Catalytic Performance of Molecular Sieves with Different Structures in 1-Butene Cracking

SAPO-18 with different contents of Si were synthesized and characterized by XRD, SEM and NH3-TPD. Catalytic performance of H-ZSM-5(MFI), H-Beta (*BEA) and SAPO-18(AEI) as different types of molecular sieves have been investigated for of 1-butene cracking reaction in a fixed-bed microreactor. It was found that the acidity and structure of molecular sieves play key roles in the catalytic results of 1-butene catalytic cracking process. These results showed that the high acidity of catalysts improved the 1-butene conversion but led to the decrease of the selectivities of propylene owing to the side reactions (such as hydrogen transfer, aromatization) derived from additional acid sites. What is more, the pore dimension and channel structure determined the available selectivity of propene. SAPO-18-0.8 with eight-ring pore and pear-shaped cage was achieved satisfactory propylene selectivity approach 59.1% with 1-butene conversion was 60.7% under the TOS of 20 min condition.