The influence of the pyrolysis conditions in a rotary oven on the characteristics of the products

The pyrolysis of 1:1 blends of reinforcing fibre (RF) from tyre wastes with low rank bituminous coal was carried out in a rotary oven. The pyrolysis conditions were modified in order to study their influence on the yield and characteristics of the char and oil obtained. The variables studied were as follows: rotation speed, final pyrolysis temperature, N₂ flow and heating rate. The textural characteristics of the char were studied by means of N₂ adsorption at 77 K, whereas the oil composition was studied by infrared spectroscopy and gas chromatography. 

Modification of the variables did not have any effect on the composition or textural properties of RF/coal char. However, an increase in the nitrogen flow, rotary speed and a decrease in the heating rate led to a higher oil yield with more oxygenated groups and less aromaticity. These conditions also caused an increase in the contribution of the light oil to the oil yield. Moreover, an increment in the final temperature also resulted in a higher percentage of light oil, a greater amount of aromatic compounds and smaller number of oxygenated groups.