Scania in comprehensive biofuel tests: Bio-based synthetic diesel sharply cuts emissions

Scania joins forces with Neste in Finland to try out a new low-emission biobased diesel fuel. Produced in a facility in southern Finland, the new fuel is tailored to diesel combustion. Efficiency remains high, while NOx emissions are down almost 20% and particulates close to 30% compared to standard diesel. In addition, the fuel reduces fossil CO2 emissions by up to 80%.

“Scania's laboratory tests corroborate that bio-based synthetic diesel has great potential,” says Hasse Johansson, Group Vice President R&D at Scania. “Simply switching to such fuel from standard diesel can significantly improve emissions. The possibility of mixing it freely with standard diesel makes the fuel interesting for old vehicles and engines as well. We look forward to participating in these trials.

Another attractive renewable heavy vehicle fuel on the market today is bioethanol. Emissions of fossil CO2 are reduced by up to 90%, it is readily available, production is booming, the technology is firmly established and it gives very low emissions. Scania’s third generation ethanol engines achieve the same efficiency as a conventional diesel engine, while meeting emission levels according to Euro 5, which will be introduced in 2009, as well as the tougher EEV standard, which has been adopted for city traffic in some large European urban areas.

“There is no reason to wait ‘a few more years’ for better alternatives. With the renewable fuels and the technologies available today we are off to a head start, making a significant contribution in reducing carbon dioxide emissions. Once new solutions, e.g. hybrid technology and potential new fuels, have proven their worth, they can also contribute by further speeding up the process,” concludes Mr Johansson.

Different fuels give different emissions

Bioethanol has been used as fuel for adapted diesel engine in Scania city buses sine the late 1980s with excellent environmental results, according to Stockholm Public Transport (SL). Fossil carbon dioxide emissions are reduced by up to 90% for ethanol produced from sugar cane in Brazil.

Scania has carried out laboratory tests to examine the environmental effects of other diesel fuels. The tests prove that the composition of a fuel has a direct bearing on its environmental performance and that there is scope to optimise engines for different fuels. Comparisons are made with reference used for certification according to the Euro 4 exhaust emission standard.

Swedish low-emission diesel, for example, introduced on the market in the early 1990s, in itself cuts NOx by 8% and particulates by a stunning 24%. Biofuels and synthetic fuels are also very promising in this respect.

Synthetic diesel fuel also gives considerably lower emissions of nitrogen oxides (down 18%) and particulates (down 28%). Synthetic diesel can be produced from natural gas (GTL, gas-to-liquid) or biomass (BTL, biomass-to-liquid).

With fossil carbon dioxide cut by up to 80%, BTL-fuels have the best environmental properties of synthetic diesel fuels.

Large-scale fuel trials in Stockholm and Helsinki

The new fuel from Neste, NExBTL, produced at a new facility in southern Finland, will now be subjected to environmental and operational trials, starting in autumn 2007 and lasting until the end of 2010. The tests involve monitoring of exhaust emissions and engine condition with different mixes of the fuel into standard diesel in distribution vehicles and shuttle vessels in the Stockholm region, as well as city buses in Helsinki.

Six Scania city buses form part of the trial. Four of them will run on 100% NExBTL and two on normal diesel. The project also involves tests with various mixes on some 100 vehicles operated by Posten Logistik, the logistics division of Swedish Post, and 2-3 ships in the Stockholm archipelago operated by Waxholmsbolaget.