OP-II-3

PP-III-2EFFECT OF ACID CATALYST ON THE COMPOSITION OF THELIQUID FRACTION OBTAINED IN TIRE PYROLYSISArabiourrutia M. 1 , López G. 2 , Aguado R. 3 , Olazar M. 4 , Bilbao J. 51 University of the Basque Country/Chemical Engineering Department,PO Box 644– 48080 Bilbao, (Spain), E-mail: miriam.arabiourrutia@ehu.es2,3,4 University of the Basque Country/Chemical Engineering DeparmentThe large quantity of used tire generated is increasing continuously. The forecastfor 2012 is that world generation will exceed 17 million tonnes. This makes thevalorization of used tires more interesting, and among the different technologies,pyrolysis is considered to be one of the more feasible solutions that may beeconomically profitable at large scale [1].This paper conducts a study on the in situ use of acid catalysts in the pyrolysis oftires in a conical spouted bed reactor, with the aim of exploring the effect of thecatalyst properties on the composition of the liquid fraction.The raw material is standard tire rubber containing approximately 30% of naturalrubber, 30% of styrene-butadiene rubber and 30% of carbon black. The remaining10% is made up of sulphur, zinc oxide and additives for obtaining a suitablevulcanization. The experiments have been carried out in a conical spouted bedreactor. This reactor is especially suitable for flash pyrolysis [2], given that the gasresidence time is very short. The two catalysts used have been prepared based onHZSM-5 and HY zeolites, which have been supplied by Zeolyst International. Theexperiments have been carried out at 500 °C. The tire has been fed in pulses of 2ginto a 15 g catalytic bed. The volatile product fractions monitored are: C 1 -C 4 gases(with CO and CO 2 ), non aromatic C 5 -C 10 fraction, aromatic C 10 - fraction and C 10+ (tar).In Table 1 are shown the percentages in mass of different lumps of compounds thatformed the liquid fraction obtained in thermal and catalytic pyrolysis at 500 °C.As it can be observed, the percentage of C 5 -C 10 fraction decreases considerablyin the catalytic pyrolysis, especially in the case of HY catalyst. This decrease has asconsequence the increment in aromatic and tar fractions. In the case of HZSM-5catalyst this decrease is not so important and the percentage of tar fraction alsodecreases.444