Production of catalytic-upgraded pyrolysis products from oiltea camellia shell and polypropylene using NiCe-X/Al2O3 and ZrO2 catalyst (X = Fe, Co)

Abstract

Co-pyrolysis of biomass and plastics wastes mixture into high-value products is a promising means based on the view of waste-to-energy and economic. In this study, a series of novel catalysts were prepared to product high-quality pyrolysis oil, high-value carbon nanotubes (CNTs) and hydrogen rich gas from oiltea camellia shell (OCS) and polypropylene (PP) in a two-stage catalytic pyrolysis process. The effects of active metal and support material of different pyrolysis catalysts on the characteristics of products were established. The results show that Ni-Co bimetallic catalysts showed higher hydrogen rich gas product yields. With the presence of Ni-Co bimetal, aromatic hydrocarbons reached 56.29 % (Al2O3 based) and 58.64 % (ZrO2 based). In addition, gasoline components also reached 49.55 % (Al2O3 based) and 49.57 % (ZrO2 based), which indicating that the cracking of large macromolecules was promoted. The carbon materials obtained from the NiCoCe@Al catalyst has the lowest defects and the highest degree of graphitization. NiCoCe@Al and NiCoCe@Zr catalysts showed that the filamentous carbon of over the decomposition catalysts can be judged to CNTs. Moreover, higher uniformity and lower defects of CNTs was achieved using NiCoCe@Al and NiCoCe@Zr catalysts. The efficient pyrolysis catalysts has significantly increases the quality of pyrolysis products, which were expected to enhance the large-scale promotion of biomass catalytic pyrolysis.