Evaluation of diesel fuel production from bio-oils hydrodeoxygenation using unsupported MoS2 catalysts

Diesel production from lignocellulosic biomass-derived fast pyrolysis bio-oil (FPBO) and catalytic pyrolysis bio-oil (CPBO) was investigated with an upgrading approach using unsupported MoS 2 catalysts generated in situ. Hydrodeoxygenation of FPBO and CPBO was evaluated in a continuous-flow reactor system using feed blends containing 18 wt% bio-oil in fuel oil. For FPBO, 92.9 % deoxygenation was achieved with 0.51 wt% O in oil products, resulting in low acidity (0.32 mg KOH/g), while 74.8 % deoxygenation was obtained for CPBO with 1.24 wt% O and 0.48 mg KOH/g acidity in oil products. The lower deoxygenation of CPBO suggests that oxygenates in CPBO are less reactive than those in FPBO. In both cases, low solid yields were observed from 1.2 to 2.0 g/100 g bio-oil. XRD and HRTEM detected few-layer stacked structure for the in-situ formed MoS 2 catalysts. The oil product from CPBO retained more biogenic carbon than from FPBO, with the diesel fraction from CPBO exhibiting a higher biogenic carbon content and yield. Both diesel cuts meet almost all ASTM D975 specifications, except for S content, resulting from the high S/Mo feed ratio used in the tests. Evaluation results demonstrated great potential for producing specifications-conforming diesel fractions from FPBO and CPBO upgrading using unsupported MoS 2 catalyst. • Unsupported MoS 2 is effective in HDO of both FPBO and CPBO evidenced by O removal. • Solid yields from FPBO and CPBO upgrading were low, from 1.2 to 2.0 g/100 g bio-oil. • Few-layer stacked structure of MoS 2 formed in situ was influenced by the feedstock. • FPBO upgrading exhibited higher DOD; more biocarbon retention from CPBO upgrading. • FPBO and CPBO-derived diesels meet most ASTM D975 specs.