Insight into the selective production of aldehydes and ketones by catalytic upgrading of biomass pyrolysis vapor over ZrO₂:Cellulose and xylan

Catalytic upgrading of pyrolysis gas components from cellulose and xylan was investigated over ZrO2 catalyst to produce aldehydes and ketones. The oxygen content in the bio-oil was reduced by aldol condensation and hydrogenation of aldehydes and ketones. The optimal pyrolysis temperature of cellulose and xylan were determined to be 400 C and 350 ? and the carbon yields of aldehydes and ketones reached 54.49% and 52.05% respectively. In order to explore the formation mechanism of aldehydes and ketones, the evolution of typical products by controlling the reaction time was studied. The catalytic pyrolysis was complete and the product content was maximum at 20 min H2O played a role in providing oxygen atoms and increasing ZrO2 reaction activity in the carbonylation process. The binding energy of the catalyst was calculated as-15.69 kcal/mol by density functional theory (DFT). It was found that the presence of water can remove the coke on the catalyst surface and increase the activity of ZrO2. The yield of aldehydes and ketones reached 58.17% and 55.85% of cellulose and xylan with the presence of 15 wt% H2O in the carbonylation process. According to the evolution of the above experimental products, the generation pathways of four main carbonylation products (acetone, methyl ethyl ketone, butyraldehyde and furfural) were proposed. Through this research, the effective utilization of biomass could be realized.