Co-pyrolysis characteristics of forestry and agricultural residues and waste plastics: Thermal decomposition and products distribution

Co-pyrolysis technology is an important realizable pathway for efficient resource utilization of different kinds of organic solid wastes. Thermogravimetric analysis (TGA), Fourier transform infrared spectrometer (FTIR), and pyrolyze coupled with gas chromatography/mass spectrometry (Py-GC/MS) were used to examine the thermal decomposition behavior, pyrolysis performance, and products distribution from different kinds of solid wastes. Results are presented using agricultural and forestry residues (poplar biomass and rape straw), waste plastics (polyvinyl chloride and polystyrene) and their mixtures in 1:1 mass ratio. The TGA results showed a low comprehensive pyrolysis index (CPI) for the examined agricultural and forestry residues as compared to their mixtures with waste plastics that showed improved pyrolysis performance during their co-pyrolysis. The FTIR data of forestry and agricultural residues and waste plastics showed that they have a similar functional group (-CH3, -CH2, -CH and -C-). The possible occurrence of the products in the pyrolysis was further predicted by these functional groups. The results of Py-GC/MS analysis showed that the yield of aromatic hydrocarbons in co-pyrolysis of agricultural and forestry residues and waste plastics improved compared to solo pyrolysis of agricultural and forestry residues. The study provides efficient synergistic conversion of biomass and plastics for their treatment with favorable products distribution and yields.