Pyrolysis of residual tyres: Exergy and kinetics of pyrogas

Abstract

Around 1.5 billion tyres are produced each year, with a huge percentage ending up in landfills. Residual rubber tyres have a calorific value of 39–42 MJkg−1, making them an appealing candidate for pyrolysis. The goal of this project is converting discarded tyres into pyro-energy. A single column fixed bed batch pyrolyzer was built to pyrolyzer residual tyres.The residual tyres that were left over were ground into a fine powder. An elemental analyser was used to quantify the amount of total hydrogen, sulphur, carbon and nitrogen in powdered residual tyres. Thermo Gravimetric Analysis at different rates of heating, including Thermo Gravimetric Analysis at different rates of heat, including 5 °C min−1, 10 °C min-1 and 15 °C min-1, was used to assess the thermal deterioration profile of the residual tyres.The residual tyres were thermally cracked at temperatures between 450 and 550 °C, with each increment of 50 °C. Each trail's pyro-gas was monitored separately, and the exergy was calculated using thermodynamic rules. To estimate kinetic factors such as activation energy and reaction sequence, four distinct model-free approaches were used. Friedman's activation energy on average has been determined as 127.35 kJ mol−1. At 550 °C, a high of 52.11% of Pyro-gas was detected. The maximum energy and exergy were 5.49 MJkg−1 and 4.92 MJkg−1 respectively.

Keywords

• Residual tyres
• TGA/DTG analysis
• Single column fixed bed pyrolyzer
• Pyro gas
• Kinetic analysis
• Exergy analysis