Second-generation biofuels by co-processing catalytic pyrolysis oil in FCC units

Previous research showed that hydrodeoxygenated (HDO) pyrolysis-oils could successfully be co-processed with vacuum gasoil (VGO) in a labscale fluid catalytic cracking (FCC) unit to bio-fuels. Typically the hydrodeoxygenation step takes place at ∼300 °C under 200–300 bar of hydrogen. Eliminating or replacing this step by a less energy demanding upgrading step would largely benefit the FCC co-processing of pyrolysis oils to bio-fuels. In this paper a bio-oil that has been produced by catalytic pyrolysis (catalytic pyrolysis oil or CPO) is used directly, without further upgrading, in catalytic cracking co-processing mode with VGO. The results are compared to the co-processing of upgraded (via HDO) thermal pyrolysis oil. Though small but significant differences in the product distribution and quality have been observed between the co-processing of either HDO or CPO, they could be corrected by further catalyst development (pyrolysis and/or FCC), which would eliminate the need for an up-stream hydrodeoxygenation step. Moreover, the organic yield of the catalytic pyrolysis route is estimated at approximately 30 wt.% compared to an overall yield for the thermal pyrolysis followed by a hydrodeoxygenation step of 24 wt.%.

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► FCC co-processing of hydrodeoxygenated pyrolysis-oil and catalytic pyrolysis oil.
► Conversion and product distribution are very similar for both bio-oils.
► Organic yield of the catalytic pyrolysis route is estimated 30 wt.%.
► Less energy demanding co-processing route for bio-fuels.