Catalytic hydrotreatment of the high-boiling-point fraction of soybean straw biocrude in a mixed hydrogen donor

In this study, a high-boiling point fraction (HBF, 141-220 °C) from vacuum distillation of a biocrude produced from hydrothermal liquefaction of soybean straw was hydrotreated in a hydrogen donor solvent (HDS) mixture consisting of tetralin and decalin at a mass ratio of 1:1. Effects of temperature (300–450 °C), time (1–6 h), H₂ pressure (0.01–10 MPa), and Pt/C loading (0–40 wt%) on the products distribution and properties of the treated oil were examined. Increasing the temperature, time, and catalyst loading or decreasing the H₂ pressure would reduce the treated oil yield and increase the gas and solid product yields. The presence of HDS mixture played a critical role in favoring the production of treated oil, reducing the formation of gas and solid products, and the removal of N, O, and S from the HBF. Under optimal reaction conditions, 96.3% of N, 87.1% of O, and 98.5% of S were removed from the initial feedstock. The treated oil mainly consisted of saturated hydrocarbon(∼40%, C8-C20) and aromatics(∼41%, naphthalene and benzene derivatives), which was had a comparable cetane number and better combustion characteristics relative to the market 0# diesel.