Catalytic Upgrading of Coal Pyrolysis Gaseous Tar over Hierarchical Y-Type Zeolites Synthesized Using a Microwave Hydrothermal Method

In this work, a series of hierarchical Y-type zeolites were rapidly synthesized using organosilane as templates through a microwave hydrothermal method. The effects of hierarchical Y-type zeolites on the product composition and the yield of light aromatics in gaseous tar from coal pyrolysis were studied. The results showed that the hierarchical Y-type zeolites showed better catalytic properties than the traditional microporous zeolite in the catalytic conversion of gaseous tar and can greatly increase the yield of light aromatics in the pyrolysis products. The hierarchical Y-type zeolite has abundant mesopores, which contribute to the access of bulky molecules into the porous channel and the contact of active sites. Meanwhile, the mesopores reduce the diffusion length of the reaction products, thus promoting the conversion of heavy components in gaseous tar to light aromatics.