Processes for producing liquid fuels from a mainly organic starting material with a reduced content in water and/or with a reduced content in solids are disclosed. The mainly organic starting material can be at least partially liquified and optionally further dewatered. The obtained at least partially liquid fraction can be thereafter used as feeding stream that is submitted to a pyrolysis treatment resulting in a solid gas fraction allowing the recovering of a liquid fuels after a controlled liquid solid separation treatment. There are also provided various other processes for producing liquid fuel from waste hydrocarbon and/or organic material as well as reactors, apparatuses, uses and managing systems thereof.