Experimental investigation of acrylonitrile butadiene styrene plastics plasma gasification

E-waste comprising plastics causes serious ecological problems due to low degradability, but it is capable of producing a high amount of energy by thermochemical conversion. Therefore, the current study focuses on generating clean syngas through plasma gasification of acrylonitrile butadiene styrene (ABS) based computer keyboard plastic waste (CKPW) using CO2 as a gasifying agent. The effect of feed rate, gas flow rate and plasma power on the syngas composition was studied. In addition, a comprehensive investigation of energy, exergy, economic and environmental analyses along with characterization of the obtained products was conducted to evaluate the performance of the system. Based on the experimental results, the optimum process parameters for producing syngas possessing a higher calorific value (15.80 MJ/m3) with a higher percentage of H2 (30.16 vol%) and CO (46.09 vol%) were estimated. The optimum feed flow rates of solid fuel and CO2 gas and torch power were estimated as 40 g/10 min, 0.5 lpm and 1.12 kW, respectively. At these conditions, the system could achieve a maximum energy and exergy efficiency of 46.06% and 44.34%, respectively, while the levelized cost of syngas (LCOSover) was estimated as 25.45 INR/kWh, including the social cost. Likewise, the lower values of the estimated global warming potential (370.19 gCO2eq/h) illustrate the better sustainability of the process. The obtained oil with the estimated LHV of 39.13 MJ/kg could be an alternative fuel for diesel and the residue containing a higher proportion of TiO2 has medical applications upon further enrichment. The reaction mechanism of ABS conversion to syngas under plasma gasification conditions is proposed.