Patent ID: 9259664
Filing Date: 2016-02-16
CPC Classification: B01D,C07C

Claim Text:
1. A process for purifying an unsaturated compound, comprising: feeding a mixture of the unsaturated compound and at least one of a compound of higher volatility than the unsaturated compound, a catlyst and a compound of lower volatility than the unsaturated compound to a first evaporator; vaporizing a portion of the unsaturated compound and any compound of higher volatility at a pressure of from 0.1 mbar to 20 mbar in the first evaporator; removing the vapor phase from the first evaporator and isolating the unsaturated compound from the vapor phase; transferring a portion of the nonvaporized mixture from a bottom of the first evaporator to a second evaporator having a pressure of from 0.1 mbar to 20 mbar; vaporizing a portion of the unsaturated compound in the second evaporator; condensing the unsaturated compound vapor from the second evaporator and returning the condensate to the first evaporator; wherein a mass flow of condensed vapor from the first evaporator is less than the mass flow of condensate from the second evaporator to the first evaporator, and a purity of the isolated unsaturated compound is 99% or more.