Fast pyrolysis as a tool for obtaining levoglucosan after pretreatment of biomass with niobium catalysts

• Published in: Waste management (Elmsford) 2021-05, Vol.126, p.274-282
• Main Authors: David, Geraldo Ferreira, Pereira, Sarah de Paiva Silva, Fernandes, Sergio Antonio, Cubides-Roman, Diana Catalina, Siqueira, Rogério Krohling, Perez, Victor Haber, Lacerda, Valdemar
• Format: Article
• Language: English
• Subjects: Biomass pretreatment; Fast pyrolysis; Lignocellulosic agro-industrial wastes; Niobium catalysts; Pyrolytic sugars
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2021.03.016

[Display omitted] •Biomasses were subjected to effective catalytic pretreatment prior fast pyrolysis.•Nb compounds enhanced levoglucosan yields from all biomasses.•Oxalate-Nb was the optimal catalyst for biomass pretreatment.•Levoglucosan yield was 6.5-fold higher for sugarcane bagasse than control. Levoglucosan (LGA) is a promising chemical platform derived from the pyrolysis of biomass that offers access to a variety of value-added products. We report an efficient route to produce LGA via the pretreatment of biomass with niobium compounds (oxalate, chloride and oxide) followed by fast pyrolysis coupled with gas chromatography-mass spectrometry (Py-GC–MS) at temperatures of 350–600 °C. Catalytic pretreatment reduces the quantity of lignin in the biomass, concentrates the cellulose and enhance LGA formation during fast pyrolysis. The pretreatment also removes alkaline metals, preventing competitive side reactions. The effect of several parameters such as catalyst weight, time, temperature, and solvent, with the optimal pretreatment conditions determined to be 3 (wt.%) niobium oxalate for 1 h at 23 °C in water. Pretreatment increased the LGA yields by 6.40-fold for sugarcane bagasse, 4.15-fold for elephant grass, 4.13-fold for rice husk, 2.86-fold for coffee husk, and 1.86-fold for coconut husk as compared to the raw biomasses. These results indicate that biomass pretreatment using niobium derivates prior fast pyrolysis can be a promising technique for biomass thermochemical conversion in LGA and others important pyrolytic products.