Evaluation of renewable and sustainable aviation fuel production from scrap tyres for sustainable aviation sector

In this thesis, a model has been developed for the production of sustainable aviation fuel (SAF) from waste tyres with a plant to be established in Eskişehir province (1817 tons/year capacity) or in Türkiye (202,200 tons/year capacity) within the framework of circular economy. The developed model will convert used tyres into oil, char and gas products using the vacuum pyrolysis process. The pyrolysis oil is then subjected to catalytic cracking, alkylation and hydrotreating (hydrodenitrogenation, hydrodesulfurisation and hydrodearomatisation), while the pyrolysis char is used to produce hydrogen (H2) by electrochemical oxidation. 40.99 g to 52.72 g of H2 are consumed to refine 1000 g of pyrolysis oil. With the proposed model, it is calculated that approximately 843.41-853.13 tons/year and 93853-94938 tons/year of SAF can be produced from 1817 tons and 202,200 tons of waste tyres, respectively. According to different scenarios, the lowest selling price of the fuel produced by low-capacity (1817 tones/year) and high-capacity (202,200 tones/year) plants is in the range of 0.7990-1.2634 $/L and 0.5627-1.0125 $/L, respectively. H2 used in pyrolysis oil refining is produced by electrochemical oxidation of pyrolysis char. To the best of our knowledge, H2 production by electrochemical oxidation of pyrolysis char has not been reported. In addition to the innovative H2 production model proposed, this work has demonstrated that waste tyre can be converted into value-added products such as jet fuel within the framework of the circular economy. Therefore, it is anticipated that the results of this thesis can provide a new avenue in the literature.