IMPROVED PROCESS FOR THE SOLVENT-BASED EXTRACTION OF POLYHYDROXYALKANOATES FROM BIOMASS

摘要

Improved processes for extracting polyhydroxyalkanoate from a biomass containing the polyhydroxyalkanoate including the steps of: combining the biomass containing the polyhydroxyalkanoate with a solvent selected from lower chain ketones, and mixtures thereof to form a biomass liquor wherein the biomass liquor comprises less than about 25% water; mixing the biomass liquor for from about 10 to about 300 minutes at a temperature in the range of from about 70° C to about 120 °C; separating the polyhydroxyalkanoate from the biomass liquor to form a PHA-enriched liquor, wherein the separating occurs at a temperature of at least about 40°C; mixing the PHA-enriched liquor with water to form precipitated polyhydroxyalkanoate and an impure solvent liquor, wherein the water is mixed with the PHA-enriched liquor in the ratio of from at least least 3 parts water to one part polyhydroxyalkanoate; and recovering the precipitated polyhydroxyalkanoate from the impure solvent liquor. Optional treatment with oxidizing agents or mild surfactant or mild bleach is used to enhance color and odor.