alkylene carbonate is produced by the reaction of an alkylene oxide with carbon dioxide in the presence of a phosphonium catalyst in a process in which (a) the alkylene oxide, carbon dioxide and the phosphonium catalyst are continuously introduced into a reaction zone from which a product stream containing alkylene carbonate and used phosphonium catalyst is withdrawn, (b) alkylene carbonate and a stream containing used phosphonium catalyst are separated from the product stream, (c) the alkylene carbonate, separated in step (b), is recovered as product, (d) at least a part of the stream containing used phosphonium catalyst is subjected to purification, to obtain purified phosphonium catalyst, and (e) purified phosphonium catalyst is recycled to the reaction zone, optionally in combination with another part of the stream containing used phosphonium catalyst. ® KIPO & WIPO 2009</p> |