The co-liquefaction experiments were carried out in a 250 ml
autoclave. Each time 10.00 g JG lignite, wheat straw, plastic waste,
or mixtures of the three samples were put into the reactor together
with 80 ml deionized water. Before the liquefaction experiment,
the reactor was filled with nitrogen to the desired initial pressure (2.0–5.0 MPa) and sealed; then the reactor was heated to the
desired temperature at 10 ◦C/min by a furnace and then stayed for
required time. After reaction the reactor was cooled to room temperature and depressurized to atmospheric pressure. The residue
was taken out, dried and further analyzed.