Scrap car tires gasification at high pressure in atmosphere of steam and carbon dioxide

The utilization of scrap car tires is complex task due to its complex structure. The gasification of tires is promising technology due to possibility of obtaining additional products with high value or production of thermal and/or electrical energy with high efficiency. Current study is devoted to scrap car tires gasification in carbon dioxide and steam mediums at high pressure (up to 0.5 MPa). The metal tire yarn was preliminarily removed from initial material and were cut into cubes with 5 mm size. The dependences of sample mass on time were obtained at different temperatures. The reaction rates in steam were higher than in carbon dioxide at all pressures studied. The apparent kinetic constant values – activation energy and frequency factor – were obtained for the single chemical reaction approach. The activation energy values were found to decrease with pressure of steam from 176.2 kJ/mole to 72.6 kJ/mole, while opposite dependences were obtained for carbon dioxide – the activation energy was increasing from 92.3 kJ/mole at 0.1 MPa to 178.1 kJ/mole at 0.5 MPa. This could be caused by different contribution of rubber thermal cracking and char gasification reactions in overall apparent gasification process.