Consumption of diverse plastics has posed an environmental threat because their disposal practices, landfilling and incineration, release toxic chemicals and microplastics into all environmental media. Indeed, heterogeneous matrix of plastic wastes makes them hard to be disposed. As such, this study aimed to introduce an environmentally benign/reliable disposal platform for complete decomposition of plastic wastes. Pyrolysis process was adapted to convert plastics into syngas, and a disposable diaper (DD) was used as model plastic waste, because it is composed of a variety of polymeric materials. Pyrolysis of DD resulted in the formation of gaseous products and pyrogenic oils, composed of (oxygenated) hydrocarbons. Nonetheless, reactivity of CO2 as an oxidant in pyrolysis of DD was negligible. To impart the strong/desired reactivity of CO2, Ni-based catalyst was adopted. Ni catalyst enhanced H2 and CO formations 4 and 15 times more than pyrolysis without catalyst at 700 °C under CO2. The value-added syngas production was originated from the reduction of polymeric waste, and its derivatives including aromatic compounds. Thus, CO2 offered a strategic means to produce value-added chemicals and reduce aromaticity of pyrogenic products. The observations could offer an innovative way to control the fate of toxic chemicals derived from plastic pyrolysis.
Keywords: CO(2); Catalytic pyrolysis; Circular economy; Diaper; Plastic management; Waste-to-energy.
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