System of liquid extraction folr biodiesel purification process

Author(s)

Yurany Camacho Ardila

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia Química
• Defense date: 2009-11-12

Examining board members

Maria Regina Wolf Maciel; Carlos Eduardo Vaz Rossell; Glaucia Maria Ferreira Pinto

• Advisor: Maria Regina Wolf Maciel

Abstract

Biodiesel can be defined as the mono alkyl esters of fatty acids derived from vegetable oils or animal fats, obtained through transesterification process. Besides the esters, the outlet stream of the transesterification reactor contains glycerin (a by-product of the reaction), excess alcohol, water, and small amounts of the catalyst. According to the solubility of these compounds, can have the effect that considerable amounts of esters (biodiesel) remains in the glycerin-rich phase and the ester-rich phase contains a significant amount of impurities. Because of this behavior is it necessary to understand the liquid-liquid phase equilibrium formed with the mixtures involved in order to proceed with the purification of biodiesel. Such data are not currently found in the literature, thus impracticable the real understanding of phase separation and the construction of virtual plants and the computer simulations executions. Therefore, the main objective of this work was to determine liquid-liquid equilibrium (LLE) data for the systems: BIOS + ethanol + glycerin, BIOM + ethanol + glycerin, BIOS + ethanol + water, BIOM + ethanol + water, BIOS + glycerin + water, BIOM + glycerin + water and quaternary systems involving the NaOH catalyst using 1% concentration. The terms BIOM and BIOS mean biodiesel from castor oil and soybean biodiesel. Initially, was made a physicolchemical characterization of soybean and castor oil with the aim to create the best conditions for the realization of the transesterification reactions. Biodiesel is produced by ethylic transesterification, and taken to subsequently characterization (to know its purity, because it is an important property for use in experiments performed). The study of the temperature of LLE was made by binodal curves using the method of determining the turbidity point, finding that the best temperature for the equilibrium analysis was 25 °C. The experiments for the construction of the ties lines were carried out in equilibrium cells, maintaining the system temperature constant at 25 °C and atmospheric pressure. Through factorial design 22, the agitation time (03 h) and rest time (12 h) were determined, in the experimental range studied, to reach the equilibrium. A methodology was developed by gas chromatography with FID detector (GC-FID) for biodiesel, ethanol and glycerin quantification, using methanol as solvent for GC analysis. The water was analyzed by Karl Fischer titration and the catalyst by potentiometric titration. Therefore, were determined the concentrations of each component at biodiesel - rich phases and glycerine / water - rich phase. Later, using the commercial simulator Aspen Plus 2006, the experimental data were correlated through the molecular models NRTL, UNIQUAC and Electrolytic NRTL for the calculation of the activity coefficient of each component in the liquid phase, with estimation of new parameters of interaction energy. The results were considered satisfactory, observing that NRTL was capable to represent better the equilibrium data of the studied systems. (AU)

• FAPESP's process: 07/06455-9 - System of liquid liquid extraction for biodiesel purification process
• Grantee: Yurany Camacho Ardila
• Support Opportunities: Scholarships in Brazil - Master