Production and application of activated carbons made from waste tire

Abstract

Nowadays, waste tires disposal has become a relevant environmental problem. Although pyrolysis processes seem to be a feasible alternative treatment, a proper application for generated residues is a task to be solved. In this context, the aim of this work is to valorize pyrolytic tire char by means of the production of a useful adsorbent for air purification. An activation process with CO2 was chosen to control the process of microporosity generation. The activation reaction and the textural properties were followed to achieve the understanding of porosity evolution. A change in the reaction rate in the first steps of the process was observed, followed by a linear relationship between activation time and burnoff. Microporosity is generated in two main processes. At the beginning, narrow microporosity is formed, and later, a widening of the micropores is taking place. The performance of the new obtained samples for hot gas cleaning was tested by a process of Phenanthrene (Phe) adsorption in a fixed bed reactor with a process temperature of 150 °C at low inlet concentrations. It was concluded that the porosity development, both micro- and nonmicroporosity, increases the Phe adsorption capacity of activated carbons, likely due to a multilayer adsorption process.