Process for beta-lactone production

A continuous method of making a beta-lactone from an epoxide, the method comprising steps of:

• reacting, in a reactor, the contents of a feed stream comprising an epoxide, a solvent, a carbonylation catalyst and carbon monoxide to produce a liquid reaction product stream comprising a beta-lactone and carbonylation catalyst;
• returning the liquid reaction product stream to the feed stream until the weight percent of beta-lactone in the liquid reaction product stream is in the range of about 10% to about 90%;
• and
• then separating, outside the reactor, at least a portion of the beta-lactone in the liquid reaction product stream from the carbonylation catalyst to produce:
• i) a beta-lactone stream comprising beta-lactone, and
• ii) a liquid catalyst recycling stream comprising carbonylation catalyst;
• and
• adding the liquid catalyst recycling stream to the feed stream.