Synergistic Effect of Hydrothermal Co-Liquefaction of Camellia oleifera Abel and Spirulina platensis : Parameters Optimization and Product Characteristics

Camellia oleifera Abel (COA) is a kind of oil plant widely planted in China and East Asia. It has a large annual production and consumption, making it a promising feedstock for biofuel conversion. The hydrothermal liquefaction (HTL) of COA and the hydrothermal co-liquefaction (HTCL) of COA and Spirulina platensis (SP) were investigated. The bio-oil yield of COA HTL reached 21 wt% under 320 °C, 30 min. The HTCL process can improve bio-oil yield and quality of mixed feedstock, and the maximum yield reached 36 wt% (320 °C, 40 min, 2.0) even higher than pure SP HTL bio-oil yield of 28.76 wt% (320 °C, 30 min), bio-oil had more fatty acid content, lower heterocycles content and higher HHV. The synergistic effect (SE) of HTCL shows different changing trends with operating parameters, and the maximum SE is about 8%. Moreover, the energy recovery rate was increased in HTCL, indicating better conversion efficiency.