Fig. 8. (a) Coke yield determined by TGA for catalytic cracking of PP of various molecular weight using ECAT, FCC-catalyst and crushed FCC-catalyst. (b) Cumulative yields for semi-batch catalytic cracking of 2.5 g of 3 different PP samples using 1.25 g ECAT. Gaseous products (striped fill) were analyzed using online GC, liquid products were identified using offline gas chromatography-mass spectrometry (GC-MS) and quantified using gas chromatography-flame ionization detection (GC-FID) analysis (Fig. S17†). Coke yields were determined by thermogravimetric analysis (TGA) of the spent catalyst materials. Experiments for PP23k were conducted in triplicate, overall gas and liquid yield showed a standard deviation of 2% and 1% respectively. (d) Molar flow and cumulative yield of C1–C3 products normalized by carbon number measured over time of reaction for cracking of 3 different PP samples. (c) Molar flow and cumulative yield of individual C1–C3 products excluding propylene normalized by carbon number measured over time of reaction for cracking of PP307k using ECAT without stirring (closed symbols) and stirring at 300 rpm (open symbols).
