Caracterização eletroquímica do glicerol como fonte de energia alternativa

Abstract

The increasing energy demand in modern society in order to accommodate the population growth is an issue of great concern nowadays. There is a glycerol surplus currently in the market mainly from the biodiesel production as glycerol is a by-product of this process. Glycerol becomes then a suitable candidate for use in energy generation, particularly, its use as a fuel for hydrogen generation. This paper aims to study the electrochemical characteristics of both the anode and the cathode in residual glycerol media in order to achieve a description and assessment of the behavior of a PEM (proton exchange membrane) cell for electrochemical hydrogen production from glycerol. The cathode used was deposited on nickel substrate such as porous stainless steel gas diffusion electrode (GDE). Experiments were performed in 0.5 molar sulfuric acid, and glycerol/ NaCl solution, which mimics byproduct generated in the production of biodiesel, 0.1 M NaOH, 0.86 M NaCl, and glycerol with Na2SO4. The sulfuric acid was used in the cathode evaluation as the cathode is not in contact with the solution, only with Nafion® membrane in a normal electrolyzer. The anode was a solid platinum, with its behavior identified in various solutions that mimic the glycerol generated from biodiesel production. Finally, we analyzed the behavior of the membrane-electrode assembly (MEA) in the glycerol media. Certain difficulties were encountered in the use of glycerol from biodiesel by-product related to its composition, pH, chloride content and water content in the solution. These combined factors hinder the efficiency of the PEM fuel cell.