Waste tire valorization by intermediate pyrolysis using a continuous twin-auger reactor: Operational features

Area of Science:

• Chemical Engineering
• Sustainable Chemistry
• Materials Science

Background:

• Waste tires (WT) pose environmental challenges.
• Pyrolysis offers a sustainable route for WT valorization.
• Circular economy principles necessitate efficient waste conversion.

Purpose of the Study:

• To investigate the operational characteristics of a novel twin-auger reactor for intermediate pyrolysis of WT.
• To optimize pyrolysis parameters for maximizing tire pyrolysis oil (TPO) yield.
• To minimize the yield of recovered carbon black (rCB) during WT pyrolysis.

Main Methods:

• Experimental campaign using a central composite design (CCD).
• Analysis of variance (ANOVA) to determine the influence of operating parameters.
• Optimization of reactor temperature, WT mass flow rate, solid residence time, and N2 flow rate.

Main Results:

• Reactor temperature and WT mass flow rate were identified as key parameters influencing TPO and rCB yields.
• Optimized conditions (475°C, 1.16 kg/h, 3.5 min, 300 mL/min) yielded 45 wt% TPO, 40 wt% rCB, and 15 wt% TPG.
• Characterization of TPO, rCB, and TPG confirmed their potential for further utilization.

Conclusions:

• Twin-auger pyrolyzers are effective for the intermediate pyrolysis and valorization of waste tires.
• The study demonstrates a viable pathway towards a circular economy for waste tires.
• Optimized pyrolysis parameters enable efficient production of TPO, rCB, and TPG.