Hydrotreated Vegetable Oil as Fuel for Heavy Duty Diesel Engines

Hydrotreated vegetable oil (HVO) named NExBTL is a 2^nd generation renewable diesel fuel made by a refinery-based process converting vegetable oils to paraffins. Also animal fats are suitable for feedstocks.

Properties of this non-ester type biobased fuel are very similar to GTL. It contains no sulfur, oxygen, nitrogen or aromatics. Cetane number is very high (∼90). Cloud point can be adjusted by severity of the process from -5 to -30°C, heating value is similar to diesel fuel, storage stability is good, and water solubility is low.

Emissions of two heavy duty engines and two city buses are presented with HVO and sulfur free EN 590 diesel fuel. The effect of HVO on regulated emissions compared to EN 590 fuel was:

• NO_x -7 % … -14 %
• PM -28 % … -46 %
• CO -5 % … -78 %
• HC 0 % … -48 %

Aldehydes, PAHs, mutagenicity and particulate size were also measured.