Study on the removal and depolymerization of lignin from corn stover through the synergistic effect of Brønsted acid, Lewis acid and hydrogenation sites

• Published in: Fuel (Guildford) 2021-12, Vol.305, p.121509, Article 121509
• Main Authors: Zhang, Baikai, Li, Wenzhi, Zhang, Tingwei, Li, Xu, Ogunbiyi, Ajibola T., Chen, Kun, Shen, Changcheng
• Format: Article
• Language: English
• Subjects: Acids; Aluminum; Aluminum phosphate; Biomass; Catalysts; Corn; Depolymerization; Hydrogenation; Lewis acid; Lignin; Monomer; Monomers; NMR; Nuclear magnetic resonance; Retention rate; Stover; Synergistic effect; Zeolites
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2021.121509

[Display omitted] •Reduction with H2 was very helpful to increase the acidity of NiAPO-5 zeolite.•The synergy of acid site and hydrogenation site would affect lignin’s conversion.•The retention rate of lignin and monomers' yield reached 38.09% and 35.70%. The effective transformation of lignin is an essential part of realizing the comprehensive utilization of biomass. In this study, a one-pot method for the depolymerization of corn stover lignin used aluminum phosphate (NiAPO-5) zeolite catalyst contained Brønsted acid, Lewis acid and hydrogenation sites was proposed. It was found that the number of Brønsted acid sites was increased after NiAPO-5 was reduced with H2. The yield of monomers and residue were 35.70% and 38.09% at 235 °C for 3 h, respectively. The result of 2D HSQC NMR showed that the NiAPO-5 (H2) catalyst significantly affected the cleavage of β-O-4 bonds. The distribution of products and the stability of catalyst revealed that NiAPO-5 (H2) was an efficient catalyst for the depolymerization of lignin.