Catalytic Alcoholysis of Lignin with HY and ZSM-5 Zeolite Catalysts

Abstract

Here, the zeolite catalysts HY and ZSM-5 were used for liquefaction of lignin in supercritical ethanol (Sc-EtOH) to improve the bio-oil yield and control the product distribution. The effects of the reaction temperature (260–380 °C), reaction time (30–120 min), and catalyst content (5.00–15.00 wt %) were investigated. In Sc-EtOH, lignin treated with 10.00 wt % HY catalyst at 360 °C for 60 min resulted in a bio-oil yield of 59.13 wt % and a total hydrocarbon content of 31.26%. Under the same conditions with 10.00 wt % ZSM-5 catalyst, the bio-oil yield was 51.77 wt % and the total hydrocarbon content was 10.34%. This showed that there were large differences in the bio-oil yield and distribution of hydrocarbons (alkanes, olefins, and aromatic hydrocarbons) using the two catalysts. A large amount of alkanes and aromatic hydrocarbons was produced from lignin in the presence of the HY and ZSM-5 zeolite catalysts, respectively. This revealed that the primary reaction over HY was isomerization, whereas that over ...