Catalytic fast pyrolysis of biomass impregnated with K3PO4 to produce phenolic compounds: Analytical Py-GC/MS study

• Phenolic compounds were selectively produced from K3PO4-catalyzed pyrolysis of biomass.
• Phenol and 2,6-dimethoxy phenol were the two most abundant products from poplar wood.
• The maximal peak area% of the phenolics was over 60% at high K3PO4 content.
• The formation characteristics of the individual products were revealed.

A new technique was proposed to produce phenolic-rich bio-oil from catalytic fast pyrolysis of biomass impregnated with K3PO4. In this study, analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) experiments were performed to investigate the K3PO4-catalyzed biomass pyrolysis process, mainly using poplar wood as the feedstock. The results indicated that the presence of K3PO4 would inhibit the devolatilization of holocellulose to form organic volatile compounds, and meanwhile promote the decomposition of lignin to form phenolic compounds (mainly the phenol and 2,6-dimethoxy phenol from poplar wood). With the increasing of the K3PO4 content, the yield of the total phenolic compounds was firstly increased and then decreased, while their total content was increased steadily. The maximal phenolics yield was obtained at around 7.42 wt% K3PO4, with the peak area% of 42.8%. Whereas the maximal phenolics peak area% was over 60% at high K3PO4 content.