A catalytic-pyrolysis-derived bio-oil, which was characterized by higher H/C eff ratio and lower oxygen content in comparison to fast-pyrolysis-derived bio-oil, was coprocessed with VGO in a pilot-scale FCC riser. The addition of the bio-oil up to 10 wt % gave nearly equivalent oxygenate content and also similar selectivities of gasoline, bottom oil, and coke compared to those in VGO catalytic cracking alone, suggesting the catalytic-pyrolysis-derived bio-oil was a suitable feedstock for FCC coprocessing. However, the dry gas, including hydrogen and light alkane, was significantly decreased in the coprocessing experiment mainly because of the hydrogen transfer between bio-oil and VGO. Radiocarbon analysis of the product showed that 7% carbon of gasoline was derived from the bio-oil when 10 wt % bio-oil was added to VGO. The coprocessing of biomass catalytic pyrolysis and FCC was highly promising for biomass conversion into biofuel.

A key challenge in biomass catalytic conversion, especially in pilot and practical scales, is the stability of the catalyst and its support. Depolymerization of Kraft lignin, which is characterized by structural recalcitrance and poison (metal and ash) rich nature, is a good model reaction to demonstrate the above challenge in biomass conversion. In the present study, the potential of SiC-based catalyst (commercially available SiC nanofiber-supported Ni and W, NiW/SiC) in lignin depolymerization was investigated. The results indicate the SiC-based catalyst is a milder catalyst than the state-of-the-art activated carbon-supported catalyst under the identical conditions and supplies a higher liquid product yield. More importantly, the NiW/SiC catalyst can be easily regenerated by coke combustion and subsequent acid washing, which cannot be achieved by either carbon or metallic oxidesupported catalysts. The performance of the regenerated catalyst with only 4% Ni input is almost unchanged compared with that of the fresh catalyst. These results illustrate that SiC combines the advantages of common supports such as activated carbon and metallic oxides and may be generally applicable as catalyst support in biomass conversion.

A stable bifunctional catalyst for hydro-deoxygenation of lignin derived phenolic compounds was obtained through simple selective deposition of Pt on alumina in a commonly used Al2O3-ZSM-5 nanocomposite, and the catalyst retained its complete deoxygenation capacity for more than 500 h.

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