Regulating light olefins or aromatics production in ex-situ catalytic pyrolysis of biomass by engineering the structure of tin modified ZSM-5 catalyst

• Published in: Bioresource technology 2021-06, Vol.330, p.124975-124975, Article 124975
• Main Authors: Shang, Jingyuan, Fu, Guangbin, Cai, Zhenping, Feng, Xiang, Tuo, Yongxiao, Zhou, Xin, Yan, Hao, Peng, Chong, Jin, Xin, Liu, Yibin, Chen, Xiaobo, Yang, Chaohe, Chen, De
• Format: Article
• Language: English
• Subjects: Alkenes; Aromatics; Biomass; Catalysis; Catalytic pyrolysis; Light olefins; Pyrolysis; Sn/hollow ZSM-5; Tin
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2021.124975

Ex-situ catalytic pyrolysis of pine over Sn/ZSM-5 and Sn/hollow-ZSM-5 can obtain the maximum carbon yield of aromatics or C2-C4 olefins, respectively. [Display omitted] •Ex-situ catalytic pyrolysis of pine was investigated in a fixed bed reactor.•Sn/conventional ZSM-5 catalyst exhibited the highest carbon yield of aromatics.•Hollow ZSM-5 supported Sn obtained the maximum carbon yield of C2-C4 olefins.•Reaction pathways were tuned by synergy between ZSM-5 pore structure and Sn metal. Valorization of biomass to olefin or aromatics harbours tremendous practical value due to growing concerns about sustainable production of chemicals. Herein, the olefin or aromatics yields of ex-situ catalytic pyrolysis of pine can be regulated by impregnating Sn on hollow-structured ZSM-5 (M-ZSM-5) and microporous ZSM-5 catalysts in fixed-bed reactor, respectively. Results showed that Sn/ZSM-5 catalyst simultaneously increased medium acidic sites and maintained strong acidic sites, which obtained the maximum carbon yield of aromatics (33.77%) due to enhanced cracking and deoxygenation reactions. In addition, Sn boosted alkylation between olefin and aromatics, generating more alkylbenzene. In contrast, Sn/M-ZSM-5 catalyst produced the highest olefins carbon yield (12.39%) because the reduction of strong acidic sites and microporous volume inhibited the olefin aromatization. Moreover, olefins were easier to desorb from Sn/M-ZSM-5 due to the enhanced mass transfer ability, which weakened the alkylation reactions. The synergistic effect harbours great significance to manipulate the distribution of products.