Method for producing liquid hydrocarbon by converting carbonaceous material contained in one or more feedstocks, the method comprising - Providing a feed material from one or more feedstocks; - Pressurizing the feed material to a predetermined process pressure of at least 150 bar; - Heating the pressurized feed material to a predetermined process temperature of at least 370 degrees; - Reacting the pressurized and heated feed material for a predetermined period of time; - Cooling the reacted feed material to a temperature below 200° C; - Mechanically separating a higher viscosity fraction from the converted feed material at operational pressure by use of a mechanical filter with filter openings between 1μm and 500 μm; - wherein the temperature of the filters is controlled to be in the range 40 to 200 °C; - where the mechanically separated higher viscosity fraction is extracted from the process; - where the extraction is performed through altering mechanical filters between at least one online and at least one offline filter; - where a filter is made online and hereby opened for inflow and a filter is made offline and hereby closed for inflow by opening and closing, respectively, system valves upstream and downstream of the filter; - where further a drain valve located between the closed system valves and upstream the filter element, is opened towards a lower pressure area, in order to release the mechanically separated high viscosity fraction from the filter and through the drain valve; - where the drain valve is closed and the chamber is filled with an incompressible fluid prior to pressurizing the filter chamber through opening the system valves; - Conveying the remaining converted feed mass through a pressure reduction system and further through a separation system. - Providing a feed material from one or more feedstocks; - Pressurizing the feed material to a predetermined process pressure of at least 150 bar; - Heating the pressurized feed material to a predetermined process temperature of at least 370 degrees; - Reacting the pressurized and heated feed material for a predetermined period of time; - Cooling the reacted feed material to a temperature below 200° C; - Mechanically separating a higher viscosity fraction from the converted feed material at operational pressure by use of a mechanical filter with filter openings between 1μm and 500 μm; - wherein the temperature of the filters is controlled to be in the range 40 to 200 °C; - where the mechanically separated higher viscosity fraction is extracted from the process; - where the extraction is performed through altering mechanical filters between at least one online and at least one offline filter; - where a filter is made online and hereby opened for inflow and a filter is made offline and hereby closed for inflow by opening and closing, respectively, system valves upstream and downstream of the filter; - where further a drain valve located between the closed system valves and upstream the filter element, is opened towards a lower pressure area, in order to release the mechanically separated high viscosity fraction from the filter and through the drain valve; - where the drain valve is closed and the chamber is filled with an incompressible fluid prior to pressurizing the filter chamber through opening the system valves; - Conveying the remaining converted feed mass through a pressure reduction system and further through a separation system.