A highly efficient and recyclable bone char for catalytic pyrolysis of polypropylene

Chemical upcycling of recycled polypropylene (PP) waste plastics for fuel production has emerged as a promising avenue. In this study, the catalytic pyrolysis behavior of bone char (BC) on polypropylene plastics with different experimental parameters and different carbonization temperatures was investigated. Under optimal conditions (500 °C, 1:1 plastic-to-catalyst ratio), BC500 exhibited good thermocatalytic performance and was able to achieve a high liquid oil yield (73.33 wt%) and attained 33.12 % C₉H₁₈ selectivity. Meanwhile, 90.59 % and 81.63 % selectivities were used for gasoline (C₅-C₁₂) and jet fuel (C₈-C₁₆). The reaction mechanism of bone char in PP pyrolysis catalysis was also revealed. Notably, the BC500 maintained outstanding stability in cyclic tests (70.67 wt% liquid oil yield and up to 38.58 % C₉H₁₈ content), confirming its potential for practical application. This study demonstrates that bone char synthesized from waste animal bone exhibits excellent thermocatalytic activity for pyrolyzing polypropylene into high-quality fuels, thereby providing a valuable guide for the industrial utilization of waste animal bone into functional catalysts.