Atmospheric dispersion calculation at Elkem Rana -Emissions from the CCS process

NILU has carried out dispersion and deposition calculations of amines and amines’ degradation products from the Elkem Rana conceptual Carbon Capture and Storage (CCS) plant in Mo.

The study has been commissioned by Elkem Rana as part of the pre-Front End Engineering Design (FEED) project to develop a concept for CCS at the smelter facility in Rana.

The estimated maximum yearly concentration of the sum of nitrosamines and nitramines in air has been compared with the Norwegian Institute of Public Health (NIPH) recommendation of 0.3 ng/m³ for the relevant solvents.

From deposition analysis and by using water catchment and precipitation data the concentration in drinking water has been estimated and compared with the NIPH recommended level in drinking water (4 ng/l) for relevant recipients in the region around Mo i Rana.

The dispersion calculations have been conducted using the WRF-EMEP, an atmospheric dispersion model which in this case is driven by the weather forecasting model WRF. The formation of amine degradation products is post-processed where the relevant chemical and physical processes have been taken into account.

The figure below shows a typical resulting concentration field of nitramines and nitrosamines from the method applied. The concentrations are within the NIPH recommendations with a significant margin.