Abstract: An apparatus (110) for heating a feedstock is proposed. The apparatus (110) comprises a plurality of electrically conductive pipelines (114) for accommodating the feedstock. The pipelines (114) are arranged so as to enable parallel feedstock flow. The apparatus (110) includes at least one power source and/or voltage source (126) set up to supply an electrical current to the pipelines (114) which heats the pipelines (114) by Joule heat which arises as the electrical current passes through conductive pipe material, in order to heat the feedstock. Each of the pipelines (110) has a first end (116) and a second end (118). At least one electrical insulator (132) is disposed at the first end (116) and the second end (118) such that the respective pipeline (114) and at least one supplying pipeline (120) and at least one discharging pipeline (122) are galvanically isolated from one another. The individual pipelines (114) are electrically interconnected in a series connection.