Preem makes the tall oil diesel greener
The upgrading of SunPines tall oil diesel at the Preem refinery in Gothenburg makes the product meet all specifications for Swedish Environmental Class 1 (MK1) diesel. “We believe making a product based on renewable forestry feedstock is important,” says Sören Eriksson, coordinator of Preem’s product development. “If we can also help recreate the competitiveness of the forest industry it is a plus.”
The art of converting fatty acids to diesel hydrocarbons has been well known for at least 4 to 5 years. Preem, and Finnish company Neste who developed the technology, is at the forefront globally in the implementation of the technology. After the upgrading the tall oil diesel molecule is identical to ordinary petro-based diesel oil molecules – it has been converted into an ordinary diesel carbohydrate. This makes it possible to blend in high ratios of tall oil diesel into petro-based diesels and get “greener” diesel fuels. Most biodiesels are limited to a ratio of around 5%. The tall oil diesel has no limit. For the time being a blending ratio of 20 % is under discussion. In Ireland, Italy and Brazil attempts to create similar processes have been made but the Scandinavian producers are still ahead.
Investing SEK 235 million
To upgrade the tall oil diesel Preem is investing SEK 235 million (€23 million, $33 million) in its Gothenburg refinery. The plant is designed so that it can also receive other feedstocks meeting the EU sustainability criteria but the expectation is to primarily use tall oil diesel. The fuel made from forest feedstock has higher energy efficiency and greenhouse gas reduction than biofuels based on, for example, rapeseed oil or animal fats.
“But tall oil availability is limited and if competition in the future is causing prices to sky-rocket we need to be prepared to use also other feedstocks,” explains Eriksson.
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To upgrade the tall oil diesel Preem is investing SEK 235 million (€23 million, $33 million) in its Gothenburg refinery.
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Distribution in western Sweden
The Preem green diesel will be available starting summer ’10. Initially the fuel will be distributed in western Sweden, in the region close to the refinery. In particular the distribution is a difficult issue as filling stations may need to be rebuilt. It may also be that some customers will use their own filling stations.
Diesel specifications a challenge
The specification for the exact percentage addition of tall oil diesel has not yet been decided. The proportion of tall oil diesel affects the ability of the new product to meet Swedish standards in terms of low temperature properties.
“One of the challenges is to meet cold flow properties,” notes Thomas Ögren, press spokesman at Preem. “One option is to build an isomerizer plant in which the molecules are transformed from linear to branched; a second alternative is to use a somewhat lower percentage of tall oil diesel in the blend. We are evaluating the alternatives but have not yet decided which route to go.”
Since last year Preem is selling a green summer diesel with 30% rapeseed methyl ester (RME) content distributed at four filling stations in western and middle Sweden. At such high percentages of biodiesel the engine manufacturers require shorter service intervals.
“Our investment in SunPine is strict business. At the same time it gives us the possibility to work with second- and third-generation biofuels in a very concrete manner,” says Ögren. “We have several such projects running, including the BioDME project together with Chemrec and Volvo. We’re making steady progress in these areas to meet the big demand for biofuels and reduced carbon dioxide emissions.”