Thermochemical conversion of mulching film waste via pyrolysis with the addition of cattle excreta

Abstract

Herein, the pyrolysis of mulching film waste (an agricultural plastic waste) with cattle excreta (livestock organic waste) was investigated as the efficient simultaneous treatment of plastic and organic wastes. For pyrolysis of mulching film waste or cattle excreta, an increase in temperature increased the yield of non-condensables and decreased the yield of condensables or solid residue. The mulching film waste-derived pyrolytic product was composed largely of a wide range of hydrocarbons (C1–C44), while the cattle excreta-derived pyrolytic product was composed of a variety of chemical groups such as oxygenates, polycyclic aromatic compounds, N-, S-, and B-containing compounds, and halogenated compounds. Pyrolysis temperature had no significant effect on the selectivity toward each chemical groups found in the condensables derived from either the mulching film waste or cattle excreta. The addition of the cattle excreta to the pyrolysis of the mulching film waste increased the yield of non-condensables and enhanced selectivity toward H2 between 500 °C and 900 °C, compared to the pyrolysis of the mulching film waste only. The pyrolysis of the mulching film waste/cattle excreta mixture led to the condensables with lower contents of N, S, B, and halogens than the pyrolysis of a single feedstock. This study is to propose thermochemical conversion pathway of agricultural plastic waste along with livestock organic waste as an effective strategy for waste-to-resources.