The refinery has a broad crude oil portfolio and processes raw materials from many fields in Scandinavia and Africa. Some of the condensate is delivered from the Sleipner area, and some comes by ship from Equinor's processing facility at Kårstø in Nord-Rogaland.
The oldest part of the refinery was built in 1961. After expansion in 1995, it can accept a larger proportion of condensate, allowing it to produce petrol with a lower content of benzene. Deliveries of petrol with 1% benzene to the Danish market started in 1997. The refinery also supplies petrol and diesel with under 50 parts per million (0.005%) of sulphur.
The production capacity at Kalundborg is up to 5.5 million tonnes of oil products per year, depending on the type of raw material.