Effectively combating global warming requires a significant reduction in CO2 emissions. This poses enormous challenges, especially for the energy-intensive process and production industry, as this industry accounts for one third of total energy consumption. What is needed is intelligent electrification across all operational processes. Electrification has such a large potential impact on decarbonisation because it allows clean, renewable electricity to power processes that previously used emissions-intensive technologies (such as gas burners). This means that a process that previously produced high emissions can become absolutely emission-free when powered by renewable energy.

Electrical resistance heating, which is also known as Joule heating, resistive heating, or Ohmic heating, is the effect of producing heat by passing an electric current through a conductive material. Electric resistance heating is nearly 100% energy efficient in the sense that all the incoming electric energy is converted to heat. For electric heaters, there are various heating resistors available that can be used to convert electrical energy into thermal energy. A very simple form is a high-resistance wire, also called as heating conductor. Depending on the design of the resistor, the heating component will be a heating conductor, cartridge, coil, tape, register, sleeve or pad. For example, the heating cartridge is a cylindrical cartridge made of metal that contains a heating coil. The heating elements can be designed quite flexibly and can be used, among other things, for direct heating of industrial plants and machines. Heat for industrial processes can also be provided by heating process gases. Simple configurations are well-known in which, for example, a wire heated with electrical energy in a heating coil releases heat to a flow of air streaming past. Further implementation options for effective heating of gases in the high power range consist of applying an electric current to bulk materials (for instance pebble beds in Figure 1)) through which the gas to be heated flows. Owing to their robustness and flexibility such heating components are very well suited for a harsh industrial environment and will be considered within CITADEL. The advantages of resistance heating are the uniform and high temperature, the very short heating time, the high efficiency, the low maintenance and the reduced metal scale formation. Moreover, electric resistance heating systems are characterised by a high flexibility and a very fast and exact controllability by variations of current and electrical resistance.