Synergistic effects and products distribution during Co-pyrolysis of biomass and plastics

Co-pyrolysis of agricultural biomass and plastic wastes is examined here from the perspective of enhanced value products, energy production, and pollution reduction. The effect of different species of plastic on the products distribution during co-pyrolysis with biomass, or rapeseed stalk (RS) with polyethylene terephthalate (PET), polypropylene (PP) and polyvinyl chloride (PVC) was performed using a pyrolyzer coupled with gas chromatography/mass spectrometry (Py-GC/MS). The results showed co-pyrolysis of rapeseed stalk with different plastics had little effect on the evolved product species. However, significant differences were observed on the content and yield of products. The co-pyrolysis of rapeseed stalk and polyethylene terephthalate provided primarily the monocyclic aromatic hydrocarbon (MAH). The co-pyrolysis of rapeseed stalk and polypropylene provided aliphatic hydrocarbons (mainly olefins) and promoted the generation of aliphatic hydrocarbons and alcohols due to the synergistic effect. The co-pyrolysis of rapeseed stalk and polyvinyl chloride could promote the production of phenols but inhibited the production of liquid products. The results also showed relatively high product quality from the co-pyrolysis of rapeseed stalk and polypropylene. The results provided plausible pathways for effective utilization of residual agricultural wastes and selected waste plastics for enhanced product quality and content.