Abstract:
In order to improve yield of aromatics from catalytic pyrolysis of lignin, alkali lignin was used for rapid pyrolysis experiments under a binary catalysis system of alkali lignin char and ZSM-5. Influence of catalyst ratio and pyrolysis temperature as well as pyrolysis time on aromatics quantity and mechanism of synergistic catalysis of alkali lignin char and ZSM-5 were investigated. The results show that quantity of aromatics has increased from 17 mg/g (without char) to 33 mg/g (with char addition of 1 g), which is about doubled. The optimal conditions for preparation of aromatics are under alkali lignin∶alkali lignin char∶ZSM-5=1∶1∶1 at 500℃ for 10 min. Meanwhile, the mechanism analysis shows that alkali lignin char mainly plays a role in bond breaking during pyrolysis, while ZSM-5 can act as selective aromatization to obtain higher aromatics yield, whose synergistic effects result in higher aromatic yield.
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