Temperature is the main factor affecting the characteristics and output of waste tire pyrolysis. The performance is as the increase of pyrolysis temperature, the total amount of gas and oil products increases, and the amount of solid products decreases. In the process of temperature rise, the oil product will reach a maximum value. As the temperature continues to rise, the content of solid and oil products begins to decrease and eventually reaches stability.
When the reaction temperature in the waste tire pyrolysis furnace is between 400 and 600°C, the total amount of gas products increases, and the increase of nitrogen equivalent ratio will make the material gasify faster and more completely; when the reaction temperature is higher than 600°C, the properties of the generated carbon black are very similar, and the tar produced is very small; when the reaction temperature is higher than 700°C, the gasification effect is no longer obvious. Therefore, we recommend that the appropriate temperature and equivalence ratio for waste tire pyrolysis are 650~700℃and 0.2~0.4 respectively. At this time, the calorific value of the generated gas is 4000~9000KJ/Nm³, the output is 18~37Nm³/kg, the specific surface area ofcarbon black is about 20~30m³/g, and the output is 550~650g/kg. Temperature is one of the main factors affecting the yield and characteristics of pyrolysis coke. When the temperature rises from 400℃to 500℃, the coke yield decreases by about 25.8%, and the coke composition does not change much; when the temperature rises from 500℃to 900℃, the coke yield changes little, but the composition changes significantly, and the content of hydrogen and oxygen elements decreases significantly.
Therefore, in the process of thermal pyrolysis, the demand for products is different, and the corresponding pyrolysis temperature should be controlled according to the different target products. If you need to increase the content of oil products, you can use electric heating or pyrolysis gas heating to control the pyrolysis temperature in the range of 400℃~800℃. Because its temperature rise is slow, it can prevent the occurrence of secondary reactions. If you need to increase the gas production rate, you can use plasma technology to pyrolyze waste tires. No liquid oil products are generated, the reaction is rapid, the pyrolysis gas has a high calorific value, and no harmful gases are generated. The gas products are mainly C2H4, CH4, C2H2, H2, and CO, and the gas production rate has reached 77%.
