Increasing the recovery of automobile shredder residue (ASR) through assimilation to a solid recovered fuel (SRF): the results of a feasibility study

This study analyzes the possibility of assimilating some fractions extracted from the shredder light fraction (SLF) to a solid recovered fuel (SRF). Italian Ministerial Decree D.M. 22/2013 fixes the criteria for the assimilation in the compliance of three parameters (heating value and chlorine and mercury content) and a number of heavy metals with threshold values. A sample of SLF underwent a product composition analysis. The results demonstrated that polyurethane foam (PUR) and heavy textile were the most abundant fractions, with 46.0% and 23.5% by weight (b.w.) respectively. Because of their size, amounts equal to 50% b.w. of PUR and to 75% of heavy textile could be separated by using a 150 mm sieve. The mixture of the separated products had a net heating value of 25.7 kJ/g, that made it suitable to be classified as a first class SRF. The content of heavy metals was well below the threshold values fixed by D.M. 22/2013, with the only exception of nickel, the concentration of which in the mixture of the two products was 40 mg/kg, 33.3% higher than the threshold value. The results of the analyses and tests demonstrated that PUR and heavy textile were good candidates to be assimilated to a SRF and, furthermore, they could integrate the conventional fuel in cement factories, foundries or other thermal plants.