Hydrothermal liquefaction of separated dairy manure for production of bio-oils with simultaneous waste treatment

► The hydrothermal liquefaction (HTL) process produced 3.45 g (±0.21) of usable oils. ► The average HHV for acetone soluble oil (ASF) was 32.16 (±0.23) MJ kg−1. ► The maximum ASF yield was 4.8 g at 350 °C using 1 g of Na2CO3 catalyst. ► The best ASF yield corresponded to 67.6% or energy contained in raw manure. ► The HTL process can simultaneously treat the wastes and lower COD by up to 75%.