Patent ID: 9650469
Date: 2017-05-16
CPC Classifications: C07C,C08G,C12P

Claim:
1. A process for producing polyhydroxyalkanoates (PHA), namely homo-, co- or heteropolymer types, by chemical synthesis from volatile fatty acid (VFA) molecules, referred to as precursors, said volatile fatty acid (VFA) molecules being produced by anaerobic fermentation from fermentable biomass, comprising: a) extracting the volatile fatty acid (VFA) molecules, without stopping the fermentation and under conditions that are at least non-lethal for all the microorganisms, via an extraction means chosen from liquid or solid extraction means that are, at least, insoluble in the fermentation medium; b) collecting, outside the fermentation reactor, the volatile fatty acid (VFA) molecules once they have been extracted; c) synthesizing, by chemical synthesis, a given α-halo acid by halogenation, using a volatile fatty acid (VFA) chosen from the volatile fatty acids collected in step b) and said volatile fatty acid (VFA) is defined according to the desired type of PHA and at a temperature below the boiling point of the volatile fatty acid (VFA); d) synthesizing from this a-halo acid molecules of a given a-hydroxy acid by reaction with a base; and e) polymerizing using the a-hydroxy acid obtained a defined polyhydroxyalkanoate (PHA).