Effects of ZnCl2 on the Distribution of Aldehydes and Ketones in Bio-oils from Catalytic Pyrolysis of Different Biomass

Bio-oil can serve as an alternative fuel source or resource to extract high value-added chemicals. This paper focuses on the effect of six types of biomass (rape straw, corn straw, walnut shell, chestnut shell, camphor wood, and pine wood) and ZnCl2 catalyst on the bio-oil yield and chemicals in the bio-oil, including aldehydes, ketones, and four high-value chemicals (1-hydroxy-2-butanone, propionaldehyde, 5-H MF, 2(5H)-furanon). The results showed that the yields of bio-oil decreased when the ZnCl2 was the catalyst. The ZnCl2 promoted the production of aldehydes and ketones. The higher contents of aldehydes and ketones were obtained from camphor and pine wood, at 58.9 wt% and 42.0 wt%, respectively. The ZnCl2 catalyst exhibited an active influence on the production of 1-hydroxy-2-butanone, propionaldehyde, 5-H MF, and 2(5H)-furanon. Compared with the non-catalytic pyrolysis, the content of 1-hydroxy-2-butanone and 2(5H)-furanone in bio-oil increased by 936% and 612%, respectively. The contents of propionaldehyde and 5-HMF in catalytic bio-oil were the highest from rape straw and increased by 193% and 86%, respectively.