Determination of biodiesel percentage in biodiesel : diesel mixtures using mid-infrared spectroscopy

Considered the best substitute for diesel, biodiesel can be blended with diesel in any ratio, bringing lots of environmental, economic and social advantages. Brazilian law N degrees 11097/2005, proposes the introduction of biodiesel in to the Brazilian energy matrix, mixed with diesel at a minimum percentage of 2%. For consumers and sellers to be sure that the commercialized mixture of biodiesel: diesel contains the correct percentage, it is necessary to develop analytical methodologies to quantify the amount of biodiesel added. This work presents a fast, low-cost and simple methodology to determine the biodiesel proportion in mixtures of biodiesel:diesel, based on infrared spectroscopy.