Thermodynamic modeling and optimization of thermolysis and air gasification of waste tire

- Penalty function method was used to minimize the Gibbs free energy.
- Gibbs energy minimization was used to predict the gaseous component of waste tire thermolysis and gasification.
- Optimum thermodynamic condition of CGE of waste tire thermolysis and gasification were obtained.

Thermolysis and air gasification are the best thermal alternatives to manage waste tires, which can cause a significant environmental impact. In this research, waste tire thermolysis and air gasification processes are modeled based on the thermodynamic framework. To determine the final product distribution, the Gibbs free energy function is minimized considering mass balance equations as equality constraints. To account the mass balance constraints in the objective function, the penalty method is used. To prove the accuracy of the developed model, predicted adiabatic temperature and product distribution through propane combustion and air gasification of a rubber-wood are compared with the reported data in the literature. Then, the effect of pressure, temperature and air to fuel ratio on the performance of thermolysis and gasification processes is investigated. Finally, the optimum condition of tire thermolysis and gasification are determined. The results show that maximum hydrogen efficiency in the pyrolysis and gasification process is 35.45% and 98.03%, respectively. The results prove performance of air gasification over thermolysis process to convert waste tire.