Methods of PHA extraction and recovery using non-halogenated solvents

A method for recovering PHA from biomass comprising:

• providing biomass containing PHA;
• dissolving PHA with a non-halogenated PHA-good solvent to produce PHA-enriched solvent and residual biomass materials;
• separating the residual biomass materials from the PHA-enriched solvent;
• precipitating PHA polymer from the PHA-enriched solvent by adding a PHA-poor solvent;
• and
• recovering the precipitated PHA polymer, wherein:
• the PHA is selected from the group consisting of poly(hydroxybutyrate-co-hydroxyvalerate (PHBV), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3HB4HB), and polymers and copolymers of hydroxyterminated polyhydroxybutyrate (PHB-OH);
• and
• when the PHA is 3HB4HB or PHB-OH, the PHA good solvent is selected from the group consisting of:
• cyclic and acyclic R'--OH alcohols where R'=C.sub.4 -C.sub.10, dimethyl glutarate, dimethyl adipate, isobutyl acetate, ethyl lactate, isoamyl acetate, benzyl acetate, 2-methoxy ethyl acetate, tetrahydrofurfuryl acetate, propyl propionate, pentyl propionate, butyl butyrate, isobutyl isobutyrate, ethyl butyrate, ethyl valerate, methyl valerate, benzyl benzoate, methyl benzoate, methyl propionate, allyl alcohol, tetrahydrofurfuryl alcohol, furfuryl alcohol, ethyl benzene, 1,3-dimethoxybenzene, cumene, benzaldehyde, 2-furaldehyde, 1,2-propanediol, 1,2-diaminopropane, ethylene glycol diethyl ether, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3-dioxane, 1-nitropropane, toluene-2,4-diisocyanate, acetic acid, acrylic acid, acetic anhydride, alpha-methyl styrene, propylene carbonate, methyl isobutyl ketone, methyl n-amyl ketone, 5-methyl-2-hexanone, and acetophenone, dimethyl acetamide;
• and when the PHA is PHBV, the PHA-good solvent is selected from the group consisting of cumene, benzaldehyde, 2-furaldehyde, toluene-2,4-diisocyanate, alpha-methylstyrene, acetic acid, acrylic acid, acetic anhydride, 1,2-diaminopropane, 1-nitropropane, and an amyl alcohol mixed isomeric solution comprising 1-pentanol, 2-methyl-1-butanol, and 3-methyl-1-butanol;
• and
• the PHA-poor solvent is selected from solvents which dissolve less than 1% of the PHA at temperatures less than their boiling points.

A method for recovering PHA from oil-bearing seeds comprising:

• providing seeds containing PHA;
• co-dissolving the PHA and oil with a non-halogenated solvent to produce a PHA-enriched solvent/oil mixture and residual biomass materials;
• separating the residual biomass materials from the PHA-enriched solvent/oil mixture;
• and
• separating the PHA from the PHA-enriched solvent/oil mixture;
• wherein the PHA is selected from the group consisting of poly(hydroxybutyrate-cohydroxyvalerate (PHBV), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (3HB4HB), and polymers and copolymers of hydroxyterminated polyhydroxybutyrate (PHB-OH);
• and
• when the PHA is 3HB4HB or PHB-OH, the solvent is selected from the group consisting of:
• cyclic and acyclic R'--OH alcohols where R'=C.sub.4 -C.sub.10, allyl alcohol, tetrahydrofurfuryl alcohol, furfuryl alcohol, cumene, benzaldehyde, 2-furaldehyde, 1,2-propanediol, 1,2-diaminopropane, ethylene glycol diethyl ether, 1-nitropropane, toluene-2,4-diisocyanate, acetic acid, acrylic acid, acetic anhydride, alpha-methylstyrene, methyl isobutyl ketone, methyl n-amyl ketone, 5-methyl-2-hexanone, acetophenone, dimethyl glutarate, dimethyl adipate, ethyl benzene 1,3-dimethoxybenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, propylene carbonate, isobutyl acetate, ethyl lactate, isoamyl acetate, benzyl acetate, 2-methoxy ethyl acetate, tetrahydrofurfuryl acetate, propyl propionate, pentyl propionate, butyl butyrate, isobutyl isobutyrate, ethyl butyrate, ethyl valerate, methyl valerate, benzyl benzoate, and methyl benzoate;
• and when the PHA is PHBV, the solvent is selected from the group consisting of cumene, benzaldehyde, 2-furaldehyde, toluene-2,4-diisocyanate, alpha-methylstyrene, acetic acid, acrylic acid, acetic anhydride, 1,2-diaminopropane, 1-nitropropane, and an amyl alcohol mixed isomeric solution comprising 1-pentanol, 2-methyl-1-butanol, and 3-methyl-1-butanol.