(126e) Detailed Hydrocarbon Characterization of Diesel Fractions From Co-Hydroprocessing Canola Oil and HVGO Blends

Industry and R&D community are facing a major challenge to reduce the carbon footprints or greenhouse gas (GHG) emission during the production, upgrading and refining of Canadian oil sands bitumen into clean transportation fuels. Co-processing biomass and petroleum/bitumen derived feedstocks may provide an alternative solution since the GHG emission from the production and processing of renewable biomass to produce biofuels is considered to be significantly lower than that from fossil resources. In addition, co-processing paraffinic biomass feeds and aromatic bitumen feeds may generate synergy to improve gasoline and diesel qualities.

One of the research objectives at CanmetENERGY is to investigate the impacts and benefits of co-hydroprocessing biomass derived feeds with bitumen derived feeds in terms of fuel composition and quality. In this study four diesel fractions were obtained by co-hydroprocessing blends of low-grade canola oil and bitumen derived heavy vacuum gas oil (HVGO) at different canola oil /HVGO blending ratios, 0/100, 5/95, 10/90, and 20/80.  A commercial hydroprocessing catalyst was used in the experiments under typical industrial operating conditions. These diesel fractions were fully characterized using standard ASTM methods and advanced two-dimensional gas chromatography (GC×GC).

Characterization results of the diesel fractions showed that with the increased canola oil content in the feed blends, the contents of aromatics and cycloparaffins decreased and the content of iso-paraffins remained relatively constant whereas the content of normal paraffins increased. This observed increase in the normal paraffins in the diesel fractions was attributed to the hydrodeoxygenation and hydrodecarboxylation of triglycerides contained in the canola oil. The normal paraffins in the diesel were mostly normal heptadecane (product of hydrodecarboxylation) and normal octadecane (product of hydrodeoxygenation) with traces of other lighter/heavier normal paraffins. The formation of normal heptadecane and normal octadecane resulted in changes in other physical and combustion properties of the diesel fractions, such as density, boiling point distribution (or boiling curve), cetane index/number. Detailed discussion on the characterization, property changes and final fuel quality will be presented.