Optimized usage of NExBTL renewable diesel fuel: OPTIBIO

Helsinki Region Transport, Neste Oil, Proventia Emission Control, VTT Technical Research Centre of Finland and Aalto University carried out a 3.5 year PPP venture "OPTIBIO" to demonstrate the use of paraffinic renewable diesel (hydrotreated vegetable oil HVO) in city buses. The project cooperated with the bus manufacturer Scania. The fleet test in Metropolitan Helsinki, involving some 300 buses at four bus operators, was the largest one in the world to demonstrate this new fuel. The fuels were a 30 % HVO blend and 100 % HVO. The field test was supplemented by a comprehensive in-laboratory research programme on fuel effects on exhaust emissions and low-temperature operability. All in all, the vehicles accumulated some 50 million kilometres between September 2007 and December 2010, of which some 1.5 million kilometres on 100 % HVO. Average distance per vehicle was some 170,000 km. The amounts of fuel used were about 22 million litres of blended fuel and 1 million litres of neat HVO. The project confirmed that HVO actually works as a drop-in fuel, meaning that HVO can replace diesel fuel 100 % without any modifications to the refuelling system or to the vehicles, without causing any operational problems. The emission testing, both the screening and the follow-up measurements, demonstrated significant and permanent emission benefits. Based on the findings of the OPTIBIO project, Scania has approved the use of 100 % HVO (NExBTL) in its city and intercity buses with DC9 engines. After the demonstration phase, the markets will determine the future of high concentration HVO fuels in Finland. Low-level blending is already used commercially to fulfil the general biofuels obligation.