In Situ Synergistic Catalysis Hydrothermal Liquefaction of Spirulina by CuO–CeO(2) and Ni–Co to Improve Bio-oil Production

[Image: see text] Hydrothermal liquefaction (HTL) is one of the most promising technologies for biofuel production. The preparation and application of catalysts for HTL have been the research focus in recent years. In this study, a new synergistic catalytic process strategy is proposed. CuO–CeO(2)/γ-Al(2)O(3) was used as an in situ hydrogen donor catalyst and Ni–Co/SAPO-34 was synthesized for hydroprocessing to improve bio-oil production process. The results of XRD and XPS demonstrated that the metal components were well supported on the catalyst. When the two catalysts were mixed, the yield of bio-oil increased from 51.00% to 64.51%, the carbon recovery rate raised from 69.53% to 88.18%, the energy recovery rate grew from 63.42% to 80.22%, and the S content is relatively reduced by 83.3%. Also, TG analysis showed that the content of light components in bio-oil increased. Moreover, the hydrocarbons and alcohols were observed to a higher proportion from the GC-MS analysis. This new method still has high catalytic activity after repeated use for five times. This study provides a new idea for preparing higher yield and superior quality bio-oil.