CO2 based co-gasification of printed circuit board with high ash coal

Abstract

Electronic wastes are accumulated in the environment due to their non-degradability nature, which makes them unsuitable for landfills. Printed circuit board (PCB) is one of the e-wastes significantly occupying the generated wastes. To utilize them efficiently, in the present study, PCB is thermally treated under N2 and CO2 conditions by pyrolysis and gasification processes at various temperatures. A maximum tar yield of 7.46% is obtained during PCB pyrolysis at 500 °C with a tar calorific value of 31.28 MJ/kg. CO2 gasification of PCB mixture at 1000 °C achieved the highest conversion of 97.6% resulting in a cold gas efficiency (CGE) of 91.9% and exergy efficiency of 82.9%. Further, high ash Indian coal is co-gasified with PCB mixture. It is found that the addition of PCB mixture, PCB resin, and PCB plastic in a 4:1 ratio (HAC: PCB) with HAC increased the CGE by 6.81%, 4.26%, and 2.3%, respectively. Further, the BET analyses of the co-gasification residue showed the generation of surface area as high as 186 m2/g and therefore, it can be suitable as a catalyst for cracking reactions. Further, the residue contains CaCO3, TiO2, and SnO2, which are potential additives in the concrete material for the construction of buildings.