Products characterization study of a slow pyrolysis of biomass-plastic mixtures in a fixed-bed reactor

• Co-pyrolysis of biomass-plastic mixtures in a fixed-bed reactor.
• Determination of the pyrolysis yields for solid, liquid and gas products.
• A synergy in the oil yield of biomass-PET mixtures.
• The gas yields of biomass-PVC mixtures positively existed during pyrolysis.
• Characterization of the products by using FT-IR, GC–MS and SEM.

In this study, co-pyrolysis of plastic wastes; polyvinyl chloride (PVC) and polyethylene terephthalate (PET) with different agricultural wastes such as cotton stalk, hazelnut shells, and sunflower residues near an arid land plant Euphorbia rigida was investigated. Thermal behaviors of raw materials were investigated by using thermogravimetric analyzer. Experiments were conducted at a heating rate of 10 °C min−1 from room temperature to 800 °C in the presence of N2 atmosphere with a flow rate of 100 cm3 min−1. In the light of the experimental results, an appropriate temperature for the fixed-bed pyrolysis of biomass-plastic mixtures at (1/1, w/w) was determined and the raw materials were pyrolyzed at the same conditions except until the final temperature of 500 °C. Solid product (char) and liquid product (tar) of the pyrolysis were characterized by using different types of characterization techniques. Pyrolysis experiments showed that mixing by biomass and plastic materials had a positive effect on the liquid and gas yields. In addition, the characterization studies showed that biomass and plastic materials could be used to convert into valuable chemicals.