Factorial design application to evaluate thermochemical conversion of shredder residues

Abstract

Abstract Among the different wastes generated by steel industry, there is the shredder residue (SR). SR is a highly heterogeneous mixture, which is most commonly destined to a landfill of industrial waste by the Brazilian steel industry. Considering the high variation of its composition, the use of statistical tools is recommended to obtain consistent data. Pyrolysis can be considered a solution to dispose of this residue. This work aimed at evaluating the SR pyrolysis process using a 2k factorial design. The following variables were investigated: temperature, heating rate, inert gas (N2) flow rate, and CaO/SR ratio. Lower heating rate resulted in higher non-condensable gas yields (>50% w/w). CaO was efficient for CO2 capture in non-condensable gas, thus increasing calorific value. Higher heating rate resulted in higher condensable vapor yields, and the main compound found in this stream was styrene. The thermochemical conversion process, through pyrolysis, presented high potential for SR reuse rather than the disposal in landfills.