A 2-year internal testing programme has successfully verified Hydro Karmøy’s technology pilot plant with its HAL4e primary aluminium production technology.
The testing programme has verified that the technology pilot produces aluminium with an energy consumption at 12.3 kWh/kg – around 15 % below the world average – and furthermore, to bring the direct CO2 emissions from the electrolysis process well below Hydro’s low-carbon aluminium average of 1.67 kg CO2/kg Al.
Technology pilot verified energy consumption below 12.3 kWh/kg aluminium
The full-scale NOK4.6bn pilot plant consists of 60 electrolysis cells using Hydro-developed HAL4e technology; 12 of the cells in the pilot plant, called HAL4e Ultra, have demonstrated energy consumption potential down to 11.8 kWh/kg Al.
Twenty of the 60 HAL4e pots were selected for the final performance test, which was conducted for 75 days between October and December. During the test period, a range of additional measurements were performed on a number of parameters and exact production figures were traced and recorded. The energy results came in at 12.27 kWh/kg Al – below the set target of 12.3 kWh/kg Al. The performance test furthermore demonstrated a record low level of direct CO2 emissions from the electrolysis process of below 1.45 kg CO2/kg Al.
Technology elements of the Karmøy pilot to be implemented in other production lines
Next up for the technology pilot is to further optimize operations and support systems and prepare for the second-generation cells. These are under development at Hydro’s reference centre in Årdal, Norway, including the prototyping of a cell concept that will be important for potential carbon capture technology. Technology elements from Hydro’s Karmøy pilot are also continuing to be implemented in Hydro’s other production lines, to continuously improve operational and environmental performance. Technology elements have been installed at Hydro Husnes B line, which was re-started in November.