Preem accounts for about 80% of Swedish fuel production capacity, providing roughly half of all liquid fuel used in Sweden. The company also produces heating and lubricating oils. Around two-thirds of the fuel production is sold to international customers, mainly in Northern Europe. Preem’s production takes place at two refineries on the west coast of Sweden, to the north of Helsingborg in Gothenburg and Lysekil. Both are among Europe's most modern refineries. Together, they have the possibility of producing up to 18mn m³ of fuel annually. The company aims to achieve a climate-neutral value chain with net zero emissions by 2035.

Historically, the terminal had served as a distribution point for fossil fuels to resellers and customers since the late-1960s, forming an integral part of the energy supply chain. However, with a gradual decline in gasoline and diesel volumes, Preem recognised the need for about 340,000 m³ of additional storage capacity for renewable feedstock.

Securing sustainable storage space was essential to prevent the need for offloading volumes, emphasising the strategic importance of expanding or repurposing existing infrastructure.

Preem identified its Helsingborg terminal as the optimal candidate, offering a potential storage capacity of 130,000 m³. Transforming Helsingborg to a hub for renewable feedstock proved to be more cost-effective than renting tanks elsewhere. Furthermore, the investment required upgrading existing tanks, estimated to be four to eight times lower cost than constructing new tanks.

Given a strong business case the investment gained approval in 2019.

Over several years, 11 tanks have been converted – nine dedicated to renewable feedstock and two for pre-wash water. The conversion process was executed in two stages to maintain process integrity and operational efficiency. Phase one began in 2019, focused on the initial conversion of several tanks. In spring 2023, the terminal ceased fossil operations, marking the start of the next phase of the transition.

The conversion process was initiated with a comprehensive preliminary study to determine the requirements for storing various feedstocks, including raw tall diesel (RTD), animal by-product fats (ABP) and used cooking oil (UCO). This assessment also evaluated how these new products would affect different materials used throughout the facility.

A preliminary study was carried out on tanks to identify requirements for storing various feedstocks 
Photo: Preem

Drawing on previous experience from tank conversions at the Gothenburg refinery, Preem was able to leverage expertise for the Helsingborg depot. Engineers from the refinery provided technical guidance on both construction and design. These studies were instrumental in identifying the necessary investments for tank upgrades.

Storing renewable feedstock requires the ability to heat the products efficiently. To achieve this, an investigation was launched in 2020/2021 to convert to district heating, including detailed calculations of pressure drop and heat loss. District heating was ultimately selected as the terminal’s primary heat source moving forward.

To further optimise energy efficiency and maintain the correct storage temperature, all tanks and tank roofs – covering a total area of 8,600 m² – were externally insulated using Trac-loc insulation for rapid installation. Tube heating elements and jet mixing systems were then installed to ensure uniform temperature distribution. The project also involved rebuilding pipelines and installing new export pumps. In total, approximately 2,500 metres of piping were insulated and fitted with electric heat tracing, with district heating pipes connected to each tank and container. Notably, insulating the tank roofs (4,480 m²) has resulted in annual energy savings exceeding 4 GWh.

To ensure the facility was fully prepared to handle the new range of feedstocks, comprehensive surface treatment and corrosion protection measures were implemented for the tanks. All tanks were initially blasted and painted – covering the floors and extending one metre up the walls. Additionally, selected tanks, including those designated for pre-wash water, received internal painting on their roofs and walls to further guard against corrosion. In total, 4,300 m² of surface area was painted.

Data was taken from external long-term laboratory tests of raw materials to measure corrosion at different temperatures and materials. Based on those results, a vinyl-based anti-corrosion coating has been applied. It was crucial to ensure that the entire tank, including access hatches on the roofs and, for example, roof trusses, were painted. Floating roofs have also been considered a protective measure against corrosion for products where the environment is corrosive in the gas phase.

The conversion project involved extensive refurbishment and modernisation of existing tanks, pipelines and support systems. A new import pipeline was constructed to facilitate the delivery of renewable feedstock from ships. To maximise resource efficiency, the project prioritised re-use of materials from the facility wherever possible, including relocation and repurposing of pipelines. In addition, the former truck loading bay was transformed into truck unloading bays.

