Hydrogen production by waste tire recycling by photo-pyrolysis

Abstract

Waste tires are a major environmental concern due to their non-degradable nature and the large area occupied by them in landfills worldwide. Several recycling processes have been applied to minimize the high amount of waste tire disposal; in particular, pyrolysis has gained more attention since it can minimize the emission of toxic gases. In this study, we present a new process for treating waste tires called “photo-pyrolysis”. End-of-life tires, in the form of powder (100–200 μm) and/or small shreds, were converted in a few seconds (2.4 to 20 s), by using high-intensity flash light irradiation from a xenon lamp, into valuable products such as tire pyrolysis oil (TPO) and syngas, and a carbon-rich solid residue. 44 wt% was recovered as a solid of which 32.3 wt% was related to carbon and 11.7 wt% to the metals and inorganic fillers. The next 36 wt% was attributed to a mixture of gases (mainly hydrogen, ethylene, and methane) and the remaining 20 wt% was produced as a liquid fraction (TPO). Therefore, photo-pyrolysis is proposed as a new and eco-friendly strategy for recycling end-of-life tires, which can be industrialized with continuous processing systems, and used not only for tire recycling but also for other solid organic wastes.