Green synthesis of ZSM-5 using silica fume and catalytic co-cracking of lignin and plastics for production of monocyclic aromatics

ZSM-5 with hierarchical pore structure was synthesized by a simple two-step hydrothermal crystallization from silica fume without using any organic ammonium templates. The synthesized ZSM-5 were oval shaped particles with a particle size about 2.0 lm and weak acid-dominated with proper Bronsted (B) and Lewis (L) acid sites. The ZSM-5 was used for catalytic co-cracking of n-octane and guaiacol, lowdensity polyethylene (LDPE) and alkali lignin (AL) to enhance the production of benzene, toluene, ethylbenzene and xylene (BTEX). The most significant synergistic effect occurred at n-octane/guaiacol at 1:1 and LDPE/AL at 1:3, under the condition, the achieved BTEX selectivity were 24% and 33% (mass) higher than the calculated values (weighted average). The highest BTEX selectivity reached 88.5%, which was 3.7% and 54.2% higher than those from individual cracking LDPE and AL. The synthesized ZSM-5 exhibited superior catalytic performance compared to the commercial ZSM-5, indicating potential application prospect.(c) 2023 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.