Moeltner, L., Konstantinoff, L., and Schallhart, V., "Hydrotreated Vegetable Oils, Biomass to Liquid and Fatty Acid Methyl Ester as Biogen Admixtures for Diesel Engines in Passenger Cars," SAE Int. J. Fuels Lubr. 10(2):2017, doi:10.4271/2017-01-9375.
The increasingly stringent emission legislation worldwide and the demand for independence from fossil energy carriers represent major challenges for the future development of diesel engines, particularly for maintaining the diesel engine’s positive characteristics, such as its dynamic driving performance and fuel economy, while drastically reducing emissions. This survey investigates alternative fuel blends used in a state-of-the-art EURO 6 diesel engine with different shares of biomass to liquid, hydrotreated vegetable oils and fatty acid methyl ester, which present a possibility to meet these requirements. In particular, the reduction of particulate matter and, as a result, the possibility to reduce nitrogen oxides emissions holds remarkable potential for the application of synthetic fuels in diesel engines. The investigated fuel blends generally demonstrate good applicability when used in the test engine with standard settings. Adaptions to engine parameters (e.g., injection timing or exhaust gas recirculation) hold further potential. With respect to the EU’s targeted 10% bio-quota by 2020 two ternary fuel blends containing conventional diesel fuel, fatty acid methyl ester and biomass to liquid or hydrotreated vegetable oils were also tested and featured excellent performance in terms of emissions and efficiency.