Renewable energy sources and biofuel, including biodiesel, have been gaining increasing attention recently as a replacement for fossil fuels. However, their implementation in the general market depends on making these fuels more competitive. A convenient way to lower the cost of biofuel is to use the by-products as a potential source of energy, rather than treating them as waste. The industrial conversion of renewable resources into useful compounds, namely bio-based materials, has been receiving much attention from the environmental point of view. The crude glycerol from biodiesel production...