3.4.2.1. Fuel characteristics. The bio-oils were dark brown in color
as all bio-oils obtained from biomasses. Elemental analysis and
higher heating value results of HTL bio-oils obtained at different
temperatures are given in Table 4. Bio-oil samples were named
as following the ‘‘Process–Temperature” sequence (e.g. HTL-225
stands for hydrothermal liquefaction conducted at 225 C).