Abstract: A carbonaceous material liquefaction apparatus which uses a nozzle assembly to supply a pressurised liquid towards a carbonaceous material as a high velocity liquid. A supply line (46, 39) supplies the high pressure liquid to the nozzle assembly (38). The high velocity liquid reacts with the carbonaceous material (35) in a reaction zone (40) to produce a processed carbonaceous material. A product return line (34, 42) returns the processed carbonaceous material and entrained liquid to a processing plant. The processing plant comprises a heat exchanger (44) to transfer heat from the product return line to the supply line, a high pressure pump (48) to provide the high pressure liquid to the supply line, a separator (52) in the product return line downstream of the heat exchanger to separate gas (54) and oil (56) product from the entrained liquid, at least part of the liquid (58) being recycled (64) to the high pressure pump. The reaction can be carried out in-situ or in an above ground reaction chamber (70).