Environmental impact and sustainability study on biofuels for transportation applications

A review on lifecycle analysis of energy consumption and greenhouse gas (GHG) emission for various biofuel vehicles has been performed. Four potential vehicular biofuels are simulated: corn ethanol, switchgrass ethanol, soybean biodiesel, and bio-hydrogen from corn ethanol. A fuel-cycle model developed at Argonne National Laboratory, called the GREET model, is employed to evaluate the biomass-to-tank (BTT) energy and emissions impacts of various biofuels. The fuel economies of three types of vehicles, i.e., flexible fuel vehicles (FFVs), diesel vehicles (DVs), and fuel cell vehicles (FCVs) are also determined using the simulation tools in MATLAB/Simulink. The effects of replacing conventional gasoline vehicles (GVs) by the aforementioned biofuel vehicles on the lifecycle GHG emission and energy consumption are examined. The results showed that the FFVs fueled with an ethanol fuel blend of 85% switchgrass ethanol and 15% gasoline (E85) have the greatest benefits in GHG emission reduction by 59.4%, but suffer from 101.3% total energy consumption compared to the baseline system.