Liquification of Prosopis farcta plant stems by hydrothermal liquefaction method, characterization of liquid and solid products obtained

In this study, the effect of temperature and catalyst on hydrothermal liquefaction of biomass was investigated. At the end of the experiments, Prosopis farcta plant was transformed to solid residue (bio-char) and liquid products (heavy bio-oil, light bio-oil) at temperatures of 250, 300 and 350 °C with catalyst (H3BO3, Na2B4O7·10H2O, NaOH) and without catalyst by hydrothermal liquefaction. The liquid and solid products obtained at the end of the experiments were analyzed by GC–MS, FT-IR, 1H NMR, SEM and elemental analysis methods. The highest liquid product yield was obtained at 350 °C with sodium tetraborate catalyst as 35.69%. According to the elemental analysis results, the HHV values of the liquid products range from 19.75 to 29.54 MJ kg−1 for 300 °C and from 18.06 to 30.02 MJ kg−1 for 350 °C. HHV values of all obtained liquid products were found to be higher than raw materials.