Catalytic co-pyrolysis of Yunnan pine and hydrogen donor over desilicated ZSM-5 for light aromatics

Abstract

To improve the effective hydrogen-to-carbon ratio (H/Ceff) of a substrate, ex-situ catalytic co-pyrolysis of hydrogen donors and wood over ZSM-5 was conducted. The co-feeding of methanol and wood greatly increased the total aromatic content from 79.00% to 91.79% and the BTX content from 21.62% to 61.63%. To further improve the catalytic properties of ZSM-5, desilication with a Na2CO3 solution was applied. Treatment with the Na2CO3 solution gently removed the Si from ZSM-5, decreased the Brønsted site density, but created more mesopores, improving the accessibility of Brønsted sites in the pores and the diffusion properties of ZSM-5. Desilication of ZSM-5 with a 0.4 mol/L Na2CO3 solution increased the desirable BTX content from 61.63% to 66.35% and reduced the polycyclic aromatic content from 11.92% to 9.72%.