Bamboo wastes catalytic pyrolysis with N-doped biochar catalyst for phenols products

Biomass catalytic pyrolysis for valuable O-containing chemicals is a promising approach for better utilization of oxygen in biomass resource, where the catalyst, with the properties of green, low cost, high activity and stability, is a critical point. In this study, we proposed a novel and green method to produce phenols through biomass (bamboo wastes) catalytic pyrolysis with N-doped biochar catalyst, which was investigated in a fixed bed reactor to explore the catalytic pyrolysis mechanism of N-doped biochar catalyst. N-doped biochar catalysts, with different nitrogen content and specific surface area, were by products came from biomass N-enriched pyrolysis. Results showed that N-doped biochar catalyst greatly promoted the generation of phenols (reached 82%), especially valuable 4-vinyl phenol with 31% content and 6.65 wt% yield, as well as 16% 4-ethyl phenol with 3.04 wt% yield, based on biomass. It also promoted aromatics formation, while inhibited the generation of O-species and acetic acid with more CO2 and H2O release, thus greatly improved bio-oil quality. Furthermore, N-containing groups in N-doped biochar catalyst showed good stability, while O-containing groups decreased largely. N-doped biochar mainly acted as adsorbent, catalyst, and reactant during catalytic pyrolysis, and the possible catalytic pyrolysis mechanism was proposed based on experiment results and quantum calculations. In conclusion, N-doped biochar catalyst showed excellent catalytic property for biomass catalytic pyrolysis for phenols products.