The present invention relates to an ablative thermolysis reactor (12) comprising a reaction vessel (20), and inlet (14) into the reaction vessel (20) for receiving feedstock, and an outlet from the reaction vessel (20) for discharging thermolysis product. Within the reaction vessel (20), is provided an ablative surface (20a) defining the periphery of a cylinder, and heating means (22) are arranged to heat the ablative surface (20a) to an elevated temperature. In addition at least one rotatable surface (28) having an axis of rotation coincident with the longitudinal axis of said cylinder. The rotatable surface (28) is provided relative to the ablative surface (20a) such that feedstock is pressed between a part of the rotatable surface (28) and said ablative surface (20a) and moved along the ablative surface (20a) by the rotatable surface (28), whereby to thermolyse said feedstock.