Biomass-derived carbon co-processed in a laboratory-scale coking unit: Detailed chemical evaluation of liquid products and their distillation cuts

The insertion of biofuels into conventional refineries is a promising option that can increase the green carbon content of traditional fossil fuels and products. However, the influence of bio-oil (BO) inclusion in the typical steps of conventional refineries is still understudied. This work aims to perform individual chemical structural elucidation of coking liquid products from slow pyrolysis bio-oils co-processed with vacuum residue (VR), as well as their distilled fractions to evaluate the influence of BO inclusion in a conventional refinery process. Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry and Orbitrap high-resolution mass spectrometry with electrospray ionization in positive and negative modes were used. Liquid products were obtained in a laboratory-scale coking unit using three batch loadings: (A) 100 % VR, (B) 95 % VR and 5 % BO; and (C) 90 % VR and 10 % BO. The biomass-derived carbon inclusion in the coking batch promoted the reduction of alkane, olefin, and alkyl-thiophene concentrations in the liquid product. Biogenic C1-alkyl-cyclopentenones (42.7 μg g⁻¹) and C1-C3 alkyl-cyclopentenones (392.3 μg g⁻¹) were detected in liquid product B and C, respectively. After distillation, a greater bio-oil contribution was observed in light gasoils. Thus, biomass-derived carbon co-processed in the coking unit can increase the green carbon content, particularly in naphtha and light gasoil products, and can represent a good option for a fair energy transition.