The Consideration of Different Effective Zeolite Based Catalysts and Heating Rate on the Pyrolysis of Styrene Butadiene Rubber (SBR) in a Stirred Reactor

The pyrolysis products as well as composition of the condensed products generated from Styrene Butadiene Rubber (SBR) degradation have been investigated with reference to different zeolite based catalysts. The effects of different catalysts containing used FCC, gallium promoted used FCC (Ga/FCC), HZSM-5, and mordenite have been studied on the SBR degradation using a stirred semi-batch reactor. Main products obtained were light hydrocarbons within the gasoline range, though the Ga/FCC and used FCC tended to produce more condensed products with aromatics as the main product. Meanwhile, the nonisothermal mass losses of SBR were measured using a thermogravimetric analyzer (TGA) at heating rates of 5, 15, 30, 45, and 90 degrees C min(-1) until the furnace wall temperature reached 600 degrees C. The TGA degradation trends of SBR were in between the TGAs of a usual plastic and polybutadiene rubber. Activation energies decreased by increasing the heating rate (154.7-131.5 kJ mol(-1)), although activation energy of the fast pyrolysis shows a significant decrease in comparison with the others. In slow pyrolysis, the double bonds in SBR chains could prepare the proper media for the cross-link mechanism, while phenyl groups boost the chain scission and unzipping mechanisms. In other words, the fast pyrolysis follows the chain scission and unzipping mechanisms along the most times of degradation.