A method for processing of plastic waste comprising: - a step of providing waste plastics into a first pyrolysis reactor said first pyrolysis reactor comprising an agitator configured to agitate said waste plastics therein; - a pyrolysis step of heating, at a first temperature, waste plastics in the pyrolysis reactor to provide pyrolysis gases and char; - a step of measuring the dryness of the char in the first pyrolysis reactor by measuring the load of said agitator, - a completion step of completing the pyrolysis step; - a cook-off step of heating at a second temperature, the inside of the first pyrolysis reactor when the load of said agitator reaches a predetermined threshold, said second temperature being higher than the first temperature. and, after completing said cook-off step, - a step of removing char from a system for treatment of waste plastics comprising a screw conveyor unit (10, 20, 30) for removing char from said system, said screw conveyor unit comprising: - a screw conveyor (11,21,31), comprising a char contacting surface (12, 32) and - a cooling chamber (13, 23, 33) adapted to contain a cooling fluid, arranged such that - the cooling chamber (13, 23, 33) is physically isolated from the char contacting surface (12, 32) of the screw conveyor (11, 21, 31) and - the screw conveyor (11, 21, 31) and the cooling chamber (13, 23, 33) are configured to allow, in operation, a heat exchange between the cooling fluid and the char when the cooling chamber (13, 23, 33) contains a cooling fluid, said step of removing char comprising: - providing a cooling fluid to the screw conveyor unit; - receiving the char into the screw conveyor unit; - conveying the char by the screw conveyor wherein the char is in contact with a char contacting surface of the screw conveyor; - lowering the temperature of the char by heat exchange between the cooling fluid and the char contacting surface of the screw conveyor unit. - a step of providing waste plastics into a first pyrolysis reactor said first pyrolysis reactor comprising an agitator configured to agitate said waste plastics therein; - a pyrolysis step of heating, at a first temperature, waste plastics in the pyrolysis reactor to provide pyrolysis gases and char; - a step of measuring the dryness of the char in the first pyrolysis reactor by measuring the load of said agitator, - a completion step of completing the pyrolysis step; - a cook-off step of heating at a second temperature, the inside of the first pyrolysis reactor when the load of said agitator reaches a predetermined threshold, said second temperature being higher than the first temperature. and, after completing said cook-off step, - a step of removing char from a system for treatment of waste plastics comprising a screw conveyor unit (10, 20, 30) for removing char from said system, said screw conveyor unit comprising: - a screw conveyor (11,21,31), comprising a char contacting surface (12, 32) and - a cooling chamber (13, 23, 33) adapted to contain a cooling fluid, arranged such that - the cooling chamber (13, 23, 33) is physically isolated from the char contacting surface (12, 32) of the screw conveyor (11, 21, 31) and - the screw conveyor (11, 21, 31) and the cooling chamber (13, 23, 33) are configured to allow, in operation, a heat exchange between the cooling fluid and the char when the cooling chamber (13, 23, 33) contains a cooling fluid, - a screw conveyor (11,21,31), comprising a char contacting surface (12, 32) and - a cooling chamber (13, 23, 33) adapted to contain a cooling fluid, arranged such that - the cooling chamber (13, 23, 33) is physically isolated from the char contacting surface (12, 32) of the screw conveyor (11, 21, 31) and - the screw conveyor (11, 21, 31) and the cooling chamber (13, 23, 33) are configured to allow, in operation, a heat exchange between the cooling fluid and the char when the cooling chamber (13, 23, 33) contains a cooling fluid, said step of removing char comprising: - providing a cooling fluid to the screw conveyor unit; - receiving the char into the screw conveyor unit; - conveying the char by the screw conveyor wherein the char is in contact with a char contacting surface of the screw conveyor; - lowering the temperature of the char by heat exchange between the cooling fluid and the char contacting surface of the screw conveyor unit. - providing a cooling fluid to the screw conveyor unit; - receiving the char into the screw conveyor unit; - conveying the char by the screw conveyor wherein the char is in contact with a char contacting surface of the screw conveyor; - lowering the temperature of the char by heat exchange between the cooling fluid and the char contacting surface of the screw conveyor unit.