Measurement of consumption rates of viscous biofuels

This work investigates the measurement of the consumption rates of viscous biofuels used in internal combustion engines. Most commercial instruments are suitable for traditional petroleum-based fuels, and may exhibit material incompatibility with alternative fuels. Further, some experimental low-grade straight vegetable oils are viscous and relatively quickly degrading fuels, which often need to be heated to assure adequate flow through the fuel system as some are solid at room temperatures. In this study, fuel consumption of straight vegetable oils was measured using an electrically heated fuel tank placed on a scale, and determined as the first derivative of the instantaneous tank mass. While the data were noisy and subject to oscillations and experimental error, repeatable values of the total consumption over various cycles were obtained on diesel fuel, biodiesel and heated rapeseed oil. The measured values were compared with the fuel consumption derived from the exhaust emissions of carbon dioxide and carbon content of the respective fuels. As the advantages of each method are complementary, their parallel use might be beneficial.