SANTIAGO, Natália de Oliveira.
Résumé:
The society development is associated to the increasing use of fossil fuels,
creating serious climatic problems such as global warning and air pollution. The
ecological disasters, like floods and droughts, are a consequence of the
increasing release of CO2 and other greenhouse gases. Besides these
environmental problems, the costs relied to the extraction, production and
supply of oil, are increasing due to its availability. Changes are necessary to
control this situation and a way out is the use of another fuel in order to
guarantee sustainability. This fuel of the future can be hydrogen, mainly due to
its high conversion efficiency, recycling and non-polluting nature. It is
particularly attractive as a promising substitute of the fossil fuels. This work
presents the production of hydrogen by alkaline water electrolysis (potassium
hydroxide, KOH) using nickel foam based electrodes. The evaluation of the
electrolytic reactor, consisting of a unit cell, was performed by the statistical
method of response surface experiments through two plans with two dependent
variables: applied tension and KOH concentration. The response is the
hydrogen flow (L/h) in order to analyze the reactor behavior in different
situations. The optimum point of the reactor operation for both schedules was
obtained with a concentration of 16,6% KOH and an applied voltage of 2.6 V,
producing 0,841 L/h of H2.
