Co-Hydrotreatment of Pyrolytic Lignin and Waste Cooking Oil to Produce Hydrocarbons

• Published in: Energy & fuels Vol. 38; no. 9; pp. 7917 - 7928
• Main Authors: Manrique, Raiza, Chejne, Farid, Olarte, Mariefel, García-Pérez, Manuel
• Format: Journal Article
• Language: English
• Published: American Chemical Society 02.05.2024
• Subjects: Bioenergy, Biofuels, and Biorefinery
• ISSN: 0887-0624; 1520-5029
• DOI: 10.1021/acs.energyfuels.3c05177

The co-hydrotreatment of pyrolysis bio-oils and vegetable oils could facilitate the integration of bioderived fuels into existing fuel infrastructures without significant modifications. Co-hydrotreatment studies with different PL/WCO blend ratios (0, 10, 20, 30, and 40 wt %) were conducted over the NiMo/γ-Al2O3 catalyst. The coke formation value for WCO was 0.7 wt % and ranged between 1.5 and 2.5 wt % with the increase of pyrolytic lignin in the blend. The data suggest that coke is formed from both the sugar- and lignin-derived oligomers since the coke yield reported in this study is comparable with the coke yield obtained by coprocessing the bio-oil fraction without light oxygenate compounds, based on previous studies. All blends are recommended for co-hydrotreatment based on coke yield. The resulting organic phase was distilled into hydrocarbons at <150 °C, 150 to 250 °C, and 250 to 350 °C. The organic product’s overall hydrocarbon distribution was strongly dependent on the pyrolytic lignin concentration. The yield of the distillation cut with a boiling point range between 250 and 350 °C was higher in the hydrotreated samples, with more than 20% during distillation. Two-dimensional GC×GC was used to determine carbon distribution on the combustibles. FTIR and UV fluorescence spectra showed that most feedstocks were converted to potential combustibles for transportation applications after hydrotreatment. The distillation cuts properties, such as density, viscosity, and surface tension, were reported and compared to transportation fuel properties. Hydrocarbon yields reveal the potential of cohydrotreatment to upgrade pyrolytic lignin into valuable products. These findings provide useful insights into utilizing pyrolytic lignin to produce promising combustibles suitable for transportation applications.