Cenospheric and sand fluidized bed as an environment for waste rubber combustion-comparisons of decomposition dynamics and flue gas emission

Abstract

The results of thermal recycling of rubber in the fluidized bed are presented. Two different types of the bed material were used: sand and low density spheres (cenospheres). For two bed types, rubber decomposition time, as the mass and the bed temperature functions, were determined. Time of the samples residence time was calculated with the assumption, that reactor and the analytical block may be described with the well-stirred model. Time of samples decomposition, decrease with increasing temperature, as expected. It was also established, there are significant deviations between shirking core model, and obtained results of the residence time as a mass function. Cenospheric bed application allows to reduce of the process pressure drop, and caused shift of the gas decomposition products zone to the deeper region of the bed. Acoustic and optical effects confirmed significant differences between combustion of sand and cenospheric bed. Higher frequency of bubbles explosions and reduction of diffusive flames number were observed during incineration in cenospheric bed. The relationship between exhaust emission (VOC, CO, NOx) and type of the bed was not confirmed, the identical situation is observed for the samples combustion time. In the presented manuscript, the above physical quantity depends almost completely on sample type and bed temperature.