Patent ID: 7795376

Claim:
A method of isolating a PHA from a biomass containing the PHA, the method comprising: contacting the biomass with a PHA extraction solvent to form a first combination comprising a PHA phase and a residual biomass phase; separating the PHA phase from the residual biomass phase; introducing the PHA phase into a PHA receiving solvent, thereby forming a second combination, wherein the PHA extraction solvent is capable of forming a minimum boiling azeotrope with the PHA receiving solvent; maintaining the second combination at a temperature and pressure such that the PHA extraction solvent of the PHA phase and a portion of the PHA receiving solvent are removed from the second combination in the gaseous state as an azeotropic mixture; and precipitating the PHA from the second combination when the PHA extraction solvent is substantially removed from the second combination; wherein: the PHA extraction solvent is selected from the group consisting of ketones, esters, alcohols and alkanes; the PHA receiving solvent is water; and the PHA extraction solvent has a higher boiling point than the PHA receiving solvent.