Pyrolysis of End-Of-Life Tires: Moving from a Pilot Prototype to a Semi-Industrial Plant Using Auger Technology

Area of Science:

• Chemical Engineering
• Materials Science
• Sustainable Chemistry

Background:

• End-of-life tires (ELTs) pose a significant waste management challenge.
• Pyrolysis offers a promising route for ELT valorization into valuable products.
• Scaling up pyrolysis technologies requires validation of process robustness and product consistency.

Purpose of the Study:

• To demonstrate the robustness of an auger reactor for ELT pyrolysis at Technology Readiness Level 7 (TRL-7).
• To compare pyrolysis products from a TRL-7 auger reactor with those from a TRL-5 pilot plant.
• To validate the scalability and reliability of the auger pyrolysis technology for industrial application.

Main Methods:

• Pyrolysis of tire truck (TT) end-of-life tires (ELTs) in a TRL-7 auger reactor and a TRL-5 pilot plant.
• Mimicking TRL-5 operating conditions: specific temperature profiles (450-775 °C), vapor residence time (30 s), and solid residence time (15 min).
• Comparative analysis of yields, properties, and characteristics of tire pyrolysis oil (TPO), tire pyrolysis gas (TPG), and raw recovered carbon black (RRCB).

Main Results:

• Yields and characteristics of TPO, TPG, and RRCB were in good agreement between the TRL-7 and TRL-5 plants.
• TPO from both plants contained comparable valuable chemicals (e.g., benzene, toluene, xylene) and similar simulated distillation curves.
• TPG was rich in H2 and CH4 with a calorific value of 52-54 MJ/Nm3 (N2 free basis); RRCB showed comparable characteristics despite requiring more labor.

Conclusions:

• The auger reactor technology for ELT pyrolysis is robust and reliable, validated at TRL-7.
• Experimental results demonstrate the feasibility of scaling up the pyrolysis process using auger technology.
• The consistent quality of pyrolysis products confirms the industrial potential of this sustainable waste management solution.