Removal of free and total glycerol from soybean biodiesel by adsorption on light expanded clay aggregates

• Grant number: 17/21844-3
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2018
• End date: July 31, 2018
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Gustavo Nakamura Alves Vieira
• Grantee: Pedro Gimenes Guião Maroni
• Host Institution: Instituto de Química (IQ). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

One of the quality criterium required for the commercialization of biodiesel is its free and total glycerol content. In general, in order to meet the requirement of this and other criteria, biodiesel is submitted to an extraction process using water as solvent (washing). Consequently, a large amount of water is used in this process and this process stream must be submitted to residuary treatment. Alternatively, biodiesel might be submitted to an adsorption process, in which impurities are adsorbed on a surface of a solid material. Such procedure is already used in other purification processes, such as the removal of metallic cations, organic substances (mainly dyes) etc. from wastewaters. Within the possible adsorbents, light expanded clay aggregates are a potential material for these applications, due to the fact that they present a low cost, high particle porosity and are composed basically by aluminosilicates. In general, this material is used as a thermoacoustic insulator and gardening material. In this context, the main objective of this proposal will be the analysis of the technical viability of the use of light expanded clay aggregates as an adsorbent material for the purification of biodiesel. Firstly, fatty acid methyl esters from soybean oil (biodiesel) will be synthesized by homogenous alkaline catalysis, based on reaction conditions already available in scientific literature. Once biodiesel is synthesized and settled in separating funnels (but not washed), it will be submitted to batch adsorption processes. Samples of the biodiesel will be withdrawn during the adsorption process and after thermodynamic equilibrium is attained and their free and total glycerol content will be analyzed based on Brazilian norms. It is expected that an alternative for the purification of biodiesel is proposed in this project, so that the volume of wastewaters is reduced in comparison to the traditional extraction process. (AU)