Catalytic liquefaction of pine sawdust and in-situ hydrogenation of biocrude over bifunctional Co-Zn/HZSM-5 catalysts

Catalytic liquefaction is an effective method for bio-crude production, but the development of efficient catalysts remains a challenge. Bifunctional Co/HZSM-5, Zn/HZSM-5 and Co-Zn/HZSM-5 catalysts were integrated with zinc hydrolysis to produce upgraded bio-crude. Co or Zn modified HZSM-5 catalysts improved the yields of bio-crude and gas compared to no catalyst treatment. Co or Zn modified HZSM-5 catalysts decreased the contents of oxygenated compounds including ketones, acids, alcohols and phenols. Co or Zn loaded HZSM-5 catalysts improved the hydrocarbons contents. Compared to monometallic Co/HZSM-5 and Zn/HZSM-5, bimetallic Co-Zn/HZSM-5 generated bio-crude with higher quality due to the synergistic effect of Co and Zn on HZSM-5 support. Co-Zn/HZSM-5 produced the highest bio-crude yield at 67.38 wt%, and the highest hydrocarbons content of biocrude produced was 18.59%.