PARTIAL DESULFURIZATION OF CRUMB RUBBER IN THE PRESENCE OF METALLIC OXIDES.

Sulfur has been used for a long time as a vulcanizing agent for polybutadiene and polyisoprene rubber. The presence of sulfur in the used crumb rubber powder reduces its dispersion in the bitumen and favors its separation from the colloidal structure of the bitumen. For this reason, it does not allow the use of this waste to modify the road bitumen. In this paper, the desulfurization of used crumb rubber is studied by reactive adsorption in the presence of metal oxide adsorbents in pulverized form. Metal oxide adsorbents were prepared based on Fe, Cu and a mixture of the two metal oxides with a bimodal particle size distribution and an average particle diameter between 500 and 800 nm, by the sol-gel precipitation method, in the presence of a Pluronic® surfactant. The morphology of the prepared adsorbents was investigated by Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and nitrogen porosimetry analyses (BET method). The desulfurization of crumb rubber experiments was carried out in a high-pressure Parr stainless steel reactor with electric heating and stirring in an inert gas atmosphere (nitrogen). The conversion in the desulfurization process of vulcanized rubber was influenced both by the size of the adsorbent particles and also by the nature of the adsorbent. [ABSTRACT FROM AUTHOR]