Method for the complete anaerobic digestion of polymer mixtures

A process for disposing of biomass in a biogas plant, the process comprising:

• A) collecting or dispensing the biomass into a package, the package prepared from a composition comprising a polymer mixture;
• B) transporting the package in a waste management vehicle to a biogas plant;
• and
• C) fermenting the package anaerobically in a biogas plant to make biogas,
• wherein the polymer mixture in step A) comprises:
• (1) a polyhydroxylalkanoate of 25 to 95% by weight;
• and (2) an aliphatic polyester of 5 to 75% by weight,
• wherein the polyhydroxylalkanoate of (1) is selected from the group consisting of poly-4-hydroxybutyrate, poly-3-hydroxybutyrate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), and poly(3-hydroxybutyrate-co-4-hydroxybutyrate, wherein the aliphatic polyester of (2) comprises:
• (i) a diol/diacid component;
• and (ii) at least one polyfunctional compound of 0 to 2% by weight,
• wherein the diacid component in the diol/diacid component of (i) is of 65 to 100 mol % of succinic acid, or a derivative thereof, and 0 to 35 mol % of an aliphatic C5-C36-dicarboxylic acid, or a derivative thereof, or a mixture of the dicarboxylic acid and the derivative,
• wherein the diol component in the diol/diacid component of (i) is a C2-C8-alkylenediol or C2-C6-oxyalkylenediol,
• wherein the diol/diacid component of (i) has a diol/diacid molar ratio between 0.98:1 and 1:1, and
• wherein the at least one polyfunctional compound of (ii) comprises at least two isocyanate, isocyanurate, oxazoline or epoxide groups, or at least three alcohol or carboxylic acid groups.