Production of green hydrogen from electrochemical treatment of industrial effluents

Abstract

The global search for clean energy systems is a consequence of the increasing world demand for energy and, in this scenario, hydrogen has been considered as a promising energetic source. However, most part of the H2 production derived from non-renewable sources, such as natural gas, being responsible for the emission of large quantities of CO2. New routes for the sustainable generation of hydrogen have been investigated, including the electrolytic route based on water splitting to generate high purity H2, also known as "green hydrogen", especially interesting for application in fuel cells, in which the H2 would work as an energy storage vector for posterior conversion into electricity. Despite all advantages, the wide use of electrolytic H2 still bumps into its high production cost. Aiming to make the green hydrogen economically competitive, in this project we propose to study two different strategies: 1) testing and evaluation of new cathodes with higher electrocatalytic power for the hydrogen evolution reaction (HER), and 2) modifying the conventional electrolyzers by replacing the anodic reaction of oxygen evolution reaction (OER) by the electrooxidation of organic pollutants present in aqueous industrial effluents. Acting in a synergetic way, the proposed electrolyzer, besides producing H2, would also contribute to overcome an environmental issue. In this project different cathodes and anodes will be evaluated in an electrochemical flow reactor, in a semi-pilot scale. The H2 production will be evaluated according to the gas purity and production rate, while the organic pollutant degradation will be evaluated in terms of the removal of total organic carbon. The performance of both processes will be evaluated as a function of the main operational parameters that can affect the kinetics, efficiency and energy consumption. (AU)