Example of heating package inside a tank 
Photo: Preem

Conversion activities included complete internal coating of tanks; installation of glass reinforced plastic (GRP) roofs on selected tanks; addition of stainless steel heating coils and tubes; installation of agitators; installation of stillpipes for radar systems; increase of design temperatures for tanks (now rated up to 80°C); comprehensive insulation of tanks and pipelines; integration with district heating system; and installation of electric heat tracing. By the end of 2023, the first tanks were fully prepared for the import and storage of renewable feedstock.

The company also launched an internal process to consider whether to use weighbridges or mass flow meters since the business transaction for feedstock often is handled in metric tonnes. Staff carried out external site visits to learn from other companies and opted for a weighbridge. These visits also served to strengthen internal knowledge about handling the new types of products.

Project challenges and solutions  
As with all major projects, this initiative faced several challenges along the way. The work was carried out during the COVID-19 pandemic, which created significant obstacles for on-site activities. Many contractor companies relied on foreign workers who were unable to travel, and depot staff were restricted from meeting project managers or contractors due to infection risks.

Another challenge arose from the design temperature requirements of the new import pipeline, which necessitated extensive modifications of the existing infrastructure to accommodate thermal expansion and changes in temperature. When it became apparent that the heating of the products was not progressing as quickly as anticipated, new heat exchangers were installed and all tank roofs were insulated. These measures enabled the tanks to reach the heating targets.

There were sometimes long, drawn-out consultation processes and discussions with authorities to acquire permits to handle new types of products/feedstock depending on the material classifications. It took almost two years, during which time additional requests were added.

With increased imports by truck, it was necessary to expand capacity at the loading bays. The discharge system was adapted so that two types of refinery feedstock could be managed at the three truck discharge bays, and a new sampler for fat was installed.

The official inauguration of the terminal was celebrated in September 2025, featuring a demonstration of equipment designed for the automatic sampling of renewable raw materials from tank trucks. Although this technology has primarily been used for crude oils in the past, it is now utilised for renewable feedstocks.

The Kimman Process Solutions (KPS) sampler that was initially configured for crude oil was adapted for bio-based feedstocks by adjusting the sample rate and a smaller sampling bottle. Also, supply pipes were lined to keep the feedstock at sufficient temperature to avoid blockage in the pipes. The sampler will save money compared to employing independent surveyors for every truckload; it will also provide more accurate results as it samples over the entire discharge period.

The project involved several partners, including sampling equipment expert KPS, AmSpec – an independent inspector, and renewable raw materials supplier Connex. Participants from the Energy Institute group HMC6 attended the event, fostering collaboration and development of new guidelines for the inspection, storage and carriage of bio-feedstocks.

 Collaboration was key for development of the Helsingborg distribution terminal 
Photo: Preem 
 

Key success factors  
Collaboration between Preem colleagues and external partners was essential for driving the conversion of the distribution terminal forward and overcoming the challenges encountered throughout the project.

Alongside the physical changes, Preem implemented staff training on green feedstock. This has involved around 30 online lectures on various topics related to the handling of green feedstock, covering everything from logistics chains, product properties, regulations and handling at depots. Several studies/investigations have been conducted on the raw materials and their properties, and how they affect facilities and material choices, which were then shared with the organisation and formed the basis for ongoing and upcoming projects.

While renewable feedstock has been stored at the facility since early 2023, the terminal reached full operational capacity in spring 2025, with all tanks commissioned for renewable storage and truck unloading activities fully underway. Solidifying the terminal’s role as a strategic logistics hub in Preem’s transition toward sustainable energy.

• Further reading: ‘British Gas parent buys Isle of Grain LNG terminal for £1.5bn’. Details of UK energy company Centrica’s purchase of Grain LNG from National Grid, in partnership with US energy infrastructure firm Energy Capital Partners.
• ‘World first’ green hydrogen transport and storage demo to use existing terminal infrastructure’. Demonstration of commercial-scale transport and storage of green hydrogen in existing terminal infrastructure using liquid organic hydrogen carriers (LOHC) at Exolum’s terminal in Immingham, the UK’s largest freight port.