XIX IMEKO World Congress Fundamental and Applied Metrology September 6−11, 2009, Lisbon, Portugal METROLOGICAL APPROACH IN THE CHARACTERIZATION OF VISCOSITY OF CORN BIODIESEL RELATIVE TO TEMPERATURE, USING CAPILLARY VISCOMETERS Alex Pablo Ferreira Barbosa 1 , Claudio Roberto da Costa Rodrigues 2 , Dalni Malta do Espírito Santo Filho³, José RenatoReal Siqueira 4 ,Roberto Guimarães Pereira 5 , Luiz Henrique Paraguassu de Oliveira 6 1 Inmetro, Duque de Caxias, Brazil, afbarbosa@inmetro.gov.br 2 Inmetro, Duque de Caxias, Brazil, crrodrigues@inmetro.gov.br 3 Inmetro/PGMEC-UFF, Duque de Caxias/Niterói, Brazil, dsfilho@inmetro.gov.br 4 Inmetro, Duque de Caxias, Brazil, jrsiqueira@inmetro.gov.br 5 PGMEC-UFF, Niterói, Brazil, temrobe@vm.uff.br 6 Inmetro, Duque de Caxias, Brazil, paraguassu@inmetro.gov.br Abstract: in this article we study the behavior of biodiesel viscosity from corn biodiesel, transesterified with methanol, in relation to temperature. These quantities were measured with capillary viscometers, from 20 ºC to 40 ºC. Measurement uncertainty was calculated. The behavior of viscosity with temperature is analyzed considering the estimated uncertainty. Keywords: corn biodiesel, capillary viscometer, uncertainty of measurement 1. INTRODUCTION With the increasing oil prices and environmental concerns about the Earth’s pollution by the GHG, governments are looking for alternative ways to generate energy. Brazil is leading this process which involves two main aspects: reducing the dependence on fossil fuel to help building an environmetally cleaner world and to promote a more effective social inclusion with the upcoming economic opportunities in a new and growing field. Despite the self- sufficiency of Brazil in crude oil production, the refined products show some peculiarities. Gasoline, for instance, due to the amount of bioethanol in the blend – 25% of bioethanol - for domestic consumption, has a large volume being exported. On the other hand, diesel due to the transport matrix is being imported to fulfill the strong growing need in Brazil. The volume of diesel imported in 2006 was around 10% of consumption. In January 2008, a Brazilian law (Law 11097/2005) [1] established a mandatory addition of 2% of biodiesel to petrodiesel. From July 2008 the mandatory addition changed to 3%, representing a volume of, biodiesel equivalent to 1,6% of the market. Brazil has a great possibility of producing several different types of biodiesel. In addition to the transesterified vegetable oils being studied here, there are still various types of biodiesel that can be produced from animal fats. The fuel performance in an engine is dependent on many variables characterized as quality parameters presented as Fuel Standards. Among these variables, the density and the viscosity play important roles. To study the behavior of the viscosity with the temperature, as well as the behavior of biodiesel obtained from different sources, including the large number of vegetable oils and animal fats, it is an important step to optimize the use of biodiesel as a petrodiesel substitute. In this study we show the viscosity behavior of corn oil as well as the behavior of this methyl ester between 20 °C and 40 °C. The viscosity of a liquid is its internal resistance to flow [2]. The capillary viscometers used in this study belong to the Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (Inmetro) [3], and are national standards [4]. In the chain of traceability, the viscometers are calibrated starting from the viscosity of water. 2. EXPERIMENTAL PROCEDURE The motivation for this study relies on the following facts: 1) viscosity behavior as a function of temperature that characterize biodiesel obtained from corn biodiesel, considering the estimated measurement uncertainty, is not completely known yet; 2) viscosity curve as a function of temperature of mixtures of biodiesel from corn oil with 1199 ISBN 978-963-88410-0-1 © 2009 IMEKO