Advertisement Together, Haldor Topsoe and Preem have concluded the revamp of Preem’s Gothenburg refinery, which is part of Preem’s endeavour to reduce Sweden’s total carbon emissions by 20%. This is the second revamp of the hydrotreater, following a revamp in 2010 that upgraded the unit to co-process 30% renewable feedstock using Topsoe’s HydroFlex ™ technology. The unit was one of the first in the world capable of processing renewable feedstock. With the second revamp, Preem and Topsoe have achieved 85% co-processing of renewable feedstock and continue to advance the field of renewable fuel production. Preem uses tallow and raw tall diesel as the main feedstocks.