Study of the organic extraction and acidic leaching of chars obtained in the pyrolysis of plastics, tire rubber and forestry biomass wastes

Chars produced via co-pyrolysis of plastics, used tires, and pine biomass wastes were characterized. The use of solvents with different polarities for the removal and recovery of the pyrolysis liquid products trapped in the raw chars was analyzed. The results from the organic solvent extractions showed that this process ensures an efficient decontamination of the chars and allowed the recovery of a significant fraction of the pyrolysis oil and/or condensed by-products, improving the yield of the pyrolysis liquid products. The chars presented high ash contents, particularly those resulting from the waste mixtures with tires that were not compatible within a safe reutilization or valorization of these materials. The acidic demineralization procedure was successfully applied and high efficiency removals of the majority of the metallic elements were achieved. The obtained chars exhibited sufficient quality and characteristics to be used as fuel to provide energy or reused as adsorbents or precursors of activated carbon. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES (Prague, Czech Republic 8/25-29/2012).