Recovery of renewable aromatic and aliphatic hydrocarbon resources from microwave pyrolysis/co-pyrolysis of agro-residues and plastics wastes

Abstract

The present study focussed on recovering the valuable carbon resources from agro-residues (wheat straw, rice husk) and waste plastics (polypropylene, polystyrene) using microwave pyrolysis and co-pyrolysis. The main objective of this study is to investigate the effect of the susceptor blending mechanism on the co-pyrolysis product distribution. Graphite was mixed with feedstock in a new approach to achieving homogeneity, and microwave power of 600 W was used. The average heating rate (52–67 (°C/min)), microwave energy required (2267–2936 (J/g)), heat energy utilized (1410–1444 (J/g)), and conductive heat losses (85–110 (J/g)) were analyzed. The selectivity of cyclic alkanes and alkenes (65.5%) was found to be high in polypropylene pyrolysis oil. Polystyrene pyrolysis oil predominantly contained cyclooctatetraene (61%) compound. Bio-oil obtained from wheat straw predominantly contained aromatic hydrocarbons (85%), whereas rice husk oil also contains high selectivity aromatic hydrocarbons (37.8%) along with aliphatic hydrocarbons (54.9%). The co-pyrolysis oils has high selectivity of aromatics.