Hydrocarbon produced from upgrading rich phenolic compound bio-oil with low catalyst coking

• Achieved high hydrocarbon yield (75% C) from catalytic process on liquid–liquid extracted bio-oil.
• Low catalyst coking and high catalysis efficiency was achieved, with high recovery.
• Aldehyde, ketone and other small active molecular contributed to catalyst coking.

Catalytic upgrading of raw bio-oil and liquid–liquid extracted bio-oil (high concentrated phenolic with trace acid and acetaldehyde) with methanol over ZSM-5 catalyst had been studied in this work. Temperature played vital function and leaded to increasing gas yield but less catalyst coking. It also changed both chemical distribution and selectivity on both gas and liquid products, with aromatic concentration increasing by 34.42%. Temperature of 400 °C was selected as the optimized reaction conditions with liquid yield of 10.47 wt.% and 75.00% aromatic hydrocarbon in liquid product from 100 g biomass, only with coke yield of 1.42 wt.%. Phenolic-rich extracted bio-oil obtained higher aromatic hydrocarbon yield (7.3 wt.% increased from 1.1 wt.%) and lower coke yield (1.42 wt.% decrease from 15.79 wt.%) than raw bio-oil. Catalyst regenerated from this type of feedstock also achieved higher activity and longer useable running times on aromatic yield compared to fresh catalyst. This result suggested that lignin derived phenolic and guaiacol compounds were not the only reason caused catalyst coking on ZSM-5 catalyst. Small high active molecules of acetic acid and acetaldehyde also acted as important precursors of catalyst coke formation.