The Saskatchewan Research Council (SRC), in cooperation with Natural Resources Canada and Agriculture and Agri-Food Canada, investigated the use of conventional refinery technology to convert vegetable oils into a product resembling diesel fuel. SRC found that the use of a medium severity refinery hydroprocess yielded a product ('super cetane') in the diesel boiling range with a high cetane value (55-90). Preliminary engine testing by ORTECH has shown that the impact of the 'super cetane'/diesel mixture ('green diesel') on engine emissions is similar to the impact cetane enhancement via a nitrate additive has when added to conventional diesel fuel Advantages of hydroprocessing over esterification in the Canadian context include lower processing cost, compatibility with infrastructure, engines and fuel standards, and feed stock flexibility. Further research in the areas of process optimization, alternative feed stock selection, cold flow properties, and multi-cylinder emission resting is planned. In cooperation with a commercialization partner Arbokem Inc., pilot testing of the hydroprocess was done and was proven successful. A fleet demonstration and evaluation is currently underway. (C) 1996 Elsevier Science Ltd.