Table 2.
Bioplastics biodegradation and biogas production potential through the AD process as an EoL option.
| Bioplastic type | Anaerobic conditions | Time (day) | Findings in term of bioenergy recovery and E-LCA | References |
|---|---|---|---|---|
| PLA | 35–37 °C | 40–150 | • Mineralization was less than 1 and reached 7% | [149] |
| PLA | Mesophilic conditions | 70–280 | • Degradation: 10.8–66% | [[150], [151], [152]] |
| PLA | 37 °C | 100 | • Degradation: 60% | [153] |
| PLA | 55 °C | 30–60 | • Degradation: 24–68% | [154] |
| Starch-based polymer and PLA | pH 8.3, 55 °C, C/N 4.2 | 33 | • AD of bioplastics can be a sustainable approach, reducing bioplastic leakage and producing bioenergy, respecting circular economy principles | |
| • AD may represent a valorization treatment for bioplastics' wastes contributing positively to the sustainability of the entire bioplastics' life cycle. | [155] | |||
| PHB and PLA | 35.7 °C and 350 rpm | 170 | • PHB and PLA pretreatment increased average methane production by 100%. | |
| • AD co-digesters of PHB with sludge caused 80–98% conversion of PHB to methane | ||||
| • AD or co-digestion is a feasible EoL option for bio-based plastics. | [152] | |||
| PLA | PLA size (125–250 μm), 37 °C, and co-digestion with cow manure and vegetable waste | 277 | • Biodegradation: 49% | |
| • Methane production: 4.82 L | [154] | |||
| PBS | PBS size (125–250 μm), 37 °C, and co-digestion with cow manure and vegetable waste | 30 | • Methane production reached 0.81 L | |
| • PBS was not biodegraded by anaerobic sludge bacteria | [154] | |||
| Cellulose-based metallised film | Particle size (1 × 1 cm), co-digested with domestic food waste and card packaging | 65 | • Weight loss: 78.2% | |
| • Methane yield: 0.374 m3 CH4 per kg VS | [150] | |||
| Starch-based film blend 1 | Particle size (1 × 1 cm), co-digested with domestic food waste and card packaging | 65 | • Weight destruction: 7.9% | |
| • Methane yield: 0.113 m3 CH4 per kg VS | [150] | |||
| Mater-Bi® (a family of maize starch-based flexible films) | 37 °C, co digestion with anaerobic sludge | NA | • Methane yield: 33 mL per g VS | [156] |
| Starch-based bioplastic | Cut into a size of 20 × 20 mm, co-digestion with anaerobic sludge from OFMSW and food waste, 55 °C and static incubation | 23 | • Biodegradation: 85% | [157] |
| Cellulose based bioplastic, foil | Cut into a size of 1 × 1 cm, co-digested with anaerobic sludge (thermophilic sludge), 55 °C static incubation | 35 | • Biodegradation: 18.3% | |
| • Methane yield: 283 mL per g VS | [158] |
Abbreviations: AD, anaerobic digestion; EoL, end-of-life; PBS, polybutylene succinate; PHA, polyhydroxyalkanoates; PHB, polyhydroxy butyrate; PLA, polylactic acid.